Feyter, P.J. de

Carotid plaque burden as a measure of subclinical coronary artery disease in patients with heterozygous familial hypercholesterolemia (Article)

2013-05-01T00:00:00Z

Patients with familial hypercholesterolemia (FH) are at markedly increased risk of developing premature coronary artery disease. The objective of the present study was to evaluate the role of carotid ultrasonography as a measure of subclinical coronary artery disease in patients with FH. The present prospective study compared the presence of subclinical carotid and coronary artery disease in 67 patients with FH (mean age 55 ± 8 years, 52% men) to that in 30 controls with nonanginal chest pain (mean age 56 ± 9 years, 57% men). The carotid intima-media thickness and carotid plaque burden were assessed using B-mode ultrasonography, according to the Mannheim consensus. Coronary artery disease was assessed using computed tomographic coronary angiography. A lumen reduction >50% was considered indicative of obstructive coronary artery disease. The patients with FH and the controls had a comparable carotid intima-media thickness (0.64 vs 0.66 mm, p = 0.490), prevalence of carotid plaque (93% vs 83%, p = 0.361), and median carotid plaque score (3 vs 2, p = 0.216). Patients with FH had a significantly greater median coronary calcium score than did the controls (62 vs 5, p = 0.015). However, the prevalence of obstructive coronary artery disease was comparable (27% vs 31%, p = 0.677). No association was found between the carotid intima-media thickness and coronary artery disease. An association was found between the presence of carotid plaque and coronary artery disease in the patients with FH and the controls. The absence of carotid plaque, observed in 5 patients (7%) with FH, excluded the presence of obstructive coronary artery disease. In conclusion, the patients with FH had a high prevalence of carotid plaque and a significantly greater median coronary calcium score than did the controls. A correlation was found between carotid plaque and coronary artery disease in patients with FH; however, the presence of carotid plaque and carotid plaque burden are not reliable indicators of obstructive coronary artery disease.

The effect of LDLR-negative genotype on CT coronary atherosclerosis in asymptomatic statin treated patients with heterozygous familial hypercholesterolemia (Article)

2013-04-01T00:00:00Z

Objective: To evaluate the influence of LDL receptor (LDLR) -negative mutational status on CT coronary atherosclerosis in asymptomatic statin treated patients with heterozygous familial hypercholesterolemia (FH). Methods: Coronary CT angiography (CCTA) was performed in 145 FH patients (93 men; mean age 52 ± 8) screened for LDLR and apolipoprotein B (APOB) mutations. The extent of coronary plaque was compared between two groups: 1) 59 patients (41%) heterozygous for LDLR-negative mutations (LDLR-negative) and 2) 86 patients (59%) with reduced or normal LDLR function (LDLR-positive) consisting of 32 LDLR-defective mutations, 8 APOB mutations and 46 patients in whom no mutation could be identified.The diseased segments score (DSS) was the primary study endpoint defined as the number of coronary artery segments (0-17) with >20% luminal diameter narrowing. We compared the DSS between LDLR-negative and LDLR-positive patients. Within the LDLR-positive group a secondary analysis was performed between identified (LDLR-defective, APOB) and unidentified mutational status. Results: The median DSS was higher in LDLR-negative than in LDLR-positive patients (4 (1-7) and 2 (0-5); P = 0.017). After adjustment for risk factors, LDLR-negative mutational status remained an independent predictor of the DSS (B = 1.09; P = 0.047). The DSS in the LDLR-positive group was similar for patients with identified and patients with unidentified mutational status. Conclusion: In asymptomatic statin treated patients with a clinical diagnosis of FH, LDLR-negative mutational status is associated with a higher extent of subclinical CT coronary atherosclerosis.

Quantification of myocardial blood flow by adenosine-stress CT perfusion imaging in pigs during various degrees of stenosis correlates well with coronary artery blood flow and fractional flow reserve (Article)

2013-04-01T00:00:00Z

AimsOnly few preliminary experimental studies demonstrated the feasibility of adenosine stress CT myocardial perfusion imaging to calculate the absolute myocardial blood flow (MBF), thereby providing information whether a coronary stenosis is flow limiting. Therefore, the aim of our study was to determine whether adenosine stress myocardial perfusion imaging by Dual Source CT (DSCT) enables non-invasive quantification of regional MBF in an animal model with various degrees of coronary flow reduction.Methods and resultsIn seven pigs, a coronary flow probe and an adjustable hydraulic occluder were placed around the left anterior descending coronary artery to monitor the distal coronary artery blood flow (CBF) while several degrees of coronary flow reduction were induced. CT perfusion (CT-MBF) was acquired during adenosine stress with no CBF reduction, an intermediate (15-39) and a severe (40-95) CBF reduction. Reference standards were CBF and fractional flow reserve measurements (FFR). FFR was simultaneously derived from distal coronary artery pressure and aortic pressure measurements. CT-MBF decreased progressively with increasing CBF reduction severity from 2.68 (2.31-2.81)mL/g/min (normal CBF) to 1.96 (1.83-2.33) mL/g/min (intermediate CBF-reduction) and to 1.55 (1.14-2.06)mL/g/min (severe CBF-reduction) (both P < 0.001). We observed very good correlations between CT-MBF and CBF (r 0.85, P < 0.001) and CT-MBF and FFR (r 0.85, P < 0.001).ConclusionAdenosine stress DSCT myocardial perfusion imaging allows quantification of regional MBF under various degrees of CBF reduction. © The Author 2012.

Assessment of atherosclerotic plaques at coronary bifurcations with multidetector computed tomography angiography and intravascular ultrasound-virtual histology (Article)

2012-08-01T00:00:00Z

We evaluated the distribution and composition of atherosclerotic plaques at bifurcations with intravascular ultrasound-virtual histology (IVUS-VH) and multidetector computed tomography (MDCT) in relation to the bifurcation angle (BA). In 33 patients (age 63±11 years, 79% male) imaged with IVUS-VH and MDCT, 33 bifurcations were matched and studied. The analysed main vessel was divided into a 5 mm proximal segment, the in-bifurcation segment, and a 5 mm distal segment. Plaque contours were manually traced on MDCT and IVUS-VH. Plaques with >10% confluent necrotic core and <10% dense calcium on IVUS-VH were considered high risk, whereas plaque composition by MDCT was graded as non-calcified, calcified, or mixed. The maximum BA between the main vessel and the side branch was measured on diastolic MDCT data sets. Overall the mean plaque area decreased from the proximal to the distal segment [8.5±2.8 vs. 6.0±3.0 mm2 (P<0.001) by IVUS-VH and 9.0±2.6 vs. 6.5±2.5 mm2 (P<0.001) by MDCT]. Similarly, the necrotic core area was higher in the proximal compared with the distal segment (1.12±0.7 vs. 0.71±0.7 mm2, P=0.001). The proximal segment had the higher percentage of high-risk plaques (13/25, 52%), followed by the in-bifurcation (6/25, 24%), and the distal segment (6/25, 24%); these plaques were characterized by MDCT as non-calcified (72%) or mixed (28%). The presence of high-risk and non-calcified plaques in the proximal segment was associated with higher BA values (71±19° vs. 55±19°, P=0.028 and 74±20° vs. 50±14°, P=0.001, respectively). The proximal segment of bifurcations is more likely to contain high-risk plaques, especially when the branching angle is wide.

Major adverse cardiac events and the severity of coronary atherosclerosis assessed by computed tomography coronary angiography in an outpatient population with suspected or known coronary artery disease (Article)

2012-01-01T00:00:00Z

PURPOSE: To investigate the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major adverse cardiac events (MACEs) in patients with suspected or known coronary artery disease (CAD). MATERIALS AND METHODS: Seven hundred and sixty-seven consecutive patients (496 men, age 62±11 y) with suspected or known heart disease referred to an outpatient clinic underwent 64-slice CTCA. The patients were followed for the occurrence of MACE (ie, cardiac death, nonfatal myocardial infarction, unstable angina). RESULTS: Eleven thousand five hundred and sixty-four coronary segments were assessed. Of these, 178 (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed the absence of CAD in 219 (28.5%) patients, nonobstructive CAD (coronary plaque ≤50%) in 282 (36.8%) patients, and obstructive CAD in 266 (34.7%) patients. A total of 21 major cardiac events (4 cardiac deaths, 12 myocardial infarctions, and 5 unstable angina) occurred during a mean follow-up of 20 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD, and 4 events occurred in the group with nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. In multivariate analysis, the presence of obstructive CAD and diabetes were the only independent predictors of MACE. CONCLUSIONS: Coronary plaque evaluation by CTCA provides an independent prognostic value for the prediction of MACE. Patients with normal CTCA findings have an excellent prognosis at follow-up. Copyright

Coronary plaque burden in patients with stable and unstable coronary artery disease using multislice CT coronary angiography (Article)

2011-12-01T00:00:00Z

Purpose: We evaluated the multislice computed tomography (MSCT) coronary plaque burden in patients with stable and unstable angina pectoris. Materials and methods: Twenty-one patients with stable and 20 with unstable angina pectoris scheduled for conventional coronary angiography (CCA) underwent MSCT-CA using a 64-slice scanner offering a fast rotation time (330 ms) and higher X-ray tube output (900 mAs). To determine the MSCT coronary plaque burden, we assessed the extent (number of diseased segments), size (small or large), type (calcific, noncalcific, mixed) of plaque, its anatomic distribution and angiographic appearance in all available ≥2-mm segments. In a subset of 15 (seven stable, eight unstable) patients, the detection and classification of coronary plaques by MSCT was verified by intracoronary ultrasound (ICUS). Results: Sensitivity and specificity of MSCT compared with ICUS to detect significant plaques (defined as ≥1-mm plaque thickness on ICUS) was 83% and 87%. Overall, 473 segments were examined, resulting in 11.6±1.5 segments per patient. Plaques were present in 62% of segments and classified as large in 47% of diseased segments. Thirty-two percent were noncalcific, 25% calcific and 43% mixed. Plaques were most frequently located in the proximal and mid segments. Plaque was found in 33% of segments classified as normal on CCA. Unstable patients had significantly more noncalcific plaques when compared with stable patients (45% vs. 21%, p<0.05). Conclusions: MSCT-CA provides important information regarding the coronary plaque burden in patients with stable and unstable angina.

Different Algorithms for Quantitative Analysis of Myocardial Infarction with DE MRI. Comparison with Autopsy Specimen Measurements. (Article)

2011-12-01T00:00:00Z

Rationale and Objectives: To compare two semiautomated methods for measurement of infarcted myocardium area on delayed contrast enhanced magnetic resonance imaging, with histopathology findings as standard of reference. Materials and Methods: Percentage area of myocardial infarction was measured in 10 Yorkshire landrace pigs manually and using two semiautomated methods. The first (standard deviation method) used two operator-selected regions of interest (ROIs) and nine different cutoff values (one to nine times the standard deviation of signal intensity in normal myocardium) to identify infarction. The second (threshold method) used threshold values based on percentages of maximum signal intensity to identify infarction. Results were compared with histopathology findings. Results: Difference between percentage area of infarction obtained with standard deviation method and autopsy specimens was in the range: -13.5% to +13.2%. With threshold method (thresholds from 30% to 90% of signal intensity), difference was -15% to +23%. Manual contouring underestimated infarcted area by 2% comparing to autopsy results. The best agreement between histopathology and semi-automated software was achieved for 4 standard deviations with standard deviation method: difference -0.45%, and for a percentage threshold of 70% (difference +0.67%) with threshold method. However, with standard deviation method, there was statistically significant difference between ROIs based on their location in viable myocardium: mean difference 1.7 ± 4%, P < .0001. Conclusion: Semiautomated measurement of myocardial infarcted area on delayed enhanced magnetic resonance images performs well compared to autopsy. The threshold method, based on percentages of maximum signal intensity is preferable over standard deviation method, which is more susceptible to variability from location of ROIs within viable myocardium.

Image quality and radiation exposure using different low-dose scan protocols in dual-source CT coronary angiography: Randomized study (Article)

2011-12-01T00:00:00Z

Purpose: To compare image quality, radiation dose, and their relationship with heart rate of computed tomographic (CT) coronary angiographic scan protocols by using a 128-section dual-source CT scanner. Materials and Methods: Institutional review board approved the study; all patients gave informed consent. Two hundred seventy-two patients (175 men, 97 women; mean ages, 58 and 59 years, respectively) referred for CT coronary angiography were categorized according to heart rate: less than 65 beats per minute (group A) and 65 beats per minute or greater (group B). Patients were randomized to undergo prospective high-pitch spiral scanning and narrow-window prospective sequential scanning in group A (n = 160) or wide-window prospective sequential scanning and retrospective spiral scanning in group B (n = 112). Image quality was graded (1 = nondiagnostic; 2 = artifacts present, diagnostic; 3 = no artifacts) and compared (Mann-Whitney and Student t tests). Results: In group A, mean image quality grade was significantly lower with high-pitch spiral versus sequential scanning (2.67 ± 0.38 [standard deviation ] vs 2.86 ± 0.21; P <.001). In a subpopulation (heart rate, <55 beats per minute), mean image quality grade was similar (2.81 ± 0.30 vs 2.94 ± 0.08; P =.35). In group B, image quality grade was comparable between sequential and retrospective spiral scanning (2.81 ± 0.28 vs 2.80 ± 0.38; P =.54). Mean estimated radiation dose was significantly lower (high-pitch spiral vs sequential scanning) in group A (for 100 kV, 0.81 mSv ± 0.30 vs 2.74 mSv ± 1.14 [ P <.001]; for 120 kV, 1.65 mSv ± 0.69 vs 4.21 mSv ± 1.20 [ P <.001]) and in group B (sequential vs retrospective spiral scanning) (for 100 kV, 4.07 mSv ± 1.07 vs 5.54 mSv ± 1.76 [P =.02]; for 120 kV, 7.50 mSv ± 1.79 vs 9.83 mSv ± 3.49 [P =.1]). Conclusion: A high-pitch spiral CT coronary angiographic protocol should be applied in patients with regular and low (<55 beats per minute) heart rates; a sequential protocol is preferred in all others.

Accelerated subclinical coronary atherosclerosis in patients with familial hypercholesterolemia (Article)

2011-12-01T00:00:00Z

Objectives: We determined the extent, severity, distribution and type of coronary plaques in cardiac asymptomatic patients with familial hypercholesterolemia (FH) using computed tomography (CT). Background: FH patients have accelerated progression of coronary artery disease (CAD) with earlier major adverse cardiac events. Non-invasive CT coronary angiography (CTCA) allows assessing the coronary plaque burden in asymptomatic patients with FH. Materials and methods: A total of 140 asymptomatic statin treated FH patients (90 men; mean age 52 ± 8 years) underwent CT calcium scoring (Agatston) and CTCA using a Dual Source CT scanner with a clinical follow-up of 29 ± 8 months. The extent, severity (obstructive or non-obstructive plaque based on >50% or <50% lumen diameter reduction), distribution and type (calcified, non-calcified, or mixed) of coronary plaque were evaluated. Results: The calcium score was 0 in 28 (21%) of the patients. In 16% of the patients there was no CT-evidence of any CAD while 24% had obstructive disease. In total 775 plaques were detected with CT coronary angiography, of which 11% were obstructive. Fifty four percent of all plaques were calcified, 25% non-calcified and 21% mixed. The CAD extent was related to gender, treated HDL-cholesterol and treated LDL-cholesterol levels. There was a low incidence of cardiac events and no cardiac death occurred during follow-up. Conclusion: Development of CAD is accelerated in intensively treated male and female FH patients. The extent of CAD is related to gender and cholesterol levels and ranges from absence of plaque in one out of 6 patients to extensive CAD with plaque causing >50% lumen obstruction in almost a quarter of patients with FH.

Stable angina pectoris: Head-to-head comparison of prognostic value of cardiac CT and exercise testing (Article)

2011-11-01T00:00:00Z

Purpose: To determine and compare the prognostic value of cardiac computed tomographic (CT) angiography, coronary calcium scoring, and exercise electrocardiography (ECG) in patients with chest pain who are suspected of having coronary artery disease (CAD). Materials and Methods: This study complied with the Declaration of Helsinki, and the local ethics committee approved the study. Patients (n = 471) without known CAD underwent exercise ECG and dual-source CT at a rapid assessment outpatient chest pain clinic. Coronary calcification and the presence of 50% or greater coronary stenosis (in one or more vessels) were assessed with CT. Exercise ECG results were classified as normal, ischemic, or nondiagnostic. The primary outcome was a major adverse cardiac event (MACE), defined as cardiac death, nonfatal myocardial infarction, or unstable angina requiring hospitalization and revascularization beyond 6 months. Univariable and multivariable Cox regression analysis was used to determine the prognostic values, while clinical impact was assessed with the net reclassification improvement metric. Results: Follow-up was completed for 424 (90%) patients;the mean duration of follow-up was 2.6 years. A total of 44 MACEs occurred in 30 patients. Four of the MACEs were cardiac deaths and six were nonfatal myocardial infarctions. The presence of coronary calcification (hazard ratio [HR], 8.22 [95% confidence interval {CI}: 1.96, 34.51]), obstructive CAD (HR, 6.22 [95% CI: 2.77, 13.99]), and nondiagnostic stress test results (HR, 3.00 [95% CI: 1.26, 7.14]) were univariable predictors of MACEs. In the multivariable model, CT angiography findings (HR, 5.0 [95% CI: 1.7, 14.5]) and nondiagnostic exercise ECG results (HR, 2.9 [95% CI: 1.2, 7.0]) remained independent predictors of MACEs. CT angiography findings showed incremental value beyond clinical predictors and stress testing (global χ2, 37.7 vs 13.7; P<.001), whereas coronary calcium scores did not have further incremental value (global χ2, 38.2 vs 37.7; P = .40). Conclusion: CT angiography findings are a strong predictor of future adverse events, showing incremental value over clinical predictors, stress testing, and coronary calcium scores.

CT coronary angiography: A new unique prognosticator? (Article)

2011-09-01T00:00:00Z

Is there a difference in the diagnostic accuracy of computed tomography coronary angiography between women and men? (Article)

2011-09-01T00:00:00Z

OBJECTIVE: To assess the influence of sex on the diagnostic performance of computed tomography coronary angiography (CTCA). METHODS: A total of 916 symptomatic patients (30.5% women) without earlier history of coronary artery intervention underwent both CTCA and invasive coronary angiography. Descriptive diagnostic parameters, to detect obstructive coronary artery disease (CAD; ≥50% lumen diameter narrowing) on CTCA, were compared between women and men on a per-patient, per-vessel, and per-segment level. Adjusted values were calculated for clustered segments and differences in sex variables using logistic multivariate regression models in general estimated equations. RESULTS: Women were older, had less typical chest complaints, and had a lower prevalence, extent, and severity of CAD compared with men. Multivariate analysis on a per-patient level revealed no difference in sensitivity (98 vs. 99%, P=0.15), specificity (78 vs. 82%, P=0.65), positive predictive value (PPV; 87 vs. 95%, P=0.10), negative predictive value (NPV; 97 vs. 98%, P=0.63), and diagnostic odds ratio (DOR; 198 vs. 721, P=0.07). No difference was found on per-vessel level analysis (sensitivity 95 vs. 97%, P=0.14; specificity 89 vs. 87%, P=0.93; PPV 73 vs. 79%, P=0.06; NPV 98 vs. 98%, P=0.72; and DOR 143 vs. 240, P=0.08). Per-segment analysis revealed a lower sensitivity (88 vs. 94%, P<0.001) and DOR (163 vs. 302, P=0.002) in women compared with men, without a difference in specificity (96 vs. 95%, P=0.19), PPV (64 vs. 69%, P=0.07), and NPV (99 vs. 99%, P=0.08). CONCLUSION: CTCA can accurately rule out obstructive CAD in both women and men. CTCA is less accurate in women to detect individual obstructive disease.

The role of multi-slice computed tomography in stable angina management: a current perspective (Article)

2011-08-01T00:00:00Z

Contrast-enhanced CT coronary angiography (CTCA) has evolved as a reliable alternative imaging modality technique and may be the preferred initial diagnostic test in patients with stable angina with intermediate pre-test probability of CAD. However, because CTCA is moderately predictive for indicating the functional significance of a lesion, the combination of anatomic and functional imaging will become increasingly important. The technology will continue to improve with better spatial and temporal resolution at low radiation exposure, and CTCA may eventually replace invasive coronary angiography. The establishment of the precise role of CTCA in the diagnosis and management of patients with stable angina requires high-quality randomised study designs with clinical outcomes as a primary outcome.

Computed tomography-coronary angiography in the detection of coronary artery disease (Article)

2011-08-01T00:00:00Z

Computed tomography-coronary angiography (CT-CA) is a well-tolerated and reliable non-invasive imaging technique and can now be achieved at low levels of radiation exposure. CT-CA is highly valuable to exclude coronary artery disease, but due to over- and underestimation of the severity of coronary lesions, CT-CA cannot replace invasive coronary angiography. Coronary calcium scoring has an incremental independent prognostic value beyond traditional risk factor scores (Framingham, European Score) and may be useful to reclassify risk in asymptomatic individuals at intermediate risk. Appropriate indications for CT-CA are evolving, but studies are lacking to demonstrate that CT coronary imaging improves patient outcome.

Correlates on MSCT of paravalvular aortic regurgitation after transcatheter aortic valve implantation using the medtronic corevalve prosthesis (Article)

2011-07-27T00:00:00Z

Background: To investigate the causes of paravalvular aortic regurgitation (PAR) after the implantation of the Medtronic CoreValve prosthesis (MCRS). Methods and Results: Fifty-six patients underwent MSCT before TAVI with a MCRS and PAR was assessed with transthoracic echocardiography (TTE) between 5 and 10 days after TAVI. The aortic annulus smallest and largest orthogonal diameters and the mean diameter from the area were determined on MSCT on an axial image at the nadir of all three native leaflets. PAR was related to relevant anatomical structures on MSCT according to a clockface in the orientation of the parasternal short axis view on TTE. PAR ≥ 1 was present in 25% of the patients and was associated with a larger annulus, a lower degree of over sizing and with more aortic root calcification. On MSCT post TAVI malapposition was seen predominantly at the aorto-mitral fibrous continuity and the aspect of the largest diameter of the aortic annulus on the inside curve of the ascending aorta. PAR was predominantly seen at these two anatomic locations and less frequent in the area that contains the ventricular membranous septum and the area between the non- and right coronary sinus. Conclusions: Mild to moderate PAR is common after TAVI with the MCRS. The availability of additional (larger) prosthesis sizes in combination with improved sizing based on mean annulus diameter (e.g., DCSA) may help to reduce PAR.

Non-invasive diagnostic workup of patients with suspected stable angina by combined computed tomography coronary angiography and magnetic resonance perfusion imaging (Article)

2011-07-01T00:00:00Z

Background: To evaluate additional adenosine magnetic resonance perfusion (MRP) imaging in the diagnostic workup of patients with suspected stable angina with computed tomography coronary angiography (CTCA) as first-line diagnostic modality. Methods and Results: Two hundred and thirty symptomatic patients (male, 52%; age, 56 year) with suspected stable angina underwent CTCA. In patients with a stenosis of >50% as visually assessed, MRP was performed and the quantitative myocardial perfusion reserve index (MPRI) was calculated. Coronary flow reserve (CFR) using invasive coronary flow measurements served as the standard of reference. CTCA showed non-significant CAD in 151/230 (66%) patients and significant CAD in 79/230 patients (34%), of whom 50 subsequently underwent MRP and CFR. MRP showed reduced perfusion in 32 patients (64%), which was confirmed by CFR in 27 (84%). All 18 cases of normal MRP (36%) were confirmed by CFR. The positive likelihood ratio of MRP for the presence of functional significant disease in patients with a lesion on CTCA was 4.49 (95% confidence interval [CI] 2.12-9.99). The negative likelihood ratio was 0.05 (95%CI 0.01-0.34). Conclusions: CTCA as first-line diagnostic modality excluded coronary artery disease in a high percentage of patients referred for diagnostic workup of suspected stable angina. MRP made a significant contribution to the detection of functional significant lesions in patients with a positive CTCA.

Transaortic flow velocity from dual-source MDCT for the diagnosis of aortic stenosis severity (Article)

2011-07-01T00:00:00Z

Objectives: To describe a method for the estimation of transaortic flow from multidetector computer tomography (MDCT). Background: Cardiac MDCT may not allow instantaneous flow measurement yet the components of flow, namely, volume change over time and lumenal area are recorded. Methods: In 36 patients, the transaortic flow velocity was determined on transthoracic echocardiography and also with cardiac MDCT as follows: On MDCT an axial orientation through the aortic root was obtained so that the nadir of all three aortic leaflets could be seen simultaneously in one axial image. Aortic valve area (AVA) was determined by planimetry and left ventricular volumes by endocardial border mapping at every 5% increment of the RR intervals. Flow velocity was then calculated as the incremental ejection volume Ã· duration of the increment Ã· AVA. Results: The transthoracic echocardiography (TTE) peak velocity and MDCT peak velocity were highly correlated (r = 0.75, P < 0.01). Transaortic peak velocity was higher when measured by MDCT as compared to TTE, with respectively a median [IQ-range] of 4.5 [2.9-5.3] and 4.0 [3.0-4.6], P < 0.01. For the diagnosis of severe aortic stenosis greater concordance with TTE peak velocity was seen with MDCT peak velocity (sensitivity 100%, specificity 76%) than with MDCT AVA (sensitivity 74%, specificity 76%). Conclusions: We show for the first time that transaortic flow velocity can be estimated by dual-source MDCT and has a better sensitivity for the detection of severe aortic stenosis than AVA planimetry when compared to the gold standard of TTE peak flow velocity. Copyright

CT coronary plaque burden in asymptomatic patients with familial hypercholesterolaemia (Article)

2011-07-01T00:00:00Z

Objective: To determine the calcium score and coronary plaque burden in asymptomatic statin-treated patients with heterozygous familial hypercholesterolaemia (FH) compared with a control group of patients with low probability of coronary artery disease, having non-anginal chest pain, using CT. Design, setting and patients: 101 asymptomatic patients with FH (mean age 53±7 years; 62 men) and 126 patients with non-anginal chest pain (mean age 56±7 years; 80 men) underwent CT calcium scoring and CT coronary angiography. All patients with FH were treated with statins during a period of 10±8 years before CT. The coronary calcium score and plaque burden were determined and compared between the two patient groups. Results: The median total calcium score was significantly higher in patients with FH (Agatston score=87, IQR 5-367) than in patients with non-anginal chest pain (Agatston score=7, IQR 0-125; p<0.001). The overall coronary plaque burden was significantly higher in patients with FH (p<0.01). Male patients with FH, whose low-density lipoprotein cholesterol levels were reduced by statins below 3.0 mmol/l, had significantly less coronary calcium (p<0.01) and plaque burden (p=0.02). Conclusion: The coronary plaque burden is high in asymptomatic middle-aged patients with FH despite intense statin treatment.

First-line evaluation of coronary artery disease with coronary calcium scanning or exercise electrocardiography (Article)

2011-06-20T00:00:00Z

Background: Although conventional (CAG) and computed tomography angiography (CTA) are reliable diagnostic modalities for exclusion of obstructive coronary artery disease (CAD), they are costly and with considerable exposure to radiation and contrast media. We compared the accuracy of coronary calcium scanning (CCS) and exercise electrocardiography (X-ECG) as less expensive and non-invasive means to rule out obstructive CAD. Methods: In a rapid-access chest pain clinic, 791 consecutive patients with stable chest pain were planned to undergo X-ECG and dual-source CTA with CCS. According to the Duke pre-test probability of CAD patients were classified as low (< 30%), intermediate (30-70%) or high risk (> 70%). Angiographic obstructive CAD (> 50% stenosis by CAG or CTA) was found in 210/791 (27%) patients, CAG overruling any CTA results. Results: Obstructive CAD was found in 12/281 (4%) patients with no coronary calcium and in 73/319 (23%) with a normal X-ECG (p < 0.001). No coronary calcium was associated with a substantially lower likelihood ratio compared to X-ECG; 0.11, 0.13 and 0.13 vs. 0.93, 0.55 and 0.46 in the low, intermediate and high risk group. In low risk patients a negative calcium score reduced the likelihood of obstructive CAD to less than 5%, removing the need for further diagnostic work-up. CCS could be performed in 754/756 (100%) patients, while X-ECG was diagnostic in 448/756 (59%) patients (p < 0.001). Conclusions: In real-world patients with stable chest pain CCS is a reliable initial test to rule out obstructive CAD and can be performed in virtually all patients.

A clinical prediction rule for the diagnosis of coronary artery disease: Validation, updating, and extension (Article)

2011-06-01T00:00:00Z

AimsThe aim was to validate, update, and extend the DiamondForrester model for estimating the probability of obstructive coronary artery disease (CAD) in a contemporary cohort. Methods and resultsProspectively collected data from 14 hospitals on patients with chest pain without a history of CAD and referred for conventional coronary angiography (CCA) were used. Primary outcome was obstructive CAD, defined as <50 stenosis in one or more vessels on CCA. The validity of the DiamondForrester model was assessed using calibration plots, calibration-in-the-large, and recalibration in logistic regression. The model was subsequently updated and extended by revising the predictive value of age, sex, and type of chest pain. Diagnostic performance was assessed by calculating the area under the receiver operating characteristic curve (c-statistic) and reclassification was determined. We included 2260 patients, of whom 1319 had obstructive CAD on CCA. Validation demonstrated an overestimation of the CAD probability, especially in women. The updated and extended models demonstrated a c-statistic of 0.79 (95 CI 0.770.81) and 0.82 (95 CI 0.800.84), respectively. Sixteen per cent of men and 64 of women were correctly reclassified. The predicted probability of obstructive CAD ranged from 10 for 50-year-old females with non-specific chest pain to 91 for 80-year-old males with typical chest pain. Predictions varied across hospitals due to differences in disease prevalence. Conclusion Our results suggest that the DiamondForrester model overestimates the probability of CAD especially in women. We updated the predictive effects of age, sex, type of chest pain, and hospital setting which improved model performance and we extended it to include patients of 70 years and older.

Cardiac magnetic resonance imaging in stable ischaemic heart disease (Article)

2011-05-16T00:00:00Z

Cardiac magnetic resonance imaging (CMR) is a new robust versatile non-invasive imaging technique that can detect global and regional myocardial dysfunction, presence of myocardial ischaemia and myocardial scar tissue in one imaging session without radiation, with superb spatial and temporal resolution, inherited three-dimensional data collection and with relatively safe contrast material. The reproducibility of CMR is high which makes it possible to use this technique for serial assessment to evaluate the effect of revascularisation therapy in patients with ischaemic heart disease.

The influence of boundary conditions on wall shear stress distribution in patients specific coronary trees (Article)

2011-04-07T00:00:00Z

Patient specific geometrical data on human coronary arteries can be reliably obtained multislice computer tomography (MSCT) imaging. MSCT cannot provide hemodynamic variables, and the outflow through the side branches must be estimated. The impact of two different models to determine flow through the side branches on the wall shear stress (WSS) distribution in patient specific geometries is evaluated. Murray's law predicts that the flow ratio through the side branches scales with the ratio of the diameter of the side branches to the third power. The empirical model is based on flow measurements performed by Doriot et al. (2000) in angiographically normal coronary arteries. The fit based on these measurements showed that the flow ratio through the side branches can best be described with a power of 2.27. The experimental data imply that Murray's law underestimates the flow through the side branches. We applied the two models to study the WSS distribution in 6 coronary artery trees. Under steady flow conditions, the average WSS between the side branches differed significantly for the two models: the average WSS was 8% higher for Murray's law and the relative difference ranged from -5% to +27%. These differences scale with the difference in flow rate. Near the bifurcations, the differences in WSS were more pronounced: the size of the low WSS regions was significantly larger when applying the empirical model (13%), ranging from -12% to +68%. Predicting outflow based on Murray's law underestimates the flow through the side branches. Especially near side branches, the regions where atherosclerotic plaques preferentially develop, the differences are significant and application of Murray's law underestimates the size of the low WSS region.

Combining magnetic resonance viability variables better predicts improvement of myocardial function prior to percutaneous coronary intervention (Article)

2011-03-16T00:00:00Z

Objective: To optimize the predictive value of cardiac magnetic resonance imaging (MRI) for improvement of myocardial dysfunction prior to percutaneous coronary intervention (PCI). Methods: We performed cardiac MRI in 72 patients (male 87%, age 60 years) before and 6 months after successful PCI (43/72) or unsuccessful PCI (29/72) of a chronic total coronary occlusion (CTO). Before PCI, 5 viability parameters were evaluated: transmural extent of infarction (TEI), contractile reserve during dobutamine, end diastolic wall thickness, unenhanced rim thickness and segmental wall thickening of the unenhanced rim (SWTur). Multivariate analysis was performed and based on the regression coefficient (RC) a predictive score was constructed. Diagnostic performance to predict improvement in myocardial function for each parameter and for the viability score was determined. Results: The predictive value of a combination of contractile reserve, SWTur and TEI was incremental to TEI alone (AUROC 0.91 vs. 0.77; p < 0.001). A viability score of ≥ 5 based on contractile reserve (RC = 4), SWTur (RC = 1) and TEI (RC = 2) was 91% sensitive and 84% specific in predicting improvement of myocardial function. Conclusion: Combining viability parameters results in a better prediction of improvement of dysfunctional myocardial segments after a successful PCI.

Epicardial adipose tissue: An emerging role for the development of coronary atherosclerosis (Article)

2011-03-01T00:00:00Z

Comparison of adenosine magnetic resonance perfusion imaging with invasive coronary flow reserve and fractional flow reserve in patients with suspected coronary artery disease (Article)

2011-02-17T00:00:00Z

Current applications and limitations of coronary computed tomography angiography in stable coronary artery disease (Article)

2011-02-01T00:00:00Z

Prognostic value of CT coronary angiography: Focus on obstructive vs. nonobstructive disease and on the presence of left main disease (Article)

2011-02-01T00:00:00Z

Purpose: The authors investigated the prognostic value of computed tomography coronary angiography (CTCA) for major adverse cardiac events (MACE) in patients with suspected or known coronary artery disease (CAD), with particular focus on left main (LM) disease and obstructive vs. nonobstructive disease. Materials and methods: A total of 727 consecutive patients (485 men, age 62±11years) with suspected (514; 70.1%) or known (213; 29.9%) CAD underwent CTCA. Patients were followed up for the occurrence of MACE (i.e. cardiac death, nonfatal myocardial infarction, unstable angina, percutaneous/surgical revascularisation). Results: A total of 117 MACE [five cardiac deaths, 11 acute myocardial infarctions (AMI), five unstable angina, 86 percutaneous coronary interventions, ten coronary artery bypass grafts] occurred during a mean follow-up of 20 months. Severity and extension of CAD was associated with a progressively worse prognosis. The event rate was 0% among patients with normal coronary arteries at CTCA. The presence of LM disease was not associated with a worse prognosis either in patients with no history of CAD or in those with a history of CAD. At multivariate analysis, presence of obstructive CAD and diabetes were the only independent predictors of MACE. Conclusions: Evaluation of atherosclerotic burden by CTCA provides an independent prognostic value for prediction of MACE. Patients with normal CTCA findings have an excellent prognosis at follow-up.

Incremental value of the CT coronary calcium score for the prediction of coronary artery disease (Article)

2010-10-01T00:00:00Z

Objectives:: To validate published prediction models for the presence of obstructive coronary artery disease (CAD) in patients with new onset stable typical or atypical angina pectoris and to assess the incremental value of the CT coronary calcium score (CTCS). Methods:: We searched the literature for clinical prediction rules for the diagnosis of obstructive CAD, defined as≥50% stenosis in at least one vessel on conventional coronary angiography. Significant variables were re-analysed in our dataset of 254 patients with logistic regression. CTCS was subsequently included in the models. The area under the receiver operating characteristic curve (AUC) was calculated to assess diagnostic performance. Results:: Re-analysing the variables used by Diamond & Forrester yielded an AUC of 0.798, which increased to 0.890 by adding CTCS. For Pryor, Morise 1994, Morise 1997 and Shaw the AUC increased from 0.838 to 0.901, 0.831 to 0.899, 0.840 to 0.898 and 0.833 to 0.899. CTCS significantly improved model performance in each model. Conclusions:: Validation demonstrated good diagnostic performance across all models. CTCS improves the prediction of the presence of obstructive CAD, independent of clinical predictors, and should be considered in its diagnostic work-up. © 2010 The Author(s).

Impact of tube current in the quantitative assessment of acute reperfused myocardial infarction with 64-slice delayed-enhancement CT: A porcine model [Impatto della corrente del tubo sulla valutazione quantitativa dell'infarto miocardico acuto riperfuso mediante TC 64 strati e tecnica di delayed enhancement: esperienza in modello animale porcino] (Article)

2010-10-01T00:00:00Z

Purpose: This study evaluated the impact of tube current (mAs) in delayed-enhancement computed tomography (CT) imaging for assessing acute reperfused myocardial infarction in a porcine model. Materials and methods: In five domestic pigs (mean weight 24 kg), the circumflex coronary artery was balloon-occluded for 2 h and then reperfused. After 5 days, CT imaging was performed following administration of iodinated contrast material. A 64-slice CT system was used to perform first-pass coronary angiography with a tube current of 15 mAs/kg [Arterial Phase (ART)] followed by two delayed-enhancement (DE) scans 15 min after contrast material administration, with a tube current of 15 mAs/kg and 37.5 mAs/kg, respectively (DE1 and DE2). The mean heart rate decreased to 51±9 beats/min after administration of zatebradine (10 mg/kg IV). The data set was reconstructed during the end-diastolic phase of the cardiac cycle. Areas with DE, no reflow and remote myocardium [remote left ventricular (LV)] were calculated. CT values expressed in Hounsfield units (HU) were measured using five regions of interest (ROI): DE, no reflow, remote LV, LV cavity (LV lumen) and in air, respectively. Differences, correlations, image quality [signal-to-noise ratio (SNR)] and contrast resolution [contrast-to-noise ratio (CNR)] were calculated. Results: Significant differences were found between attenuation of areas of DE, no reflow and remote LV (p<0.001) within the different scans. There was a fair correlation between DE and no-reflow attenuation (r=0.6; p<0.001). In DE 1 vs. DE2, areas of DE and no reflow were not significantly different (p>0.05). The SNR and CNR were not significantly different in DE1 vs. DE2 (p>0.05). Conclusions: Tube current does not significantly affect infarction area, image quality or contrast resolution of DE imaging with CT.

3D fusion of intravascular ultrasound and coronary computed tomography for in-vivo wall shear stress analysis: A feasibility study (Article)

2010-10-01T00:00:00Z

Wall shear stress, the force per area acting on the lumen wall due to the blood flow, is an important biomechanical parameter in the localization and progression of atherosclerosis. To calculate shear stress and relate it to atherosclerosis, a 3D description of the lumen and vessel wall is required. We present a framework to obtain the 3D reconstruction of human coronary arteries by the fusion of intravascular ultrasound (IVUS) and coronary computed tomography angiography (CT). We imaged 23 patients with IVUS and CT. The images from both modalities were registered for 35 arteries, using bifurcations as landmarks. The IVUS images together with IVUS derived lumen and wall contours were positioned on the 3D centerline, which was derived from CT. The resulting 3D lumen and wall contours were transformed to a surface for calculation of shear stress and plaque thickness. We applied variations in selection of landmarks and investigated whether these variations influenced the relation between shear stress and plaque thickness. Fusion was successfully achieved in 31 of the 35 arteries. The average length of the fused segments was 36.4 ± 15.7 mm. The length in IVUS and CT of the fused parts correlated excellently (R2= 0.98). Both for a mildly diseased and a very diseased coronary artery, shear stress was calculated and related to plaque thickness. Variations in the selection of the landmarks for these two arteries did not affect the relationship between shear stress and plaque thickness. This new framework can therefore successfully be applied for shear stress analysis in human coronary arteries.

Contractile reserve in segments with nontransmural infarction in chronic dysfunctional myocardium using low-dose dobutamine CMR (Article)

2010-06-01T00:00:00Z

Objectives: This study sought to quantify contractile reserve of chronic dysfunctional myocardium, in particular in segments with intermediate transmural extent of infarction (TEI), using low-dose dobutamine cardiac magnetic resonance (CMR) in patients with a chronic total coronary occlusion (CTO). Background: Recovery of dysfunctional segments with intermediate TEI after percutaneous coronary intervention is variable and difficult to predict, and may be related to contractility of the unenhanced rim. Methods: Fifty-one patients (mean age 60 ± 9 years, 76% male) with a CTO underwent CMR at baseline and 35 patients underwent CMR at follow-up to quantify segmental wall thickening (SWT) at rest during 5 and 10 μg/kg/min dobutamine, and at follow-up. Delayed-enhancement CMR was performed to quantify TEI. Dysfunctional segments were stratified according to TEI, end-diastolic wall thickness (EDWT), or unenhanced rim thickness, and SWT was quantified. Segments with an intermediate TEI (25% to 75%) were further stratified according to baseline SWT of the unenhanced rim (SWTUR) (<45% and >45%), and SWT was quantified. For each parameter, odds ratio (OR) and diagnostic performance for the prediction of contractile reserve were calculated. Results: Significant contractile reserve was present in dysfunctional segments with EDWT >6 mm, unenhanced rim thickness >3 mm, or TEI of <25%; only TEI had significant relation with contractile reserve (OR: 0.98; 95% confidence interval [CI]: 0.96 to 0.99; p = 0.02). In segments with intermediate TEI (n = 58), mean SWT did not improve significantly. However, segments with SWTUR<45% showed contractile reserve and improved at follow-up, whereas segments with SWTUR>45% were unchanged. SWTURhad a significant relation with contractile reserve (OR: 0.98; 95% CI: 0.97 to 0.99; p = 0.02). Conclusions: CMR quantification of transmurality of infarcted myocardium allows the assessment of the potential of dysfunctional segments to improve in function during dobutamine of most segments. However, in segments with intermediate TEI, measurement of baseline contractility of the epicardial rim better identifies which segments maintain contractile reserve.

Lumen enhancement influences absolute noncalcific plaque density on multislice computed tomography coronary angiography: Ex-vivo validation and in-vivo demonstration (Article)

2010-05-01T00:00:00Z

Aim: The purpose of this study was to define the in-vitro and in-vivo effects of intracoronary enhancement on the absolute density values of coronary plaques during multislice computed tomography. Methods: We studied seven ex-vivo left coronary artery specimens surrounded by olive oil and filled with isotonic saline and four solutions with decreasing dilutions of contrast material: control (isotonic saline), 1/200, 1/80, 1/50, and 1/20. The multislice computed tomography protocol was: slice/collimation 32 × 2 × 0.6 mm and rotation time 330 ms. The attenuation (Hounsfield units) value of atherosclerotic plaques was measured for each dilution in lumen, plaque (noncalcified coronary wall thickening), calcium, and surrounding oil. In-vivo assessment was performed in 12 patients (nine men; mean age 58.7 ± 9.9 years) who underwent two subsequent multislice computed tomography scans (arterial and delayed) after intravenous administration of a single bolus of contrast material. The attenuation values of lumen and plaques during arterial and delayed computed tomography were compared. The results were compared with one-way analysis of variance and correlated with Pearson's test. Results: Mean lumen (45 ± 38-669 ± 151 HU) and plaque (11 ± 35-101 ± 72 HU) attenuation differed significantly (P < 0.001) among the different dilutions. The attenuation of lumen and plaque of coronary plaques showed moderate correlation (r = 0.54, P < 0.001). The mean attenuation value in vivo for the arterial and delayed phase scans differed significantly (P < 0.001) for lumen (325 ± 70 and 174 ± 46 HU, respectively) and plaque (138 ± 71 and 100 ± 52 HU, respectively). Conclusion: Coronary plaque attenuation values are significantly modified by differences in lumen contrast densities both ex vivo and in vivo. This should be taken into account when considering the distinction between lipid and fibrous plaques.

Does slice thickness affect diagnostic performance of 64-slice CT coronary angiography in stable and unstable angina patients with a positive calcium score? (Article)

2010-04-22T00:00:00Z

Background: Coronary calcification can lead to over-estimation of the degree of coronary stenosis. Purpose: To evaluate whether thinner reconstruction thickness improves the diagnostic performance of 64-slice CT coronary angiography (CTCA) in angina patients with a positive calcium score. Material and Methods: We selected 20 scans from a clinical study comparing CTCA to conventional coronary angiography (CCA) in stable and unstable angina patients based on a low number of motion artifacts and a positive calcium score. All images were acquired at 64Ã0.625 mm and each CTCA scan was reconstructed at slice thickness/increment 0.67 mm/0.33 mm, 0.9 mm/0.45 mm, and 1.4 mm/0.7 mm. Two reviewers blinded for CCA results independently evaluated the scans for the presence of significant coronary artery disease (CAD) in three randomly composed series, with â¥2 weeks in between series. The diagnostic performance of CTCA was compared for the different slice thicknesses using a pooled analysis of both reviewers. Significant CAD was defined as >50% diameter narrowing on quantitative CCA. Image noise (standard deviation of CT numbers) was measured in all scans. Inter-observer variability was assessed with kappa. Results: Significant CAD was present in 8% of 304 available segments. Median total Agatston calcium score was 181.8 (interquartile range 34.9815.6). Sensitivity at 0.67 mm, 0.9 mm, and 1.4 mm slice thickness was 70% (95% confidence interval 5783%), 74% (6286%), and 70% (5783%), respectively. Specificity was 85% (8288%), 84% (8187%), and 84% (8187%), respectively. The positive predictive value was 30 (2138%), 29 (2137%), and 28 (2036%), respectively. The negative predictive value was 97% (9598%), 97% (9699%), and 97% (9699%), respectively. Kappa for inter-observer agreement was 0.56, 0.58, and 0.59. Noise decreased from 32.9 HU at 0.67 mm, to 23.2 HU at 1.4 mm (P<0.001). Conclusion: Diagnostic performance of CTCA in angina patients with a positive calcium score was not markedly affected by modest variations in reconstruction slice thickness.

Three dimensional evaluation of the aortic annulus using multislice computer tomography: Are manufacturer's guidelines for sizing for percutaneous aortic valve replacement helpful? (Article)

2010-04-01T00:00:00Z

AimsTo evaluate the effects of applying current sizing guidelines to different multislice computer tomography (MSCT) aortic annulus measurements on Corevalve (CRS) size selection.Methods and resultsMultislice computer tomography annulus diameters [minimum: Dmin; maximum: Dmax; mean: Dmean= (Dmin+ Dmax)/2; mean from circumference: Dcirc; mean from surface area: DCSA] were measured in 75 patients referred for percutaneous valve replacement. Fifty patients subsequently received a CRS (26 mm: n = 22; 29 mm: n = 28). Dmin and Dmax differed substantially [mean difference (95 CI) = 6.5 mm (5.7-7.2), P < 0.001]. If Dmin were used for sizing 26 of 75 patients would be ineligible (annulus too small in 23, too large in 3), 48 would receive a 26 mm and 12 a 29 mm CRS. If Dmax were used, 39 would be ineligible (all annuli too large), 4 would receive a 26 mm, and 52 a 29 mm CRS. Using Dmean, Dcirc, or DCSAmost patients would receive a 29 mm CRS and 11, 16, and 9 would be ineligible. In 50 patients who received a CRS operator choice corresponded best with sizing based on DCSA and Dmean(76, 74), but undersizing occurred in 20 and 22 of which half were ineligible (annulus too large).ConclusionEligibility varied substantially depending on the sizing criterion. In clinical practice both under-and oversizing were common. Industry guidelines should recognize the oval shape of the aortic annulus.

Complete percutaneous revascularization for multivessel disease in patients with impaired left ventricular function: Pre- and post-procedural evaluation by cardiac magnetic resonance imaging (Article)

2010-03-01T00:00:00Z

Objectives: The aim of this study was to investigate the effect of complete, incomplete, and unsuccessful revascularization by percutaneous coronary intervention (PCI) on left ventricular ejection fraction (EF) in patients with multivessel disease and impaired left ventricular function and assess the diagnostic accuracy of cardiac magnetic resonance imaging (MRI) for improvement in EF. Background: The effect of PCI for multivessel coronary artery disease on long-term myocardial function and the predictive value of cardiac MRI on global function are incompletely investigated. Methods: Cardiac MRI was performed in patients with multivessel disease before and 6 months after complete revascularization (n = 34) or incomplete revascularization (n = 22) or in patients without successful revascularization (n = 15). For the prediction of recovery of EF, wall thickening was quantified on cine images at rest and during 5- and 10-μg/kg/min dobutamine. The transmural extent of infarction was quantified on delayed enhancement cardiac MRI. Results: The EF improved significantly after complete revascularization (46 ± 12% to 51 ± 13%; p < 0.0001) but did not change after incomplete (49 ± 11% to 49 ± 10%; p = 0.88) or unsuccessful revascularization (49 ± 13% to 47 ± 13%; p = 0.11). Sensitivity, specificity, positive and negative predictive value for the prediction of improvement in EF of >4% after PCI were 100%, 75%, 74%, and 100%, respectively, for dobutamine-cardiac MRI and 70%, 77%, 70%, and 77%, respectively, for delayed enhancement-cardiac MRI. Conclusions: Complete revascularization for multivessel coronary artery disease improves EF, whereas EF did not change in patients after incomplete or unsuccessful revascularization. Improvement in EF can be predicted by performing cardiac MRI before PCI.

Impact of contrast material volume on quantitative assessment of reperfused acute myocardial infarction using delayed-enhancement 64-slice CT: Experience in a porcine model (Article)

2010-02-01T00:00:00Z

Purpose: Our purpose in this study was to compare the impact of contrast material volume in delayed-enhancement computer tomography (CT) imaging for assessing acute reperfused myocardial infarction. Materials and methods: In five domestic pigs (20-30 kg), the circumflex coronary artery (CX) was balloon-occluded for 2 h followed by reperfusion. After 5 days, CT imaging was performed after intravenous administration of iodinated contrast material (Iomeprol 400mgI/ml; Bracco, Italy). A 64-slice multidetector CT (MDCT) (Sensation 64, Siemens) scanner was used for imaging, with standard angiography characteristics. Three scans were performed: first, coronary angiography at first pass with 1.25 gI/kg of contrast material (ART); and remaining delayed-enhancement (DE1-DE2) 15 min after administration of 1.25 (DE1) and 15 min after additional administration of 2.50 gI/kg (=total 3.75 gI/kg-DE2). Mean heart rate decreased to 51±9 bpm after intravenous administration of Zatebradine (10 mg/kg). Data sets were reconstructed during the end-diastolic phase of the cardiac cycle. Areas of infarction-enhanced (DE), no-reflow (no-reflow) and remote myocardial [remote left ventricle (LV)] were manually contoured. CT attenuation values (Hounsfield units) were measured using five regions of interest: DE, no-reflow, remote LV, left ventricular cavity (lumen LV) and in air. Differences, correlations, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Results: We found significant differences between the attenuation of DE, no-reflow and remote LV (p<0.001). DE and no-reflow size were assessed accurately with DEMDCT. In particular, SNR and CNR showed higher values in DE2(∼6.0 and 3.5, respectively; r2=0.90) vs. DE1(∼4.0 and 2.2, respectively; r2=0.85). Conclusions: The increase of contrast material volume determines a significant improvement in myocardial infarction image quality with DE-MDCT.

Diagnostic accuracy of computed tomography coronary angiography in patients with a zero calcium score (Article)

2010-01-01T00:00:00Z

To evaluate the diagnostic accuracy of 64-slice CT coronary angiography (CT-CA) for the detection of significant coronary artery stenosis in patients with zero on the Agatston Calcium Score (CACS). We enrolled 279 consecutive patients (96 male, mean age 48±12 years) with suspected coronary artery disease. Patients were symptomatic (n=208) or asymptomatic (n=71), and underwent conventional coronary angiography (CAG). For CT-CA we administered an IV bolus of 100 ml of iodinated contrast material. CT-CA was compared to CAG using a threshold for significant stenosis of ≤50%. The prevalence of disease demonstrated at CAG was 15% (1.4% in asymptomatic). The population at CAG showed no or non-significant disease in 85% (238/279), single vessel disease in 9% (25/279), and multi-vessel disease in 6% (16/279). Sensitivity, specificity, and positive and negative predictive values of CT-CA vs. CAG on the patient level were 100%, 95%, 76%, and 100% in the overall population and 100%, 100%, 100%, and 100% in asymptomatic patients, respectively. CT-CA proves high diagnostic performance in patients with or without symptoms and with zero CACS. The prevalence of significant disease detected by CT-CA was not negligible in asymptomatic patients. The role of CT-CA in asymptomatic patients remains uncertain.

Small coronary calcifications are not detectable by 64-slice contrast enhanced computed tomography (Article)

2010-01-01T00:00:00Z

Recently, small calcifications have been associated with unstable plaques. Plaque calcifications are both in intravascular ultrasound (IVUS) and multi-slice computed tomography (MSCT) easily recognized. However, smaller calcifications might be missed on MSCT due to its lower resolution. Because it is unknown to which extent calcifications can be detected with MSCT, we compared calcification detection on contrast enhanced MSCT with IVUS. The coronary arteries of patients with myocardial infarction or unstable angina were imaged by 64-slice MSCT angiography and IVUS. The IVUS and MSCT images were registered and the arteries were inspected on the presence of calcifications on both modalities independently. We measured the length and the maximum circumferential angle of each calcification on IVUS. In 31 arteries, we found 99 calcifications on IVUS, of which only 47 were also detected on MSCT. The calcifications missed on MSCT (n = 52) were significantly smaller in angle (27° ± 16° vs. 59° ± 31°) and length (1.4 ± 0.8 vs. 3.7 ± 2.2 mm) than those detected on MSCT. Calcifications could only be detected reliably on MSCT if they were larger than 2.1 mm in length or 36° in angle. Half of the calcifications seen on the IVUS images cannot be detected on contrast enhanced 64-slice MSCT angiography images because of their size. The limited resolution of MSCT is the main reason for missing small calcifications.

Left ventricular remodelling and systolic function measurement with 64 multi-slice computed tomography versus second harmonic echocardiography in patients with coronary artery disease: A double blind study (Article)

2010-01-01T00:00:00Z

The present study evaluated LV volumes, ejection fraction (LVEF) and stroke volume (SV) obtained by 64-MDCT and to compare these data with those obtained by second harmonic 2D Echo, in patients referred for non-invasive coronary vessels evaluation. The most common technique in daily clinical practice used for determination of LV function is two-dimensional echocardiography (2D-TTE). Multi-detector computed tomography (MDCT) is an emerging new technique to detect coronary artery disease (CAD) and was recently proposed to assess LV function. 93 patients underwent to 64-MDCT for LV function and volumes assessment by segmental reconstruction algorithm (Argus) and compared with recent (2 months) 2D-TTE, all images were processed and interpreted by two observers blinded to the Echo and MDCT results. A close correlation between TTE and 64 MDCT was demonstrated for the ejection fraction LVEF (r = 0.84), end-diastolic volume LVEDV (r = 0.80) and end-systolic volume LVESV (r = 0.85); acceptable correlation was recruited for stroke volume LVSV (r = 0.58). Optimal results were recruited for inter-observer variability for 64-MDCT measured in 45 patients: LVESV (r = 0.82, p < 0.001), LVEDV (r = 0.83, p < 0.001), LVEF (r = 0.69, p < 0.002) and SV (r = 0.66, p < 0.001). Our results, showed that functional and temporal information contained in a coronary 64-MDCT study can be used to assess left ventricular (LV) systolic function and LV dimensions with good reproducibility and acceptable correlation respect to 2D-TTE. The combination of non-invasive coronary artery imaging and assessment of global LV function might became in the future a fast and conclusive cardiac work-up in patients with CAD.

"in-house" pharmacological management for computed tomography coronary angiography: Heart rate reduction, timing and safety of different drugs used during patient preparation (Article)

2009-12-01T00:00:00Z

We retrospectively evaluated the effect, timing and safety of different pharmacological strategies during 64-slice CT coronary angiography (CT-CA). From the institutional database of CT-CA we enrolled 560 consecutive patients with suspected coronary artery disease. The type of drug preparation (group 1 = no treatment; group 2 = oral metoprolol; group 3 = other; group 4=intravenous (IV) atenolol; group 5=IV atenolol + nitrates; NR = non-responders), timing, and adverse effects were recorded. Heart rate (HR) during different preparation phases was recorded. Four adverse effects were recorded, none of which was attributable to pharmacological treatment. In all groups, except group 1, the HR on arrival was significantly reduced by the pharmacological treatment (p<0.01). Group 4 showed the best (-16±8 bpm) HR reduction. There was no significant effect on HR due to nitrates (p=0.49), while a slight increase due to contrast material was noted (p<0.05). Average time required for preparation was 44±25 min. Groups 4 and 5 showed the most effective timing (8±9 min and 8±8 min, respectively; p<0.01). Pharmacological preparation in patients undergoing CT-CA is safe and effective. Best results in terms of HR reduction and fast preparation are obtained with IV administration of beta-blockers.

Is there a role for CT coronary angiography in patients with symptomatic angina? Effect of coronary calcium score on identification of stenosis (Article)

2009-12-01T00:00:00Z

Present guidelines discourage the use of CT coronary angiography (CTCA) in symptomatic angina patients. We examined the relation between coronary calcium score (CS) and the performance of CTCA in patients with stable and unstable angina in order to understand under which conditions CTCA might be a gate-keeper to conventional coronary angiography (CCA) in such patients. We included 360 patients between 50 and 70 years old with stable and unstable angina who were clinically referred for CCA irrespective of CS. Patients received CS and CCTA on 64-slice scanners in a multicenter cross-sectional trial. The institutional review board approved the study. Diagnostic performance of CTCA to detect or rule out significant coronary artery disease was calculated on a per patient level in pre-defined CS categories. The prevalence of significant coronary artery disease strongly increased with CS. Negative CTCA were associated with a negative likelihood ratio of <0.1 independent of CS. Positive CTCA was associated with a high positive likelihood ratio of 9.4 if CS was <10. However, for higher CS the positive likelihood ratio never exceeded 3.0 and for CS >400 it decreased to 1.3. In the 62 (17%) patients with CS <10, CTCA reliably identified the 42 (68%) of these patients without significant CAD, at no false negative CTCA scans. In symptomatic angina patients, a negative CTCA reliably excludes significant CAD but the additional value of CTCA decreases sharply with CS >10 and especially with CS >400. In patients with CS <10, CTCA provides excellent diagnostic performance.

Impact of heart rate frequency and variability on radiation exposure, image quality, and diagnostic performance in dual-source spiral CT coronary angiography (Article)

2009-12-01T00:00:00Z

Purpose: To investigate the effect of heart rate frequency (HRF) and heart rate variability (HRV) on radiation exposure, image quality, and diagnostic performance to help detect significant stenosis (≥50% lumen diameter reduction) by using adaptive electrocardiographic (ECG) pulsing at dual-source (DS) spiral computed tomographic (CT) coronary angiography. Materials and Methods: Institutional review committee approval and informed consent were obtained. No prescan β-blockers were applied. Unenhanced CT and CT coronary angiography with adaptive ECG pulsing were performed in 927 consecutive patients (600 men, 327 women; mean age, 60.3 years ± 11.0 [standard deviation]) divided in three HRF groups: low, intermediate, and high (≤65, 66-79, and ≥80 beats/min, respectively), and four HRV groups given mean interbeat difference (IBD) during CT coronary angiography: normal, minor, moderate, and severe (IBDs of 0-1, 2-3, 4-10, and >10, respectively). Radiation exposure and image quality were also evaluated. In 444 of these, diagnostic performance was presented as sensitivity, specificity, positive predictive values (PPVs), and negative predictive values and likelihood ratios with corresponding 95% confidence intervals by using quantitative coronary angiography as the reference standard. Results: CT coronary angiography yielded good image quality in 98% of patients and no significant differences in image quality were found among HRF and HRV groups. Radiation exposure was significantly higher in patients with low versus high HRF and in patients with severe versus normal HRV. No significant differences among HRF and HRV groups in image quality and diagnostic performance were found. A nonsignificant trend was found toward a lower specificity and PPV in patients with a high HRF or severe HRV when compared with low HRF or normal HRV in patients with a low calcium score (Agatston score <100). Conclusion: DS spiral CT coronary angiography performed with adaptive ECG pulsing results in preserved diagnostic image quality and performance independent of HRF or HRV at the cost of limited dose reduction in arrhythmic patients.

CT coronary angiography in patients suspected of having coronary artery disease: Decision making from various perspectives in the face of uncertainty (Article)

2009-12-01T00:00:00Z

Purpose: To determine the cost-effectiveness of computed tomographic (CT) coronary angiography as a triage test, performed prior to conventional coronary angiography, by using a Markov model. Materials and Methods: A Markov model was used to analyze the cost-effectiveness of CT coronary angiography performed as a triage test prior to conventional coronary angiography from the perspective of the patient, physician, hospital, health care system, and society by using recommendations from the United Kingdom, the United States, and the Netherlands for cost-effectiveness analyses. For CT coronary angiography, a range of sensitivities (79%-100%) and specificities (63%-94%) were used to help diagnose significant coronary artery disease (CAD). Optimization criteria (ie, outcomes considered) were: revised posttest probability of CAD, life-years, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). Extensive sensitivity analysis was performed. Results: For a prior probability of CAD of less than 40%, the probability of CAD after CT coronary angiography with negative results was less than 1%. The Markov model calculations from the patient/physician perspective suggest that CT coronary angiography maximizes life-years respectively in 60-year-old men and women at a prior probability of less than 38% and 24% and maximizes QALYs at a prior probability of less than 17% and 11%. From the hospital/health care perspective, CT coronary angiography helps reduce health care and direct nonhealth care-related costs (according to UK/U.S. recommendations), regardless of prior probability, and lowers all costs, including production losses (Netherlands recommendations) at a prior probability of less than 87%-92%. Analysis performed from a societal perspective by using a willingness-topay threshold level of €80 000/QALY suggests that CT coronary angiography is cost-effective when the prior probability is lower than 44% and 37% in men and women, respectively. Sensitivity analyses showed that results changed across the reported range of sensitivity of CT coronary angiography. Conclusion: The optimal diagnostic work-up depends on the optimization criterion, prior probability of CAD, and the diagnostic performance of CT coronary angiography.

Parameters for coronary plaque vulnerability assessed with multidetector computed tomography and intracoronary ultrasound correlation (Article)

2009-11-01T00:00:00Z

In the absence of a fixed relationship between plaque vulnerability and flow-limiting stenosis, alternative morphological expressions exist that could predict the liability of coronary lesions to rapidly progress or rupture, causing acute coronary syndromes. Modern multidetector computed tomography technology is capable of noninvasively detecting lesion location, attenuation, remodeling and calcification pattern, which may be considered as surrogate morphological markers of vulnerability and could contribute to increase the prognostic value of individual coronary plaque burden.

Geometry and Degree of Apposition of the CoreValve ReValving System With Multislice Computed Tomography After Implantation in Patients With Aortic Stenosis (Article)

2009-09-01T00:00:00Z

Objectives: Using multislice computed tomography (MSCT), we sought to evaluate the geometry and apposition of the CoreValve ReValving System (CRS, Medtronic, Luxembourgh, Luxembourgh) in patients with aortic stenosis. Background: There are no data on the durability of percutaneous aortic valve replacement. Geometric factors may affect durability. Methods: Thirty patients had MSCT at a median 1.5 months (interquartile range [IQR] 0 to 7 months) after percutaneous aortic valve replacement. Axial dimensions and apposition of the CRS were evaluated at 4 levels: 1) the ventricular end; 2) the nadir; 3) central coaptation of the CRS leaflets; and 4) commissures. Orthogonal smallest and largest diameters and cross-sectional surface area were measured at each level. Results: The CRS (26-mm: n = 14, 29-mm: n = 16) was implanted at 8.5 mm (IQR 5.2 to 11.0 mm) below the noncoronary sinus. None of the CRS frames reached nominal dimensions. The difference between measured and nominal cross-sectional surface area at the ventricular end was 1.6 cm2(IQR 0.9 to 2.6 cm2) and 0.5 cm2(IQR 0.2 to 0.7 cm2) at central coaptation. At the level of central coaptation the CRS was undersized relative to the native annulus by 24% (IQR 15% to 29%). The difference between the orthogonal smallest and largest diameters (degree of deformation) at the ventricular end was 4.4 mm (IQR 3.3 to 6.4 mm) and it decreased progressively toward the outflow. Incomplete apposition of the CRS frame was present in 62% of patients at the ventricular end and was ubiquitous at the central coaptation and higher. Conclusions: Dual-source MSCT demonstrated incomplete and nonuniform expansion of the CRS frame, but the functionally important mid-segment was well expanded and almost symmetrical. Undersizing and incomplete apposition were seen in the majority of patients.

Anatomical and functional assessment of single left internal mammary artery versus arterial T-grafts 12 years after surgery (Article)

2009-09-01T00:00:00Z

We determined whether ultrasonographic left internal mammary artery (LIMA) findings correspond with 64 multislice computed tomography (MSCT) in patients 12 years after coronary artery bypass grafting. We included 34 patients (63.2±9.2 years), 16 with conventional single LIMA (group I) and 18 arterial T-grafts (group II), in a cross-sectional study. Patients underwent transthoracic proximal LIMA ultrasonography at rest and during the Azoulay maneuver, transthoracic echocardiography of the left ventricle and 64-MSCT, 11.5±1.4 years postoperatively. MSCT scans showed three string sign LIMA grafts (19%) in group I and three distal string sign LIMA grafts (17%) and 16 occluded T-graft anastomoses (22%) in group II. LIMA diameters and areas are significantly larger in group II in the origin, 3.5±0.7 vs. 2.5±0.5 mm, P=0.00007 and 0.09±0.04 vs. 0.05±0.02 cm2, P=0.00019 and in the third intercostal space, 3.4±0.7 vs. 2.5±0.5 mm, P=0.00009 and 0.09±0.03 vs. 0.05±0.02 cm2, P=0.000047. Most ultrasonographic LIMA findings do not differ between the groups. Thus, proximal LIMA diameters and areas are significantly larger in T-grafts and ultrasonographic variables equalize between the groups at rest and during the Azoulay maneuver 12 years after surgery.

Rediscovery of Infarct Imaging by Cardiac CT (Article)

2009-09-01T00:00:00Z

Comparison of Frequency of Calcified Versus Non-Calcified Coronary Lesions by Computed Tomographic Angiography in Patients With Stable Versus Unstable Angina Pectoris (Article)

2009-08-01T00:00:00Z

Computed tomographic coronary angiography (CTCA) can noninvasively identify calcified and noncalcified coronary plaques. The aim of this study was to compare the phenotypes of all plaques and of culprit plaques between patients with unstable angina pectoris (UAP) and those with stable angina pectoris (SAP), because plaque characteristics may differ between these patients. In 110 patients with UAP and 189 with SAP from a multicenter study comparing 64-slice CTCA with conventional coronary angiography, the number and phenotypes (noncalcified, mixed, and calcified) of coronary plaques were compared. In a subanalysis in 50 patients with UAP and 64 with SAP, culprit plaque characteristics, including culprit plaque cross-sectional area relative to total vessel cross-sectional area, culprit plaque length, remodeling index, and spotty calcification, were determined. Odds ratios for the presence of UAP, adjusted for clinical variables and the total number of plaques, were calculated for plaque characteristics on CTCA. Although the number of plaques was similar for patients with UAP and those with SAP, plaques in patients with UAP were more frequently noncalcified than in patients with SAP. The odds ratio for UAP was 1.3 (95% confidence interval [CI] 1.1 to 1.5) per noncalcified plaque. In the culprit plaque subanalysis, odds ratios for UAP were 0.99 (95% CI 0.96 to 1.01) per millimeter culprit plaque length, 2.7 (95% CI 1.2 to 6.4) for noncalcified culprit plaque, and 1.06 (95% CI 0.99 to 1.13) per percentage relative culprit plaque cross-sectional area. No significant relation was found between remodeling index or spotty calcification and UAP. In conclusion, noncalcified plaques and large noncalcified culprit plaques are more frequently found in patients with UAP than in those with SAP.

Diagnostic Accuracy of Computed Tomography Angiography in Patients After Bypass Grafting. Comparison With Invasive Coronary Angiography (Article)

2009-07-01T00:00:00Z

Objectives: We sought to evaluate the contribution of noninvasive dual-source computed tomography angiography (CTA) in the comprehensive assessment of symptomatic patients after coronary artery bypass grafting (CABG). Background: Assessment of bypass grafts and distal runoffs by invasive coronary angiography is cumbersome and often requires extra procedure time, contrast load, and radiation exposure. Methods: Dual-source CTA was performed in 52 (41 men, mean age 66.6 ± 13.2 years) symptomatic post-CABG patients scheduled for invasive coronary angiography. No oral or intravenous beta blockers or sedation were administered before the scan. Mean interval between CABG surgery and CTA was 9.6 ± 7.2 (range 0 to 20) years. Mean heart rate during scanning was 64.5 ± 13.2 (range 48 to 92) beats/min. Seventy-five percent of patients had both arterial and venous grafts. A total of 152 graft segments and 142 distal runoffs vessels were analyzed. Native coronary segments were divided into nongrafted (n = 118) and grafted segments (n = 289). A significant stenosis was defined as ≥50% lumen diameter reduction, and quantitative coronary angiography served as reference standard. Results: The diagnostic accuracy of CTA for the detection or exclusion of significant stenosis in arterial and venous grafts on a segment-by-segment analysis was 100%. Sensitivity, specificity, positive predictive value, and negative predictive value to detect significant stenosis were 95% (95% confidence interval [CI]: 73% to 100%), 100% (95% CI: 96% to 100%), 100% (95% CI: 79% to 100%), 99% (95% CI: 95% to 100%) in distal runoffs respectively; 100% (95% CI: 97% to 100%), 96% (95% CI: 90% to 98%), 97% (95% CI: 93% to 99%), 100% (95% CI: 95% to 100%) in grafted native coronary arteries respectively; and 97% (95% CI: 83% to 100%), 92% (95% CI: 83% to 96%), 83% (95% CI: 67% to 92%), 99% (95% CI: 92% to 100%) in nongrafted native coronary arteries, respectively. Conclusions: Noninvasive CTA is successful for evaluating bypass grafts in symptomatic post-CABG patients, whereas invasive coronary angiography is still required for the assessment of significant stenosis in distal runoffs and native coronary arteries.

Preserved diagnostic performance of dual-source CT coronary angiography with reduced radiation exposure and cancer risk (Article)

2009-07-01T00:00:00Z

Purpose: To evaluate the effects of standard and optimal electrocardiographic (ECG) pulsing on diagnostic performance, radiation dose, and cancer risk in symptomatic patients in a "real-world" clinical setting. Materials and Methods: The institutional review board approved the study, and all patients gave informed consent. Dual-source computed tomographic (CT) coronary angiography was performed in 436 symptomatic patients (301 men, 135 women; mean age, 61.6 years ± 10.6 [standard deviation]; age range, 23-89 years) referred for conventional coronary angiography. Standard and optimal ECG pulsing was performed in 327 and 109 patients, respectively. The diagnostic performance of dual-source CT coronary angiography for detection of significant stenosis (≥50 luminal diameter reduction), with quantitative coronary angiography as the reference standard, was reported as sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. The mean effective radiation dose, additional fatal cancer risk, and age- and sex-specific cancer risks related to one CT coronary angiographic examination were determined from data averaged over the study population. Results: Mean effective doses with standard and optimal ECG pulsing were 14.2 mSv ± 3.2 and 10.7 mSv ± 3.6, respectively. Optimal ECG pulsing resulted in a 43% overall reduction in mean effective radiation dose and cancer risk compared with a nonpulsing protocol (18.8 mSv ± 3.5) and a 25% overall reduction in mean effective dose compared with the standard pulsing protocol. At patient-by-patient analysis, CT coronary angiography with standard ECG pulsing yielded sensitivity, specificity, and positive and negative predictive values of 100% (95% confidence interval [CI]: 99%, 100%), 85% (95% CI: 81%, 88%), 94% (95% CI: 91%, 96%), and 99% (95% CI: 98%, 100%), respectively, for detection of significant stenosis. Optimal ECG pulsing yielded similar results: Sensitivity, specificity, and positive and negative predictive values were 100% (95% CI: 100%, 100%), 88% (95% CI: 82%, 94%), 97% (95% CI: 93%, 100%), and 100%, respectively. Conclusion: Compared with a nonpulsing protocol, optimal ECG pulsing resulted in significant (P < .001) reductions in patient radiation dose and cancer risk (up to 55% reduction in patients with high heart rates) while preserving the diagnostic performance of dual-source CT coronary angiography.

Fluoroscopic three-dimensional left atrial image integration during ablation for cardiac ablation procedures (Article)

2009-06-01T00:00:00Z

Learning curve for coronary CT angiography: What constitutes sufficient training? (Article)

2009-05-01T00:00:00Z

Purpose: To prospectively evaluate the effect of experience with coronary computed tomographic (CT) angiography on the capability to detect coronary stenoses of 50% or more. Materials and Methods: The institutional review board approved the study protocol. All patients gave consent to undergo CT angiography before conventional coronary angiography after being informed of the additional radiation dose. They also consented to the use of their data for future research. Three radiologists and one cardiologist inexperienced with coronary CT angiography attended this institution's cardiac CT unit for a 1-year fellowship. Fellows were involved in the acquisition and reading of 12-15 coronary CT angiograms per week (about 600 per year). To assess the progression in diagnostic performance, fellows (readers) independently read 50 CT angiographic test cases in patients who also underwent conventional coronary angiography. Cases were repeatedly assigned in random order at baseline and at 4, 8, 26, and 52 weeks. The same cases were examined by two experts in consensus. Sensitivity, specificity, and diagnostic odds ratios (DORs) were calculated and compared with conventional coronary angiography as the reference standard. Results: Respective reader ranges for sensitivity, specificity, and DOR were 33%-72%, 70%-94%, and 3.8-8.1 at baseline; 43%-80%, 71%-88%, and 8.8-15.2 after 6 months; and 66%-75%, 87%-92%, and 14.7-25.8 after 1 year. For expert physicians, respective results were 95%, 93%, and 255.9. Between baseline and 6 months, readers 1-3 showed nonsignificantly improved sensitivities, while specificities remained similar. Reader 4 showed significantly improved specificity, while sensitivity remained similar; all readers nonsignificantly improved DORs. Between baseline and 1 year: readers 1 and 2 significantly improved sensitivity but not specificity; reader 4 significantly improved specificity but not sensitivity; readers 1, 2, and 4 improved DOR significantly; reader 3 nonsignificantly improved sensitivity, specificity, and DOR. Conclusion: Increasing experience with coronary CT angiography improved the diagnostic performance of inexperienced physicians. However, acquiring expertise in coronary CT angiography was slow and may take more than 1 year.

Pre-Procedural Dual Source 64-Slice Computed Tomography in Unprotected Left Main Intervention (Article)

2009-05-01T00:00:00Z

Integration of Multislice Computed Tomography With Magnetic Navigation Facilitates Percutaneous Coronary Interventions Without Additional Contrast Agents (Article)

2009-03-03T00:00:00Z

Objectives: We hypothesized that percutaneous coronary intervention (PCI) without additional contrast agents can be performed by directly integrating multislice computed tomography coronary angiography (CTCA) within the magnetic navigation system (MNS). Background: Increasingly, CTCA is being used in the diagnostic work-up of patients with coronary disease. Its inherent 3-dimensional information should be exploited, as it potentially offers advantages over 2-dimensional radiography in guiding invasive diagnostic and therapeutic interventions. Methods: CTCA-derived centerlines from 15 patients were coregistered and overlaid on real-time fluoroscopic images employing the MNS. Vessels were manually wired with a magnetically enabled guidewire assisted by variable local magnetic fields. Fractional flow reserve (FFR) determined the lesion severity, and the dimensions were quantified by intravascular ultrasound (IVUS). Locations of the IVUS catheter probe along the lesion were incorporated in software to facilitate stenting without contrast agents. Results: The average crossing and fluoroscopic times were 105.3 ± 35.5 s and 83.4 ± 38.6 s, respectively, with no contrast agents used in 11 of 15 patients (73.3%). Contrast agents were used in only 1 of 10 patients (10%) in whom an IVUS was performed. In 4 patients, apart from a "blinded" safety check angiogram, the entire PCI (lesion crossing, stent sizing, positioning, and deployment) was performed without additional contrast agents following the coregistration of the IVUS probe position in the MNS. Conclusions: The integration of pre-procedural CTCA within the MNS can facilitate PCI without additional contrast agents.

Prognostic value of computed tomography coronary angiography in patients with suspected coronary artery disease: A 24-month follow-up study (Article)

2009-02-18T00:00:00Z

The aim of this study was to determine the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major cardiac events in patients with suspected coronary artery disease (CAD). A total of 187 consecutive patients (119 men, age 62.5±10.5 years) without known heart disease underwent single-source 64-slice CTCA (Somatom Sensation 64, Siemens) for clinical suspicion of CAD. Patients underwent follow-up for the occurrence of cardiac death, nonfatal myocardial infarction, unstable angina and cardiac revascularization. In total, 2,822 coronary segments were assessed. Forty-two segments (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed absence of CAD in 65 (34.7%) patients, nonobstructive CAD (coronary plaque >50%) in 87 (46.5%) patients and obstructive CAD (>50%) in 35 (18.8%) patients. A total of 20 major cardiac events (3 myocardial infarctions, 16 cardiac revascularizations, 1 unstable angina) occurred during a mean follow-up of 24 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD and three events occurred in the group of nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. CTCA has a 100% negative predictive value for major cardiac events at 24-month follow-up in patients with normal coronary arteries.

"Radio-lucent" and "radio-opaque" coronary stents characterized by multislice computed tomography (Article)

2009-02-06T00:00:00Z

A 71-year-old man was admitted with stable angina pectoris. The coronary lesion in the obtuse marginal branch was successfully treated with a BVS bioabsorbable poly-l-lactic acid everolimus-eluting coronary stent and a Cypher stent. On multislice computed tomography (MSCT) coronary angiography performed after stenting, the in-stent lumen within radio-lucent polymer struts of the BVS stent was clearly depicted. In contrast, the metallic struts of the Cypher stent hampered precise in-stent luminal evaluation due to blooming artifact. Non-metallic coronary stents composed of radio-lucent polymers might have potential advantages compared to metallic stents with respect to non-invasive MSCT imaging.

Diagnostic Accuracy of 64-Slice Computed Tomography Coronary Angiography. A Prospective, Multicenter, Multivendor Study (Article)

2008-12-16T00:00:00Z

Objectives: This study sought to determine the diagnostic accuracy of 64-slice computed tomographic coronary angiography (CTCA) to detect or rule out significant coronary artery disease (CAD). Background: CTCA is emerging as a noninvasive technique to detect coronary atherosclerosis. Methods: We conducted a prospective, multicenter, multivendor study involving 360 symptomatic patients with acute and stable anginal syndromes who were between 50 and 70 years of age and were referred for diagnostic conventional coronary angiography (CCA) from September 2004 through June 2006. All patients underwent a nonenhanced calcium scan and a CTCA, which was compared with CCA. No patients or segments were excluded because of impaired image quality attributable to either coronary motion or calcifications. Patient-, vessel-, and segment-based sensitivities and specificities were calculated to detect or rule out significant CAD, defined as ≥50% lumen diameter reduction. Results: The prevalence among patients of having at least 1 significant stenosis was 68%. In a patient-based analysis, the sensitivity for detecting patients with significant CAD was 99% (95% confidence interval [CI]: 98% to 100%), specificity was 64% (95% CI: 55% to 73%), positive predictive value was 86% (95% CI: 82% to 90%), and negative predictive value was 97% (95% CI: 94% to 100%). In a segment-based analysis, the sensitivity was 88% (95% CI: 85% to 91%), specificity was 90% (95% CI: 89% to 92%), positive predictive value was 47% (95% CI: 44% to 51%), and negative predictive value was 99% (95% CI: 98% to 99%). Conclusions: Among patients in whom a decision had already been made to obtain CCA, 64-slice CTCA was reliable for ruling out significant CAD in patients with stable and unstable anginal syndromes. A positive 64-slice CTCA scan often overestimates the severity of atherosclerotic obstructions and requires further testing to guide patient management.

Strain distribution over plaques in human coronary arteries relates to shear stress (Article)

2008-10-01T00:00:00Z

Once plaques intrude into the lumen, the shear stress they are exposed to alters with hitherto unknown consequences for plaque composition. We investigated the relationship between shear stress and strain, a marker for plaque composition, in human coronary arteries. We imaged 31 plaques in coronary arteries with angiography and intravascular ultrasound. Computational fluid dynamics was used to obtain shear stress. Palpography was applied to measure strain. Each plaque was divided into four regions: upstream, throat, shoulder, and downstream. Average shear stress and strain were determined in each region. Shear stress in the upstream, shoulder, throat, and downstream region was 2.55 ± 0.89, 2.07 ± 0.98, 2.32 ± 1.11, and 0.67 ± 0.35 Pa, respectively. Shear stress in the downstream region was significantly lower. Strain in the downstream region was also significantly lower than the values in the other regions (0.23 ± 0.08% vs. 0.48 ± 0.15%, 0.43 ± 0.17%, and 0.47 ± 0.12%, for the upstream, shoulder, and throat regions, respectively). Pooling all regions, dividing shear stress per plaque into tertiles, and computing average strain showed a positive correlation; for low, medium, and high shear stress, strain was 0.23 ± 0.10%, 0.40 ± 0.15%, and 0.60 ± 0.18%, respectively. Low strain colocalizes with low shear stress downstream of plaques. Higher strain can be found in all other plaque regions, with the highest strain found in regions exposed to the highest shear stresses. This indicates that high shear stress might destabilize plaques, which could lead to plaque rupture. Copyright

Accurate Automatic Papillary Muscle Identification for Quantitative Left Ventricle Mass Measurements in Cardiac Magnetic Resonance Imaging (Article)

2008-10-01T00:00:00Z

Rationale and Objectives: We sought to evaluate the automatic detection of the papillary muscle and to determine its influence on quantitative left ventricular (LV) mass assessment. Materials and Methods: Twenty-eight Yorkshire-Landrace swine and 10 volunteers underwent cardiac magnetic resonance imaging (CMR) of the left ventricle. The variability in measurements of LV papillary muscles traced automatically and manually were compared to intra- and interobserver variabilities. CMR-derived LV mass with the papillary muscle included or excluded from LV mass measurements was compared to true mass at autopsy of the Yorkshire-Landrace swine. Results: Automatic LV papillary muscle mass from all subjects correlated well with manually derived LV papillary muscle mass measurements (r = 0.84) with no significant bias between both measurements (mean difference ± SD, 0.0 ± 1.5 g; P = .98). The variability in results related to the contour detection method used was not statistically significant different compared to intra- and interobserver variabilities (P = .08 and P = .97, respectively). LV mass measurements including the papillary muscle showed significantly less underestimation (-10.6 ± 7.1 g) with the lowest percentage variability (6%) compared to measurements excluding the papillary muscles (mean underestimation, -15.1 ± 7.4 g percentage variability, 7%). Conclusion: The automatic algorithm for detecting the papillary muscle was accurate with variabilities comparable to intra- and interobserver variabilities. LV mass is determined most accurately when the papillary muscles are included in the LV mass measurements. Taken together, these observations warrant the inclusion of automatic contour detection of papillary muscle mass in studies that involve the determination of LV mass.

Optimal electrocardiographic pulsing windows and heart rate: Effect on image quality and radiation exposure at dual-source coronary CT angiography (Article)

2008-09-01T00:00:00Z

Purpose: To determine the optimal width and timing of the electrocardiographic (ECG) pulsing window within the cardiac cycle in relation to heart rate (HR), image quality, and radiation exposure in patients who are suspected of having coronary artery disease. Materials and Methods: The institutional review board approved the study, and all patients gave informed consent. Dual-source computed tomography (CT) was performed in 301 patients (mean HR, 70.1 beats per minute ± 13.3 [standard deviation]; range, 43-112 beats per minute) by using a wide ECG pulsing window (25%-70% of the R-R interval). Data sets were reconstructed in 5% steps from 20%-75% of R-R interval. Image quality was assessed by two observers on a per-segment level and was classified as good or impaired. High-quality data sets were those in which each segment was of good quality. The width and timing of the image reconstruction window was calculated. On the basis of these findings, an optimal HR-dependent ECG pulsing protocol was designed, and the potential dose-saving effect on effective dose (in millisieverts) was calculated. Results: At low HR (≤65 beats per minute), high-quality data sets were obtained during end diastole (ED); at high HR (≥80 beats per minute), they were obtained during end systole (ES); and at intermediate HR (66-79 beats per minute), they were obtained during both ES and ED. Optimal ECG pulsing windows for low, intermediate, and high HR were at 60%-76%, 30%-77%, and 31%-47% of the R-R interval, respectively, and with these levels, the effective dose was decreased at low HR from 18.7 to 6.8 mSv, at intermediate HR from 14.7 to 13.4 mSv, and at high HR from 11.3 to 4.2 mSv. Conclusion: With optimal ECG pulsing, radiation exposure to patients, particularly those with low or high HR, can be reduced with preservation of image quality.

Comprehensive Assessment of Coronary Artery Stenoses. Computed Tomography Coronary Angiography Versus Conventional Coronary Angiography and Correlation With Fractional Flow Reserve in Patients With Stable Angina (Article)

2008-08-19T00:00:00Z

Objectives: We sought to determine the diagnostic accuracy of noninvasive visual (computed tomography coronary angiography [CTCA]) and quantitative computed tomography coronary angiography (QCT) to predict the hemodynamic significance of a coronary stenosis, using intracoronary fractional flow reserve (FFR) as the reference standard. Background: It has been demonstrated that CTCA provides excellent diagnostic sensitivity for identifying coronary stenoses, but may lack accurate delineation of the hemodynamic significance. Methods: We investigated 79 patients with stable angina pectoris who underwent both 64-slice or dual-source CTCA and FFR measurement of discrete coronary stenoses. CTCA and conventional coronary angiography (CCA), and QCT and quantitative coronary angiography (QCA), were performed to determine the severity of a stenosis that was compared with FFR measurements. A significant anatomical or functional stenosis was defined as ≥50% diameter stenosis or an FFR <0.75. Stented segments and bypass grafts were not included in the analysis. Results: A total of 89 stenoses were evaluated of which 18% (16 of 89) had an FFR <0.75. The diagnostic accuracy of CTCA, QCT, CCA, and QCA to detect a hemodynamically significant coronary lesion was 49%, 71%, 61%, and 67%, respectively. Correlation between QCT and QCA with FFR measurement was weak (R values of -0.32 and -0.30, respectively). Correlation between QCT and QCA was significant, but only moderate (R = 0.53; p < 0.0001). Conclusions: The anatomical assessment of the hemodynamic significance of coronary stenoses determined by visual CTCA, CCA, or QCT or QCA does not correlate well with the functional assessment of FFR. Determining the hemodynamic significance of an angiographically intermediate stenosis remains relevant before referral for revascularization treatment.

Computed Tomography Coronary Angiography for Screening Asymptomatic Subjects. A Bridge Too Far?**Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology. (Article)

2008-07-29T00:00:00Z

Physiopathology of the Aging Heart (Article)

2008-07-01T00:00:00Z

Coronary heart disease remains the leading cause of morbidity and mortality in older adults, despite improved survival and declining mortality. Prevalence in and impact of heart disease on elderly people, increasing risk factors, and the underlying physiologic changes of aging are briefly reviewed. High prevalence of clinical and subclinical heart disease provides a basis for considering opportunities for prevention and follow-up. This article focuses on recently developed noninvasive techniques, such as cardiac multislice CT and cardiac MR imaging.

Dual source coronary computed tomography angiography for detecting in-stent restenosis (Article)

2008-07-01T00:00:00Z

Objective: To evaluate the performance of dual source CT coronary angiography (DSCT-CA) in the detection of instent restenosis (≥50% luminal narrowing) in symptomatic patients referred for conventional angiography (CA). Design/patients: 100 patients (78 males, age 62 (SD 10)) with chest pain were prospectively evaluated after coronary stenting. DSCT-CA was performed before CA. Setting: Many patients undergo coronary artery stenting; availability of a non-invasive modality to detect in-stent restenosis would be desirable. Results: Average heart rate (HR) was 67 (SD 12) (range 46-106) bpm. There were 178 stented lesions. The interval between stenting and inclusion in the study was 35 (SD 41) (range 3-140) months. 39/100 (39%) patients had angiographically proven restenosis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of DSCT-CA, calculated in all stents, were 94%, 92%, 77% and 98%, respectively. Diagnostic performance at HR <70 bpm (n = 69; mean 58 bpm) was similar to that at HR ≥70 bpm (n = 31; mean 78 bpm); diagnostic performance in single stents (n = 95) was similar to that in overlapping stents and bifurcations (n = 83). In stents ≥3.5 mm (n = 78), sensitivity, specificity, PPV, NPV were 100%; in 3 mm stents (n = 59), sensitivity and NPV were 100%, specificity 97%, PPV 91%; in stents ≤2.75 mm (n = 41), sensitivity was 84%, specificity 64%, PPV 52%, NPV 90%. Nine stents ≤2.75 mm were uninterpretable. Specificity of DSCT-CA in stents ≥3.5 mm was significantly higher than in stents ≤2.75 mm (OR = 6.14; 99%CI: 1.52 to 9.79). Conclusion: DSCT-CA performs well in the detection of in-stent restenosis. Although DSCT-CA leads to frequent false positive findings in smaller stents (≤2.75 mm), it reliably rules out in-stent restenosis irrespective of stent size.

Recommendations or mere prose? Reply (Article)

2008-06-01T00:00:00Z

Quantification of coronary plaque by 64-slice computed tomography: A comparison with quantitative intracoronary ultrasound (Article)

2008-05-01T00:00:00Z

BACKGROUND: Noninvasive assessment of coronary atherosclerotic plaque may be useful for risk stratification and treatment of atherosclerosis. MATERIALS AND METHODS: We studied 47 patients to investigate the accuracy of coronary plaque volume measurement acquired with 64-slice multislice computed tomography (MSCT), using newly developed quantification software, when compared with quantitative intracoronary ultrasound (QCU). Quantitative MSCT coronary angiography (QMSCT-CA) was performed to determine plaque volume for a matched region of interest (regional plaque burden) and in significant plaque defined as a plaque with ≥50% area obstruction in QCU, and compared with QCU. Dataset with image blurring and heavy calcification were excluded from analysis. RESULTS: In 100 comparable regions of interest, regional plaque burden was highly correlated (coefficient r = 0.96; P < 0.001) between QCU and QMSCT-CA, but QMSCT-CA overestimated the plaque burden by a mean difference of 7 ± 33 mm (P = 0.03). In 76 significant plaques detected within the regions of interest, plaque volume determined by QMSCT-CA was highly correlated (r = 0.98; P < 0.001) with a slight underestimation of 2 ± 17 mm (P = not significant) when compared with QCU. Calcified and mixed plaque volume was slightly overestimated by 4 ± 19 mm (P = ns) and noncalcified plaque volume was significantly underestimated by 9 ± 11 mm (P < 0.001) with QMSCT-CA. Overall, the limits of agreement for plaque burden/volume measurement between QCU and QMSCT-CA were relatively large. Reproducibility for the measurements of regional plaque burden with QMSCT-CA was good, with a mean intraobserver and interobserver variability of 0% ± 16% and 4% ± 24%, respectively. CONCLUSIONS: Quantification of coronary plaque within selected proximal or middle coronary segments without image blurring and heavy calcification with 64-slice CT was moderately accurate with respect to intravascular ultrasound and demonstrated good reproducibility. Further improvement in CT resolution is required for more reliable measurement of coronary plaques using quantification software.

Diagnostic performance of coronary CT angiography by using different generations of multisection scanners: Single-center experience (Article)

2008-02-01T00:00:00Z

Purpose: To retrospectively compare sensitivity and specificity of four generations of multidetector computed tomographic (CT) scanners for diagnosing significant (≥50%) coronary artery stenosis, with quantitative conventional coronary angiography as reference standard. Materials and Methods: The institutional review board approved this study. All patients consented to undergo CT studies prior to conventional coronary angiography, after they were informed of the additional radiation dose, and to the use of their data for future retrospective research. Two hundred four patients (157 men, 47 women; mean age, 58 years ± 11 [standard deviation]), classified in four groups of 51 patients each, underwent coronary CT angiography with four-section, first- and second-generation 16-section, and 64-section CT scanners. Patients in sinus rhythm scheduled for conventional coronary angiography (stable angina, atypical chest pain) were included. Patients with bypass grafts and stents were excluded. Two readers unaware of results of conventional coronary angiography evaluated CT scans. Coronary artery segments of 2 mm or larger in diameter were included for comparative evaluation with quantitative coronary angiography. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for detection of significant stenoses (≥50% luminal diameter reduction) were calculated. Results: Image quality was rated poor for the following percentages of coronary artery segments: 33.1% at four-section CT, 14.4% at first-generation 16-section CT, 6.3% at second-generation 16-section CT, and 2.6% at 64-section CT. Sensitivity, specificity, PPV, and NPV, respectively, were as follows: 57%, 91%, 60%, and 90% at four-section CT; 90%, 93%, 65%, and 99% at first-generation 16-section CT; 97%, 98%, 87%, and 100% at second-generation 16-section CT; and 99%, 96%, 80%, and 100% at 64-section CT. Diagnostic performance of four-section CT was significantly poorer than that of second-generation 16-section CT (odds ratio = 4.57) and 64-section CT (odds ratio = 2.89). Conclusion: Diagnostic performance of coronary CT angiography varies among scanners of different generations. Earlier-generation scanners (four sections) had significantly poorer performance; performance of 16- compared with 64-section CT scanners showed progressive, although not significant, improvement.

Cardiac computed tomography: Indications, applications, limitations, and training requirements - Report of a Writing Group deployed by the Working Group Nuclear Cardiology and Cardiac CT of the European Society of Cardiology and the European Council of Nuclear Cardiology (Article)

2008-02-01T00:00:00Z

As a consequence of improved technology, there is growing clinical interest in the use of multi-detector row computed tomography (MDCT) for non-invasive coronary angiography. Indeed, the accuracy of MDCT to detect or exclude coronary artery stenoses has been high in many published studies. This report of a Writing Group deployed by the Working Group Nuclear Cardiology and Cardiac CT (WG 5) of the European Society of Cardiology and the European Council of Nuclear Cardiology summarizes the present state of cardiac CT technology, as well as the currently available data concerning its accuracy and applicability in certain clinical situations. Besides coronary CT angiography, the use of CT for the assessment of cardiac morphology and function, evaluation of perfusion and viability, and analysis of heart valves is discussed. In addition, recommendations for clinical applications of cardiac CT imaging are given and limitations of the technique are described.

Evaluation of Left Ventricular Function Three Years After Percutaneous Recanalization of Chronic Total Coronary Occlusions (Article)

2008-01-15T00:00:00Z

We investigated early and late effects of percutaneous revascularization for chronic total coronary occlusion on left ventricular (LV) function and volumes. Magnetic resonance imaging was performed in 21 patients before and 5 months and 3 years after recanalization. Global LV function and volumes and segmental wall thickening (SWT) were quantified on cine images. The 2 viability indexes used were the transmural extent of infarction (TEI) on delayed contrast enhancement images and end-diastolic wall thickness at baseline. Significant decreases in mean end-diastolic (86 ± 14 to 78 ± 15 ml/m2; p = 0.02) and mean end-systolic volume indexes (35 ± 13 to 30 ± 13 ml/m2; p = 0.03) were observed 3 years after recanalization. Mean ejection fraction tended to improve (60 ± 9% to 63 ± 11%; p = 0.11). SWT significantly increased at 5-months' follow-up (p <0.001), and an additional improvement was found at 3 years' (p = 0.04) follow-up in segments with TEI <25%. In segments with TEI of 25% to 75%, SWT was unchanged at 5-month follow-up (p = 0.89), but improved at 3 years (p = 0.04). SWT was unchanged in segments with transmural scars. For segmental functional recovery, TEI was a better predictor than end-diastolic wall thickness at baseline (odds ratio 5.6, 95% confidence interval 1.5 to 21.1, p = 0.01 vs odds ratio 2.5, 95% confidence interval 0.7 to 8.3, p = 0.14). In conclusion, a positive effect on LV remodeling and ejection fraction was observed up to 3 years after recanalization. Both early and late improvements in regional LV function were observed in the perfusion territory of chronic total coronary occlusion and were related to the transmural extent of infarction on pretreatment magnetic resonance imaging.

Addition of the long-axis information to short-axis contours reduces interstudy variability of left-ventricular analysis in cardiac magnetic resonance studies (Article)

2008-01-01T00:00:00Z

OBJECTIVES: To reduce interstudy variability using long-axis information for correcting short-axis (SA) contours at basal and apical level for left-ventricular analysis by magnetic resonance imaging. MATERIALS AND METHODS: A total of 20 patients with documented heart failure and 20 volunteers underwent magnetic resonance imaging examination twice for measuring endocardial end-diastolic volume, endocardial end-systolic volume, mass, and ejection fraction. The boundary of the left ventricle, the mitral valve plane, and apex were marked manually on the 2- and 4-chamber long-axis images. Automatic epicardial and endocardial contour detection was performed on the SA images using the intersection of the outlines from the long axis as starting positions. The same observer compared the interstudy variability of this method with analysis that was based on the SA images only. RESULTS: The interstudy variability decreased when information from the long axis was included; for end-systolic volume, 9.6% versus 4.7% (P = 0.00014); for end-diastolic volume, 4.9% versus 2.5% (P = 0.0011); for mass, 7.4% versus 5.0% (P = 0.11); and for ejection fraction 12.2% versus 5.6% (P = 0.0017), respectively. CONCLUSIONS: Identification of the mitral valve plane and apex on long-axis images to limit the extent of volume at the base and the apex of the heart reduces interstudy variability for left-ventricular functional assessment.

Post-processing using multislice computed tomography coronary angiography improves image interpretability in patients with fast heart rates and heart-rate variations (Article)

2007-12-01T00:00:00Z

Comparison of Diagnostic Accuracy of 64-Slice Computed Tomography Coronary Angiography in Women Versus Men With Angina Pectoris (Article)

2007-11-15T00:00:00Z

We compared the diagnostic accuracy of 64-slice computed tomographic (CT) coronary angiography to detect significant coronary artery disease (CAD) in women and men. The 64-slice CT coronary angiography was performed in 402 symptomatic patients, 123 women and 279 men, with CAD prevalence of 51% and 68%, respectively. Significant CAD, defined as ≥50% coronary stenosis on quantitative coronary angiography, was evaluated on a patient, vessel, and segment level. The sensitivity and negative predictive value to detect significant CAD was very good, both for women and men (100% vs 99%, p = NS; 100% vs 98%, p = NS), whereas diagnostic accuracy (88% vs 96%; p <0.01), specificity (75% vs 90%, p <0.05), and positive predictive value (81% vs 95%, p <0.001) were lower in women. The per-segment analysis demonstrated lower sensitivity in women compared with men (82% vs 93%, p <0.001). The sensitivity in women did not show a difference in proximal and midsegments, but was significantly lower in distal segments (56% vs 85%, p <0.05) and side branches (54% vs 89%, p <0.001). In conclusion, CT coronary angiography reliably rules out the presence of obstructive CAD in both men and women. Specificity and positive predictive value of CT coronary angiography were lower in women. The sensitivity to detect stenosis in small coronary branches was lower in women compared with men.

64-Slice CT coronary angiography in patients with non-ST elevation acute coronary syndrome (Article)

2007-11-01T00:00:00Z

Background: A high diagnostic accuracy of 64-slice CT coronary angiography (CTCA) has been reported in selected patients with stable angina pectoris, but only scant information is available in patients with non-ST elevation acute coronary syndrome (ACS). Objectives: To study the diagnostic performance of 64-slice CTCA in patients with non-ST elevation ACS. Patients and methods: 64-slice CTCA was performed in 104 patients (mean (SD) age 59 (9) years) with non-ST elevation ACS. Two independent, blinded observers assessed all coronary arteries for stenosis, using conventional quantitative angiography as a reference. Coronary lesions with ≥50% luminal narrowing were classified as significant. Results: Conventional coronary angiography demonstrated the absence of significant disease in 15% (16/104) of patients, and the presence of single-vessel disease in 40% (42/104) and multivessel disease in 44% (46/104) of patients. Sensitivity for detecting significant coronary stenoses on a patient-by-patient analysis was 100% (88/88; 95% CI 95 to 100), specificity 75% (12/16; 95% CI 47 to 92), and positive and negative predictive values were 96% (88/92; 95% CI 89 to 99) and 100% (12/12; 95% CI 70 to 100), respectively. Conclusion: 64-slice CTCA has a high sensitivity to detect significant coronary stenoses, and is reliable to exclude the presence of significant coronary artery disease in patients who present with a non-ST elevation ACS.

64-Slice Computed Tomography Coronary Angiography in Patients With High, Intermediate, or Low Pretest Probability of Significant Coronary Artery Disease (Article)

2007-10-09T00:00:00Z

Objectives: We assessed the usefulness of 64-slice computed tomography coronary angiography (CTCA) to detect or rule out coronary artery disease (CAD) in patients with various estimated pretest probabilities of CAD. Background: The pretest probability of the presence of CAD may impact the diagnostic performance of CTCA. Methods: Sixty-four-slice CTCA (Sensation 64, Siemens, Forchheim, Germany) was performed in 254 symptomatic patients. Patients with heart rates ≥65 beats/min received beta-blockers before CTCA. The pretest probability for significant CAD was estimated by type of chest discomfort, age, gender, and traditional risk factors and defined as high (≥71%), intermediate (31% to 70%), and low (≤30%). Significant CAD was defined as the presence of at least 1 ≥50% coronary stenosis on quantitative coronary angiography, which was the standard of reference. No coronary segments were excluded from analysis. Results: The estimated pretest probability of CAD in the high (n = 105), intermediate (n = 83), and low (n = 66) groups was 87%, 53%, and 13%, respectively. The diagnostic performance of the computed tomography (CT) scan was different in the 3 subgroups. The estimated post-test probability of the presence of significant CAD after a negative CT scan was 17%, 0%, and 0% and after a positive CT scan was 96%, 88%, and 68%, respectively. Conclusions: Computed tomography coronary angiography is useful in symptomatic patients with a low or intermediate estimated pretest probability of having significant CAD, and a negative CT scan reliably rules out the presence of significant CAD. Computed tomography coronary angiography does not provide additional relevant diagnostic information in symptomatic patients with a high estimated pretest probability of CAD.

Effect of perindopril on coronary remodelling: Insights from a multicentre, randomized study (Article)

2007-10-01T00:00:00Z

Aims: This study sought to evaluate the effect of perindopril in coronary remodelling. Methods and results: In this sub-study of a double-blind, multicentre trial, patients without clinical evidence of heart failure were randomized to perindopril 8 mg/day or placebo for at least 3 years and IVUS investigation was performed at both time-points. Positive and negative remodelling were defined as a relative increase (positive remodelling) or decrease (negative remodelling) of the mean vessel cross-sectional area (CSA) > 2 SD of the mean intra-observer difference. A total of 118 matched evaluable IVUS (711 matched 5 mm segments) were available at follow-up. After a median follow-up of 3.0 (inter-quartile range 1.9, 4.1) years, there was no significant difference in the change of plaque CSA between perindopril (360 segments) and placebo (351 segments) groups, P = 0.27. Conversely, the change in vessel CSA was significantly different between groups (perindopril -0.18 ± 2.4 mm2vs. placebo 0.19 ± 2.4, P = 0.04). Negative remodelling occurred more frequently in the perindopril than in the placebo group (34 vs. 25%, P = 0.01). In addition, the placebo group showed a larger, although not significant, mean remodelling index (RI) than the perindopril group (1.03 ± 0.2 vs. 1.00 ± 0.2, P = 0.06). The temporal change in vessel dimensions assessed by the RI was significantly correlated with the change in plaque dimensions (r = 0.48, P < 0.0001). Conclusion: In this sub-analysis of a multicentre, controlled study, long-term administration of perindopril was associated with a constrictive remodelling pattern without affecting the lumen.

Computed tomography of the coronary arteries: An alternative? (Article)

2007-10-01T00:00:00Z

Multislice Computed Tomography Coronary Angiography (CTCA) has emerged as a promising non-invasive modality for the detection of coronary artery stenosis. Image quality is still limited when compared to conventional coronary angiography. However, CTCA has been demonstrated to be highly reliable to rule out coronary artery stenosis. Technological improvements and the combination of CTCA with other non-invasive modalities are expected to further increase diagnostic accuracy. Although CTCA has clearly left the research environment, the precise role of CTCA in the diagnostic work-up of coronary artery disease needs further research.

Spiral multislice computed tomography coronary angiography: A current status report (Article)

2007-09-01T00:00:00Z

Multislice computed tomography coronary angiography (MSCT-CA) has emerged as a powerful noninvasive diagnostic modality to visualize the coronary arteries and to detect significant coronary stenoses. The latest generation 64-slice computed tomography (CT) scanners is a robust technique which allows high-resolution, isotropic, nearly motion-free coronary imaging. Coronary stenoses are detected with high sensitivity and a normal scan accurately rules out the presence of a coronary stenosis. With the introduction of further novel concepts in CT-technology one may expect that MSCT-CA will become a clinically used diagnostic tool.

Reliable High-Speed Coronary Computed Tomography in Symptomatic Patients (Article)

2007-08-21T00:00:00Z

Objectives: Our objective was to prospectively evaluate the diagnostic performance of the high-speed dual-source computed tomography scanner (DSCT), with an increased temporal resolution (83 ms), for the detection of significant coronary lesions (≥50% lumen diameter reduction) in a clinically wide range of patients. Background: Cardiac motion artifacts may decrease coronary image quality with use of earlier computed tomography scanners that have a limited temporal resolution. Methods: We prospectively studied 100 symptomatic patients (79 men, 21 women, mean age 61 ± 11 years) with atypical (18%) or typical (55%) angina pectoris, or unstable coronary artery disease (27%) scheduled for conventional coronary angiography. Mean scan time was 8.58 ± 1.52 s. Mean heart rate was 68 ± 11 beats/min. Quantitative coronary angiography was used as the standard of reference. Irrespective of image quality or vessel size, all segments were included for analysis. Results: Invasive coronary angiography demonstrated no significant disease in 23%, single-vessel disease in 31%, and multivessel disease in 46% of patients; 1,489 coronary segments, containing 220 significant (14.8%) stenoses, were available for analysis. Sensitivity, specificity, and positive and negative predictive values of DSCT coronary angiography for the detection of significant lesions on a segment-by-segment analysis were 95% (95% confidence interval [CI] 90 to 97), 95% (95% CI 93 to 96), 75% (95% CI 69 to 80), 99% (95% CI 98 to 99), respectively, and on a patient-based analysis 99% (95% CI 92 to 100), 87% (95% CI 65 to 97), 96% (95% CI 89 to 99), and 95% (95% CI 74 to 100), respectively. Conclusions: Noninvasive DSCT coronary angiography is highly sensitive to detect and to reliably rule out the presence of a significant coronary stenosis in patients presenting with atypical or typical angina pectoris, or unstable coronary artery disease.

Detection and characterization of coronary bifurcation lesions with 64-slice computed tomography coronary angiography (Article)

2007-08-01T00:00:00Z

Aims: To compare the performance of 64-slice computed tomography coronary angiography (CTCA) and invasive coronary angiography (ICA) in the detection and classification (according to the Medina system) of bifurcation lesions (BLs). Methods and results: We studied 323 consecutive patients undergoing 64-slice CTCA prior to ICA. All coronary segments ≥2 mm in diameter were evaluated for the presence of a significant (≥50% diameter reduction on quantitative coronary angiography) BL. Evaluation of BL by CTCA included the assessment of significant lumen obstruction in both main and side branch vessels. Forty-one out of 43 patients (46/48 lesions) with significant BL were identified by CTCA. Excluding coronary segments with non-diagnostic image quality (5%), the sensitivity, specificity, and positive and negative predictive values of CTCA for detecting significant BL were 96, 99, and 85 and 99%, respectively. In 39 of these 41 patients, CTCA assessment was concordant with the Medina lesion classification on ICA. Conclusion: Sixty-four-slice CTCA allows accurate assessment of complex BL.

Adjunctive value of CT coronary angiography in the diagnostic work-up of patients with typical angina pectoris (Article)

2007-08-01T00:00:00Z

Aims: To determine the adjunctive value of CT coronary angiography (CTCA) in the diagnostic work-up of patients with typical angina pectoris. Methods and results: CTCA was performed in 62 consecutive patients (45 male, mean age 58.8 ± 7.7 years) with typical angina undergoing diagnostic work-up including exercise-ECG and conventional coronary angiography. Only patients with sinus heart rhythm and ability to breath hold for 20 s were included. Patients with initial heart rates ≥70 beats/min received β-blockers. We determined the post-test likelihood ratios, to detect or exclude patients with significant (≥50% lumen diameter reduction) stenoses, of exercise-ECG and CTCA separately, and of CT performed after exercise-ECG testing. The prevalence of patients with significant coronary artery disease (CAD) was 74%. Positive and negative likelihood ratios for exercise-ECG were 2.3 [95% confidence interval (CI): 1.0-5.3] and 0.3 (95% CI: 0.2-0.7) and for CTCA 7.5 (95% CI: 2.1-27.1) and 0.0 (95% CI: 0.0-8), respectively. CTCA increased the post-test probability of significant CAD after a negative exercise-ECG from 58 to 91%, and after a positive exercise-ECG from 89 to 99%, while CT correctly identified patients without CAD (probability 0%). Conclusion: Non-invasive CTCA is a potentially useful tool, in the diagnostic work-up of patients with typical angina pectoris, both to detect and to exclude significant CAD.

Use of multidetector computed tomography for the assessment of acute chest pain: A consensus statement of the North American Society of Cardiac Imaging and the European Society of Cardiac Radiology (Article)

2007-08-01T00:00:00Z

Use of multidetector computed tomography for the assessment of acute chest pain: A consensus statement of the North American Society of Cardiac Imaging and the European Society of Cardiac Radiology (Article)

2007-08-01T00:00:00Z

Long-Term Effect of Perindopril on Coronary Atherosclerosis Progression (from the PERindopril's Prospective Effect on Coronary aTherosclerosis by Angiography and IntraVascular Ultrasound Evaluation [PERSPECTIVE] Study) (Article)

2007-07-15T00:00:00Z

The multicenter EUROPA trial of 12,218 patients showed that perindopril decreased adverse clinical events in patients with established coronary heart disease. The PERSPECTIVE study, a substudy of the EUROPA trial, evaluated the effect of perindopril on coronary plaque progression as assessed by quantitative coronary angiography and intravascular ultrasound (IVUS). In total 244 patients (mean age 57 years, 81% men) were included. Evaluable paired quantitative coronary angiograms were obtained from 96 patients randomized to perindopril and from 98 patients to placebo. Concomitant treatment at baseline consisted of aspirin (90%), lipid-lowering agents (70%), and β blockers (60%). The primary and secondary end point was the difference of minimum and mean lumen diameters (quantitative coronary angiography) or mean plaque cross-sectional area (IVUS) measured at baseline and 3-year follow-up between the perindopril and placebo groups. After a median follow-up of 3.0 years (range 1.9 to 4.1), no differences in change in quantitative coronary angiographic or IVUS measurements were detected between the perindopril and placebo groups (minimum and mean luminal diameters -0.07 ± 0.4 vs -0.02 ± 0.4 mm, p = 0.34; mean luminal diameter -0.05 ± 0.2 vs -0.05 ± 0.3 mm, p = 0.89; mean plaque cross-sectional area -0.18 ± 1.2 vs -0.02 ± 1.2 mm2, p = 0.48). In conclusion, we found no progression in coronary artery disease by quantitative coronary angiography and IVUS with long-term administration of perindopril or placebo, possibly because most patients were on concomitant treatment with a statin.

Chronic total occlusion treatment in post-CABG patients: Saphenous vein graft versus native vessel recanalization - Long-term follow-up in the drug-eluting stent era (Article)

2007-07-01T00:00:00Z

Objective: To compare the postprocedural and long-term clinical outcomes of two groups of patients, all presenting with chronic saphenous vein graft (SVG) occlusion, who underwent either SVG or native vessel reopening. Background: Chronic total occlusions (CTO) treatment in patients who underwent previous surgical revascularization is a dilemma and the choice of performing native vessel or SVG recanalization is not always easy. Methods: Between July 2002 and October 2004, a total of 260 patients were successfully treated for a CTO. Of them, we selected all patients (n = 24) who had previous bypass surgery with graft occlusion. Of this final group, 13 patients underwent a percutaneous graft recanalization while 11 underwent native vessel reopening. Results: Primary end points were in-hospital and 3-year rates of death, myocardial infarction, target lesion revascularization, and target vessel revascularization. No events occurred in either group during the in-hospital period. Cumulative 3-year event-free survival in the native vessel and SVG group was 81.8% and 83.9% respectively (P = NS). One death and one TVR occurred in each group. Conclusion: In selected cases, SVG reopening instead of the native vessel is feasible. In such a high-risk population, drug-eluting stent implantation in both SVG and native CTO lesions is associated with good long-term outcomes.

Optimal fluoroscopic view selection for percutaneous coronary intervention by multislice computed tomography (Article)

2007-06-12T00:00:00Z

We present 2 cases of patients with stenotic and occlusive coronary lesions, which were detected by multislice computed tomography (MSCT) coronary angiography and treated with percutaneous coronary intervention (PCI) using CT-oriented optimal fluoroscopic views. Preprocedural MSCT allowed us to select the optimal fluoroscopic angle to visualize the target lesions, which provided least amount of foreshortening and minimal overlap of side branches during the PCI procedures. Given its three-dimensional nature, MSCT provides additional anatomical information in the evaluation of complex coronary lesions prior to PCI.

Usefulness of 64-Slice Multislice Computed Tomography Coronary Angiography to Assess In-Stent Restenosis (Article)

2007-06-05T00:00:00Z

Objectives: This study sought to evaluate the diagnostic accuracy of 64-slice multislice computed tomography (MSCT) coronary angiography in the follow-up of patients with previous coronary stent implantation. Background: Recent investigations have shown increased image quality and diagnostic accuracy for noninvasive coronary angiography with 64-slice MSCT as compared with previous-generation MSCT scanners, but data on the evaluation of coronary stents are scarce. Methods: In 182 patients (152 [84%] male, ages 58 ± 11 years) with previous stent (≥2.5 mm diameter) implantation (n = 192), 64-slice MSCT angiography using either a Sensation 64 (Siemens, Forchheim, Germany) or Aquilion 64 (Toshiba, Otawara, Japan) was performed. At each center, coronary stents were evaluated by 2 experienced observers and evaluated for the presence of significant (≥50%) in-stent restenosis. Quantitative coronary angiography served as the standard of reference. Results: A total of 14 (7.3%) stented segments were excluded because of poor image quality. In the interpretable stents, 20 of the 178 (11.2%) evaluated stents were significantly diseased, of which 19 were correctly detected by 64-slice MSCT. Accordingly, sensitivity, specificity, and positive and negative predictive value to identify in-stent restenosis in interpretable stents were 95.0% (95% confidence interval [CI] 85% to 100%), 93.0% (95% CI 90% to 97%), 63.3% (95% CI 46% to 81%), and 99.3% (95% CI 98% to 100%), respectively. Conclusions: In-stent restenosis can be evaluated with 64-slice MSCT with good diagnostic accuracy. In particular, a high negative predictive value of 99% was observed, indicating that 64-slice MSCT may be most valuable as a noninvasive method of excluding in-stent restenosis.

Use of high-resolution spiral CT for the diagnosis of coronary artery disease (Article)

2007-03-01T00:00:00Z

Multislice CT coronary angiography (CTCA) is a rapidly emerging technique for the noninvasive visualization of coronary arteries. Over the past 5 years, several scanner generations have been introduced with a progressive improvement in the diagnostic accuracy in the detection of coronary artery stenosis in selected patient populations. The introduction of 64-slice technology, which allows high resolution and nearly motion-free coronary artery imaging, has resulted in further improvement in the diagnostic accuracy. This technique is on the verge of widespread clinical implementation, and even in the absence of large clinical trials, a high demand for CTCA is already observed all over the world. Copyright

Non-invasive visualization of coronary atherosclerosis: State-of-art (Article)

2007-03-01T00:00:00Z

Coronary artery disease remains the leading cause of death in the Western world. Non-invasive coronary artery imaging challenges any diagnostic modality because the coronary arteries are small and tortuous, whereas cardiac contraction and respiration cause motion artifacts. Therefore, non-invasive coronary imaging requires high spatial and temporal resolution. This review discusses the feasible applications in coronary imaging of magnetic resonance imaging and multi-slice computed tomography (MSCT), which are currently the only non-invasive diagnostic modalities for direct coronary atherosclerosis imaging. Particular attention and focus is devoted to the potential indications and clinical impact of MSCT due to its fast development and the robust results recently reported. MSCT of the coronary arteries is a promising imaging modality for the assessment of the coronary lumen and wall.

Spiral Computed Tomography Coronary Angiography. A New Diagnostic Tool Developing Its Role in Clinical Cardiology**Editorials published in the Journal of American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology. (Article)

2007-02-27T00:00:00Z

Assessment of acute reperfused myocardial infarction with delayed enhancement 64-MDCT. (Article)

2007-02-01T00:00:00Z

OBJECTIVE: The purpose of this study was to evaluate the utility of delayed enhancement 64-MDCT in the assessment of myocardial infarct size in a porcine model of acute reperfused myocardial infarction. CT can be used for noninvasive assessment of coronary artery stenosis, but to our knowledge, evaluation of myocardial viability in the subacute phase of acute myocardial infarction has not been validated. We performed delayed enhancement imaging on six domestic swine 5 days after reperfused acute myocardial infarction and assessed the relation between delayed enhancement patterns in vivo and the extent of viable and nonviable myocardium at postmortem histochemical analysis. CONCLUSION: Delayed enhancement imaging with 64-MDCT can be used for accurate assessment of the size of reperfused acute myocardial infarcts.

Plaque Composition in the Left Main Stem Mimics the Distal But Not the Proximal Tract of the Left Coronary Artery. Influence of Clinical Presentation, Length of the Left Main Trunk, Lipid Profile, and Systemic Levels of C-Reactive Protein (Article)

2007-01-02T00:00:00Z

Objectives: We sought to investigate whether plaques located in the left main stem (LMS) differ in terms of necrotic core content from those sited in the proximal tract of the left coronary artery. Background: Plaque composition, favoring propensity to vulnerability, might be nonuniformly distributed along the vessel, which might explain the greater likelihood for plaque erosion or rupture to occur in the proximal but not in the distal tracts of the coronary artery or in LMS. Methods: A total of 72 patients were included prospectively; 48 (32 men; mean age 57 ± 11 years; 25 with stable angina and 23 affected by acute coronary syndromes) underwent a satisfactory nonculprit vessel investigation through spectral analysis of intravascular ultrasound radiofrequency data (IVUS-Virtual Histology, Volcano Corp., Rancho Cordova, California). The region of interest was subsequently divided into LMS and LMS carina, followed by 6 consecutive nonoverlapping 6-mm segments in left anterior descending artery in 34 patients or in circumflex artery in 14 patients. Results: Necrotic core content (%): 1) was minimal in LMS (median [interquartile range]: 4.6 [2 to 7]), peaked in the first 6-mm coronary segment (11.8 [8 to 16]; p < 0.01), and then progressively decreased distally; 2) was overall greater in patients with acute coronary syndromes (11.4 [5.5 to 19.8]) than stable angina (7.3 [3.2 to 12.9]; p < 0.001); 3) was largely independent from plaque size; and 4) did not correlate to systemic levels of C-reactive protein or lipid profile. Conclusions: Plaques located in the LMS carry minimal necrotic content. Thus, they mimic the distal but not the proximal tract of the left coronary artery, where plaque rupture or vessel occlusion occurs more frequently.

Meta-Analysis of the Studies Assessing Temporal Changes in Coronary Plaque Volume Using Intravascular Ultrasound (Article)

2007-01-01T00:00:00Z

To assess the temporal effect of statin therapy on coronary atherosclerotic plaque volume measured by intravascular ultrasound (IVUS), we searched PubMed for eligible studies published between 1990 and January 2006. Inclusion criteria for retrieved studies were (1) IVUS volume analysis at baseline and follow-up and (2) statin therapy in ≥1 group of patients. All data of interest were abstracted in prespecified structured collection forms. Statistical analysis was performed with Review Manager 4.2. Random-effect weighted mean difference (WMD) was used as summary statistics for comparison of continuous variables. Nine studies of 985 patients (with 11 statin treatment arms) were selected. After a mean follow-up of 9.8 ± 4.9 months, we found a significant decrease in coronary plaque volume (WMD -5.77 mm3, 95% confidence interval -10.36 to -1.17, p = 0.01), with no significant heterogeneity across studies (p = 0.47). Prespecified subgroup analyses showed similar trends. Studies in which the achieved low-density lipoprotein (LDL) cholesterol level was <100 mg/dl showed a trend for plaque regression (WMD -7.88 mm3, 95% confidence interval -16.31 to 0.55, p = 0.07), whereas studies in which the achieved level of LDL cholesterol was ≥100 mg/dl, the trend was less evident (WMD -4.22 mm3, 95% confidence interval -10.27 to 1.82, p = 0.17). Plaque volume remained essentially unchanged in patients not treated with statins (WMD 0.13 mm3, 95% confidence interval -4.42 to 4.68, p = 0.96). In conclusion, statin therapy, particularly when achieving the target LDL level, appears to promote a significant regression of coronary plaque volume as measured by IVUS.

Coronary computed tomography angiography in patients after percutaneous coronary intervention (PCI): focus on post-processing and visualization techniques. (Article)

2007-01-01T00:00:00Z

Coronary stent imaging with computed tomography is challenging because of high-density artifacts. However, noninvasive coronary angiography with computed tomography is gaining acceptance as a valid alternative to cardiac catheterization in a broader array of clinical settings, and the work-up of patients after coronary stent implantation represents an application of pressing clinical utility. Only a minority of patients who develop recurrent chest pain after stent implantation have myocardial ischemia, thus a sensitive noninvasive study is desirable. With an awareness of the limitations of the technique, the systematic application of dedicated strategies of data post-processing and display techniques permits partial compensation of the technical limitations brought about by metallic struts. ADVANCES IN KNOWLEDGE: 1. The role of coronary computed tomography angiography in the diagnostic work-up of patients with symptoms after stent placement 2. Systematization of post-processing, display, and review techniques for optimal evaluation of coronary stents with coronary computed tomography angiography. SUMMARY STATEMENT: The follow-up of patients after coronary stenting is an appealing but challenging application of coronary computed tomography angiography. The presence of intrinsic limitations requires the use of dedicated post-processing and visualization techniques.

High-resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography. (Article)

2005-10-11T00:00:00Z

BACKGROUND: The diagnostic performance of the latest 64-slice CT scanner, with increased temporal (165 ms) and spatial (0.4 mm3) resolution, to detect significant stenoses in the clinically relevant coronary tree is unknown. METHODS AND RESULTS: We studied 52 patients (34 men; mean age, 59.6+/-12.1 years) with atypical chest pain, stable or unstable angina pectoris, or non-ST-segment elevation myocardial infarction scheduled for diagnostic conventional coronary angiography. All patients had stable sinus rhythm. Patients with initial heart rates > or =70 bpm received beta-blockers. Mean scan time was 13.3+/-0.9 seconds. The CT scans were analyzed by 2 observers unaware of the results of invasive coronary angiography, which was used as the standard of reference. All available coronary segments, regardless of size, were included in the evaluation. Lesions with > or =50 luminal narrowing were considered significant stenoses. Invasive coronary angiography demonstrated the absence of significant disease in 25% (13 of 52), single-vessel disease in 31% (16 of 52), and multivessel disease in 45% (23 of 52) of patients. One unsuccessful CT scan was classified as inconclusive. Ninety-four significant stenoses were present in the remaining 51 patients. Sensitivity, specificity, and positive and negative predictive values of CT for detecting significant stenoses on a segment-by-segment analysis were 99% (93 of 94; 95% CI, 94 to 99), 95% (601 of 631; 95% CI, 93 to 96), 76% (93 of 123; 95% CI, 67 to 89), and 99% (601 of 602; 95% CI, 99 to 100), respectively. CONCLUSIONS: Noninvasive 64-slice CT coronary angiography accurately detects coronary stenoses in patients in sinus rhythm and presenting with atypical chest pain, stable or unstable angina, or non-ST-segment elevation myocardial infarction.

Intravenous contrast material administration at helical 16-detector row CT coronary angiography: effect of iodine concentration on vascular attenuation. (Article)

2005-08-01T00:00:00Z

The institutional review board approved this study, and all patients gave written informed consent. One hundred twenty-five patients scheduled to undergo retrospectively electrocardiographically gated 16-detector row computed tomographic coronary angiography were prospectively randomized into the following five groups with respect to the intravenous administration of a 140-mL bolus of contrast material at 4 mL/sec: group 1 (iohexol [300 mg of iodine per milliliter]), group 2 (iodixanol [320 mg I/mL]), group 3 (iohexol [350 mg I/mL]), group 4 (iomeprol [350 mg I/mL]), and group 5 (iomeprol [400 mg I/mL]). Attenuation was measured in the descending aorta and coronary arteries. One-way analysis of variance was used to compare groups. Mean attenuation values in the descending aorta were significantly (P < .05) lower in group 1 and higher in group 5 compared with the mean values in the other three groups. The same pattern was observed in the coronary arteries. Contrast materials with higher iodine concentrations yield significantly higher attenuation in the descending aorta and coronary arteries.

Recovery of left ventricular function after primary angioplasty for acute myocardial infarction. (Article)

2005-06-01T00:00:00Z

AIMS: To study recovery of segmental wall thickening (SWT), ejection fraction (EF), and end-systolic volume (ESV) after acute myocardial infarction (AMI) in patients who underwent primary stenting with drug-eluting stents. Additionally, to evaluate the predictive value of magnetic resonance imaging (MRI)-based myocardial perfusion and delayed enhancement (DE) imaging. METHODS AND RESULTS: Twenty-two patients underwent cine-MRI, first-pass perfusion, and DE imaging 5 days after successful placement of a drug-eluting stent in the infarct-related coronary artery. Regional myocardial perfusion and the transmural extent of DE were evaluated. A per patient perfusion score was calculated and consisted of a summation of all segmental scores. Myocardial infarct size was quantified by measuring the volume of DE. At 5 months after AMI, cine-MRI was performed and SWT, EF, and ESV were quantified. EF increased from 48+/-11 to 55+/-9% (P<0.01). SWT at 5 months was inversely related to baseline segmental DE scores (P<0.001) and segmental perfusion scores (P<0.001). EF and ESV at 5 months were related to acute infarct size (R(2)=0.65; P<0.001 and R(2)=0.78; P<0.001, respectively) and the calculated perfusion score (R(2)=0.23; P=0.02 and R(2)=0.14; P=0.09, respectively) at baseline. CONCLUSION: Marked recovery of left ventricular function was observed in patients receiving a drug-eluting stent for AMI. DE imaging appears to be a better prognosticator than perfusion imaging.

Short- and long-term clinical outcome after drug-eluting stent implantation for the percutaneous treatment of left main coronary artery disease: insights from the Rapamycin-Eluting and Taxus Stent Evaluated At Rotterdam Cardiology Hospital registries (RESEARCH and T-SEARCH). (Article)

2005-03-22T00:00:00Z

BACKGROUND: The impact of drug-eluting stent (DES) implantation on the incidence of major adverse cardiovascular events in patients undergoing percutaneous intervention for left main (LM) coronary disease is largely unknown. METHODS AND RESULTS: From April 2001 to December 2003, 181 patients underwent percutaneous coronary intervention for LM stenosis at our institution. The first cohort consisted of 86 patients (19 protected LM) treated with bare metal stents (pre-DES group); the second cohort comprised 95 patients (15 protected LM) treated exclusively with DES. The 2 cohorts were well balanced for all baseline characteristics. At a median follow-up of 503 days (range, 331 to 873 days), the cumulative incidence of major adverse cardiovascular events was lower in the DES cohort than in patients in the pre-DES group (24% versus 45%, respectively; hazard ratio [HR], 0.52 [95% CI, 0.31 to 0.88]; P=0.01). Total mortality did not differ between cohorts; however, there were significantly lower rates of both myocardial infarction (4% versus 12%, respectively; HR, 0.22 [95% CI, 0.07 to 0.65]; P=0.006) and target vessel revascularization (6% versus 23%, respectively; HR, 0.26 [95% CI, 0.10 to 0.65]; P=0.004) in the DES group. On multivariate analysis, use of DES, Parsonnet classification, troponin elevation at entry, distal LM location, and reference vessel diameter were independent predictors of major adverse cardiovascular events. CONCLUSIONS: When percutaneous coronary intervention is undertaken at LM lesions, routine DES implantation, which reduces the cumulative incidence of myocardial infarction and the need for target vessel revascularization compared with bare metal stents, should currently be the preferred strategy.

One year clinical follow up of paclitaxel eluting stents for acute myocardial infarction compared with sirolimus eluting stents (Article)

2005-01-01T00:00:00Z

OBJECTIVE: To compare clinical outcome of paclitaxel eluting stents (PES) versus sirolimus eluting stents (SES) for the treatment of acute ST elevation myocardial infarction. DESIGN AND PATIENTS: The first 136 consecutive patients treated exclusively with PES in the setting of primary percutaneous coronary intervention for acute myocardial infarction in this single centre registry were prospectively clinically assessed at 30 days and one year. They were compared with 186 consecutive patients treated exclusively with SES in the preceding period. SETTING: Academic tertiary referral centre. RESULTS: At 30 days, the rate of all cause mortality and reinfarction was similar between groups (6.5% v 6.6% for SES and PES, respectively, p = 1.0). A significant difference in target vessel revascularisation (TVR) was seen in favour of SES (1.1% v 5.1% for PES, p = 0.04). This was driven by stent thrombosis (n = 4), especially in the bifurcation stenting (n = 2). At one year, no significant differences were seen between groups, with no late thrombosis and 1.5% in-stent restenosis (needing TVR) in PES versus no reinterventions in SES (p = 0.2). One year survival free of major adverse cardiac events (MACE) was 90.2% for SES and 85% for PES (p = 0.16). CONCLUSIONS: No significant differences were seen in MACE-free survival at one year between SES and PES for the treatment of acute myocardial infarction with very low rates of reintervention for restenosis. Bifurcation stenting in acute myocardial infarction should, if possible, be avoided because of the increased risk of stent thrombosis.

Non-invasive multislice CT coronary imaging (Article)

2005-01-01T00:00:00Z

Long term outcome after intracoronary beta radiation therapy (Article)

2005-01-01T00:00:00Z

OBJECTIVES: To determine the long term outcome after intracoronary beta radiation therapy (IRT). SETTING: Tertiary referral centre. METHODS: The rate of major adverse cardiac events (MACE) was retrospectively determined in 301 consecutive patients who were treated with IRT. MACE was defined as death, myocardial infarction, or any reintervention. Long term clinical outcome was obtained from an electronic database of hospital records and from questionnaires to the patients and referring physicians. Long term survival status was assessed by written inquiries to the municipal civil registries. RESULTS: The mean (SD) follow up was 3.6 (1.2) years. The cumulative incidence of MACE at six months was 19.1%, at one year 36.4%, and at four years 58.3%. The target lesion revascularisation (TLR) rate at six months was 12.9%, at one year 28.3%, and at four years 50.4%. From multivariate analysis, dose < 18 Gy was the most significant predictor of TLR. At four years the cumulative incidence of death was 3.8%, of myocardial infarction 13.4%, and of coronary artery bypass surgery 11.3%. Total vessel occlusion was documented in 12.3% of the patients. CONCLUSIONS: In the long term follow up of patients after IRT, there are increased adverse cardiac events beyond the first six months.

Actinomycin-eluting stent for coronary revascularization: a randomized feasibility and safety study: the ACTION trial. (Article)

2004-10-06T00:00:00Z

OBJECTIVES: We sought to demonstrate the safety and performance of the actinomycin D-coated Multilink-Tetra stent(Guidant Corp., Santa Clara, California) in the treatment of patients with single de novo native coronary lesions. BACKGROUND: Drug-eluting stents (DES) releasing sirolimus or paclitaxel dramatically reduce restenosis. The anti-proliferative drug, actinomycin D, which is highly effective in reducing neointimal proliferation in preclinical studies, was selected for clinical evaluation. METHODS: The multi-center, single-blind, three-arm ACTinomycin-eluting stent Improves Outcomes by reducing Neointimal hyperplasia (ACTION) trial randomized 360 patients to receive a DES (2.5 or 10 microg/cm(2) of actinomycin D) or metallic stent (MS). The primary end points were major adverse cardiac events (MACE) at 30 days, diameter stenosis by angiography, tissue effects, and neointimal volume by intravascular ultrasound (IVUS) at six months. When early monitoring revealed an increased rate of repeat revascularization, the protocol was amended to allow for additional follow-up for DES patients. Angiographic control of MS patients was no longer mandatory. RESULTS: The biased selection of DES patients undergoing IVUS follow-up invalidated the interpretation of the IVUS findings. The in-stent late lumen loss and that at the proximal and distal edges were higher in both DES groups than in the MS group and resulted in higher six-month and one-year MACE (34.8% and 43.1% vs. 13.5%), driven exclusively by target vessel revascularization without excess death or myocardial infarction. CONCLUSIONS: The results of the ACTION trial indicate that all anti-proliferative drugs will not uniformly show a drug class effect in the prevention of restenosis.

Clinical outcomes for sirolimus-eluting stent implantation and vascular brachytherapy for the treatment of in-stent restenosis. (Article)

2004-07-01T00:00:00Z

Abstract The purpose of this study was to compare the mid-term clinical outcome of sirolimus-eluting stent (SES) implantation and vascular brachytherapy (VBT) for in-stent restenosis (ISR). We assessed the 9-month occurrence of major adverse cardiac events (MACE) in 44 consecutive patients with ISR treated with SES implantation and 43 consecutive patients treated with VBT in the period immediately prior. Baseline clinical and angiographic characteristics of the two groups were similar. During follow-up, three patients (7%) died in the VBT group and none in the SES group. The incidence of myocardial infarction was 2.3% in both groups. Target lesion revascularization was performed in 11.6% of the VBT patients and 16.3% of the SES patients (P = NS). The 9-month MACE-free survival was similar in both groups (79.1% VBT vs. 81.5% SES; P = 0.8 by log rank). The result of this nonrandomized study suggests that sirolimus-eluting stent implantation is at least as effective as vascular brachytherapy in the treatment of in-stent restenosis.

Incidence of High-Strain Patterns in Human Coronary Arteries: Assessment With Three-Dimensional Intravascular Palpography and Correlation With Clinical Presentation (Article)

2004-06-08T00:00:00Z

BACKGROUND: Rupture of thin-cap fibroatheromatous plaques is a major cause of acute myocardial infarction (AMI). Such plaques can be identified in vitro by 3D intravascular palpography with high sensitivity and specificity. We used this technique in patients undergoing percutaneous intervention to assess the incidence of mechanically deformable regions. We further explored the relation of such regions to clinical presentation and to C-reactive protein levels. METHOD AND RESULTS: Three-dimensional palpograms were derived from continuous intravascular ultrasound pullbacks. Patients (n=55) were classified by clinical presentation as having stable angina, unstable angina, or AMI. In every patient, 1 coronary artery was scanned (culprit vessel in stable and unstable angina, nonculprit vessel in AMI), and the number of deformable plaques assessed. Stable angina patients had significantly fewer deformable plaques per vessel (0.6+/-0.6) than did unstable angina patients (P=0.0019) (1.6+/-0.7) or AMI patients (P<0.0001) (2.0+/-0.7). Levels of C-reactive protein were positively correlated with the number of mechanically deformable plaques (R2=0.65, P<0.0001). CONCLUSIONS: Three-dimensional intravascular palpography detects strain patterns in human coronary arteries that represent the level of deformation in plaques. The number of highly deformable plaques is correlated with both clinical presentation and levels of C-reactive protein. Further studies will assess the potential role of the technique to identify patients at risk of future clinical events

Post-sirolimus-eluting stent restenosis treated with repeat percutaneous intervention: late angiographic and clinical outcomes. (Article)

2004-06-01T00:00:00Z

BACKGROUND: We evaluated the clinical and angiographic outcomes of patients presenting with restenosis after sirolimus-eluting stent (SES) implantation treated with repeated percutaneous intervention. METHODS AND RESULTS: A total of 24 consecutive patients have undergone repeated percutaneous intervention to treat post-SES restenosis (27 lesions). The restenosis was located within the stent in 93% of lesions. From the 27 lesions, 1 (4%) was re-treated with a bare stent, 3 (11%) were treated with balloon dilatation, and the remaining 23 lesions (85%) were treated with repeated drug-eluting stent implantation (SES in 12 lesions [44%], paclitaxel-eluting stents in 11 lesions [41%]). The event-free survival rate was 70.8% after a median follow-up of 279 days from the post-SES treatment. The overall recurrent restenosis rate was 42.9%. The risk of recurrent restenosis was increased for patients with hypercholesterolemia, previous angioplasty, failed brachytherapy, post-SES restenosis needing early (<6 months) treatment, and post-SES restenosis treated with balloon dilatation. The recurrent restenosis rate of originally de novo lesions re-treated with drug-eluting stents was 18.2%. CONCLUSIONS: Even though de novo lesions treated with SES at baseline and re-treated with drug-eluting stents had reasonably better outcomes than other lesion types and strategies, our study shows that the treatment of post-SES restenosis is currently suboptimal and warrants further investigation.

Very long sirolimus-eluting stent implantation for de novo coronary lesions. (Article)

2004-04-01T00:00:00Z

Long-length stenting has a poor outcome when bare metal stents are used. The safety and efficacy of the sirolimus-eluting stent (SES) in long lesions has not been evaluated. Therefore, the aim of the present study was to evaluate the clinical and angiographic outcomes of SES implantation over a very long coronary artery segment. Since April 2002, all patients treated percutaneously at our institution received a SES as the device of choice as part of the Rapamycin Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry. During the RESEARCH registry, stents were available in lengths of 8, 18, and 33 mm. The present report includes a predefined study population consisting of patients treated with >36-mm-long stented segments. Patients had a combination of >or=2 overlapping stents at a minimum length of 41 mm (i.e., one 33-mm SES overlapping an 8-mm SES) to treat native de novo coronary lesions. The incidence of major cardiac adverse events (death, nonfatal myocardial infarction, and target lesion revascularization) was evaluated. The study group comprised 96 consecutive patients (102 lesions). Clinical follow-up was available for all patients at a mean of 320 days (range 265 to 442). In all, 20% of long-stented lesions were chronic total occlusions, and mean stented length per lesion was 61.2 +/- 21.4 mm (range 41 to 134). Angiographic follow-up at 6 months was obtained in 67 patients (71%). Binary restenosis rate was 11.9% and in-stent late loss was 0.13 +/- 0.47 mm. At long-term follow-up (mean 320 days), there were 2 deaths (2.1%), and the overall incidence of major cardiac events was 8.3%. Thus, SES implantation appears safe and effective for de novo coronary lesions requiring multiple stent placement over a very long vessel segment.

Clinical and angiographic outcomes after overdilatation of undersized sirolimus-eluting stents with largely oversized balloons: an observational study. (Article)

2004-04-01T00:00:00Z

The purpose of this study was to assess the safety and effectiveness of sirolimus-eluting stent (SES) postdilatation with largely oversized balloons. We evaluated the clinical outcome of 68 consecutive patients enrolled in the Rapamycin-Eluting Stent Evaluated at Rotterdam Cardiology Hospital (RESEARCH) registry who underwent percutaneous coronary intervention with SES implantation and further postdilatation with balloons > 1 mm larger than the stent nominal size. Angiographic follow-up was either scheduled for selected subgroups or clinically driven. Overall, 75 lesions were treated. The procedure was successful in 98.5% of the cases. One patient (1.5%) underwent emergency coronary bypass surgery for acute vessel occlusion. During 10.1 +/- 1.7 months of follow-up, three patients (4.5%) died, one (1.5%) had acute myocardial infarction, and four (6%) had target vessel revascularization. At angiographic follow-up, loss index was 0.13 +/- 0.34 and restenosis rate was 7.7%. Although not routinely recommended in every patient, SES postdilatation with largely oversized balloons appears a safe and effective strategy for selected patients.

Clinical, angiographic, and procedural predictors of angiographic restenosis after sirolimus-eluting stent implantation in complex patients (Article)

2004-03-23T00:00:00Z

BACKGROUND: The factors associated with the occurrence of restenosis after sirolimus-eluting stent (SES) implantation in complex cases are currently unknown. METHODS AND RESULTS: A cohort of consecutive complex patients treated with SES implantation was selected according to the following criteria: (1) treatment of acute myocardial infarction, (2) treatment of in-stent restenosis, (3) 2.25-mm diameter SES, (4) left main coronary stenting, (5) chronic total occlusion, (6) stented segment >36 mm, and (7) bifurcation stenting. The present study population was composed of 238 patients (441 lesions) for whom 6-month angiographic follow-up data were obtained (70% of eligible patients). Significant clinical, angiographic, and procedural predictors of post-SES restenosis were evaluated. Binary in-segment restenosis was diagnosed in 7.9% of lesions (6.3% in-stent, 0.9% at the proximal edge, 0.7% at the distal edge). The following characteristics were identified as independent multivariate predictors: treatment of in-stent restenosis (OR 4.16, 95% CI 1.63 to 11.01; P<0.01), ostial location (OR 4.84, 95% CI 1.81 to 12.07; P<0.01), diabetes (OR 2.63, 95% CI 1.14 to 6.31; P=0.02), total stented length (per 10-mm increase; OR 1.42, 95% CI 1.21 to 1.68; P<0.01), reference diameter (per 1.0-mm increase; OR 0.46, 95% CI 0.24 to 0.87; P=0.03), and left anterior descending artery (OR 0.30, 95% CI 0.10 to 0.69; P<0.01). CONCLUSIONS: Angiographic restenosis after SES implantation in complex patients is an infrequent event, occurring mainly in association with lesion-based characteristics and diabetes mellitus.

Treatment of very small vessels with 2.25-mm diameter sirolimus-eluting stents (from the RESEARCH registry). (Article)

2004-03-01T00:00:00Z

A total of 91 patients with 112 lesions received 2.25-mm sirolimus-eluting stents (SESs), and these lesions were compared with those treated with SESs of ≥2.5-mm diameter in the same procedure (n = 109). The reference diameters were 1.88 ± 0.34 and 2.52 ± 0.57 mm, respectively (p <0.01). At follow-up, the late lumen loss was 0.07 ± 0.48 mm for the 2.25-mm SES versus 0.03 ± 0.38 mm for the larger SES (p = 0.5), and the binary restenosis rate was 10.7% versus 3.9%, respectively (p = 0.1). The 12-month target lesion revascularization rate was 5.5%. In conclusion, 2.25-mm SESs were associated with low rates of clinical and angiographic late complications.

Unrestricted utilization of sirolimus-eluting stents compared with conventional bare stent implantation in the "real world": the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry. (Article)

2004-01-20T00:00:00Z

BACKGROUND: The effectiveness of sirolimus-eluting stents in unselected patients treated in the daily practice is currently unknown. METHODS AND RESULTS: Sirolimus-eluting stent implantation has been used as the default strategy for all percutaneous procedures in our hospital as part of the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry. Consecutive patients with de novo lesions (n=508) treated exclusively with sirolimus-eluting stents (SES group) were compared with 450 patients who received bare stents in the period just before (pre-SES group). Patients in the SES group more frequently had multivessel disease, more type C lesions, received more stents, and had more bifurcation stenting. At 1 year, the cumulative rate of major adverse cardiac events (death, myocardial infarction, or target vessel revascularization) was 9.7% in the SES group and 14.8% in the pre-SES group (hazard ratio [HR], 0.62 [95% CI, 0.44 to 0.89]; P=0.008). The 1-year risk of clinically driven target vessel revascularization in the SES group and in the pre-SES group was 3.7% versus 10.9%, respectively (HR, 0.35 [95% CI, 0.21 to 0.57]; P<0.001). CONCLUSIONS: Unrestricted utilization of sirolimus-eluting stents in the "real world" is safe and effective in reducing both repeat revascularization and major adverse cardiac events at 1 year compared with bare stent implantation.

Intravascular ultrasound evaluation after sirolimus eluting stent implantation for de novo and in-stent restenosis lesions (Article)

2004-01-01T00:00:00Z

AIMS: The aim of this study is to compare the efficacy of sirolimus-eluting stents (SES) on neointimal growth and vessel remodelling for in-stent restenosis versus de novo coronary artery lesions using serial intravascular ultrasound (IVUS). METHODS AND RESULTS: The study population consisted of 86 patients with in-stent restenosis (ISR) (n=41) or de novo lesions (n=45) treated with SES and evaluated by IVUS post-procedure and at follow-up. One 18-mm SES was used for de novo lesions while 16 patients with ISR received >1SES (total stented length 17.9 mm vs 22.0 mm respectively; P=0.004). At follow-up, no differences were observed between the ISR and de novo groups with respect to changes in the mean external elastic membrane (1.7% vs 1.3%; P=0.53), plaque behind the stent (1.2% vs 3.4%; P=0.49), and lumen areas (0.7% vs 1.9%; P=0.58). No positive remodelling or edge effect was observed. A gap between stents was observed in two patients with ISR, where more prominent, though non-obstructive, neointimal proliferation was noted. CONCLUSION: Sirolimus-eluting stenting is equally effective at inhibiting neointimal proliferation in de novo and ISR lesions without inducing edge restenosis or positive vascular remodelling.

Images in cardiovascular medicine. Pseudoaneurysms of the ascending aorta demonstrated with "motion-free" multislice computed tomography. (Article)

2004-01-01T00:00:00Z

Images in cardiovascular medicine. Multislice computed tomography for the evaluation and follow-up of stenting of aortic coarctation. (Article)

2004-01-01T00:00:00Z

Images in cardiovascular medicine. Right coronary artery arising from the left circumflex demonstrated with multislice computed tomography. (Article)

2004-01-01T00:00:00Z

A 38-year-old man was referred to our institution for suspected coronary artery disease. Because of his young age and rather atypical symptoms, we decided to perform multislice computed tomography coronary angiography be- fore other invasive studies.

Intravenous contrast material administration at 16-detector row helical CT coronary angiography: test bolus versus bolus-tracking technique. (Article)

2004-01-01T00:00:00Z

PURPOSE: To compare test bolus and bolus-tracking techniques for intravenous contrast material administration at 16-detector row computed tomographic (CT) coronary angiography. MATERIALS AND METHODS: This study had institutional review board approval, and patients gave informed consent. Thirty-eight patients (mean age, 60 years; three women) were randomized into two groups according to bolus timing technique: group 1 (20-mL test bolus with 100-mL main bolus) and group 2 (bolus tracking with 100-mL main bolus). All patients underwent electrocardiography-gated 16-detector row CT coronary angiography with 12 detectors (collimation, 0.75 mm; rotation time, 420 msec). In group 1, test bolus peak attenuation was used as a delay, while in group 2, a +100-HU threshold in ascending aorta triggered angiographic acquisition, with an additional 4-second delay for patient instruction. Attenuation was measured in the longitudinal direction throughout the examination in three main vessels: ascending aorta (region of interest [ROI] 1), descending aorta (ROI 2), and main pulmonary artery (ROI 3). Mean attenuation and slope of bolus geometry curve were calculated in each patient and ROI. Attenuation at origin of coronary arteries was measured. Student t test was used to compare results. RESULTS: Mean scan delay was 6 seconds longer in group 2 (P < .05). Average attenuation values were 306.6 HU +/- 44.0 (standard deviation) and 328.2 HU +/- 58.6 (P > .05) in ROI 1, 291.6 HU +/- 45.1 and 326.4 HU +/- 62.6 (P > .05) in ROI 2, and 354.7 HU +/- 78.0 and 305.3 HU +/- 71.4 (P < .05) in ROI 3 for groups 1 and 2, respectively. Average slope values were 5.8 and -0.8 (P < .05) in ROI 1, 7.7 and 0.7 (P < .05) in ROI 2, and -1.0 and -13.3 (P < .05) in ROI 3 for groups 1 and 2, respectively. Average attenuation values in left main, left anterior descending, and left circumflex arteries were higher in group 2 (P < .05); there were no differences (P > .05) between groups in right coronary artery. CONCLUSION: Bolus-tracking yields more homogeneous enhancement than does the test bolus technique.

Adjustment method for mechanical Boston scientific corporation 30 MHz intravascular ultrasound catheters connected to a Clearview console. Mechanical 30 MHz IVUS catheter adjustment. (Article)

2004-01-01T00:00:00Z

Intracoronary ultrasound (ICUS) is often used in studies evaluating new interventional techniques. It is important that quantitative measurements performed with various ICUS imaging equipment and materials are comparable. During evaluation of quantitative coronary ultrasound (QCU) software, it appeared that Boston Scientific Corporation (BSC) 30 MHz catheters connected to a Clearview ultrasound console showed smaller dimensions of an in vitro phantom model than expected. In cooperation with the manufacturer the cause of this underestimation was determined, which is described in this paper, and the QCU software was extended with an adjustment. Evaluation was performed by performing in vitro measurements on a phantom model consisting of four highly accurate steel rings (perfect reflectors) with diameters of 2, 3, 4 and 5 mm. Relative differences (unadjusted) of the phantom were respectively: 15.92, 13.01, 10.10 and 12.23%. After applying the adjustment: -0.96, -1.84, -1.35 and -1.43%. In vivo measurements were performed on 24 randomly selected ICUS studies. These showed differences for not adjusted vs. adjusted measurements of lumen-, vessel- and plaque volumes of -10.1 +/- 1.5, -6.7 +/- 0.9 and -4.4 +/- 0.6%. An off-line adjustment formula was derived and applied on previous numerical QCU output data showing relative differences for lumen- and vessel volumes of 0.36 +/- 0.51 and 0.13 +/- 0.31%. 30 MHz BSC catheters connected to a Clearview ultrasound console underestimate vessel dimensions. This can retrospectively be adjusted within QCU software as well as retrospectively on numerical QCU data using a mathematical model.

A biplane angiographic study on cardiac motion of coronary artery stents: options to minimize the target volume for high-precision external beam radiotherapy of coronary artery in-stent restenosis. (Article)

2004-01-01T00:00:00Z

PURPOSE: High-precision external beam radiotherapy (EBRT) has been suggested as a potential alternative to endovascular brachytherapy for the treatment of coronary artery in-stent restenosis. The purpose of our study was to investigate and compare different options to define a smallest feasible target volume. METHODS AND MATERIALS: The cardiac motion of 17 coronary artery stents in 17 patients was studied by use of biplane conventional angiography, recorded during breath-hold. Each stent was reconstructed in three dimensions by use of biplane sets of frames covering an entire cardiac cycle. The volume traversed by the stent during the entire or part of the cardiac cycle was determined. Four options to define the stent-traversed volume (STV) as a target for high-precision EBRT were investigated. RESULTS: The mean STV during the entire cardiac cycle was 3.5 cm3; the STV represented less than 1% of the heart volume in all patients. The STV during the diastolic and systolic phase resulted in a mean reduction of 26.6% and 29.1%, respectively, compared with the STV during the entire cardiac cycle. The smallest STV, measured during a 160-ms interval within the cardiac cycle, resulted in a mean maximal reduction of 75.9% compared with the STV during the entire cardiac cycle. CONCLUSIONS: The STV during the entire cardiac cycle represents a small potential target volume for high-precision EBRT. A significant reduction of this target volume is possible in case of definition during a selected interval within the cardiac cycle.

Beneficial effects of fluvastatin following percutaneous coronary intervention in patients with unstable and stable angina: results from the Lescol intervention prevention study (LIPS) (Article)

2004-01-01T00:00:00Z

AIMS: To investigate the effect on risk of major adverse cardiac events (MACE) of lipid lowering treatment with fluvastatin 80 mg/day after a first percutaneous coronary intervention in patients with stable and unstable angina. METHOD AND RESULTS: This prespecified subgroup analysis of the LIPS (Lescol intervention prevention study) analysed 1658 patients with documented diagnosis; 824 had unstable angina (417 randomly assigned to fluvastatin, 407 to placebo) and 834 had stable angina (including silent ischaemia; fluvastatin, 418; placebo, 416). Median follow up was 3.9 years. There was no significant effect of anginal status on long term risk of MACE. Fluvastatin treatment reduced the risk of MACE by 28% compared with placebo (p = 0.03) among patients with unstable angina, with no difference between patients with stable and patients with unstable angina (relative risk 1.07, 95% confidence interval 0.87 to 1.30, p = 0.53). Fluvastatin reduced coronary atherosclerotic events (MACE excluding restenosis) by 36% (p = 0.006) among patients with unstable angina and 31% (p = 0.02) among patients with stable angina. Fluvastatin caused similar reductions in total cholesterol and low density lipoprotein cholesterol concentrations in both patient groups. CONCLUSION: Treatment with fluvastatin 80 mg/day produced significant reductions in MACE and coronary atherosclerotic events after percutaneous coronary intervention in patients with average cholesterol concentrations. The beneficial effects of fluvastatin are observed in patients with unstable or stable angina alike.

Long-term follow-up of incomplete stent apposition in patients who received sirolimus-eluting stent for de novo coronary lesions: an intravascular ultrasound analysis. (Article)

2003-12-02T00:00:00Z

BACKGROUND: Incomplete stent apposition (ISA) has been previously documented after sirolimus-eluting stent (SES) implantation. The aim of this study was to investigate the long-term intravascular ultrasound (IVUS) findings of ISA in patients who received SES. METHODS AND RESULTS: A total of 13 patients who received SES and showed ISA at follow-up IVUS (follow-up I) were investigated. IVUS was performed on all of these patients 12 months later (follow-up II). Quantitative ISA area measurement was also performed at follow-up I and II. No vascular remodeling was observed in the vessel segment with ISA; external elastic membrane area was 19.4+/-6.6 versus 19.5+/-6.4 mm2 at follow-up I and II, respectively. There was also no significant change in external elastic membrane area between vessel segment with ISA and without ISA (+1.5% versus -3.0%, respectively; P=0.27) at late follow-up. The ISA area, either including (2.5+/-1.7 versus 3.8+/-6.3 mm2; P=NS) or excluding (2.5+/-1.8 versus 2.4+/-1.7 mm2; P=NS) a single patient with aneurysm formation, was not significantly different between follow-up I and II. One patient manifested a coronary aneurysm in the stented segment at late follow-up that was probably present at the initial follow-up but masked by thrombus. It was successfully treated with a covered stent. All patients were asymptomatic, and no patient experienced late thrombotic occlusion. CONCLUSIONS: Vessel dimensions and area of ISA did not change over time, except for 1 coronary aneurysm that became apparent. ISA after implantation of a SES was not associated with adverse events at late follow-up.

Evaluation of patients after coronary artery bypass surgery: CT angiographic assessment of grafts and coronary arteries. (Article)

2003-12-01T00:00:00Z

PURPOSE: To evaluate the accuracy of electrocardiography (ECG)-gated multi-detector row computed tomography (CT) in enabling the detection of obstruction of both bypass grafts and coronary arteries in symptomatic patients who have undergone coronary artery bypass grafting. MATERIALS AND METHODS: ECG-gated contrast material-enhanced multi-detector row CT angiography was performed in 24 patients after bypass surgery. Two independent blinded observers evaluated all graft and coronary segments (> or =2.0-mm diameter) for occlusion and stenosis (50%-99% luminal reduction). Conventional angiography was regarded as the standard of reference. Descriptive parameters were calculated, and the results for arterial grafts, venous grafts, and coronary arteries, as well as for high and low heart rates, were compared by using a two-sided Fisher exact test. RESULTS: The following results were obtained by observers 1 and 2, respectively: Of the 60 venous graft segments, 60 (100%) and 57 (95.0%) were assessable, with an overall detection of all 17 occlusions (both observers) and three (50.0%) and five (83.3%) of six stenoses. Of 26 arterial graft segments, 19 (73.1%) and 15 (57.7%) were assessable. In the assessable segments, four of four (100%) and two of three (66.7%) stenoses and occlusions were detected, while one and two obstructions were located in nonassessable segments. Of 211 coronary segments, 146 (69.2%) and 140 (66.4%) were assessable, and detection of 50%-100% obstruction yielded a sensitivity of 89.9% (71 of 79) and 79.4% (54 of 68) and a specificity of 74.6% (50 of 67) and 72.2% (52 of 72) for each observer. Unlike the assessment of venous and arterial grafts, assessment of the coronary arteries with multi-detector row CT was significantly better in patients with low heart rates (P <.01). CONCLUSION: Multi-detector row CT allows noninvasive angiographic evaluation of both coronary arteries and bypass grafts in patients who have undergone bypass surgery. Multi-detector row CT is more effective in examining venous grafts compared with arterial grafts and diffusely diseased coronary arteries.

Usefulness of shear stress pattern in predicting neointima distribution in sirolimus-eluting stents in coronary arteries. (Article)

2003-12-01T00:00:00Z

The true 3-dimensional neointimal thickness distribution in sirolimus-eluting stents was investigated in relation to the shear stress distribution, which was obtained from computational fluid dynamics calculations. Small pits were observed between the stent struts in all patients, and a significant inverse relation between neointimal thickness and shear stress was found, indicating that deeper pits were present in the outside curve of the stented segments.

Sirolimus-eluting stent implantation in ST-elevation acute myocardial infarction: a clinical and angiographic study. (Article)

2003-10-21T00:00:00Z

BACKGROUND: Sirolimus-eluting stents (SES) have recently been proven to reduce restenosis and reintervention compared with bare stents. Safety and effectiveness of SES in acute myocardial infarction remain unknown. METHODS AND RESULTS: Since April 16, 2002, a policy of routine SES implantation has been instituted in our hospital, with no clinical or anatomic restrictions, as part of the RESEARCH (Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital) registry. During 6 months of enrollment, 96 patients with ST-elevation acute myocardial infarction underwent percutaneous recanalization and SES implantation; these patients comprise the study population. The incidence of major adverse cardiac events (death, nonfatal myocardial infarction, reintervention) was evaluated. Six-month angiographic follow-up was scheduled per protocol. At baseline, diabetes mellitus was present in 12.5% and multivessel disease in 46.9%. Primary angioplasty was performed in 89 patients (92.7%). Infarct location was anterior in 41 (42.7%) of the cases, and 12 patients (12.5%) had cardiogenic shock. Postprocedural TIMI-3 flow was achieved in 93.3% of the cases. In-hospital mortality was 6.2%. One patient (1.1%) had reinfarction and target lesion reintervention the first day as a result of distal dissection and acute vessel occlusion. During follow-up (mean follow-up of 218+/-75 days), 1 patient died (1.1%), no patient had recurrent myocardial infarction, and there were no additional reinterventions. No early or late stent thromboses were documented. At angiographic follow-up (70%), late loss was -0.04+/-0.25, and no patient presented angiographic restenosis. CONCLUSIONS: In this study, sirolimus-eluting stent implantation for patients with ST-elevation acute myocardial infarction was safe without documented angiographic restenosis at 6 months.

Impact of different anatomical patterns of left main coronary stenting on long-term survival. (Article)

2003-09-15T00:00:00Z

Acute myocardial infarction is a common disease with serious consequences in mortality, morbidity, and cost to the society. Coronary atherosclerosis plays a pivotal part as the underlying substrate in many patients. In addition, a new definition of myocardial infarction has recently been introduced that has major implications from the epidemiological, societal, and patient points of view. The advent of coronary-care units and the results of randomised clinical trials on reperfusion therapy, lytic or percutaneous coronary intervention, and chronic medical treatment with various pharmacological agents have substantially changed the therapeutic approach, decreased in-hospital mortality, and improved the long-term outlook in survivors of the acute phase. New treatments will continue to emerge, but the greatest challenge will be to effectively implement preventive actions in all high-risk individuals and to expand delivery of acute treatment in a timely fashion for all eligible patients

Sonotherapy; antirestenotic therapeutic ultrasound in coronary arteries: the first clinical experience. (Article)

2003-09-01T00:00:00Z

We studied the safety and feasibility of intracoronary sonotherapy (IST) and its effect on the coronary vessel at 6 months. Thirty-seven patients with stable or unstable angina were included (40 lesions). The indication was de novo lesion (n = 26), restenosis (n = 2), in-stent restenosis (n = 11), and a total occlusion of a venous bypass graft. After successful angioplasty, IST was performed using a 5 Fr catheter with three serial ultrasound transducers operating at 1 MHz. IST was successfully performed in 36 lesions (success rate, 90%). IST exposure time per lesion was 718 ± 127 sec. During hospital stay, one patient died due to a bleeding complication. At 6-month follow-up, one patient experienced acute myocardial infarction, eight patients underwent repeat PTCA. No patient underwent CABG. Late lumen loss was 1.05 ± 0.70 mm with a restenosis rate of 25%. IVUS analysis revealed a neointima burden of 25% ± 11%. IST can be applied safely and with high acute procedural success. Sonotherapy-related major adverse events were not observed. Late lumen loss and neointimal growth were similar to conventional PTCA approaches. These results justify the initiation of randomized clinical efficacy studies.

Coronary restenosis after sirolimus-eluting stent implantation: morphological description and mechanistic analysis from a consecutive series of cases. (Article)

2003-07-22T00:00:00Z

BACKGROUND: We describe the clinical and morphological patterns of restenosis after sirolimus-eluting stent (SES) implantation. METHODS AND RESULTS: From 121 patients with coronary angiography obtained >30 days after SES implantation, restenosis (diameter stenosis >50%) was identified in 19 patients and 20 lesions (located at the proximal 5-mm segment in 30% or within the stent in 70%). Residual dissection after the procedure or balloon trauma outside the stent was identified in 83% of the proximal edge lesions. Lesions within the stent were focal, and stent discontinuity was identified in some lesions evaluated by intravascular ultrasound. CONCLUSIONS: Sirolimus-eluting stent edge restenosis is frequently associated with local trauma outside the stent. In-stent restenosis occurs as a localized lesion, commonly associated with a discontinuity in stent coverage. Local conditions instead of intrinsic drug-resistance to sirolimus are likely to play a major role in post-SES restenosis.

Extension of increased atherosclerotic wall thickness into high shear stress regions is associated with loss of compensatory remodeling. (Article)

2003-07-08T00:00:00Z

BACKGROUND: Atherosclerosis preferentially develops at average low shear stress (SS) locations. SS-related signaling maintains lumen dimensions by inducing outward arterial remodeling. Prolonged plaque accumulation at low SS predilection locations explains an inverse relation between wall thickness (WT) and SS. No data exist on WT-SS relations when lumen narrowing and loss of compensatory remodeling commence. METHODS AND RESULTS: In 14 patients, an angiographically normal artery (stenosis <50%) was investigated with ANGiography and ivUS (ANGUS) to provide 3D lumen and wall geometry. Selection of segments >5 mm in length, in between side branches, yielded 25 segments in 12 patients. SS at the wall was calculated by computational fluid dynamics. WT smaller than 0.2*lumen diameter was defined as normal. Largest arc of normal WT defined reference cross sections. Lumen area relative to the reference cross sections defined area stenosis (AS). Average segmental AS smaller or greater than 10% defined preserved or narrowed lumen, respectively. Total vessel area relative to the reference defined vascular remodeling (VR). For the preserved lumens (n=11, AS=1.7+/-5.6%, P=NS), axially averaged WT and SS were inversely related (slope, -0.46+/-0.55 mm/Pa, P<0.05) and VR was positive (7+/-9%, P<0.05). Narrowed segments (n=13, 1 excluded, AS=18+/-6%, P<0.05) showed no relation between WT and SS or vascular remodeling. CONCLUSIONS: In patient coronary arteries, the often-reported inverse WT-SS relationship appears restricted to lumen preservation and positive vascular remodeling. Its disappearance with lumen narrowing suggests a growing importance of non-SS-related plaque progression.

TAXUS III Trial: In-Stent Restenosis Treated With Stent-Based Delivery of Paclitaxel Incorporated in a Slow-Release Polymer Formulation (Article)

2003-02-04T00:00:00Z

BACKGROUND: The first clinical study of paclitaxel-eluting stent for de novo lesions showed promising results. We performed the TAXUS III trial to evaluate the feasibility and safety of paclitaxel-eluting stent for the treatment of in-stent restenosis (ISR). METHODS AND RESULTS: The TAXUS III trial was a single-arm, 2-center study that enrolled 28 patients with ISR meeting the criteria of lesion length < or =30 mm, 50% to 99% diameter stenosis, and vessel diameter 3.0 to 3.5 mm. They were treated with one or more TAXUS NIRx paclitaxel-eluting stents. Twenty-five patients completed the angiographic follow-up at 6 months, and 17 of these underwent intravascular ultrasound (IVUS) examination. No subacute stent thrombosis occurred up to 12 months, but there was one late chronic total occlusion, and additional 3 patients showed angiographic restenosis. The mean late loss was 0.54 mm, with neointimal hyperplasia volume of 20.3 mm3. The major adverse cardiac event rate was 29% (8 patients; 1 non-Q-wave myocardial infarction, 1 coronary artery bypass grafting, and 6 target lesion revascularization [TLR]). Of the patients with TLR, 1 had restenosis in a bare stent implanted for edge dissection and 2 had restenosis in a gap between 2 paclitaxel-eluting stents. Two patients without angiographic restenosis underwent TLR as a result of the IVUS assessment at follow-up (1 incomplete apposition and 1 insufficient expansion of the stent). CONCLUSIONS: Paclitaxel-eluting stent implantation is considered safe and potentially efficacious in the treatment of ISR. IVUS guidance to ensure good stent deployment with complete coverage of target lesion may reduce reintervention.

Usefulness of percutaneous left ventricular assistance to support high-risk percutaneous coronary interventions. (Article)

2003-02-01T00:00:00Z

Sirolimus-eluting stent for treatment of complex in-stent restenosis: the first clinical experience. (Article)

2003-01-15T00:00:00Z

The treatment of ISR remains a therapeutic challenge, since many pharmacological and mechanical approaches have shown disappointing results. The SESs have been reported to be effective in de-novo coronary lesions.

Late-Late Occlusion After Intracoronary Brachytherapy (Article)

2003-01-01T00:00:00Z

A 57-year-old man with a history of anterior myocardial infarction in April 1997, initially treated with successful thrombolysis, underwent cardiac catheterization due to persistent postinfarction angina.

Images in cardiovascular medicine. Neointimal hyperplasia in carotid stent detected with multislice computed tomography. (Article)

2003-01-01T00:00:00Z

The latest generation of 16-row multislice computed tomography (MSCT) scanner offers high temporal and submillimeter spatial resolution, which allows the visualiza- tion of carotid artery atherosclerosis.

Intravascular palpography for high-risk vulnerable plaque assessment. (Article)

2003-01-01T00:00:00Z

Extension of increased atherosclerotic wall thickness into high shear stress regions is associated with loss of compensatory remodeling. (Article)

2003-01-01T00:00:00Z

Inflammation and atherosclerosis: mechanisms underlying vulnerable plaque. (Article)

2003-01-01T00:00:00Z

Introduction Atherosclerosis belongs to the chronic diseases with the highest mortality in the Western world. While the disease has traditionally been explained by risk factors like high cholesterol and hypertension, evidence is now accumulating for a role of the immune system in the progression of atherosclerosis. This article will explore the role of innate and adaptive immunity in atherosclerosis only. It does not aim at describing all facets of the immune system. In order to facilitate the reading of the article the pathophysiology of the immune system in atherosclerosis is preceded by the relevant physiology.

Non-invasive coronary angiography with multislice spiral computed tomography: impact of heart rate. (Article)

2002-11-01T00:00:00Z

Persistent inhibition of neointimal hyperplasia after sirolimus-eluting stent implantation: long-term (up to 2 years) clinical, angiographic, and intravascular ultrasound follow-up. (Article)

2002-09-24T00:00:00Z

Background— Early results of sirolimus-eluting stent implantation showed a nearly complete abolition of neointimal hyperplasia. The question remains, however, whether the early promising results will still be evident at long-term follow-up. The objective of our study was to evaluate the efficiency of sirolimus-eluting stent implantation for up to 2 years of follow-up. Methods and Results— Fifteen patients with de novo coronary artery disease were treated with 18-mm sirolimus-eluting Bx-Velocity stents (Cordis) loaded with 140 µg sirolimus/cm2 metal surface area in a slow release formulation. Quantitative angiography (QCA) and intravascular ultrasound (IVUS) were performed according to standard protocol. Sirolimus-eluting stent implantation was successful in all 15 patients. During the in-hospital course, 1 patient died of cerebral hemorrhage after periprocedural administration of abciximab, and 1 patient underwent repeat stenting after 2 hours because of edge dissection that led to acute occlusion. Through 6 months and up to 2 years of follow-up, no additional events occurred. QCA analysis revealed no significant change in stent minimal lumen diameter or percent diameter stenosis, and 3-dimensional IVUS showed no significant deterioration in lumen volume. In 2 patients, additional stenting was performed because of significant lesion progression remote from the sirolimus-eluting stent. Conclusion— Sirolimus-eluting stents showed persistent inhibition of neointimal hyperplasia for up to 2 years of follow-up.

A new intracoronary measurement catheter, MetriCath, compared to intravascular ultrasound and quantitative coronary angiography in a stented porcine coronary model. (Article)

2002-09-01T00:00:00Z

The purpose of this study was to compare measurements by MetriCath to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). The MetriCath system consists of a low-pressure (200 mm Hg) balloon catheter connected to a pressure transducer and infusion pump linked to a computer that records pressure-volume curves. Cross-sectional area of blood vessels is obtained directly from the unrestrained and in-stent pressure-volume measurements. We compared stent cross-sectional area measurements by MetriCath, IVUS, and QCA in a porcine stented coronary artery model. Comparison of area measurements in 14 stents showed no significant differences between the three methods (P = 0.66). On average, values differed 0.37 ± 0.60mm2 between MetriCath and QCA, 0.13 ± 0.55 mm2 between MetriCath and IVUS, and 0.22 ± 0.80 mm2 between IVUS and QCA. This corresponds to 6.2% ± 10%, 3.0% ± 9.0%, and 3.1% ± 12.9% relative difference from the average of two corresponding measurements. Linear regression analysis showed excellent correlation between measurements (r ± 0.99 for all comparisons). The differences in in-stent area measurements between MetriCath and both QCA and IVUS were small. Considering the ease and rapidity of obtaining MetriCath results, this technique may form an alternative to the others in evaluating stent expansion. Based on these findings, clinical evaluation seems warranted.

Intravascular Ultrasound Findings in the Multicenter, Randomized, Double-Blind RAVEL (RAndomized study with the sirolimus-eluting VElocity balloon-expandable stent in the treatment of patients with de novo native coronary artery Lesions) Trial (Article)

2002-08-13T00:00:00Z

Background— The goal of this intravascular ultrasound investigation was to provide a more detailed morphological analysis of the local biological effects of the implantation of a sirolimus-eluting stent compared with an uncoated stent. Methods and Results— In the RAVEL trial, 238 patients with single de novo lesions were randomized to receive either an 18-mm sirolimus-eluting stent (Bx VELOCITY stent, Cordis) or an uncoated stent (Bx VELOCITY stent). In a subset of 95 patients (sirolimus-eluting stent=48, uncoated stent=47), motorized intravascular ultrasound pullback (0.5 mm/s) was performed at a 6-month follow-up. Stent volumes, total vessel volumes, and plaque-behind-stent volumes were comparable. However, the difference in neointimal hyperplasia (2±5 versus 37±28 mm3) and percent of volume obstruction (1±3% versus 29±20%) at 6 months between the 2 groups was highly significant (P<0.001), emphasizing the nearly complete abolition of the proliferative process inside the drug-eluting stent. Analysis of the proximal and distal edge volumes showed no significant difference between the 2 groups in external elastic membrane or lumen and plaque volume at the proximal and distal edges. There was also no evidence of intrastent thrombosis or persisting dissection at the stent edges. Although there was a higher incidence of incomplete stent apposition in the sirolimus group compared with the uncoated stent group (P<0.05), it was not associated with any adverse clinical events at 1 year. Conclusions— Sirolimus-eluting stents are effective in preventing neointimal hyperplasia without creating edge effect and without affecting the plaque burden behind the struts.

The TRAPIST Study. A multicentre randomized placebo controlled clinical trial of trapidil for prevention of restenosis after coronary stenting, measured by 3-D intravascular ultrasound (Article)

2002-07-01T00:00:00Z

Routine intracoronary beta-irradiation. Acute and one year outcome in patients at high risk for recurrence of stenosis (Article)

2002-07-01T00:00:00Z

AIMS: Intracoronary radiation is a promising therapy potentially reducing restenosis following catheter-based interventions. Currently, only limited data on this treatment are available. The feasibility and outcome in daily routine practice, however, is unknown. METHODS AND RESULTS: In 100 consecutive patients, intracoronary beta-radiation was performed with a (90)Strontium system (Novoste Beta-Cathtrade mark) following angioplasty. Predominantly complex (73% type B2 and C) and long lesions (length 24.3+/-15.3 mm) were included (37% de novo, 19% restenotic and 44% in-stent restenotic lesions). Radiation success was 100%. Mean prescribed dose was 19.8+/-2.5 Gy. A pullback procedure was performed in 19% lesions. Geographic miss occurred in 8% lesions. Periprocedural thrombus formation occurred in four lesions, dissection in nine lesions. During hospital stay, no death, acute myocardial infarction, or repeat revascularization was observed. Major adverse cardiac events occurred predominantly between 6 and 12 months after the index procedure with major adverse cardiac event-free survival of 66% at 12 months (one death, 10 Q-wave myocardial infarctions, 23 target vessel revascularizations; ranked for worst event). CONCLUSION: Routine catheter-based intracoronary beta-radiation therapy after angioplasty is safe and feasible with a high acute procedural success. The clinical 1-year follow-up showed delayed occurrence of major adverse cardiac events between 6 and 12 months after the index procedure

Coronary stent traversed volume during the cardiac cycle defined as a target for high-precision radiotherapy by using biplane angiograms. (Article)

2002-06-24T00:00:00Z

Three-dimensional reconstructions of 19 coronary artery stents from biplane angiograms were used for measurement of the volume through which the stents traversed during the cardiac cycle. This volume, less than 0.8% of the whole heart volume in all patients, represents a target volume for high-precision radiotherapy to treat coronary artery in-stent restenosis.

Usefulness of multislice computed tomography for detecting obstructive coronary artery disease. (Article)

2002-04-15T00:00:00Z

The latest generation of multislice spiral computed tomography (MSCT) scanners is capable of noninvasive coronary angiography. We evaluated its diagnostic accuracy to detect stenotic coronary artery disease (CAD). In 53 patients with suspected CAD, contrast-enhanced MSCT and conventional angiography were performed. The CT data were acquired within a single breathhold, and isocardiophasic slices were reconstructed by means of retrospective electrocardiographic gating. Coronary segments of ≥2 mm in diameter, measured by quantitative angiography, were evaluated. In 70% of the 358 available segments, image quality was regarded as adequate for assessment. The overall sensitivity, specificity, and positive and negative predictive values to detect ≥50% stenotic lesions in the assessable segments were 82% (42 of 51 lesions), 93% (285 of 307 nonstenotic segments), and 66% and 97%, respectively, regarding conventional quantitative angiography as the gold standard. Proximal segments were assessable in 92%, and distal segments and side branches in 71% and 50%, respectively. Including the undetected lesions in nonassessable segments, overall sensitivity decreased to 61% but remained 82% for lesions in proximal coronary segments. MSCT correctly predicted absent, single, or multiple lesions in 55% of patients. Thus, despite potentially high image quality, current MSCT protocols offer only reasonable diagnostic accuracy in an unselected patient group with a high prevalence of CAD.

Initial observation regarding changes in vessel dimensions after balloon angioplasty and stenting followed by catheter-based beta-radiation. Is stenting necessary in the setting of catheter-based radiotherapy? (Article)

2002-04-01T00:00:00Z

AIMS: We sought to compare the effect of intracoronary beta-radiation on the vessel dimensions in de novo lesions using three-dimensional intravascular ultrasound quantification after balloon angioplasty and stenting. METHODS AND RESULTS: Forty patients (44 vessels; 28 balloon angioplasty and 16 stenting) treated with catheter-based beta-radiation and 18 non-irradiated control patients (18 vessels; 10 balloon angioplasty and 8 stenting) were investigated by means of three-dimensional volumetric intravascular ultrasound analysis post-procedure and at 6-8 months follow-up. Total vessel (EEM) volume enlarged after both balloon angioplasty and stenting (+37 mm(3) vs +42 mm(3), P=ns), but vessel wall volume (plaque plus media) also increased similarly (+33 mm(3) vs +49 mm(3), P=ns) in the irradiated patients. Lumen volume remained unchanged in both groups (+3 mm(3) vs -7 mm(3), P=ns). In the stent-covered segments, neointima at follow-up was significantly smaller in the irradiated group than the control group (8 mm(3) vs 27 mm(3), P=0.001, respectively), but the total amount of tissue growth was similar in both groups (33 mm(3) vs 29 mm(3), P=ns). CONCLUSIONS: Intracoronary beta-radiation induces vessel enlargement after balloon angioplasty and/or stenting, accommodating tissue growth. Additional stenting may not play an important role in the prevention of constrictive remodelling in the setting of catheter-based intracoronary beta-radiotherapy.

Definition of a moving gross target volume for stereotactic radiation therapy of stented coronary arteries. (Article)

2002-02-01T00:00:00Z

PURPOSE: To measure the effect of cardiac motion on coronary artery stent position during the cardiac cycle as a first step toward exploring the feasibility of stereotactic external beam radiation therapy targeted at restenotic stented coronary arteries. METHODS AND MATERIALS: The three-dimensional (3D) position of eight coronary artery stents in 8 patients immobilized in a stereotactic body frame was studied noninvasively by single-breathhold ECG-gated multislice spiral computed tomography (MSCT) during 10 retrospectively selected phases, equally distributed throughout the R-R interval of consecutive cardiac cycles. The volume encompassing all measured 3D positions of the stent was measured. RESULTS: Stent volumes measured by MSCT closely agreed with measurements by quantitative coronary angiography (r > 0.99). The mean of the maximum 3D stent center of mass displacement between any two phases during the cardiac cycle for all eight coronary arteries was 7.5 mm (range 3.3-20.5 mm) in the lateral direction, 8.6 mm (range 2.7-21.6 mm) in the ventrodorsal direction, and 8.2 mm (range 2.5-19.7 mm) in the craniocaudal direction. As was anticipated, the volume encompassing all measured 3D positions of the stent represented only a fraction of the whole heart volume in all patients, i.e., less than 0.6%. CONCLUSIONS: ECG-gated MSCT allowed the measurement of the volume encompassing multiphase 3D positions of coronary artery stents during the cardiac cycle. This volume, a measure of the cardiac motion effect on coronary artery stent position during the cardiac cycle, represents a moving gross target for stereotactic external beam radiation therapy.

Management of acute coronary syndromes in patients presenting without persistent ST-segment elevation (Article)

2002-01-01T00:00:00Z

Comparison of coronary imaging between magnetic resonance imaging and electron beam computed tomography. (Article)

2002-01-01T00:00:00Z

Focal In-Stent Restenosis Near Step-Up (Article)

2002-01-01T00:00:00Z

A 64-year-old man with exercise-induced chest pain underwent coronary angioplasty of his stenosed left anterior descending coronary artery (segments 6 and 7). We recanalized the artery and placed a 3.0x18-mm stent distally and a 3.0x28-mm stent proximally.

Left Main Rapamycin-Coated Stent (Article)

2002-01-01T00:00:00Z

A 47-year-old man with a history of recurrent coronary interventions underwent percutaneous coronary intervention (PCI) of the left main coronary artery with implantation of a rapamycin-coated stent (BX Velocity 4.0x18 mm). At 6-month follow-up, with no physical complaints, he underwent conventional and multislice spiral computed tomography (MSCT) coronary angiography.

Non-invasive coronary angiography with multislice spiral computed tomography: impact of heart rate (Article)

2002-01-01T00:00:00Z

OBJECTIVE: To evaluate the impact of heart rate on the diagnostic accuracy of coronary angiography by multislice spiral computed tomography (MSCT). DESIGN: Prospective observational study. PATIENTS: 78 patients who underwent both conventional and MSCT coronary angiography for suspicion of de novo coronary artery disease (n=53) or recurrent coronary artery disease after percutaneous intervention (n=25). SETTING: Tertiary referral centre. METHODS: Intravenously contrast enhanced MSCT coronary angiography was done during a single breath hold, and ECG synchronised images were reconstructed retrospectively. All coronary segments of > or = 2.0 mm without stents were evaluated by two investigators and compared with quantitative coronary angiography. Patients were classified according to the average heart rate (mean (SD)) into three equally sized groups: group 1, 55.8 (4.1) beats/min; group 2, 66.6 (2.8) beats/min; group 3, 81.7 (8.8) beats/min. RESULTS: Image quality was sufficient for analysis in 78% of the coronary segments in patients in group 1, 73% in group 2, and 54% in group 3 (p < 0.01). The sensitivity and specificity for detecting significant stenoses (> or = 50% lumen reduction) in these assessable segments were: 97% (95% confidence interval (CI) 84% to 100%) and 96% in group 1; 74% (52% to 89%) and 94% in group 2; and 67% (33% to 90%) and 94% in group 3 (p < 0.05). Accounting for all segments of > or = 2.0 mm, including lesions in non-assessable segments as false negatives, the sensitivity decreased to 82% (28/34 lesions, 95% CI 69% to 91%), 61% (14/23 lesions, 42% to 77%), and 32% (6/19 lesions, 15% to 50%), respectively (p < 0.01). CONCLUSIONS: MSCT allows reliable coronary angiography in patients with low heart rates.

Bypass surgery versus stenting for the treatment of multivessel disease in patients with unstable angina compared with stable angina (Article)

2002-01-01T00:00:00Z

BACKGROUND: Earlier reports have shown that the outcome of balloon angioplasty or bypass surgery in unstable angina is less favorable than in stable angina. Recent improvements in percutaneous treatment (stent implantation) and bypass surgery (arterial grafts) warrant reevaluation of the relative merits of either technique in treatment of unstable angina. Methods and Results- Seven hundred fifty-five patients with stable angina were randomly assigned to coronary stenting (374) or bypass surgery (381), and 450 patients with unstable angina were randomly assigned to coronary stenting (226) or bypass surgery (224). All patients had multivessel disease considered to be equally treatable by either technique. Freedom from major adverse events, including death, myocardial infarction, and cerebrovascular events, at 1 year was not different in unstable patients (91.2% versus 88.9%) and stable patients (90.4% versus 92.6%) treated, respectively, with coronary stenting or bypass surgery. Freedom from repeat revascularization at 1 year was similar in unstable and stable angina treated with stenting (79.2% versus 78.9%) or bypass surgery (96.3% versus 96%) but was significantly higher in both unstable and stable patients treated with stenting (16.8% versus 16.9%) compared with bypass surgery (3.6% versus 3.5%). Neither the difference in costs between stented or bypassed stable or unstable angina ($2594 versus $3627) nor the cost-effectiveness was significantly different at 1 year. CONCLUSIONS: There was no difference in rates of death, myocardial infarction, and cerebrovascular event at 1 year in patients with unstable angina and multivessel disease treated with either stented angioplasty or bypass surgery compared with patients with stable angina. The rate of repeat revascularization of both unstable and stable angina was significantly higher in patients with stents.

Images in cardiovascular medicine. Focal in-stent restenosis near step-up: roles of low and oscillating shear stress? (Article)

2002-01-01T00:00:00Z

Fluvastatin for prevention of cardiac events following successful first percutaneous coronary intervention: a randomized controlled trial (Article)

2002-01-01T00:00:00Z

CONTEXT: Percutaneous coronary intervention (PCI) is associated with excellent short-term improvements in ischemic symptoms, yet only three fifths of PCI patients at 5 years and one third of patients at 10 years remain free of major adverse cardiac events (MACE). OBJECTIVE: To determine whether treatment with fluvastatin reduces MACE in patients who have undergone PCI. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled trial conducted at 77 referral centers in Europe, Canada, and Brazil. PATIENTS: A total of 1677 patients (aged 18-80 years) recruited between April 1996 and October 1998 with stable or unstable angina or silent ischemia following successful completion of their first PCI who had baseline total cholesterol levels between 135 and 270 mg/dL (3.5-7.0 mmol/L), with fasting triglyceride levels of less than 400 mg/dL (4.5 mmol/L). INTERVENTIONS: Patients were randomly assigned to receive treatment with fluvastatin, 80 mg/d (n = 844), or matching placebo (n = 833) at hospital discharge for 3 to 4 years. MAIN OUTCOME MEASURE: Survival time free of MACE, defined as cardiac death, nonfatal myocardial infarction, or reintervention procedure, compared between the treatment and placebo groups. RESULTS: Median time between PCI and first dose of study medication was 2.0 days, and median follow-up was 3.9 years. MACE-free survival time was significantly longer in the fluvastatin group (P =.01). One hundred eighty-one (21.4%) of 844 patients in the fluvastatin group and 222 (26.7%) of 833 patients in the placebo group had at least 1 MACE (relative risk [RR], 0.78; 95% confidence interval [CI], 0.64-0.95; P =.01). This result was independent of baseline total cholesterol levels (above [RR, 0.76; 95% CI, 0.56-1.04] vs below [RR, 0.77; 95% CI, 0.57-1.02] the median). In subgroup analysis, the risk of MACE was reduced in patients with diabetes (n = 202; RR, 0.53; 95% CI, 0.29-0.97; P =.04) and in those with multivessel disease (n = 614; RR, 0.66; 95% CI, 0.48-0.91; P =.01) who received fluvastatin compared with those who received placebo. There were no instances of creatine phosphokinase elevations 10 or more times the upper limit of normal or rhabdomyolysis in the fluvastatin group. CONCLUSION: Fluvastatin treatment in patients with average cholesterol levels undergoing their first successful PCI significantly reduces the risk of major adverse cardiac events.

Intravascular ultrasound findings in the multicenter, randomized, double-blind RAVEL (RAndomized study with the sirolimus-eluting VElocity balloon- expandable stent in the treatment of patients with de novo native coronary artery Lesions) trial (Article)

2002-01-01T00:00:00Z

BACKGROUND: The goal of this intravascular ultrasound investigation was to provide a more detailed morphological analysis of the local biological effects of the implantation of a sirolimus-eluting stent compared with an uncoated stent. METHODS AND RESULTS: In the RAVEL trial, 238 patients with single de novo lesions were randomized to receive either an 18-mm sirolimus-eluting stent (Bx VELOCITY stent, Cordis) or an uncoated stent (Bx VELOCITY stent). In a subset of 95 patients (sirolimus-eluting stent=48, uncoated stent=47), motorized intravascular ultrasound pullback (0.5 mm/s) was performed at a 6-month follow-up. Stent volumes, total vessel volumes, and plaque-behind-stent volumes were comparable. However, the difference in neointimal hyperplasia (2+/-5 versus 37+/-28 mm3) and percent of volume obstruction (1+/-3% versus 29+/-20%) at 6 months between the 2 groups was highly significant (P<0.001), emphasizing the nearly complete abolition of the proliferative process inside the drug-eluting stent. Analysis of the proximal and distal edge volumes showed no significant difference between the 2 groups in external elastic membrane or lumen and plaque volume at the proximal and distal edges. There was also no evidence of intrastent thrombosis or persisting dissection at the stent edges. Although there was a higher incidence of incomplete stent apposition in the sirolimus group compared with the uncoated stent group (P<0.05), it was not associated with any adverse clinical events at 1 year. CONCLUSIONS: Sirolimus-eluting stents are effective in preventing neointimal hyperplasia without creating edge effect and without affecting the plaque burden behind the struts.

Platelet GP IIb/IIIa receptor blockers for failed thrombolysis in acute myocardial infarction, alone or as adjunct to other rescue therapies; single centre retrospective analysis of 548 consecutive patients with acute myocardial infarction (Article)

2002-01-01T00:00:00Z

In order to study the safety of 'rescue' strategies in the treatment of patients with failed thrombolysis, all 548 patients admitted with evolving myocardial infarction to the Thoraxcenter, Rotterdam, from January 1997 until April 1999 were reviewed. Of these patients, 49% had received thrombolysis. Of patients treated with thrombolysis and not referred from other hospitals (n = 154) 36% received rescue therapy for failed thrombolysis. Three rescue therapies were used after failed thrombolysis: percutaneous coronary intervention (74%), retreatment with thrombolysis (39%) and platelet glycoprotein (GP) IIb/IIIa receptor blockers (53%), often in combination. Platelet GP IIb/IIIa receptor blockers were administered in 64% of patients treated with rescue percutaneous coronary intervention. Major bleeding occurred in 14% of all thrombolysis treated patients, and in 30% of patients who received multiple rescue therapies. Bleeding was related to heparin usage and platelet GP IIb/IIIa receptor blockers, as was the insertion of catheters for percutaneous coronary intervention or intra-aortic balloon pumps. Major bleeding resulted in one death due to a ruptured ventricle, one haemorrhagic stroke, and three cases of tamponade for which surgery was needed. Four of these patients had received combination rescue therapy. Rescue therapy is a widely used strategy for failed thrombolysis, but is associated with a high bleeding rate. Alternative reperfusion strategies to avoid failed thrombolysis should be considered in high risk patients.

Persistent inhibition of neointimal hyperplasia after sirolimus-eluting stent implantation: long-term (up to 2 years) clinical, angiographic, and intravascular ultrasound follow-up (Article)

2002-01-01T00:00:00Z

BACKGROUND: Early results of sirolimus-eluting stent implantation showed a nearly complete abolition of neointimal hyperplasia. The question remains, however, whether the early promising results will still be evident at long-term follow-up. The objective of our study was to evaluate the efficiency of sirolimus-eluting stent implantation for up to 2 years of follow-up. METHODS AND RESULTS: Fifteen patients with de novo coronary artery disease were treated with 18-mm sirolimus-eluting Bx-Velocity stents (Cordis) loaded with 140 microg sirolimus/cm2 metal surface area in a slow release formulation. Quantitative angiography (QCA) and intravascular ultrasound (IVUS) were performed according to standard protocol. Sirolimus-eluting stent implantation was successful in all 15 patients. During the in-hospital course, 1 patient died of cerebral hemorrhage after periprocedural administration of abciximab, and 1 patient underwent repeat stenting after 2 hours because of edge dissection that led to acute occlusion. Through 6 months and up to 2 years of follow-up, no additional events occurred. QCA analysis revealed no significant change in stent minimal lumen diameter or percent diameter stenosis, and 3-dimensional IVUS showed no significant deterioration in lumen volume. In 2 patients, additional stenting was performed because of significant lesion progression remote from the sirolimus-eluting stent. CONCLUSION: Sirolimus-eluting stents showed persistent inhibition of neointimal hyperplasia for up to 2 years of follow-up.

The TRAPIST Study. A multicentre randomized placebo controlled clinical trial of trapidil for prevention of restenosis after coronary stenting, measured by 3-D intravascular ultrasound. (Article)

2001-11-24T00:00:00Z

BACKGROUND: Studies have reported benefit of oral therapy with the phosphodiesterase inhibitor, trapidil, in reducing restenosis after coronary angioplasty. Coronary stenting is associated with improved late outcome compared with balloon angioplasty, but significant neointimal hyperplasia still occurs in a considerable proportion of patients. The aim of this study was to investigate the safety and efficacy of trapidil 200 mg in preventing in-stent restenosis. METHODS: Patients with a single native coronary lesion requiring revascularization were randomized to placebo or trapidil at least 1 h before, and continuing for 6 months after, successful implantation of a coronary Wallstent. The primary end-point was in-stent neointimal volume measured by three-dimensional reconstruction of intravascular ultrasound images recorded at the 6 month follow-up catheterization. RESULTS: Of 312 patients randomized at 21 centres in nine countries, 303 (148 trapidil, 155 placebo) underwent successful Wallstent implantation, and 139 patients (90%) in the placebo group and 130 (88%) in the trapidil group had repeat catheterization at 26+/-2 weeks. There was no significant difference between trapidil and placebo-treated patients regarding in-stent neointimal volume (108.6+/- 95.6 mm(3)vs 93.3+/-79.1 mm(3);P=0.16) or % obstruction volume (38+/-18% vs 36+/-21%;P=0.32), in angiographic minimal luminal diameter at follow-up (1.63+/-0.61 mm vs 1.74+/-0.69 mm;P=0.17), restenosis rate (31% vs 24%;P=0.24), cumulative incidence of major adverse cardiac events at 7 months (22% vs 20%;P=0.71) or anginal complaints (30% vs 24%;P=0.29). CONCLUSION: Oral trapidil 600 mg daily for 6 months did not reduce in-stent hyperplasia or improve clinical outcome after successful Wallstent implantation and is not indicated for this purpose.

The quest for the ideal stent. (Article)

2001-10-16T00:00:00Z

Long-term clinical outcome after coronary balloon angioplasty: identification of a population at low risk of recurrent events during 17 years of follow-up. (Article)

2001-07-20T00:00:00Z

AIMS: This study reports the clinical outcome, up to 17 years, of the first 856 consecutive patients treated by coronary angioplasty at a single centre and attempts to identify a subgroup of patients at low risk of adverse events. METHODS AND RESULTS: Follow-up status was established via hospital and general practitioner records and the civil registry. Median follow-up was 16 years. The overall 5-, 10-, 15- and 17-year survival was 90%, 78%, 64% and 58%, respectively and corresponding event-free survival was 53%, 33%, 22% and 19%. After 32% of patients had experienced a major adverse cardiac event in the first year, the annual coronary re-intervention incidence thereafter and, even beyond year 10, remained at 2%--3%. Using multivariable Cox regression, significant independent predictors of mortality were advanced age, diabetes, multivessel disease and impaired left ventricular function at the time of PTCA. A subgroup of 26% of the patients with none of these risk factors had a survival rate similar to the general Dutch population matched for age and gender (at 5 years: 96%, at 10 years: 89% and at 15 years: 83%). CONCLUSION: Although the majority of patients (>80%) experienced a further cardiac event during the 17 years after their first angioplasty procedure, in those non-diabetics under 60 years with single-vessel disease and good left ventricular function, prognosis was similar to the general population.

Three dimensional intravascular ultrasonic assessment of the local mechanism of restenosis after balloon angioplasty (Article)

2001-01-01T00:00:00Z

OBJECTIVE: To assess the mechanism of restenosis after balloon angioplasty. DESIGN: Prospective study. PATIENTS: 13 patients treated with balloon angioplasty. INTERVENTIONS: 111 coronary subsegments (2 mm each) were analysed after balloon angioplasty and at a six month follow up using three dimensional intravascular ultrasound (IVUS). MAIN OUTCOME MEASURES: Qualitative and quantitative IVUS analysis. Total vessel (external elastic membrane), plaque, and lumen volume were measured in each 2 mm subsegment. Delta values were calculated (follow up - postprocedure). Remodelling was defined as any (positive or negative) change in total vessel volume. RESULTS: Positive remodelling was observed in 52 subsegments while negative remodelling occurred in 44. Remodelling, plaque type, and dissection were heterogeneously distributed along the coronary segments. Plaque composition was not associated with changes in IVUS indices, whereas dissected subsegments had a greater increase in total vessel volume than those without dissection (1.7 mm(3) v -0.33 mm(3), p = 0.04). Change in total vessel volume was correlated with changes in lumen (p < 0.05, r = 0.56) and plaque volumes (p < 0.05, r = 0.64). The site with maximum lumen loss was not the same site as the minimum lumen area at follow up in the majority (n = 10) of the vessels. In the multivariate model, residual plaque burden had an influence on negative remodelling (p = 0.001, 95% confidence interval (CI) -0.391 to -0.108), whereas dissection had an effect on total vessel increase (p = 0.002, 95% CI 1.168 to 4.969). CONCLUSIONS: The mechanism of lumen renarrowing after balloon angioplasty appears to be determined by unfavourable remodelling. However, different patterns of remodelling may occur in individual injured coronary segments, which highlights the complexity and influence of local factors in the restenotic process.

Four-dimensional cardiac imaging with multislice computed tomography (Article)

2001-01-01T00:00:00Z

Aneurysm of the abdominal aorta (Article)

2001-01-01T00:00:00Z

Prominent role of tensile stress in propagation of a dissection after coronary stenting: computational fluid dynamic analysis on true 3d-reconstructed segment (Article)

2001-01-01T00:00:00Z

Management of acute coronary syndromes: acute coronary syndromes without persistent ST segment elevation; recommendations of the Task Force of the European Society of Cardiology. (Article)

2000-09-01T00:00:00Z

The clinical presentations of ischaemic heart disease include stable angina pectoris, silent ischaemia, unstable angina, myocardial infarction, heart failure, and sudden death. For many years, unstable angina has been con- sidered as an intermediate ‘syndrome’ between chronic stable angina and acute myocardial infarction. In recent years, its physiopathology has been clarified and there have been major advances in management.

Three-dimensional intravascular ultrasonic volumetric quantification of stent recoil and neointimal formation of two new generation tubular stents (Article)

2000-01-15T00:00:00Z

Currently, several different designs of coronary stents are available. However, only a few of the new generation stents have been investigated in large randomized trials. Mechanical behavior of first-generation stents (Palmaz-Schatz, Gianturco-Roubin) may not be applied to the new designs. We investigated the chronic mechanical behavior (recoil) of 2 stents recently approved by the Food and Drug Administration (MULTILINK and NIR). Forty-eight patients with single-stent implantation (23 MULTILINK and 25 NIR) were assessed by means of volumetric 3-dimensional intravascular ultrasound analysis after the procedure and at 6-month follow-up. In addition, volumetric assessment of neointimal formation was performed. No significant chronic stent recoil was detected in both groups (Δ MULTILINK stent volume: +5.6 ± 41 mm3 [p = NS] and Δ NIR stent volume + 2.1 ± 26 mm3 [p = NS]). A similar degree of neointimal formation at 6 months was observed between the 2 stents (MULTILINK 46 ± 31.9 mm3 vs NIR 39.9 ± 27.6 mm3, p = NS). In conclusion, these 2 second-generation tubular stents did not show chronic recoil and appeared to promote similar proliferative response after implantation in human coronary arteries.

True 3-Dimensional Reconstruction of Coronary Arteries in Patients by Fusion of Angiography and IVUS (ANGUS) and Its Quantitative Validation (Article)

2000-01-01T00:00:00Z

Background—True 3D reconstruction of coronary arteries in patients based on intravascular ultrasound (IVUS) may be achieved by fusing angiographic and IVUS information (ANGUS). The clinical applicability of ANGUS was tested, and its accuracy was evaluated quantitatively. Methods and Results—In 16 patients who were investigated 6 months after stent implantation, a sheath-based catheter was used to acquire IVUS images during an R-wave–triggered, motorized stepped pullback. First, a single set of end-diastolic biplane angiographic images documented the 3D location of the catheter at the beginning of pullback. From this set, the 3D pullback trajectory was predicted. Second, contours of the lumen or stent obtained from IVUS were fused with the 3D trajectory. Third, the angular rotation of the reconstruction was optimized by quantitative matching of the silhouettes of the 3D reconstruction with the actual biplane images. Reconstructions were obtained in 12 patients. The number of pullback steps, which determines the pullback length, closely agreed with the reconstructed path length (r=0.99). Geometric measurements in silhouette images of the 3D reconstructions showed high correlation (0.84 to 0.97) with corresponding measurements in the actual biplane angiographic images. Conclusions—With ANGUS, 3D reconstructions of coronary arteries can be successfully and accurately obtained in the majority of patients.

Outcome from balloon induced coronary artery dissection after intracoronary beta radiation (Article)

2000-01-01T00:00:00Z

OBJECTIVE: To evaluate the healing of balloon induced coronary artery dissection in individuals who have received beta radiation treatment and to propose a new intravascular ultrasound (IVUS) dissection score to facilitate the comparison of dissection through time. DESIGN: Retrospective study. SETTING: Tertiary referral centre. PATIENTS: 31 patients with stable angina pectoris, enrolled in the beta energy restenosis trial (BERT-1.5), were included. After excluding those who underwent stent implantation, the evaluable population was 22 patients. INTERVENTIONS: Balloon angioplasty and intracoronary radiation followed by quantitative coronary angiography (QCA) and IVUS. Repeat QCA and IVUS were performed at six month follow up. MAIN OUTCOME MEASURES: QCA and IVUS evidence of healing of dissection. Dissection classification for angiography was by the National Heart Lung Blood Institute scale. IVUS proven dissection was defined as partial or complete. The following IVUS defined characteristics of dissection were described in the affected coronary segments: length, depth, arc circumference, presence of flap, and dissection score. Dissection was defined as healed when all features of dissection had resolved. The calculated dose of radiation received by the dissected area in those with healed versus non-healed dissection was also compared. RESULTS: Angiography (type A = 5, B = 7, C = 4) and IVUS proven (partial = 12, complete = 4) dissections were seen in 16 patients following intervention. At six month follow up, six and eight unhealed dissections were seen by angiography (A = 2, B = 4) and IVUS (partial = 7, complete = 1), respectively. The mean IVUS dissection score was 5.2 (range 3-8) following the procedure, and 4.6 (range 3-7) at follow up. No correlation was found between the dose prescribed in the treated area and the presence of unhealed dissection. No change in anginal status was seen despite the presence of unhealed dissection. CONCLUSION: beta radiation appears to alter the normal healing process, resulting in unhealed dissection in certain individuals. In view of the delayed and abnormal healing observed, long term follow up is indicated given the possible late adverse effects of radiation. Although in this cohort no increase in cardiac events following coronary dissections was seen, larger populations are needed to confirm this phenomenon. Stenting of all coronary dissections may be warranted in patients scheduled for brachytherapy after balloon angioplasty.

Diagnosis of an Intracoronary Thrombus With Intravascular Ultrasound (Article)

2000-01-01T00:00:00Z

A60-year-old man was referred for coronary angiography because of exertional angina (Canadian Cardiovascular Society angina classification type II). Twelve years earlier, he had had a myocardial infarction with a venous bypass graft to the right coronary artery.

Stentocarditis (Article)

2000-01-01T00:00:00Z

Coronary Artery Fly-Through Using Electron Beam Computed Tomography (Article)

2000-01-01T00:00:00Z

BACKGROUND: Virtual reality techniques have recently been introduced into clinical medicine. This study examines the possibility of coronary artery fly-through using a dataset obtained by noninvasive coronary angiography with contrast-enhanced electron-beam computed tomography. METHODS AND RESULTS: Ten patients were examined, and 40 to 60 transaxial tomograms (thickness, 1.5 mm; in-plane pixel dimensions, approximately 0.5x0.5 mm) were obtained after intravenous contrast injection. The datasets were processed on a graphics workstation using volume-rendering software. For fly-throughs, the contrast-enhanced lumen was made transparent and other tissue was made opaque. Then, key frames were selected in a path through the vessel, with software interpolation of frames between key frames. A typical movie contained 150 to 300 frames (10 to 15 key frames). Fly-throughs of coronary bypass grafts (n=3), left anterior descending arteries (LAD; n=6), and the intermediate branch (n=1) were reconstructed. Coronary calcifications were seen in 3 patients. The fly-through of the intermediate branch, the bypass grafts, and one of the LADs did not show any irregularities. In 2 cases, a stenosis was visible in the LAD; its presence was confirmed by conventional coronary angiography. CONCLUSIONS: Recent developments in fast-volume rendering using special-purpose hardware in combination with noninvasive coronary angiography with electron beam computed tomography have provided the possibility of performing coronary artery fly-throughs.

Magnetic resonance angiography of a pulmonary artery stenosis late after cardiac surgery (Article)

2000-01-01T00:00:00Z

Non-invasive coronary artery imaging with electron beam computed tomography and magnetic resonance imaging (Article)

2000-01-01T00:00:00Z

MR coronary angiography with breath-hold targeted volumes: preliminary clinical results (Article)

2000-01-01T00:00:00Z

PURPOSE: To assess the clinical value of a magnetic resonance (MR) coronary angiography strategy involving a small targeted volume to image one coronary segment in a single breath hold for the detection of greater than 50% stenosis. MATERIALS AND METHODS: Thirty-eight patients referred for elective coronary angiography were included. The coronary arteries were localized during single-breath-hold, three-dimensional imaging of the entire heart. MR coronary angiography was then performed along the major coronary branches with a double-oblique, three-dimensional, gradient-echo sequence. Conventional coronary angiography was the reference-standard method. RESULTS: Adequate visualization was achieved with MR coronary angiography in 85%-91% of the proximal coronary arterial branches and in 38%-76% of the middle and distal branches. Overall, 187 (69%) of 272 segments were suitable for comparison between conventional and MR coronary angiography. The diagnostic accuracy of MR coronary angiography for the detection of hemodynamically significant stenoses was 92%; sensitivity, 68%; and specificity, 97%. The sensitivity in individual segments was 50%-77%, whereas the specificity was 94%-100%. CONCLUSION: Adequate visualization of the major coronary arterial branches was possible in the majority of patients. The observed accuracy of MR coronary angiography for detection of hemodynamically significant coronary arterial stenosis is promising, but it needs to be higher before this modality can be used reliably in a clinical setting.

MR coronary angiography with breath-hold targeted volumes: preliminary clinical results (Article)

2000-01-01T00:00:00Z

Long term outcome after coronary stent implantation: a 10 year single centre experience of 1000 patients (Article)

1999-01-01T00:00:00Z

OBJECTIVE: To describe the long term clinical outcome (up to 11 years) after coronary stenting. DESIGN: A single centre observational study encompassing 1000 consecutive patients with a first stent implantation (1560 stents) between 1986 and 1996, who were followed for at least one year with a median follow up of 29 months (range 12-132 months). RESULTS: Up to July 1997 the cumulative incidence of the major adverse cardiac events (MACE) of death, non-fatal acute myocardial infarction, coronary artery bypass grafting, and repeat percutaneous transluminal coronary angioplasty was 8.2%, 12.8%, 13.1%, and 22.4%, respectively. Survival at one, three, and five years was 95%, 91%, and 86%, respectively. Comparison of MACE incidence during the "anticoagulant era" and the "ticlopidine era" revealed significantly improved event free survival with ticlopidine (27% v 13%; p < 0.005). Multivariable analyses showed that ejection fraction < 50% (relative risk (RR) 4. 1), multivessel disease (RR 3.0), diabetes (RR 2.9), implantation in saphenous vein graft (RR 2.1), indication for unstable angina (RR 1. 9), and female sex (RR 1.7) were independent predictors of increased mortality after stenting. Independent predictors of any MACE were multivessel stenting (RR 2.0), implantation in saphenous bypass graft (RR 1.6), diabetes (RR 1.5), anticoagulant treatment (versus ticlopidine and aspirin) (RR 1.5), bailout stenting (RR 1.5), multivessel disease (RR 1.4), and multiple stent implantation (RR 1. 5). CONCLUSIONS: Long term survival and infarct free survival was good, particularly in non-diabetic men with single vessel disease and good ventricular function, who had a single stent implanted in a native coronary artery. A dramatic improvement was observed in event free survival, both early and late, with the replacement of anticoagulation by ticlopidine. This, of course, cannot be separated from improved stent implantation techniques between 1986 and 1995. Ultimately, almost 40% of the patients experienced an adverse cardiac event (mainly repeat intervention) in the long term. New advances in restenosis treatments and in secondary prevention must be directed at this aspect of patient management after stenting.

A randomized placebo-controlled trial of fluvastatin for prevention of restenosis after successful coronary balloon angioplasty; final results of the fluvastatin angiographic restenosis (FLARE) trial (Article)

1999-01-01T00:00:00Z

BACKGROUND: The 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors competitively inhibit biosynthesis of mevalonate, a precursor of non-sterol compounds involved in cell proliferation. Experimental evidence suggests that fluvastatin may, independent of any lipid lowering action, exert a greater direct inhibitory effect on proliferating vascular myocytes than other statins. The FLARE (Fluvastatin Angioplasty Restenosis) Trial was conceived to evaluate the ability of fluvastatin 40 mg twice daily to reduce restenosis after successful coronary balloon angioplasty (PTCA). METHODS: Patients were randomized to either placebo or fluvastatin 40 mg twice daily beginning 2-4 weeks prior to planned PTCA and continuing after a successful PTCA (without the use of a stent), to follow-up angiography at 26+/-2 weeks. Clinical follow-up was completed at 40 weeks. The primary end-point was angiographic restenosis, measured by quantitative coronary angiography at a core laboratory, as the loss in minimal luminal diameter during follow-up. Clinical end-points were death, myocardial infarction, coronary artery bypass graft surgery or re-intervention, up to 40 weeks after PTCA. RESULTS: Of 1054 patients randomized, 526 were allocated to fluvastatin and 528 to placebo. Among these, 409 in the fluvastatin group and 427 in the placebo group were included in the intention-to-treat analysis, having undergone a successful PTCA after a minimum of 2 weeks of pre-treatment. At the time of PTCA, fluvastatin had reduced LDL cholesterol by 37% and this was maintained at 33% at 26 weeks. There was no difference in the primary end-point between the treatment groups (fluvastatin 0.23+/-0.49 mm vs placebo 0.23+/-0.52 mm, P=0.95) or in the angiographic restenosis rate (fluvastatin 28%, placebo 31%, chi-square P=0.42), or in the incidence of the composite clinical end-point at 40 weeks (22.4% vs 23.3%; logrank P=0.74). However, a significantly lower incidence of total death and myocardial infarction was observed in six patients (1.4%) in the fluvastatin group and 17 (4.0%) in the placebo group (log rank P=0.025). CONCLUSION: Treatment with fluvastatin 80 mg daily did not affect the process of restenosis and is therefore not indicated for this purpose. However, the observed reduction in mortality and myocardial infarction 40 weeks after PTCA in the fluvastatin treated group has not been previously reported with statin therapy. Accordingly, a priori investigation of this finding is indicated and a new clinical trial with this intention is already underway.

Intracoronary ultrasound longitudinal reconstruction of a postangioplasty coronary artery dissection (Article)

1999-01-01T00:00:00Z

Magnetic resonance imaging of the coronary arteries: clinical results from three dimensional evaluation of a respiratory gated technique (Article)

1999-01-01T00:00:00Z

BACKGROUND: Magnetic resonance coronary angiography is challenging because of the motion of the vessels during cardiac contraction and respiration. Additional challenges are the small calibre of the arteries and their complex three dimensional course. Respiratory gating, turboflash acquisition, and volume rendering techniques may meet the necessary requirements for appropriate visualisation. OBJECTIVE: To determine the diagnostic accuracy of respiratory gated magnetic resonance imaging (MRI) for the detection of significant coronary artery stenoses evaluated with three dimensional postprocessing software. METHODS: 32 patients referred for elective coronary angiography were studied with a retrospective respiratory gated three dimensional gradient echo MRI technique. Resolution was 1.9 x 1.25 x 2 mm. After manual segmentation three dimensional evaluation was performed with a volume rendering technique. RESULTS: Overall 74% (range 50% to 90%) of the proximal and mid coronary artery segments were visualised with an image quality suitable for further analysis. Sensitivity and specificity for the detection of significant stenoses were 50% and 91%, respectively. CONCLUSIONS: Volume rendering of respiratory gated MRI techniques allows adequate visualisation of the coronary arteries in patients with a regular breathing pattern. Significant lesions in the major coronary artery branches can be identified with a moderate sensitivity and a high specificity.

In vivo assessment of three dimensional coronary anatomy using electron beam computed tomography after intravenous contrast administration (Article)

1999-01-01T00:00:00Z

Intravenous coronary angiography with electron beam computed tomography (EBCT) allows for the non-invasive visualisation of coronary arteries. With dedicated computer hardware and software, three dimensional renderings of the coronary arteries can be constructed, starting from the individual transaxial tomograms. This article describes image acquisition, postprocessing techniques, and the results of clinical studies. EBCT coronary angiography is a promising coronary artery imaging technique. Currently it is a reasonably robust technique for the visualisation and assessment of the left main and left anterior descending coronary artery. The right and circumflex coronary arteries can be visualised less consistently. Improvements in image acquisition and postprocessing techniques are expected to improve visualisation and diagnostic accuracy of the technique.

Reference chart derived from post-stent-implantation intravascular ultrasound predictors of 6-month expected restenosis on quantitative coronary angiography (Article)

1999-01-01T00:00:00Z

BACKGROUND: Intravascular ultrasound (IVUS)-guided stent implantation and the availability of a reference chart to predict the expected in-stent restenosis rate based on operator-dependent IVUS parameters may interactively facilitate optimal stent placement. The use of IVUS guidance protects against undue risks of dissection or rupture. METHODS AND RESULTS: IVUS-determined post-stent-implantation predictors of 6-month in-stent restenosis on quantitative coronary angiography (QCA) were identified by logistic regression analysis. These predictors were used to construct a reference chart that predicts the expected 6-month QCA restenosis rate. IVUS and QCA data were obtained from 3 registries (MUSIC [Multicenter Ultrasound Stenting in Coronaries study], WEST-II [West European Stent Trial II], and ESSEX [European Scimed Stent EXperience]) and 2 randomized in-stent restenosis trials (ERASER [Evaluation of ReoPro And Stenting to Eliminate Restenosis] and TRAPIST [TRApidil vs placebo to Prevent In-STent intimal hyperplasia]). In-stent restenosis was defined as luminal diameter stenosis >50% by QCA. IVUS predictors were minimum and mean in-stent area, stent length, and in-stent diameter. Multiple models were constructed with multivariate logistic regression analysis. The model containing minimum in-stent area and stent length best fit the Hosmer-Lemeshow goodness-of-fit test. This model was used to construct a reference chart to calculate the expected 6-month restenosis rate. CONCLUSIONS: The expected 6-month in-stent restenosis rate after stent implantation for short lesions in relatively large vessels can be predicted by use of in-stent minimal area (which is inversely related to restenosis) and stent length (which is directly related to restenosis), both of which can be read from a simple reference chart.

Coronary wallstents show significant late, postprocedural expansion despite implantation with adjunct high-pressure balloon inflations. (Article)

1998-07-15T00:00:00Z

Adjunct high-pressure balloon inflations following the delivery of oversized self-expandable Wallstents may affect their implied late, postprocedural self-expansion. Consequently, we examined 15 "Magic" Wallstents, which were implanted following a strategy of stent oversizing and subsequent adjunct high-pressure balloon inflations (16 +/- 2 atm; all > or = 12 atm). The excellent radiographic visibility of this stent permitted reliable quantitative coronary angiographic measurement of both lumen and stent dimensions (before and after stenting, and at follow-up). At follow-up, extent and distribution of in-stent neointimal proliferation were evaluated with volumetric intravascular ultrasound. Between postintervention and follow-up examination, mean stent diameter increased from 3.7 +/- 0.4 to 4.2 +/- 0.4 mm (p <0.0001); there was no significant difference in late stent expansion between proximal, mid-, and distal stent subsegments. Late stent expansion showed a significant (reverse) relation to maximum balloon size (r = -0.56, p <0.04), but not with follow-up lumen size or late lumen loss. On average, 52 +/- 18% of the stent was filled with neointimal ingrowth; neointimal volume/cm stent length was 64 +/- 22 mm3. Both late stent expansion (r = 0.36, p <0.02) and maximum balloon pressure (r = 0.41, p <0.001) were related to neointimal volume/cm stent but not to follow-up lumen size. Thus, despite high-pressure implantation, Wallstents showed significant late self-expansion, which resulted in larger stent dimensions at follow-up that assisted in accommodating in-stent neointimal proliferation. Conversely, late stent expansion had a significant relation to the extent of in-stent neointimal ingrowth. Beneficial and disadvantageous effects of the late stent expansion appear to be balanced, because a relation to late lumen loss or follow-up lumen dimensions was not found to be present.

Chromatic distortion during angioscopy: assessment and correction by quantitative colorimetric angioscopic analysis. (Article)

1998-01-01T00:00:00Z

Angioscopy represents a diagnostic tool with the unique ability of assessing the true color of intravascular structures. Current angioscopic interpretation is entirely subjective, however, and the visual interpretation of color has been shown to be marginal at best. The quantitative colorimetric angioscopic analysis system permits the full characterization of angioscopic color using two parameters (C1 and C2), derived from a custom color coordinate system, that are independent of illuminating light intensity. Measurement variability was found to be low (coefficient of variation = 0.06-0.64%), and relatively stable colorimetric values were obtained even at the extremes of illumination power. Variability between different angioscopic catheters was good (maximum difference for C1, 0.022; for C2, 0.015). Catheter flexion did not significantly distort color transmission. Although the fiber optic illumination bundle was found to impart a slight yellow tint to objects in view (deltaC1 = 0.020, deltaC2 = 0.024, P < 0.0001) and the imaging bundle in isolation imparted a slight red tint (deltaC1 = 0.043, deltaC2 = -0.027, P < 0.0001), both of these artifacts could be corrected by proper white balancing. Finally, evaluation of regional chromatic characteristics revealed a radially symmetric and progressive blue shift in measured color when moving from the periphery to the center of an angioscopic image. An algorithm was developed that could automatically correct 93.0-94.3% of this error and provide accurate colorimetric measurements independent of spatial location within the angioscopic field. In summary, quantitative colorimetric angioscopic analysis provides objective and highly reproducible measurements of angioscopic color. This technique can correct for important chromatic distortions present in modern angioscopic systems. It can also help overcome current limitations in angioscopy research and clinical use imposed by the reliance on visual perception of color.

Atherosclerotic coronary lesions with inadequate compensatory enlargement have smaller plaque and vessel volumes: observations with three dimensional intravascular ultrasound in vivo. (Article)

1998-01-01T00:00:00Z

OBJECTIVE: To compare vessel, lumen, and plaque volumes in atherosclerotic coronary lesions with inadequate compensatory enlargement versus lesions with adequate compensatory enlargement. DESIGN: 35 angiographically significant coronary lesions were examined by intravascular ultrasound (IVUS) during motorised transducer pullback. Segments 20 mm in length were analysed using a validated automated three dimensional analysis system. IVUS was used to classify lesions as having inadequate (group I) or adequate (group II) compensatory enlargement. RESULTS: There was no significant difference in quantitative angiographic measurements and the IVUS minimum lumen cross sectional area between groups I (n = 15) and II (n = 20). In group I, the vessel cross sectional area was 13.3 (3.0) mm2 at the lesion site and 14.4 (3.6) mm2 at the distal reference (p < 0.01), whereas in group II it was 17.5 (5.6) mm2 at the lesion site and 14.0 (6.0) mm2 at the distal reference (p < 0.001). Vessel and plaque cross sectional areas were significantly smaller in group I than in group II (13.3 (3.0) v 17.5 (5.6) mm2, p < 0.01; and 10.9 (2.8) v 15.2 (4.9) mm2; p < 0.005). Similarly, vessel and plaque volume were smaller in group I (291.0 (61.0) v 353.7 (110.0) mm3, and 177.5 (48.4) v 228.0 (92.8) mm3, p < 0.05 for both). Lumen areas and volumes were similar. CONCLUSIONS: In lesions with inadequate compensatory enlargement, both vessel and plaque volume appear to be smaller than in lesions with adequate compensatory enlargement.

Clinical events following excimer laser angioplasty or balloon angioplasty for complex coronary lesions: subanalysis of a randomised trial (Article)

1998-01-01T00:00:00Z

OBJECTIVES: To compare clinical outcome in patients with complex coronary lesions treated with either excimer laser coronary angioplasty (ELCA) or balloon angioplasty. PATIENTS AND DESIGN: 308 patients with stable angina and a coronary lesion of more than 10 mm in length were randomised to ELCA (151 patients, 158 lesions) or balloon angioplasty (157 patients, 167 lesions). The primary clinical end points were death, myocardial infarction, coronary bypass surgery, or repeated coronary angioplasty of the randomised segment during six months of follow up. Subanalysis was performed to identify a subgroup of patients with a beneficial clinical outcome following ELCA or balloon angioplasty. SETTING: Two university hospitals and one general hospital. RESULTS: There were no deaths. Myocardial infarction, coronary bypass surgery, and repeated angioplasty occurred in 4.6, 10.6, and 21.2%, respectively, of patients treated with ELCA compared with 5.7, 10.8, and 18.5%, respectively, of those treated with balloon angioplasty. ELCA did not yield a favourable clinical outcome in subgroups of patients with long (more than 20 mm) coronary lesions, calcified lesions, small diseased vessels (< or = 2.5 mm reference diameter), or total coronary occlusions. There was a worse clinical outcome in patients with tandem lesions treated with ELCA compared with balloon angioplasty (9/18 v 3/26 lesions; p = 0.01); while a trend towards an unfavourable clinical outcome was found in patients with vessels with a reference diameter of more than 2.5 mm (23/66 v 13/63 lesions, p = 0.07) and left circumflex coronary lesions (12/41 v 6/42 lesions, p = 0.08). CONCLUSIONS: The findings indicate a worse clinical outcome in patients with lesions of more than 10 mm treated with ELCA compared with balloon angioplasty who have tandem coronary lesions and in those with vessels with a reference diameter of more than 2.5 mm and left circumflex coronary lesions.

Intravenous coronary angiography by electron beam computed tomography: a clinical evaluation (Article)

1998-01-01T00:00:00Z

BACKGROUND:-Noninvasive detection of coronary stenoses with electron beam CT (EBCT) after intravenous injection of contrast medium has recently emerged. We sought to determine the diagnostic accuracy of EBCT angiography in the clinical setting using conventional coronary angiography as the "gold standard." METHODS AND RESULTS: Thirty-seven patients (30 men) were investigated. After intravenous injection of 150 mL of contrast medium, 40 to 60 consecutive transaxial tomograms, covering the proximal and middle parts of the coronary arteries, were obtained with ECG triggering at end diastole during breath-holding. Three-dimensional reconstructions of the proximal and middle parts of the arteries were compared with the conventional angiograms. Of the 259 proximal and middle coronary segments, 211 (81%) were analyzable by EBCT. Of the left anterior descending coronary artery (LAD) segments, 95% were assessable. Right coronary artery (RCA) and left circumflex artery (LCx) segments were assessable in 66% and 76%, respectively. Overall sensitivity and specificity to detect a >50% diameter stenosis were 77% and 94%, respectively. This was 82% and 92% for the LAD, 60% and 97% for the RCA, and 83% and 89% for the LCx (all figures based on assessable lesions). CONCLUSIONS: Intravenous EBCT coronary angiography is a promising coronary imaging technique. The technique is not yet robust enough to be an alternative to conventional coronary angiography. It can detect and rule out significant coronary artery disease of the left main proximal and mid portions of the LAD with good accuracy.

Successful directional atherectomy of de novo coronary lesions assessed with three-dimensional intravascular ultrasound and angiographic follow-up. (Article)

1997-12-15T00:00:00Z

Recent histopathologic and intravascular ultrasound (IVUS) data indicate that inadequate compensatory enlargement of atherosclerotic lesions contributes to the development of significant arterial stenoses. Such lesions may contain less plaque, which may have implications for atheroablative interventions. In this study, we compared lesions with (group A, n = 16) and without inadequate compensatory enlargement (group B, n = 30) as determined by IVUS. The acute results and the follow-up lumen dimensions of angiographically successful directional coronary atherectomy procedures were compared. Inadequate compensatory enlargement was considered present when the preintervention arterial cross-sectional area at the target lesion site was smaller than that at the (distal) reference site. Three-dimensional IVUS analysis and quantitative angiography were performed in 46 patients before and after intervention. IVUS measurements included the arterial, lumen, and plaque (arterial minus lumen) cross-sectional areas at the target lesion site (i.e., smallest lumen site) and the (distal) reference site. Angiographic follow-up was performed in 42 patients. Preintervention and postintervention angiographic measurements and IVUS lumen cross-sectional area measurements were similar in both groups. However, at follow-up, the angiographic minimum lumen and reference diameters were significantly smaller in group A compared with group B (1.71 +/- 0.47 mm vs 2.14 +/- 0.73 mm, p <0.03, and 2.97 +/- 0.29 mm vs 3.39 +/- 0.76 mm, p <0.02; group A vs B). The data of this observational study suggest that lesions with inadequate compensatory enlargement, as determined by IVUS before intervention, may have less favorable long-term lumen dimensions after directional coronary atherectomy procedures.

Variations of remodeling in response to left main atherosclerosis assessed with intravascular ultrasound in vivo. (Article)

1997-12-01T00:00:00Z

Histopathologic studies have demonstrated that vessels enlarge to compensate for an increase in plaque burden; this has been confirmed in vivo using intravascular ultrasound (IVUS). The initial studies suggested a biphasic course of lesion formation with (1) preservation of lumen dimensions up to a plaque burden of approximately 40%, and (2) luminal narrowing as plaque burden further increases. In this study, we used IVUS and angiography to assess the extent of left main (LM) atherosclerosis in 107 patients undergoing catheter-based procedures of the left anterior descending or left circumflex coronary arteries. Using IVUS, atherosclerotic plaques were found in all LM arteries, but only 26 (24%) had varying degrees of luminal narrowing on the angiogram. Nevertheless, there was an inverse relation (r = −0.62, p <0.0001) between the minimal lumen area and the plaque burden (i.e., plaque + media divided by total vessel area) that was not restricted to plaque burden values >40% (or >30%), but persisted at plaque burden values of 20% to 40%. In addition, LM arteries with a plaque burden <40% had a similar total vessel area as did LM arteries with a plaque burden ≥40% (22.9 ± 6.1 vs 21.8 ± 4.8 mm2, p = 0.30). These data suggest that lumen dimensions may not be preserved even if plaque occupies no more than 20% to 40% of the total vessel area. Thus, there is more variation in remodeling response during earlier stages of plaque accumulation within the LM artery than is commonly suggested.

Composition of Human Thrombus Assessed by Quantitative Colorimetric Angioscopic Analysis. (Article)

1997-01-01T00:00:00Z

Background Angioscopy surpasses other diagnostic tools, such as angiography and intravascular ultrasound, in detecting arterial thrombus. This capability arises in part from the unique ability of angioscopy to assess true color during imaging. In practice, hardware-induced chromatic distortions and the subjectivity of human color perception substantially limit the theoretic potential of angioscopic color. We used a novel application of tristimulus colorimetry to quantify thrombus color to both aid in its detection and assess its composition. Methods and Results A series of human thrombus models were constructed in vitro. Spatial homogeneity was ensured by light and electron microscopy. Quantitative colorimetric angioscopic analysis demonstrated excellent measurement reproducibility (mean difference, 0.07% to 0.17%), unaffected by illuminating light intensity (coefficient of variation, 0.21% to 3.67%). Colorimetric parameters C1 and C2 were strongly correlated (r=.99, P<.0001) with thrombus erythrocyte concentration. Principal components analysis transformed these parameters into a single value, the thrombus erythrocyte index, with little (0.06%) loss of content. Measured and predicted concentrations were similar (mean difference, 0.16 erythrocytes per 1 ng). Randomly ordered images were also subjected to visual analysis by three experienced angioscopists, with suboptimal levels of both intraobserver (mean =0.63) and interobserver (mean =0.48) agreement. In addition, visual ranking resulted in a Kendall rank coefficient of 0.72 to 0.76 versus a perfect 1.00 from quantitative measurement. Conclusions Quantitative colorimetric angioscopic analysis provides a new, objective, and reproducible analytic tool for assessing angioscopic images of human thrombus. Even under ideal circumstances, experienced angioscopists do a poor job of assessing color (and therefore composition) of human thrombi. This technique can, for the first time, provide quantitative information of thrombus composition during routine diagnostic imaging.

ECG-Gated Three-dimensional Intravascular Ultrasound (Article)

1997-01-01T00:00:00Z

Background Automated systems for the quantitative analysis of three-dimensional (3D) sets of intravascular ultrasound (IVUS) images have been developed to reduce the time required to perform volumetric analyses; however, 3D image reconstruction by these nongated systems is frequently hampered by cyclic artifacts. Methods and Results We used an ECG-gated 3D IVUS image acquisition workstation and a dedicated pullback device in atherosclerotic coronary segments of 30 patients to evaluate (1) the feasibility of this approach of image acquisition, (2) the reproducibility of an automated contour detection algorithm in measuring lumen, external elastic membrane, and plaque+media cross-sectional areas (CSAs) and volumes and the cross-sectional and volumetric plaque+media burden, and (3) the agreement between the automated area measurements and the results of manual tracing. The gated image acquisition took 3.9±1.5 minutes. The length of the segments analyzed was 9.6 to 40.0 mm, with 2.3±1.5 side branches per segment. The minimum lumen CSA measured 6.4±1.7 mm2, and the maximum and average CSA plaque+media burden measured 60.5±10.2% and 46.5±9.9%, respectively. The automated contour-detection required 34.3±7.3 minutes per segment. The differences between these measurements and manual tracing did not exceed 1.6% (SD<6.8%). Intraobserver and interobserver differences in area measurements (n=3421; r=.97 to.99) were <1.6% (SD<7.2%); intraobserver and interobserver differences in volumetric measurements (n=30; r=.99) were <0.4% (SD<3.2%). Conclusions ECG-gated acquisition of 3D IVUS image sets is feasible and permits the application of automated contour detection to provide reproducible measurements of the lumen and atherosclerotic plaque CSA and volume in a relatively short analysis time.

Comparison of Coronary Luminal Quantification Obtained From Intracoronary Ultrasound and Both Geometric and Videodensitometric Quantitative Angiography Before and After Balloon Angioplasty and Directional Atherectomy (Article)

1997-01-01T00:00:00Z

Background Debate exists regarding the relationship between angiographic and intracoronary ultrasound (ICUS) measurements of minimal luminal cross-sectional area after coronary intervention. We investigated this and the factors that may influence it by using ICUS and quantitative angiography. Methods and Results Patients who underwent successful balloon angioplasty (n=100) or directional atherectomy (n=50) were examined by using ICUS and quantitative angiography (edge-detection [ED] and videodensitometry [VID]) before and after intervention. Luminal damage postintervention was qualitatively graded into three categories based on angiographic results (smooth lumen, haziness, or dissection). Correlation of minimal luminal cross-sectional area measurements by ICUS and ED was .59 before and .47 after balloon angioplasty. Correlation between ICUS and VID was .50 before and .63 after balloon angioplasty. Postintervention, the difference between ICUS and VID was less than the difference between ICUS and ED (P<.01). Additionally, the correlation was .74 between ICUS and ED measurements and .78 between ICUS and VID measurements in the smooth lumen group, .46 and .63, respectively, in the presence of haziness, and .26 and .46, respectively, in lesions with dissection. Similar results were obtained after directional atherectomy: the agreement between ICUS and quantitative angiography deteriorated according to the degree of vessel damage, but less so with VID than ED. Conclusions Complex morphological changes induced by intervention may contribute to discordance between the two quantitative imaging techniques. In the absence of ICUS, VID may be a complementary technique to ED in lesions with complex morphology after balloon angioplasty and directional atherectomy.

Simpson's rule for the volumetric ultrasound assessment of atherosclerotic coronary arteries: a study with ECG-gated three-dimensional intravascular ultrasound. (Article)

1997-01-01T00:00:00Z

BACKGROUND: Volumetric intravascular ultrasound (IVUS) assessment provides complementary information on atherosclerotic plaques. The volumes can be calculated by applying Simpson's rule to cross-sectional area data of multiple IVUS images, acquired with a fixed sample spacing, which is the distance (along the vessel's axis) between two images. OBJECTIVE: To evaluate the effect of different sample spacings on the results of volumetric IVUS measurements. METHODS: A stepwise electrocardiographically gated IVUS image-acquisition and automated three-dimensional analysis approach was applied to 26 patients. Twenty-eight coronary segments with mild-to-moderate coronary atherosclerosis were examined. Volumetric measurements of five images per mm (i.e. sample spacing 0.2 mm), representing a complete scanning of the coronary segment, were considered the optimal standard, against which volumetric measurements of three, one, and one-half images per mm (i.e. larger sample spacings) were compared. RESULTS: The lumen, total vessel, and plaque volumes obtained with five images per mm were 183.3 +/- 2.8, 350.6 +/- 141.6, and 167.3 +/- 89.2 mm3. There was an excellent correlation (r = 0.99, P < 0.001) between these data and volumetric measurements with larger sample spacings. The volumetric measurements with larger sample spacings differed on average only by a little (< 0.7%) from the optimal standard measurements. However, a relatively small, but significant, increase in SD of these differences was associated with the wider sample spacings (< 3.6%, P < 0.05). CONCLUSIONS: The width of the sample spacing has a relatively small but significant impact on the variability of volumetric intravascular ultrasound measurements. This should be considered when designing future volumetric studies. The electrocardiographically gated acquisition of five IVUS images per mm axial length during a stepwise transducer pull-back is an ideal approach, particularly when addressing with IVUS volumetric changes that are assumed small, such as those expected in studies of the progression and regression of atherosclerosis.

Evolution of coronary atherosclerosis in patients with mild coronary artery disease studied by serial quantitative coronary angiography at 2 and 4 years follow up (Article)

1997-01-01T00:00:00Z

AIMS: Angiographic studies on the natural course of both focal and diffuse coronary atherosclerosis have not been performed before, but can both be assessed by quantitative coronary angiography. The objective of this study was to describe the natural course of focal and diffuse coronary atherosclerosis over time. METHODS AND RESULTS: In 129 patients with mild coronary artery disease, but not on lipid-lowering medication, three coronary angiograms were made each 2 years apart. Nine hundred and sixty five angiographically diseased and non-diseased segments were analysed by quantitative coronary angiography. Mean lumen diameter and minimal lumen diameter were used as measures of diffuse and focal coronary atherosclerosis. Mean lumen diameter and minimum lumen diameter decreased by 0.02 and 0.03 mm per year. The rate of progression was similar in the angiographically non-diseased, as in the mildly and moderately diseased segments. Progression of diffuse coronary atherosclerosis was largest in severely stenosed lesions (percentage diameter stenosis > or = 50%) and in the right coronary artery with a loss of 0.19 mm and 0.16 mm in mean lumen diameter. Progression of focal disease was most prominent in new and mild lesions and the right coronary artery, with a decrease in minimum lumen diameter of 0.34 mm and 0.22 mm. In most subgroups, progression occurred gradually over time. On a per segment level, progression and the occurrence of new lesions occurred in 4.4% and 4.2%. Regression and disappearance of a lesions was found in 2.3% and 1.9%. On a per patient level, 36% were progressors, 12% had a mixed response, 36% were stable, and 16% were regressors. CONCLUSION: Diffuse and focal coronary atherosclerosis progressed at the same rate in the first and second 2 years in stenosed and non-stenosed segments. The rate of coronary atherosclerosis progression was small, but was higher for focal than for diffuse disease. A minority of lesions progressed and spontaneous regression was rare.

Women fare no worse than men 10 years after attempted coronary angioplasty. (Article)

1996-09-01T00:00:00Z

A retrospective review of cardiac events occurring in all patients who underwent attempted coronary angioplasty in the first 5 years of our experience (1980-1985) was undertaken. Follow-up data were obtained from the civil registry, hospital records, patient, family, and referring physician. Patient survival curves were constructed and the outcome of women and men was compared. Eight hundred fifty-six patients, 172 women and 684 men with a mean age of 60.0 and 55.3 years, respectively, underwent attempted coronary angioplasty with an overall procedural success rate of 82%, 77.7% in women and 83.1% in men. Follow-up data were obtained in 837 patients (97.8%) with a mean period of 9.6 years (range 0-13.3 years). The estimated 10 year survival in women was identical to men [79%, 95% confidence interval (CI) 72.6–85.4% vs. 78%, 95% CI 74.6–81.4%] as was the 10 year event-free survival (men 36%, 95% CI 32.0–40.0% vs. women 37%, 95% CI 29.2-44.8%), with a similar proportion of major cardiac events—death, myocardial infarction, coronary artery bypass surgery, and repeat angioplasty. When women were matched to men for age and previous myocardial infarction, factors found to be associated with an adverse outcome, there was no significant difference. Additionally, outcome was compared after patients were matched for maximum nominal balloon size as an estimate of vessel size, with no significant difference between women and men. At follow-up, women complained of significantly more anginal symptoms than men (59.2% vs. 44.0%, P < 0.05) and took significantly more antianginal medication.

Utilization of translesional hemodynamics: comparison of pressure and flow methods in stenosis assessment in patients with coronary artery disease. (Article)

1996-06-01T00:00:00Z

Aim of this study is the assessment of feasibility and clinical usefulness of a new index of stenosis severity, the slope of the instantaneous transstenotic pressure gradient/velocity relationship. Twenty-one patients scheduled for percutaneous revascularization procedures were studied with simultaneous measurement of poststenotic coronary pressure and flow velocity, in basal condition and during maximal hyperemia induced with intracoronary papaverine. Reliable measurements of the transstenotic pressure gradient/velocity relationship could be obtained in 11 patients. In 64% of the cases, a quadratic equation showed the best fit for the data. Steeper increases of the transstenotic pressure gradient at any given velocity increase were observed in the lesions with the smallest cross-sectional area measured with quantitative angiography. A comparison of this new index with coronary flow reserve, maximal hyperemic velocity, stenosis flow reserve derived from quantitative angiography, basal and hyperemic transstenotic pressure gradient and fractional flow reserve is presented and the relative merits of all these parameters are discussed. This pilot experience suggests that the instantaneous relationship between pressure gradient and flow velocity changes during the cardiac cycle can accurately characterize the stenosis hemodynamics in the catheterization laboratory.

Clinical outcome 10 years after attempted percutaneous transluminal coronary angioplasty in 856 patients. (Article)

1996-06-01T00:00:00Z

Abstract OBJECTIVES: This study reports the 10-year outcome of 856 consecutive patients who underwent attempted coronary angioplasty at the Thoraxcenter during the years 1980 to 1985. BACKGROUND: Coronary balloon angioplasty was first performed in 1977, and this procedure was introduced into clinical practice at the Thoraxcenter in 1980. Although advances have been made, extending our knowledge of the long-term outcome in terms of survival and major cardiac events remains of interest and a valuable guide in the treatment of patients with coronary artery disease. METHODS: Details of survival, cardiac events, symptoms and medication were retrospectively obtained from the Dutch civil registry, medical records or by letter or telephone or from the patient's physician and entered into a dedicated data base. Patient survival curves were constructed, and factors influencing survival and cardiac events were identified. RESULTS: The procedural clinical success rate was 82%. Follow-up information was obtained in 837 patients (97.8%). Six hundred forty-one patients (77%) were alive, of whom 334 (53%) were symptom free, and 254 (40%) were taking no antianginal medication. The overall 5- and 10-year survival rates were 90% (95% confidence interval [CI] 87.6% to 92.4%) and 78% (95% CI 75.0% to 81.0%), respectively, and the respective freedom from significant cardiac events (death, myocardial infarction, coronary artery bypass surgery and repeat angioplasty) was 57% (95% CI 53.4% to 60.6%) and 36% (95% CI 32.4% to 39.6%). Factors that were found to adversely influence 10-year survival were age > or = 60 years (> or = 60 years [67%], 50 to 59 years [82%], < 50 years [88%]), multivessel disease (multivessel disease [69%], single-vessel disease [82%]), impaired left ventricular function (ejection fraction < 50% [57%], > or = 50% [80%]) and a history of previous myocardial infarction (previous myocardial infarction [72%], no previous infarction [83%]). These factors were also found to be independent predictors of death during the follow-up period by a multivariate stepwise logistic regression analysis. Other factors tested, with no influence on survival, were gender, procedural success and stability of angina at the time of intervention. CONCLUSIONS: The long-term prognosis of patients after coronary angioplasty is good, particularly in those <60 years old with single-vessel disease and normal left ventricular function. The majority of patients are likely to experience a further cardiac event in the 10 years after their first angioplasty procedure.

Repeat interventions as a long-term treatment strategy in the management of progressive coronary artery disease. (Article)

1996-05-01T00:00:00Z

Objectives. This study investigates whether repeat coronary interventions, applied over an extended time period, can successfully curtail the progression of ischemic symptoms and angiographic lumen narrowing. Background. Coronary artery disease is a chronic and generally progressive disorder, and potential treatment strategies should be examined and compared with this chronicity in mind. Percutaneous interventional revascularization procedures could theoretically be useful in controlling progression of the disease through repeated use as new coronary lesions arise. However, the outcome of this long-term management concept has not previously been subjected to detailed investigation. Methods. From a consecutive series of 4,357 interventional cardiac procedures, 544 patients were identified who received two or more interventions during the 13-year study period. These patients were categorized into one of three groups: restenosis (repeat interventions limited to the same target segment, N = 261), new stenosis (all repeat interventions directed to stenoses not previously treated, N = 155) or both (repeat interventions directed both to the same and to different target lesions, N = 128). Results. Two to five procedures were performed per patient; the time period (mean ± SD) separating each procedure was significantly less (p < 0.0001) for the restenosis group (4.2 ± 2.3 months) than for the new stenosis (24.2 ± 23.5 months) or the “both” groups (11.4 ± 11.0 months). Despite the need for repeat procedures, the severity of angina (mean New York Heart Association functional class 1.6 ± 0.9) after 6.2 ± 2.3 years of follow-up was substantially better than before the initial procedure (mean functional class 3.2 ± 0.8), with a similar magnitude of change found in all three groups. This long-term functional improvement was mirrored by a corresponding anatomic improvement, with the mean number of diseased vessels remaining constant at the time of each procedure (1.5 ± 0.7, 1.5 ± 0.7 and 1.6 ± 0.7, respectively, for the first, second and third procedures, P = NS). The restenosis and the new stenosis groups also demonstrated statistically similar annual rates of mortality (1.9% vs. 1.8%) and coronary surgery (2.3% vs. 2.6%), although the restenosis group had a lower rate of infarction (1.4% vs. 3.2%, P = 0.002). Conclusions. Repeat interventional treatment of newly acquired stenoses provides a rational approach for the long-term management of chronic coronary artery disease. In addition to yielding a favorable late outcome, the use of this strategy can result in sustained functional improvement and can check the progression of clinically significant stenoses.

Computerized assessment of coronary lumen and atherosclerotic plaque dimensions in three-dimensional intravascular ultrasound correlated with histomorphometry. (Article)

1996-01-01T00:00:00Z

Intravascular ultrasound (IVUS), which depicts both lumen and plaque, offers the potential to improve on the limitations of angiography for the assessment of the natural history of atherosclerosis and progression or regression of the disease. To facilitate measurements and increase the reproducibility of quantitative IVUS analyses, a computerized contour detection system was developed that detects both the luminal and external vessel boundaries in 3-dimensional sets of IVUS images. To validate this system, atherosclerotic human coronary segments (n = 13) with an area obstruction ≥40% (40% to 61%) were studied in vitro by IVUS. The computerized IVUS measurements (areas and volumes) of the lumen, total vessel, plaque-media complex, and percent obstruction were compared with findings by manual tracing of the IVUS images and of the corresponding histologic cross sections obtained at 2-mm increments (n = 100). Both area and volume measurements by the contour detection system agreed well with the results obtained by manual tracing, showing low mean between-method differences (−3.7% to 0.3%) with SDs not exceeding 6% and high correlation coefficients (r = 0.97 to 0.99). Measurements of the lumen, total vessel, plaque-media complex, and percent obstruction by the contour detection system correlated well with histomorphometry of areas (r = 0.94, 0.88, 0.80, and 0.88) and volumes (r = 0.98, 0.91, 0.83, and 0.91). Systematic differences between the results by the contour detection system and histomorphometry (29%, 13%, −9%, and −22%, respectively) were found, most likely resulting from shrinkage during tissue fixation. The results of this study indicate that this computerized IVUS analysis system is reliable for the assessment of coronary atherosclerosis in vivo.

Volumetric intracoronary ultrasound: a new maximum confidence approach for the quantitative assessment of progression-regression of atherosclerosis? (Article)

1995-12-01T00:00:00Z

Quantitative assessment of atherosclerosis during its natural history and following therapeutic interventions is important, as cardiovascular disease remains the most significant cause of morbidity and mortality in industrial societies. While coronary angiography delineates the vessel lumen, permitting only the indirect determination of atherosclerotic wall changes encroaching upon the lumen, intracoronary ultrasound permits direct plaque assessment and quantification. The angiographic percent diameter stenosis, previously suggested as measure of a maximum confidence approach, is still commonly used to quantify stenosis severity, but the reference segments which are required for angiographic interpolation of the normal vessel dimensions are frequently involved in the general process of atherosclerosis, including progression or regression. Considering also the variability of vascular remodeling during the evolution of atherosclerosis, including compensatory enlargement and paradoxical arterial shrinkage, intracoronary ultrasound appears currently to be the only reliable technique to measure plaque burden and progression or regression of atherosclerosis. However, correct matching of the site of measurement at follow-up with the site of the initial ultrasound study is often difficult to achieve, but is significantly facilitated by the use of volumetric intracoronary ultrasound. This approach permits not only area measurement, but also measurement of plaque volume, which appears to be the ideal measure for quantifying the atherosclerotic plaque, as it is highly reproducible and directly reflects the changes of an entire arterial segment.

Angiographic, ultrasonic, and angioscopic assessment of the coronary artery wall and lumen area configuration after directional atherectomy: the mechanism revisited. (Article)

1995-08-01T00:00:00Z

Acute clinical and angiographic results with the new AVE Micro coronary stent in bailout management. (Article)

1995-07-27T00:00:00Z

To determine the feasibility and safety of development of this new stent, we deployed 28 AVE Micro stents in 23 native coronary artery lesions in 20 patients who developed acute or threatened closure after balloon angioplasty (BA). Ten stents were deployed in the left anterior descending artery, 10 in the circumflex, and 8 in the right coronary artery. Luminal dimensions were measured using a computer-based quantitative coronary angiographic analysis system (CAAS II). Stent deployment was successful in 27 of 28 attempts (96%). In 1 patient with a threatened closure of the left anterior descending artery associated with proximal vessel tortuosity, attempted stent deployment was unsuccessful. The clinical course of the other 19 patients in whom stent deployment was successful was free of coronary reintervention, bypass surgery, and death. A myocardial infarction was observed in 2 patients (10%), in 1 of whom the stent was implanted within 24 hours after the onset of acute myocardial infarction, and in the other acute vessel occlusion was present for 58 minutes before stent implantation. No subacute occlusion was observed. Event-free survival at 30 days after stent implantation was 85% (17 of 20 patients). Minimal luminal diameter was 0.85 +/- 0.57 mm before and 1.19 +/- 0.66 mm after BA, 2.61 +/- 0.39 mm during balloon inflation, 3.26 +/- 0.46 mm during and 2.74 +/- 0.51 mm after stenting, 3.43 +/- 0.52 mm during balloon inflation after stenting (Swiss Kiss), and 2.85 +/- 0.48 mm after Swiss Kiss.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in restenosis propensity of devices for transluminal coronary intervention. A quantitative angiographic comparison of balloon angioplasty, directional atherectomy, stent implantation and excimer laser angioplasty. CARPORT, MERCATOR, MARCATOR, PARK, and BENESTENT Trial Groups. (Article)

1995-01-01T00:00:00Z

With the increasing clinical application of new devices for percutaneous coronary revascularization, maximization of the acute angiographic result has become widely recognized as a key factor in maintained clinical and angiographic success. What is unclear, however, is whether the specific mode of action of different devices might exert an additional independent effect on late luminal renarrowing. The purpose of this study was to investigate such a difference in the degree of provocation of luminal renarrowing (or 'restenosis propensity') by different devices, among 3660 patients, who had 4342 lesions successfully treated by balloon angioplasty (n = 3797), directional coronary atherectomy (n = 200), Palmaz-Schatz stent implantation (n = 229) or excimer laser coronary angioplasty (n = 116) and who also underwent quantitative angiographic analysis pre- and post-intervention and at 6-month follow-up. To allow valid comparisons between the groups, because of significant differences in coronary vessel size (balloon angioplasty = 2.62 +/- 0.55 mm, directional coronary atherectomy = 3.28 +/- 0.62 mm, excimer laser coronary angioplasty = 2.51 +/- 0.47 mm, Palmaz-Schatz = 3.01 +/- 0.44 mm; P < 0.0001), the comparative measurements of interest selected were the 'relative loss' in luminal diameter (RLoss = loss/vessel size) to denote the restenosis process, and the 'relative lumen at follow-up' (RLfup = minimal luminal diameter at follow up/vessel size) to represent the angiographic outcome. For consistency, lesion severity pre-intervention was represented by the 'relative lumen pre' (RLpre = minimal luminal diameter pre/vessel size) and the luminal increase at intervention was measured as 'relative gain' (relative gain = gain/ vessel size). Differences in restenosis propensity between devices was evaluated by univariate and multivariate analysis. Multivariate models were constructed to determine relative loss and relative lumen at follow-up, taking account of relative lumen pre-intervention, lesion location, relative gain, vessel size and the device used. In addition, model-estimated relative loss and relative lumen at follow-up at given relative lumen pre-intervention relative gain and vessel size, were compared among the four groups. Significant differences were detected among the groups both with respect to these estimates, as well as in the degree of influence of progressively increasing relative gain, on the extent of renarrowing (relative loss) and angiographic outcome (relative lumen at follow-up), particularly at higher levels of luminal increase (relative gain). Specifically, lesions treated by balloon angioplasty or Palmaz-Schatz stent implantation (the predominantly 'dilating' interventions) were associated with more favourable angiographic profiles than directional atherectomy or excimer laser (the mainly 'debulking' interventions). Significant effects of lesion severity and location, as well as the well known influence of luminal increase on both luminal renarrowing and late angiographic outcome were also noted. These findings indicate that propensity to restenosis after apparently successful intervention is influenced not only by the degree of luminal enlargement achieved at intervention, but by the device used to achieve it. In view of the clinical implications of such findings, further evaluation in larger randomized patient populations is warranted.

Ischemia-Related Lesion Characteristics in Patients With Stable or Unstable Angina (Article)

1995-01-01T00:00:00Z

Background Postmortem-derived findings support the common beliefs that lipid-rich coronary plaques with a thin, fibrous cap are prone to rupture and that rupture and superimposed thrombosis are the primary mechanisms causing acute coronary syndromes. In vivo imaging with intracoronary techniques may disclose differences in the characterization of atherosclerotic plaques in patients with stable or unstable angina and thus may provide clues to which plaques may rupture and whether rupture and thrombosis are active. Methods and Results We assessed the characteristics of the ischemia-related lesions with coronary angiography and intracoronary angioscopy and determined their compositions with intracoronary ultrasound in 44 patients with unstable and 23 patients with stable angina. The angiographic images were classified as noncomplex (smooth borders) or complex (irregular borders, multiple lesions, thrombus). Angioscopic images were classified as either stable (smooth surface) or thrombotic (red thrombus). The ultrasound characteristics of the lesion were classified as poorly echo-reflective, highly echo-reflective with shadowing, or highly echo-reflective without shadowing. There was a poor correlation between clinical status and angiographic findings. An angiographic complex lesion (n=33) was concordant with unstable angina in 55% (24 of 44); a noncomplex lesion (n=34) was concordant with stable angina in 61% (14 of 23). There was a good correlation between clinical status and angioscopic findings. An angioscopic thrombotic lesion (n=34) was concordant with unstable angina in 68% (30 of 44); a stable lesion (n=33) was concordant with stable angina in 83% (19 of 23). The ultrasound-obtained composition of the plaque was similar in patients with unstable and stable angina. Conclusions Angiography discriminates poorly between lesions in stable and unstable angina. Angioscopy demonstrated that plaque rupture and thrombosis were present in 17% of stable angina and 68% of unstable angina patients. Currently available ultrasound technology does not discriminate stable from unstable plaques.

Three dimensional reconstruction of cross sectional intracoronary ultrasound: clinical or research tool? (Article)

1995-01-01T00:00:00Z

Clinical perspective. Coronary artery disease: prevention of progression and prevention of events (Article)

1995-01-01T00:00:00Z

Antiplatelet therapy in therapy-resistant unstable angina: A pilot study with REO PRO (c7E3) (Article)

1995-01-01T00:00:00Z

Patients with unstable angina, refractory to intensive medical therapy, are at high risk of developing thrombotic complications, such as myocardial infarction and coronary occlusion during coronary angioplasty. As platelet aggregation and thrombus formation play an important role in this ongoing ischaemic process, a monoclonal platelet GPIIb/IIIa receptor antibody (c7E3) has been designed to modify the clinical course and underlying coronary lesion morphology. To evaluate whether c7E3 could influence the incidence of complications, we randomized 60 patients to c7E3 or placebo after initial angiography had demonstrated a culprit lesion amenable for angioplasty. All patients exhibited dynamic ECG changes and recurrent pain attacks, despite intensive medical therapy. After study drug bolus and infusion, angiography was repeated and angioplasty performed. Recurrent ischaemia during study drug infusion occurred in nine and 16 patients from the c7E3 and placebo groups, respectively (P = 0.06). Major events defined as death, myocardial infarction or urgent intervention occurred in one and seven patients, respectively (P = 0.03). One patient from the placebo group died as a result of recurrent infarction. Resolution of clots was only observed in the c7E3 group, combined with improvement in TIMI flow grade in 20% of patients. Quantitative angiography showed an improvement in percentage diameter stenosis in the c7E3 group, which was not observed in the placebo group, although the difference between the two treatment groups was not significant. No excess bleeding was observed in the treatment group. Thus, c7E3 bolus and infusion, combined with heparin and aspirin improved the clinical course, the coronary lesion morphology and rheology in patients with unstable angina, refractory to medical treatment.

Acute and long-term outcome of directional coronary atherectomy for stable and unstable angina (Article)

1994-10-05T00:00:00Z

The clinical efficacy and safety of directional coronary atherectomy for the treatment of stable and unstable angina were assessed in 82 patients with stable and 68 patients with unstable angina. Therefore, clinical and angiographic follow-up was obtained in a prospectively collected consecutive series of 150 atherectomy procedures. Restenosis was assessed clinically and by quantitative angiography. The overall clinical success rate of atherectomy for patients with unstable and stable angina was 88% and 91%, respectively. No significant differences were found for in-hospital event rates between the unstable and stable angina groups: death (1.5% vs 0%), myocardial infarction (10% vs 6%), and emergency bypass operation (3% vs 2%). These clinical events were related to the occurrence of abrupt occlusions (8.8% in patients with stable and 6.1% in those with unstable angina; p = NS). Clinical follow-up was achieved in 100% of the patients with stable and unstable angina at a mean interval of 923 and 903 days, respectively. Two-year survival rates were 96% and 97% in the populations with unstable and stable angina, respectively. There were no significant differences with respect to bypass surgery and angioplasty, but event-free survival at 2 years was significantly lower in the unstable (54%) than the stable (69%) angina group. Quantitative coronary angiography did not detect any difference in luminal renarrowing during the 6-month angiographic follow-up period. Although directional coronary atherectomy can be performed effectively in patients with unstable and stable angina, the long-term clinical outcome was less favorable in the unstable angina group.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal coronary angioplasty for unstable angina (In Book)

1994-01-01T00:00:00Z

Incidence, predictors, and management of acute coronary occlusion after coronary angioplasty (Article)

1994-01-01T00:00:00Z

Acute coronary occlusion occurs in 4.3% to 8.3% of patients during coronary angioplasty. Its occurrence is difficult to predict in an individual patient. At high risk are patients with unstable angina, intracoronary thrombus, extreme age, long complex lesions, and diffuse disease. "Standard" management including redilation (prolonged perfusion) thrombolytic treatment and emergency bypass surgery is only successful in approximately 50% of the patients and is associated with a high mortality and myocardial infarction rate of < 6% and 30%, respectively. Bail-out stent implantation appears to emerge as an effective alternative in suitable patients and might reduce mortality, the apparent progression to myocardial infarction, or might decrease the need for emergency bypass. New techniques including directional atherectomy, rotational ablation, or the excimer laser are associated with a similar frequency of acute occlusion. Immediate access to a surgical back-up facility remains necessary to treat refractory acute occlusions.

Temporal variability and correlation with geometric parameters in vasospastic angina: a quantitative angiographic study (Article)

1994-01-01T00:00:00Z

Long-term changes in vasocontractility were examined in 23 coronary segments from 20 patients with variant angina using computer-based quantitative coronary angiography and ergonovine provocation tests repeated at an interval of 42 +/- 14 months. Measurements of vasospasticity at the sites of fixed stenoses were compared with values predicted by an elementary geometric theory based on the assumption that the cross-sectional area of a vessel wall is constant regardless of its state of vasoconstriction. While all patients were symptomatic initially, only 11 remained symptomatic at follow-up. At the initial provocation test, the response was correctly predicted in four segments, was lower than expected in one, and was stronger in 18. At follow-up, only one of the four segments in which the response had been initially predicted correctly again showed the predicted response and the remaining three showed a response weaker than expected; the one segment which was initially hypocontractile remained hypocontractile at follow-up; and of the 18 segments which were initially hypercontractile, 12 exhibited hypercontractility again, four had the predicted value and the remaining two showed hypocontractility. In only one of 23 segments did the geometric theory predict the behaviour of vasospasticity at the site of fixed stenosis on both tests. Vasospastic responsiveness is a dynamic process demonstrating temporal variability and is not directly predicted by geometric theory.

Predictive value of reactive hyperemic response on reperfusion on recovery of regional myocardial function after coronary angioplasty in acute myocardial infarction (Article)

1994-01-01T00:00:00Z

BACKGROUND: The objective of the study was to determine the coronary vasodilatory reserve in reperfused myocardium in patients with acute myocardial infarction and its relation to regional myocardial function. METHODS AND RESULTS: The study population consisted of 22 patients with acute myocardial infarction who underwent successful coronary angioplasty. The vasodilatory reserve in the reperfused myocardium was assessed quantitatively using computer-assisted digital subtraction cine-angiography immediately after angioplasty and at follow-up angiography before hospital discharge. Myocardial contrast medium appearance time and density were determined before and after pharmacological hyperemia induced by an intracoronary injection of 12.5 mg papaverine. Global and regional left ventricular functions were determined from contrast angiography. After papaverine, the mean contrast medium appearance time decreased significantly from 3.5 +/- 0.7 to 2.7 +/- 0.7 cardiac cycles (P < .000005) immediately after successful coronary angioplasty and from 3.8 +/- 0.7 to 2.7 +/- 0.9 cardiac cycles (P < .000005) at angiography before hospital discharge. The mean contrast medium density increased significantly from 48.7 +/- 13.8 to 61.0 +/- 19.0 pixels (P < .003) and from 49.6 +/- 19.7 to 80.3 +/- 29.6 pixels (P < .000005), respectively. As a consequence, the calculated coronary flow reserve increased significantly from 1.8 +/- 0.7 to 2.6 +/- 1.0 (P < .0008). The global ejection fraction increased significantly from 52 +/- 12% to 58 +/- 14% (P < .03), primarily because of a significant improvement in the regional myocardial function of the infarct zone from 20.8 +/- 9.0% to 26.0 +/- 10.5% (P < .001). Coronary flow reserve correlated well with regional myocardial function both during the acute phase (R = .79, P < .002) and at follow-up angiography (R = .82, P < .000004). Interestingly, coronary flow reserve measurement on reperfusion, immediately after angioplasty, correlated significantly with regional myocardial function at follow-up angiography (R = .81, P < .00003). CONCLUSIONS: The results indicate that there is a pharmacologically inducible vasodilatory reserve in reperfused ischemic myocardium after successful coronary angioplasty in patients with acute myocardial infarction and that this is increased at 10-day follow-up angiography. More important, the degree of reactive hyperemic response on reperfusion has a predictive value regarding the ultimate degree of recovery of regional myocardial function. Quantitative assessment of reperfusion may be useful in investigating the role of coronary reperfusion and salvage of myocardial function.

Clinical, histologic and quantitative angiographic predictors of restenosis after directional coronary atherectomy: a multivariate analysis of the renarrowing process and late outcome (Article)

1994-01-01T00:00:00Z

OBJECTIVES. To characterize predictors of restenosis after successful directional atherectomy, we reviewed the clinical, angiographic and procedural data obtained during 132 consecutive procedures. METHODS. Clinical and angiographic follow-up data were obtained in a prospectively collected and consecutive series of 125 patients who underwent 132 atherectomy procedures for de novo (89%) or restenotic (11%) lesions in native coronary arteries. Restenosis was assessed clinically and by quantitative coronary angiography. A dual approach to data analysis was taken to gain insight into factors affecting the clinical outcome and vessel wall healing response. Therefore, multivariate analysis was performed to 1) determine the correlates of residual lumen diameter at follow-up (angiographic outcome), and 2) characterize the determinants of the late lumen loss (renarrowing process). RESULTS. Clinical and angiographic follow-up data after successful atherectomy were obtained in 100% and 95%, respectively. Atherectomy achieved an acute lumen gain of 1.28 +/- 0.48 mm (mean +/- SD), resulting in a minimal lumen diameter of 2.44 +/- 0.47 mm. At follow-up, the minimal lumen diameter decreased to 1.78 +/- 0.64 mm. The angiographic restenosis rate was 28% if the traditional 50% stenosis cutoff criterion was applied. Larger vessel size and postatherectomy minimal lumen diameter and right coronary or left circumflex artery lesions were independent predictors of a larger minimal lumen diameter (angiographic outcome). Lumen loss during follow-up (renarrowing process) was independently predicted by relative lumen gain and preprocedural minimal lumen diameter. CONCLUSIONS. In analyzing the long-term results of new interventional techniques such as directional atherectomy, the late lumen loss during follow-up (renarrowing process), which is characterized by the vessel wall healing response after an intervention, should be considered together with the residual lumen diameter at follow-up (clinical outcome). It is clear that whereas improved clinical outcome is associated with larger vessel size and postprocedural lumen diameter and non-left anterior descending artery location, greater relative gain at intervention is predictive of more extensive lumen renarrowing.

Proliferation and extracellular matrix synthesis of smooth muscle cells cultured from human coronary atherosclerotic and restenotic lesions (Article)

1994-01-01T00:00:00Z

OBJECTIVES. The purpose of this study was to examine the proliferative capacity and extracellular matrix synthesis of human coronary plaque cells in vitro. BACKGROUND. Common to both primary atherosclerosis and restenosis are vascular smooth muscle cell proliferation and production of extracellular matrix proteins. The applicability to humans of experimental animal models of these processes has been questioned. METHODS. Primary atherosclerotic and restenotic lesions were excised by percutaneous directional coronary atherectomy in 93 patients. Smooth muscle cells were cultivated by an explant technique and identified by their morphology in culture, ultrastructural features under electron microscopy and immunostaining using monoclonal antibodies to smooth muscle cell alpha-actin. Proliferation in secondary culture was assessed with growth curves and the synthesis of collagen and sulfated glycosaminoglycans by the incorporation of 3H-proline and 35S-sulfate, respectively. These studies were also performed in cells derived from human umbilical artery media. RESULTS. Success rates for primary (45%) and secondary (12%) culture of coronary cells were not influenced by clinical variables or lesion category. Primary culture success was improved by the presence of organized thrombus in the plaque and in relation to increased maximal cell density of the atherectomy specimen. Restenotic cells displayed more rapid growth than did cells of primary atherosclerotic origin, which grew in a manner similar to that of umbilical artery cells. Mean calculated population-doubling times for the three cell groups were 52 h (95% confidence interval [CI] 48 to 58 h), 71 h (95% CI 62 to 83 h) and 74 h (95% CI 65 to 84 h), respectively. Restenotic and primary atherosclerotic cells did not differ in the synthesis of collagen ([mean +/- SEM] 0.034 +/- 0.004 vs. 0.033 +/- 0.004 nmol isotope.microgram protein-1, p = NS) or sulfated glycosaminoglycans (11.47 +/- 1.07 vs. 15.37 +/- 3.10 nmol isotope.microgram protein-1, p = NS), but the coronary cells synthesized significantly more collagen and sulfated glycosaminoglycans than did umbilical artery cells (0.019 +/- 0.004 and 5.43 +/- 1.00 nmol isotope.microgram protein-1, respectively, both p < 0.05). CONCLUSIONS. These data indicate that increased smooth muscle cell proliferation contributes to coronary restenosis in humans and support the concept that the extracellular matrix synthesis of adult smooth muscle cells is important to lesion formation.

Intracoronary ultrasound and angioscopic imaging facilitating the understanding and treatment of post-infarction angina (Article)

1994-01-01T00:00:00Z

We report on the use of intravascular ultrasound, coronary angioscopy and on-line quantitative angiography in an unstable patient soon after myocardial infarction. Combined intracoronary imaging made it possible to solve the therapeutic problem posed by an unusual angiographic appearance secondary to intracoronary thrombolysis during coronary recanalization. The pathological validation of the observations performed with angioscopy and intravascular ultrasound was made possible with the concomitant use of directional atherectomy.

Acute and long-term outcome of directional coronary atherectomy for stable and unstable angina (Article)

1994-01-01T00:00:00Z

Three-dimensional reconstruction of intracoronary ultrasound images. Rationale, approaches, problems, and directions (Miscellaneous)

1994-01-01T00:00:00Z

Although intracoronary ultrasonography allows detailed tomographic imaging of the arterial wall, it fails to provide data on the structural architecture and longitudinal extent of arterial disease. This information is essential for decision making during therapeutic interventions. Three-dimensional reconstruction techniques offer visualization of the complex longitudinal architecture of atherosclerotic plaques in composite display. Progress in computer hardware and software technology have shortened the reconstruction process and reduced operator interaction considerably, generating three-dimensional images with delineation of mural anatomy and pathology. The indications for intravascular ultrasonography will grow as the technique offers the unique capability of providing ultrasonic histology of the arterial wall, and the need for a three-dimensional display format for comprehensive analysis is increasingly recognized. Consequently, three-dimensional imaging is being rapidly implemented in the catheterization laboratories for guidance of intracoronary interventions and detailed assessment of their results. However exciting the prospects may be, three-dimensional reconstructions at present remain partially artificial because the true spatial position of the imaging catheter tip is not recorded, and shifts in its location and curves of the arterial lumen result in pseudoreconstructions rather than true reconstructions. In this report, we address the principles of three-dimensional reconstruction with a critical review of its limitations. Potential solutions for refinement of this exciting imaging modality are presented.

Response of conductance and resistance coronary vessels to scalar concentrations of acetylcholine: Assessment with quantitative angiography and intracoronary Doppler echography in 29 patients with coronary artery disease (Article)

1994-01-01T00:00:00Z

Abnormal vasoreactivity of the large conductance arteries has been observed in the presence of impaired endothelial function. More recently, experimental and clinical reports have shown that in early coronary atherosclerosis the impairment of the endothelium-mediated vasodilatation also involves the resistance arteries. The aim of this study is the correlation of endothelium-dependent vasodilatation of conductance and resistance vessels in coronary arteries without significant stenoses. In 29 patients (aged 57 +/- 9 years, 24 men and 5 women) undergoing coronary angioplasty, a Doppler guide wire and a perfusion catheter were introduced into the proximal segment of an artery with less than 30% diameter stenosis. Selective infusions of papaverine (bolus of 7 mg), acetylcholine (continuous infusion of 0.036, 0.36, and 3.6 micrograms/ml at a flow rate of 2 ml/min), and isosorbide dinitrate (bolus of 3 mg) were sequentially performed. Heart rate, aortic blood pressure, and blood flow velocity were continuously measured. Mean cross-sectional areas of a proximal and a distal arterial segment were measured in baseline conditions, at the end of each infusion of acetylcholine, and at the peak effect of isosorbide dinitrate with quantitative angiography (CAAS System; Pie Medical Data, Maastricht, The Netherlands). Coronary blood flow was calculated from the time-averaged flow velocity and the cross-sectional area at the site of the Doppler sample volume. Coronary flow resistance was calculated as mean aortic pressure divided by coronary flow. All of the concentrations of acetylcholine induced a significant vasoconstriction of the studied artery. At the maximal concentration of acetylcholine all but three patients (90%) showed a reduction of cross-sectional area (-24% +/- 20% and -22% +/- 20% for the proximal and distal segments, respectively, p < 0.00001). Flow velocity showed a significant increase only with the two highest concentrations of acetylcholine. The maximal concentration induced a 105% +/- 138% increase from the baseline flow velocity (p < 0.001). The coronary flow changes after acetylcholine showed a large interpatient variability, with a mean increase from baseline after the highest dose of +43% +/- 85% (range, -60% +/- 239%), with the presence of a flow reduction in 10 patients (35%). No clinical or angiographic variables showed a significant correlation with the cross-sectional area, flow velocity, and flow changes after infusion of acetylcholine.(ABSTRACT TRUNCATED AT 400 WORDS)

Randomized trial of a GPIIb/IIIa platelet receptor blocker in refractory unstable angina (Article)

1994-01-01T00:00:00Z

BACKGROUND: Patients with unstable angina despite intensive medical therapy, ie, refractory angina, are at high risk for developing thrombotic complications: myocardial infarction or coronary occlusion during percutaneous transluminal coronary angioplasty (PTCA). Chimeric 7E3 (c7E3) Fab is an antibody fragment that blocks the platelet glycoprotein (GP) IIb/IIIa receptor and potently inhibits platelet aggregation. METHODS AND RESULTS: To evaluate whether potent platelet inhibition could reduce these complications, 60 patients with dynamic ST-T changes and recurrent pain despite intensive medical therapy were randomized to c7E3 Fab or placebo. After initial angiography had demonstrated a culprit lesion suitable for PTCA, placebo or c7E3 Fab was administered as 0.25 mg/kg bolus injection followed by 10 micrograms/min for 18 to 24 hours until 1 hour after completion of second angiography and PTCA. During study drug infusion, ischemia occurred in 9 c7E3 Fab and 16 placebo patients (P = .06). During hospital stay, 12 major events occurred in 7 placebo patients (23%), including 1 death, 4 infarcts, and 7 urgent interventions. In the c7E3 Fab group, only 1 event (an infarct) occurred (3%, P = .03). Angiography showed improved TIMI flow in 4 placebo and 6 c7E3 Fab patients and worsening of flow in 3 placebo patients but in none of the c7E3 Fab patients. Quantitative analysis showed significant improvement of the lesion in the patients treated with c7E3 Fab, which was not observed in the placebo group, although the difference between the two treatment groups was not significant. Measurement of platelet function and bleeding time demonstrated > 90% blockade of GPIIb/IIIa receptors, > 90% reduction of ex vivo platelet aggregation to ADP, and a significantly prolonged bleeding time during c7E3 Fab infusion, without excess bleeding. CONCLUSIONS: Combined therapy with c7E3 Fab, heparin, and aspirin appears safe. These pilot study results support the concept that effective blockade of the platelet GPIIb/IIIa receptors can reduce myocardial infarction and facilitate PTCA in patients with refractory unstable angina.

Usefulness of quantitative and qualitative angiographic lesion morphology, and clinical characteristics in predicting major adverse cardiac events during and after native coronary balloon angioplasty (Article)

1993-07-01T00:00:00Z

Major, adverse cardiac events (death, myocardial infarction, bypass surgery and reintervention) occur in 4 to 7% of all patients undergoing coronary balloon angioplasty. Prospectively collected clinical data, and angiographic quantitative and qualitative lesion morphologic assessment and procedural factors were examined to determine whether the occurrence of these events could be predicted. Of 1,442 patients undergoing balloon angioplasty for native primary coronary disease in 2 European multicenter trials, 69 had major, adverse cardiac procedural or in-hospital complications after ≥1 balloon inflation and were randomly matched with patients who completed an uncomplicated in-hospital course after successful angioplasty. No quantitative angiographic variable was associated with major adverse cardiac events in univariate and multivariate analyses. Univariate analysis showed that major adverse cardiac events were associated with the following preprocedural variables: (1) unstable angina (odds ratio [OR] 3.11; p < 0.0001), (2) type C lesion (OR 2.53; p < 0.004), (3) lesion location at a bend >45 ° (OR 2.34; p < 0.004), and (4) stenosis located in the middle segment of the artery dilated (OR 1.88; p < 0.03); and with the following postprocedural variable: angiographically visible dissection (OR 5.39; p < 0.0001). Muttivariate logistic analysis was performed to identify variables independently correlated with the occurrence of major adverse cardiac events. The preprocedural multivariate model entered unstable angina (OR 3.77; p < 0.0003), lesions located at a bend >45 ° (OR 2.87; p < 0.0005), and stenosis located in the middle portion of the artery dilated (OR 1.95; p < 0.04). If all variables were included, then angiographically visible dissection (OR 6.58; p < 0.0001), unstable angina (OR 3.46; p < 0.002) and lesions located at a bend >45 ° (OR 2.54; p < 0.006) were independent predictors of major adverse cardiac events.

Which angiographic variable best describes functional status 6 months after successful single-vessel coronary balloon angiopasty? (Article)

1993-01-01T00:00:00Z

OBJECTIVES. The aim of this study was to determine which quantitative angiographic variable best describes functional status 6 months after coronary balloon angioplasty. BACKGROUND. Several angiographic restenosis criteria have been developed. These can be divided into those that describe the change in lesion severity and those that merely describe lesion severity at follow-up angiography. The functional significance of these criteria is unknown. METHODS. We studied 350 patients with single-vessel coronary artery disease who underwent a single-site balloon dilation. Sensitivity and specificity curves were constructed for the prediction of anginal status and exercise electrocardiography of four quantitative angiographic variables that describe restenosis. The point of highest diagnostic accuracy for the variables was determined at the intersection of the sensitivity and specificity curves. Results of exercise electrocardiography were considered indicative for ischemia 6 months after angioplasty if horizontal or downsloping ST segment depression > or = 1 mm occurred. RESULTS. The points of highest diagnostic accuracy of the angiographic variables were similar for both anginal status and exercise electrocardiography: 1.45 and 1.46 mm for the minimal lumen diameter measurements, 45.5% and 46.5% for the percent diameter stenosis measurements at follow-up, -0.30 and -0.32 mm for change in minimal lumen diameter and -10% and -10% for the change in percent diameter stenosis at follow-up. CONCLUSIONS. Angiographic variables reflecting a change in lesion severity at follow-up angiography were only slightly less accurate than variables that describe lesion severity at follow-up. The large study group and the fact that the same optimal values for diagnostic accuracy of the various quantitative angiographic variables were obtained for the prediction of two different markers of ischemia suggests that these values reflect the lesion severity or increase in lesion severity in major epicardial vessels at which coronary flow reserve is unable to meet myocardial demands.

Digital geometric measurements in comparison to cinefilm analysis of coronary artery dimensions (Article)

1993-01-01T00:00:00Z

Six months follow-up post-PTCA angiograms from 31 patients were acquired digitally and on cinefilm and used for a comparison of geometric coronary measurements at the site of the previous dilatation. On 70 images of 34 coronary segments quantitative analysis was performed both on-line, using the Automated Coronary Analysis package of the Philips Digital Cardiac Imaging System (DCI, pixel matrix 512 x 512) and off-line, using the Cardiovascular Angiography Analysis System (CAAS). With the CAAS a cine-video conversion is performed and a 6.9 x 6.9 mm region of interest from the 18 x 24 mm cineframe is digitized into a 512 x 512 pixel matrix. In both systems the vascular contours are assessed by means of operator-independent edge detection algorithms. The angiographic catheter was used for calibration. Best agreement between DCI and CAAS was found for obstruction diameter and minimal luminal diameter, respectively (r = 0.82; y = 0.12 + 0.97x; SEE = 0.29). The reconstructed reference diameter related to a computed reference contour yields lower correlation (r = 0.76; y = 0.27 + 0.91x; SEE = 0.37). Worst results were obtained from the relative measure of percent diameter stenosis as well as from the derived parameter of plaque area. The on-line digital approach of geometric coronary assessments provides good agreement with cinefilm analysis when direct measurements of coronary dimensions are applied.

Intracoronary blood flow velocity and transstenotic pressure gradient using sensor-tip pressure and doppler guidewires: a new technology for the assessment of stenosis severity in the Catheterization Laboratory (Article)

1993-01-01T00:00:00Z

In a patient undergoing percutaneous balloon angioplasty of a stenotic proximal right coronary artery the transstenotic pressure gradient was measured using a 0.018" guidewire with a distal optical microsensor. Blood flow velocity was measured proximal to the stenosis using a 0.018" Doppler guidewire. Transstenotic pressure gradient and blood flow velocity were measured in baseline conditions and after intracoronary injection of 12.5 mg of papaverine. Coronary blood flow was calculated from the measured blood flow velocity and the corresponding cross-sectional area. The measured pressure gradients were compared with the values derived from the stenosis geometry assessed with quantitative coronary angiography (automated edge detection measurements in two orthogonal views, assuming an elliptical cross-sectional area). The measured transstenotic pressure gradient was 15 mm Hg in baseline conditions and 42 mm Hg at the peak effect of the papaverine injection. A 50% flow velocity increase was observed at peak hyperemia (time-averaged maximal flow velocity = 30 cm/s before and 45 cm/s after papaverine). The transstenotic pressure gradient calculated from the measured stenosis geometry was 20 mm Hg and 42 mm Hg in baseline and hyperemic conditions, respectively. The combined use of a pressure and a Doppler guidewire provides a complete assessment of the transstenotic pressure/coronary flow velocity relation at rest and after pharmacologically induced hyperemia and allows the characterization of stenosis hemodynamics and functional severity.

The mechanism of directional coronary atherectomy (Article)

1993-01-01T00:00:00Z

An attempt was made to assess the mechanism of directional coronary atherectomy using different methods of analysis. Quantitative coronary angiography was used as the gold standard to assess the immediate results of atherectomy, and a comparative quantitative analysis of atherectomy and balloon angioplasty was made. To determine whether the post-atherectomy cross-sectional area is close to a circle, we compared the area measurements obtained by edge detection with those obtained by videodensitometry. Finally, the extent of a 'Dotter' effect was established by quantitative angiography following crossing the stenosis with the atherectomy device. For the purpose of this study, the results of the first 113 successful atherectomy procedures were reviewed. In matched lesions, directional atherectomy induced a greater increase in minimal luminal diameter than balloon angioplasty (1.6 mm vs 0.8 mm; P < 0.0001). However, this luminal improvement is due to a substantial 'Dotter' effect induced by the bulky atherectomy device. Following atherectomy, only a slight difference in cross-sectional area measurements between edge detection and videodensitometry (mean difference: 0.28 mm2) was found. Histologic examination of an atherectomized coronary artery showed a near-circular postatherectomy area geometry. In conclusion, directional atherectomy is a very effective device with a substantially better initial result than balloon angioplasty. However, insertion of this bulky device itself causes an important 'Dotter' effect.

Maximal blood flow velocity in severe coronary stenosis measured with a doppler guidewire. Limitations for the application of the continuity equation in the assessment of stenosis severity (Article)

1993-01-01T00:00:00Z

In vitro and animal experiments have shown that the severity of coronary stenoses can be assessed using the continuity equation if the maximal blood flow velocity of the stenotic jet is measured. The large diameter and the low range of velocities measurable without frequency aliasing with the conventional intracoronary Doppler catheters precluded the clinical application of this method for hemodynamically significant coronary stenoses in humans. This article reports the results obtained using a 12 MHz steerable angioplasty guidewire in a consecutive series of 52 patients undergoing percutaneous coronary angioplasty (61 coronary stenoses). The ratio between coronary flow velocity in a reference segment and in the stenosis was used to estimate the percent cross-sectional area stenosis. A Doppler recording suitable for quantitation was obtained in the stenotic segment in only 10 of 61 arteries (16%). The time-averaged peak velocity increased from 15 +/- 5 to 115 +/- 26 cm/sec from the reference normal segment to the stenosis. Volumetric coronary flow calculated from the product of mean flow velocity and cross-sectional area was similar in the stenosis and in the reference segment (33.2 +/- 14.9 vs 33.5 +/- 17.0 mL/min, respectively, difference not significant). The percent cross-sectional area stenosis and minimal luminal cross-sectional area derived from the Doppler velocity measurements using the continuity equation and calculated with quantitative angiography were also similar (Doppler, 86.7 +/- 5.1% and 1.00 +/- 0.48 mm2; quantitative angiography, 85.9 +/- 7.9% and 1.02 +/- 0.50 mm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Intracoronary pressure and flow velocity with sensor-tip guidewires: a new methodologic approach for assessment of coronary hemodynamics before and after coronary interventions (Article)

1993-01-01T00:00:00Z

The use of miniaturized pressure and velocity sensors mounted on angioplasty guidewires allows the simultaneous measurement of coronary blood flow velocity and transstenotic pressure gradient, 2 parameters that, combined, should perfectly characterize stenosis hemodynamics. The aim of this article is assessment of the changes in coronary blood flow velocity observed with a Doppler-tipped angioplasty guidewire in 35 patients undergoing balloon angioplasty. We also report our initial experience in 16 patients with the combined use of sensor-tip pressure and Doppler guidewires, and we discuss the application of new methodologic approaches for the study of the coronary circulation allowed by these techniques, such as the instantaneous assessment of the flow velocity/pressure and pressure gradient/flow velocity relations. Before and after angioplasty, flow velocity measurements were obtained distal to the stenosis, both in baseline conditions and after intracoronary injection of 8-12.5 mg of papaverine. The Doppler guidewire was left in place during the dilation procedure and the Doppler signal was continuously recorded during balloon inflation and after deflation to monitor the development of collateral flow, the restoration of flow after balloon deflation, the phase of postocclusive reactive hyperemia, and, incidently, the development of flow-limiting complications. Merits and pitfalls of several flow velocity parameters (average peak velocity, coronary flow velocity reserve, diastolic/systolic velocity ratio), as well as of parameters derived from the combination of pressure and velocity measurements (transstenotic pressure gradient/flow velocity relation and instantaneous diastolic hyperemic flow velocity/pressure relation) were evaluated in 35 patients with, and 37 without, significant coronary stenoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Excimer laser coronary angioplasty in the Netherlands: preamble for a randomized study (Article)

1993-01-01T00:00:00Z

The immediate outcome of ELCA by XeCl excimer laser radiation is described in 53 patients who were selected to undergo ELCA from December 1990 to September 1991 in two centers that are currently performing ELCA in the Netherlands. Immediate success rates on the basis of visual assessment of the angiogram were as follows. Laser success (> 20% reduction of diameter stenosis after ELCA alone) was observed in 77% of patients, procedural success (< 50% residual stenosis after ELCA with or without adjunctive balloon dilatation [PTCA]) in 91%, and clinical success (procedural success without clinical complications) in 83% of patients. Quantitative coronary angiography by automated contour detection was performed in 31 patients who underwent ELCA in the Thoraxcenter. The minimal luminal diameter (mean +/- SD) of the treated coronary segments increased from 0.77 +/- 0.41 mm to 1.24 +/- 0.25 mm after ELCA and further to 1.67 +/- 0.29 mm after adjunctive PTCA in 25 patients. The present experience is put in perspective of results initially reported by other centers and compared with data from multicenter registries of ELCA. Finally, a short description is given of the design of a prospective, randomized trial of ELCA versus conventional PTCA (AMRO trial).

Analysis of VNTR loci amplified by the polymerase chain reaction for investigating the origin of intimal smoth muscle cells in a coronary artery lesion developing after heart transplantation in man (Article)

1993-01-01T00:00:00Z

Restenosis after directional coronary atherectomy and balloon angioplasty: comparative analysis based on matched lesions (Article)

1993-01-01T00:00:00Z

OBJECTIVES. Late lumen narrowing after directional coronary atherectomy was assessed by quantitative coronary angiography and compared with that after balloon angioplasty. BACKGROUND. Directional coronary atherectomy has been introduced as an alternative technique for balloon angioplasty and may reduce the incidence of restenosis. METHODS. A prospectively collected consecutive series of 87 native coronary artery lesions successfully treated with atherectomy were matched with 87 coronary artery lesions selected from a consecutive series of lesions that had been successfully dilated by balloon angioplasty. Late angiographic analysis was performed in 158 lesions. The net gain index represents the ultimate gain in minimal lumen diameter at follow-up study, normalized for the vessel size. This index is the result of the relative gain attained during the procedure (the ratio of the change in minimal lumen diameter and reference diameter) and the relative loss observed during the follow-up period (the ratio of the change in minimal lumen diameter during the follow-up period and the reference diameter). RESULTS. Matching for clinical and angiographic variables resulted in two comparable groups with similar baseline stenosis characteristics. Atherectomy resulted in a more pronounced increase in minimal lumen diameter than did balloon angioplasty (mean +/- SD 1.17 +/- 0.29 to 2.44 +/- 0.42 mm vs. 1.21 +/- 0.38 to 2.00 +/- 0.36 mm, p < 0.001). However, this favorable immediate result was subsequently lost during late angiographic follow-up, so that the minimal lumen diameter at follow-up and the net gain index did not differ significantly between the two groups (1.76 +/- 0.62 vs. 1.77 +/- 0.59 mm, p = 0.93, and 0.18 +/- 0.19 vs. 0.17 +/- 0.17, p = 0.70). Consequently, the relative gain and relative loss were higher in the atherectomy group. For both techniques, the relative gain was linearly related to the relative loss but the slope of the regression line was steeper for atherectomy, suggesting that the relative loss in the atherectomy group is proportionally even larger for a given relative gain compared with that in the angioplasty group. CONCLUSIONS. In matched groups of patients, atherectomy induces a greater initial gain in minimal lumen diameter than does balloon angioplasty. However, the vascular wall injury induced by the device is of a different nature (debulking vs. dilating) that leads to more relative loss over the follow-up period in the atherectomy group.

Balloon angioplasty for the the treatment of lesions in saphenous vein bypass grafts (Article)

1993-01-01T00:00:00Z

OBJECTIVES. The purpose of this review is to assess the value and limitations of balloon angioplasty for the treatment of saphenous vein bypass graft obstructions. The potential efficacy of new interventional techniques is discussed. BACKGROUND. Treatment of ischemia due to saphenous vein bypass graft obstructions poses a difficult problem that will be encountered more often as the pool of surgically treated patients continues to accumulate. Reoperation is technically demanding and is associated with high mortality and morbidity rates. Balloon angioplasty may provide a suitable alternative. METHODS. The review proposes a classification of patients with attempted saphenous vein graft angioplasty according to expected early and late outcome based on the data obtained from the relevant published data and personal experience. RESULTS. Angioplasty of a nonocclusive obstruction in a saphenous vein bypass graft has an initial success rate of approximately 90% and is a safe procedure (procedural death rate < 1%, myocardial infarction rate < 4%). The overall average restenosis rate is 42%. Surgical standby is limited and technically difficult. Angioplasty of chronic total occlusions in old grafts is associated with poor initial and long-term results. The long-term clinical results are unfavorable because of the continuing progression of disease in nontreated vein graft segments and native coronary arteries, in addition to the high restenosis rate. New techniques, although promising, have shown neither better initial results nor reduction of restenosis. Stent placement may be useful in longer graft lesions containing friable material. CONCLUSIONS. Patients may be classified into three groups according to expected early and late outcome on the basis of 1) unfavorable graft anatomy, 2) risk of cardiogenic shock in event of acute graft closure, and 3) age of grafts. The three groups are 1) those with an initial high success, low procedural risk and low restenosis rate; 2) those with an initial high success but high procedural risk and moderate to high restenosis rate; and 3) those with a low success, high risk and high restenosis rate. Balloon angioplasty to treat lesions in venous bypass grafts should be considered a palliative procedure, not a long-term solution, for ongoing progression of coronary artery and vein graft disease. The induced high restenosis rate remains a significant problem.

Intravascular ultrasound (Article)

1993-01-01T00:00:00Z

Histologic characteristics of tissue excised during directional coronary atherectomy in stable and unstable angina pectoris (Article)

1993-01-01T00:00:00Z

How to assess regression of the atherosclerotic plaque (Article)

1993-01-01T00:00:00Z

Directional atherectomy: combining basic research and intervention (Article)

1993-01-01T00:00:00Z

La relation instantanée pression-vélecité du flux coronaire, alternative à la mesure de la réserve coronaire: étude de faisabilité et reproductibilité de la méthode (Article)

1993-01-01T00:00:00Z

Animal experimentation has shown that the instantaneous pressure-velocity of coronary blood flow in the hyperaemic phase has a linear relationship. The slope of this regression evaluates coronary reserve independently of haemodynamic variables and the X-intercept (zero flow pressure or Pf = 0) determines the intra-myocardial back pressure which could influence the regulation of coronary flow. The object of this study was to evaluate the instantaneous pressure-velocity relationship of coronary flow in clinical practice and to analyse the reproducibility of this parameter. Forty-nine patients were divided into two groups, depending on whether their coronary arteries were angiographically normal (n = 34) or atheromatous with stenosis > or = 35% of the reference diameter (n = 15). Recordings of coronary flow velocity were made with a Doppler transducer mounted on a 0.018 inch guide wire. The slope of the diastolic linear segment of the pressure-velocity relationship was determined at the peak of papaverine-induced vasodilation from 4 consecutive cycles by a regression analysis. The pressure value at 0 flow was obtained by extrapolation of the regression slope to the axis of aortic perfusion pressure. A good quality spectral recording allowing reliable analysis of the velocity profile was obtained in 88% of cases (44/49). The high values of the correlation coefficient observed with each measurement of the slope confirm the applicability of linear regression analysis to the pressure-velocity relationship. The slope of the pressure-velocity relationship was significantly lower in patients with coronary stenosis (1.7 +/- 0.7 cm/s/mmHg in normal vessels versus 0.7 +/- 0.3 cm/s/mmHg in stenotic arteries, p < 10(-4)), and, similarly, the pressure at zero flow was also reduced (36.9 +/- 16 mmHg versus 25.5 +/- 12 mmHg, p = 0.03). A statistically significant correlation was observed between the slope values and coronary flow reserve but no correlation was demonstrated between the slope and intraluminal surface area of angiographically normal coronary arteries or the slope and degree of stenosis of atheromatous vessels. The linear regression slope and the pressure at zero flow were lower when the pressure-velocity relationship was measured during long diastolic periods induced by the injection of adenosine. In addition, the curvilinear appearances of the pressure-velocity relationship observed during these long periods suggest that the linear regression model is not applicable throughout the whole range of pressures and velocities, especially for the lowest values.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical and histological determinants of smooth-muscle cell outgrowth in cultured atherectomy specimens: importance of thrombus organization (Article)

1993-01-01T00:00:00Z

BACKGROUND: Coronary atherectomy provides a unique opportunity to obtain plaque tissue from a wide variety of clinical syndromes. We investigated the relation between the clinical status and histopathological substrate of tissue retrieved during directional coronary atherectomy and the proliferative and migratory potential of smooth-muscle cells judged from successful outgrowth during cell culture. METHODS: After directional coronary atherectomy, tissue samples were examined macroscopically, divided into two equal pieces, and separately subjected to cell culture and histopathological study. Cell culture was performed using an explant technique. In-vitro smooth-muscle cell outgrowth was related to clinical and histological variables. RESULTS: Atherosclerotic tissue was obtained from 98 consecutive atherectomy procedures. Histological examination revealed a broad spectrum of appearances, ranging from complex atheroma containing dense fibrous tissue, calcium deposits, macrophages, and necrotic debris to neointimal proliferation and organized thrombi. Smooth-muscle cell outgrowth was observed in 43 of the 98 samples (44%). Although not affected by any of the clinical variables, cell outgrowth was influenced by histological variables, in particular the presence of organizing thrombi. Outgrowth was successful in eight out of 10 samples with thrombus (80%) and in only 35 out of 88 (40%) without (P = 0.03). CONCLUSION: The presence of organizing thrombi in the retrieved tissue facilitates smooth-muscle cell outgrowth and suggests an enhanced proliferative and migratory potential. These findings may be relevant to the understanding of neointimal proliferation in coronary syndromes where mural thrombosis is likely to occur.

Retardation and arrest of progression or regression of cronary artery disease : a review (Article)

1993-01-01T00:00:00Z

Immediate and long term results of percutaneous coronary angioplasty in patients aged 70 and over (Article)

1992-01-01T00:00:00Z

OBJECTIVE: To study the immediate and long term clinical success of percutaneous transluminal coronary balloon angioplasty in patients over 70 years old. DESIGN--Patients undergoing percutaneous transluminal angioplasty were prospectively entered in a specially designed database. The clinical and angiographic data of all patients over 70 were reviewed. Follow up data were collected by interview, during outpatient visits, by questionnaire, or through the referring physician. SETTING--A tertiary referral cardiac centre. PATIENTS--166 patients over 70 (median 73, range 70-84) underwent coronary angioplasty because of unstable angina (81 patients), stable angina (76 patients), or acute myocardial infarction (nine patients). RESULTS--The initial clinical success rate was 86% (142 of 166 patients). A major procedural complication occurred in 10 patients (6%): four patients (2%) died, six patients (4%) underwent emergency bypass surgery, and five patients (3%) sustained an acute myocardial infarction. In 14 patients (8%) coronary angioplasty did not significantly reduce the diameter stenosis but there were no associated complications. A total of 226 lesions were attempted. The initial angiographic success rate was 192 out of 226 lesions (85%). The median follow up was 21 (range 0.5-66) months. Sixteen patients (10%) died during follow up, eight patients (5%) sustained a non-fatal myocardial infarction, 21 patients (13%) underwent a second or third balloon dilatation, and 17 patients (10%) underwent elective bypass surgery. Of the 146 survivors, 99 patients (68%) had sustained clinical improvement. The estimated survival at four years (Kaplan-Meier method) was 89 (SD 4)%. The event free survival at four years for the total study population was 61 (8)%. Multivariate logistic regression analysis showed that the extent of vessel disease was the only independent predictive factor for event free survival: the event free survival rate was 81 (10)% at four years for patients with single vessel disease, compared with 45 (12)% for patients with multivessel disease. CONCLUSIONS--Coronary angioplasty in patients over 70 was a safe and effective treatment for obstructive coronary artery disease. The extent of vessel disease, and not the completeness of revascularisation, was the only independent predictive factor for event free survival.

Restenosis after coronary angioplasty: the paradox of increased lumen diameter and restenosis (Article)

1992-01-01T00:00:00Z

Restenosis after coronary angioplasty is the single complication that most limits this revascularization procedure in clinical practice. The process is largely unpredictable and the lesion-related factors predisposing to restenosis are poorly understood, with little consensus in published reports. In this study using detailed quantitative angiographic measurements to assess 490 lesions, the simple lesion characteristics associated with restenosis were defined and the relation to the restenosis process documented. Restenosis was defined as an absolute deterioration in the minimal lumen diameter by greater than or equal to 0.72 mm, a criterion based on the 95% confidence intervals for repeat angiographic measurements. This was chosen in an attempt to separate spurious changes due to a poor angiographic result and the variability of angiographic measurements from significant changes due to the restenosis process. The principal determinants of restenosis were found to be a large improvement in the minimal lumen diameter at the time of dilation (1.13 mm for the restenosis group compared with 0.86 mm for the no restenosis group [p less than 0.0001]) and an optimal postangioplasty result (minimal lumen diameter 2.28 mm in the restenosis group compared with 2.05 mm [p less than 0.001] in the no restenosis group, corresponding to a 25% and a 30% diameter stenosis, respectively [p less than 0.0001]). These observations reported for the first time suggest that the distinction needs to be made between a "clinical restenosis" of greater than or equal to 50% diameter stenosis and the "restenosis process" as measured by the absolute changes occurring during and after angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Postangioplasty restenosis rate between segments of the major coronary arteries (Article)

1992-01-01T00:00:00Z

Conflicting data have been published regarding the rate of postangioplasty restenosis observed in diverse segments of the coronary tree. However, these studies may be criticized for their biased selection of patients, methods of analysis, and definitions of restenosis. In the present study, 1,353 patients underwent a successful coronary dilatation of greater than or equal to 1 site. In all, 1,234 patients (91%) had a follow-up angiogram after 6 months, or earlier when indicated by symptoms. All films were processed and analyzed at the thoraxcenter core laboratory with the coronary angiography analysis system (automated contour detection). Restenosis was considered present if the diameter stenosis at follow-up was greater than 50%. No differences in restenosis rates were observed between coronary segments using this categorical definition. A continuous approach was also used; absolute changes in minimal luminal diameter adjusted for vessel size were used in order to allow comparison between vessels of different sizes (relative loss). No significant differences were observed between the coronary segments with this continuous approach. These results suggest that restenosis is a ubiquitous phenomenon without any predilection for a particular site in the coronary tree.

Lumen narrowing after percutaneous transluminal coronary balloon angioplasty follows a near gaussian distribution: a quantitative angiographic study in 1,445 successfully dilated lesions (Article)

1992-01-01T00:00:00Z

To determine whether significant angiographic narrowing and restenosis after successful coronary balloon angioplasty is a specific disease entity occurring in a subset of dilated lesions or whether it is the tail end of a gaussian distributed phenomenon, 1,445 successfully dilated lesions were studied before and after coronary angioplasty and at 6-month follow-up study. The original cohort consisted of 1,353 patients of whom 1,232 underwent repeat angiography with quantitative analysis (follow-up rate 91.2%). Quantitative angiography was carried out off-line in a central core laboratory with an automated edge detection technique. Analyses were performed by analysts not involved with patient care. Distributions of minimal lumen diameter before angioplasty (1.03 +/- 0.37 mm), after angioplasty (1.78 +/- 0.36 mm) and at 6-month follow-up study (1.50 +/- 0.57 mm) as well as the percent diameter stenosis at 6-month follow-up study (44 +/- 19%) were assessed. The change in minimal lumen diameter from the post-angioplasty angiogram to the follow-up angiogram was also determined (-0.28 +/- 0.52 mm). Seventy lesions progressed toward total occlusion at follow-up. All observed distributions approximately followed a normal or gaussian distribution. Therefore, restenosis can be viewed as the tail end of an approximately gaussian distributed phenomenon, with some lesions crossing a more or less arbitrary cutoff point, rather than as a separate disease entity occurring in some lesions but not in others.

Coronary vasodilatory action of elgodipine in coronary artery disease (Article)

1992-01-01T00:00:00Z

The effects of intravenous elgodipine, a new second-generation dihydropyridine calcium antagonist, on hemodynamics and coronary artery diameter were investigated in 15 patients undergoing cardiac catheterization for suspected coronary artery disease. Despite a significant decrease in systemic blood pressure, elgodipine infused at a rate of 1.5 micrograms/kg/min over a period of 10 minutes did not affect heart rate and left ventricular end-diastolic pressure. The contractile responses during isovolumic contraction showed a slight but significant increase in maximum velocity (56 +/- 10 to 60 +/- 10 seconds-1; p less than 0.005), whereas the time constant of early relaxation was shortened from 49 +/- 11 to 44 +/- 9 ms (p less than 0.05). Coronary sinus and great cardiac vein flow increased significantly by 15 and 26%, respectively. As mean aortic pressure decreased, a significant decrease in coronary sinus (-27%) and great cardiac vein (-28%) resistance was observed, while the calculated myocardial oxygen consumption remained unchanged. In all, 69 coronary segments (including 13 stenotic segments) were analyzed quantitatively using computer-assisted quantitative coronary angiography. A significant increase in mean coronary artery diameter (2.27 +/- 0.53 to 2.48 +/- 0.53 mm; p less than 0.000001), as well as in obstruction diameter, (1.08 +/- 0.29 to 1.36 +/- 0.32 mm; p less than 0.02), was observed. The results demonstrate that elgodipine, in the route and dose described, induces significant vasodilatation of both coronary resistance and epicardial conductance vessels, without adverse effects on heart rate, myocardial oxygen demand and contractile indexes.

Histological changes in the aortic valve after balloon dilatation: evidence for a delayed healing process (Article)

1992-01-01T00:00:00Z

OBJECTIVE--To investigate whether balloon dilatation of the aortic valve induces long-term macroscopic or histological changes or both to explain the restenosis process. DESIGN--Prospective study of 39 consecutive patients. Sixteen later (mean (SD) 12 (10) months) required operation. This non-randomised subgroup was compared with 10 patients who had aortic valve replacement without prior dilatation. SETTING--University cardiology and cardiac surgery centre and pathology department. PATIENTS--16 patients who had aortic valve replacement because of failure of or restenosis after balloon dilatation of the aortic valve. Twelve resected valves were examined. INTERVENTIONS--Percutaneous balloon dilatation of the aortic valve (maximal balloon size: trefoil 3 x 12 mm balloon or bifoil 2 x 19 mm balloon) and surgical inspection before excision of the aortic valve leaflets during open-chest aortic valve replacement. Fixation, decalcification, and staining for histology. MAIN OUTCOME MEASURES--Presence of long-term pathological changes in the resected valve and their relation to restenosis after balloon dilatation. RESULTS--Macroscopically the previously dilated valves were indistinguishable from valves from the patients who had valve replacement only. Microscopically, the dilated aortic valves showed areas of young scar tissue that were not seen in a control group of surgically excised stenotic aortic valves. This persistent scarring reaction was seen around small tears or lacerations of the collagenous valve stroma, fractures in calcified areas, and splits in commissures. Young scar tissue without collagenisation was still present 24 months after dilatation. CONCLUSION--Organisation and collagenisation of scar tissue develops slowly after balloon dilatation of the aortic valve. This prolonged scarring reaction may explain the late development of restenosis in some patients.

One hundred and thirteen attempts at directional coronary atherectomy: the early and combined experience of two European centres using quantitative angiography to assess their results (Article)

1992-01-01T00:00:00Z

Directional coronary atherectomy has been introduced as an alternative to conventional balloon angioplasty when treating coronary artery stenoses with complex lesion morphology. To determine the immediate efficacy of coronary atherectomy in patients with such lesions, the first 113 attempts at directional atherectomy in two centres using quantitative angiography were reviewed in 105 patients. The lesions were classified as complex stenosis since 95% had a symmetry index less than 1.0, a length of 6.83 +/- 2.55 mm on average and an area of plaque of 9.77 +/- 6.69 mm2. Procedural success defined as a residual stenosis less than or equal to 50% after tissue retrieval was obtained in 90 (85.7%) of 105 patients. The primary angioplastic success rate, combining atherectomy and balloon angioplasty in case of failed attempt of atherectomy was 95.2%. Coronary atherectomy was unsuccessful in five patients; three were referred for emergency coronary artery bypass grafting. Major complications (death, emergency surgery and transmural infarction) were encountered in 5.7% of the patients. Assessed by quantitative coronary analysis, a residual minimal luminal diameter of 2.42 +/- 0.52 mm and a diameter stenosis of 26 +/- 12% were obtained immediately after directional coronary atherectomy. We conclude that directional coronary atherectomy is particularly suitable for the treatment of stenosis with complex lesion morphology and is associated with acceptable complication rates. Randomized trials comparing atherectomy with balloon angioplasty are warranted to clarify the role of atherectomy in the treatment of lesions in the proximal part of the three major epicardial coronary arteries.

Percutaneous directional atherectomy for discrete coronary lesions in cardiac transplant patients (Article)

1992-01-01T00:00:00Z

In-vivo validation of on-line and off-line geometric coronary measurements using insertion of stenosis phantoms in procine coronary arteries (Article)

1992-01-01T00:00:00Z

Geometric coronary artery measurements with the Phillips Digital Cardiac Imaging System (DCI) and the Cardiovascular Angiography Analysis System (CAAS) were validated using percutaneous insertion of radiolucent stenosis phantoms in swine coronary arteries. Angiographic visualization of the stenosis lumens (phi 0.5, 0.7, 1.0, 1.4, 1.9 mm) was simultaneously recorded on DCI and cinefilm. The acquisition systems were calibrated by either the diameter of the guiding catheter (catheter CAL) or the isocenter method (isocenter CAL). Minimal luminal diameters (MLD) obtained with CAAS and DCI on 20 corresponding cineframes were compared with the true phantom diameters (PD). The accuracy of MLD measurements with the CAAS using isocenter CAL was -0.07mm, the precision 0.21 mm (r = 0.91; y = 0.30 + 0.79x; SEE = 0.19), with catheter CAL the accuracy was 0.09 mm, the precision 0.23 mm (r = 0.89; y = 0.19 + 0.74x; SEE = 0.19). The accuracy of MLD measurements using the DCI with isocenter CAL was 0.08 mm, the precision 0.15 min (r = 0.96; y = 0.08 + 0.86x; SEE = 0.14), with catheter CAL the accuracy was 0.18 mm, the precision 0.21 mm (r = 0.92; y = 0.09 + 0.76x; SEE = 0.17). DCI underestimated PD with isocenter CAL (p less than 0.05) and with catheter CAL (p less than 0.001). MLD can be measured with high accuracy, both applying on-line digital as well as off-line cineangiographic analysis. The results of digital measurements demonstrate high reliability of the new digital software package.

Restenosis after coronary angioplasty: a proposal of new comparative approaches based on quantitative angiography (Article)

1992-01-01T00:00:00Z

Directional atherectomy for treatment of restenosis within coronary stents: clinical, angiographic and histologic results (Article)

1992-01-01T00:00:00Z

Abstract OBJECTIVES: The safety and long-term results of directional coronary atherectomy in stented coronary arteries were determined. In addition, tissue studies were performed to characterize the development of restenosis. METHODS: Directional coronary atherectomy was performed in restenosed stents in nine patients (10 procedures) 82 to 1,179 days after stenting. The tissue was assessed for histologic features of restenosis, smooth muscle cell phenotype, markers of cell proliferation and cell density. A control (no stenting) group consisted of 13 patients treated with directional coronary atherectomy for restenosis 14 to 597 days after coronary angioplasty, directional coronary atherectomy or laser intervention. RESULTS: Directional coronary atherectomy procedures within the stent were technically successful with results similar to those of the initial stenting procedure (2.31 +/- 0.38 vs. 2.44 +/- 0.35 mm). Of five patients with angiographic follow-up, three had restenosis requiring reintervention (surgery in two and repeat atherectomy followed by laser angioplasty in one). Intimal hyperplasia was identified in 80% of specimens after stenting and in 77% after coronary angioplasty or atherectomy. In three patients with stenting, 70% to 76% of the intimal cells showed morphologic features of a contractile phenotype by electron microscopy 47 to 185 days after coronary intervention. Evidence of ongoing proliferation (proliferating cell nuclear antigen antibody studies) was absent in all specimens studied. Although wide individual variability was present in the maximal cell density of the intimal hyperplasia, there was a trend toward a reduction in cell density over time. CONCLUSIONS: Although atherectomy is feasible for the treatment of restenosis in stented coronary arteries and initial results are excellent, recurrence of restenosis is common. Intimal hyperplasia is a nonspecific response to injury regardless of the device used and accounts for about 80% of cases of restenosis. Smooth muscle cell proliferation and phenotypic modulation toward a contractile phenotype are early events and largely completed by the time of clinical presentation of restenosis. Restenotic lesions may be predominantly cellular, matrix or a combination at a particular time after a coronary procedure.

Acute coronary artery occlusion during and after percutaneous transluminal coronary angioplasty. Frequency, prediction, clinical course, management, and follow-up (Article)

1991-01-01T00:00:00Z

BACKGROUND. Acute coronary artery occlusion after percutaneous transluminal coronary angioplasty (PTCA) continues to remain a serious complication despite significant improvement in operator performance and technological advancements. This retrospective study was performed to ascertain the frequency, predictive variables, management, and outcome of acute coronary artery occlusion. METHODS AND RESULTS. The study was based on data from 1,423 consecutive patients who underwent an elective coronary angioplasty between January 1986 and December 1988. Acute coronary artery occlusion occurred in 104 patients (7.3%). Acute occlusion developed during the dilatation procedure in 80 patients (5.6%) and within 24 hours after the procedure in 24 patients (1.7%). Four clinical and 14 angiographic variables predictive for acute coronary artery occlusion were analyzed in these 104 patients with a complicated procedure and were compared with those in 104 representative patients with successful attempts. Multivariate analysis found three independent predictive variables: unstable angina, multivessel disease, and complex lesions. The overall clinical outcome after management of acute coronary artery occlusion including immediate repeat dilatation (95 patients), use of intracoronary streptokinase (34 patients), or autoperfusion catheter (12 patients) was successful (reduction of lumen diameter to less than 50%, no death, no myocardial infarction [MI], and no emergency surgery) in 42 patients (40%), was a failure without major complication in four patients (4%), and was a failure with major complication (death, MI, and emergency surgery) in 58 patients (56%). The overall mortality rate was 6% (six patients), the overall MI rate was 36% (37 patients), and emergency bypass surgery was required in 30% of patients (31 patients). At 6 months' follow-up of 42 patients with successful management, recurrent angina pectoris due to restenosis occurred in 10 patients (24%), and a late MI occurred in one patient (3%). At 6 months' follow-up of 56 survivors with unsuccessful management (development of MI or need for emergency bypass surgery), recurrent angina occurred in nine patients (16%), and cardiac death in two patients (4%). However, the majority of patients in both groups were either symptom free or had mild angina pectoris. CONCLUSION. Acute coronary artery occlusion during PTCA is often unpredictable, but its frequency is higher in patients with unstable angina, multivessel disease, and complex lesions. Despite immediate redilatation, use of intracoronary streptokinase, and emergency bypass surgery, PTCA is associated with a high mortality and morbidity.

Acute complications of percutaneous transluminal coronary angioplasty for total occlusion (Article)

1991-01-01T00:00:00Z

The incidence of major complications after percutaneous coronary angioplasty (PTCA) of a totally occluded artery was assessed retrospectively. A total of 1649 PTCA procedures were analyzed. After exclusion of procedures for acute myocardial infarction or total occlusion that resulted from restenosis, 90 patients were selected. Forty-four patients (49%) had stable angina and 46 (51%) had unstable angina. The estimated duration of occlusion was 87 +/- 78 days in patients with stable angina, as compared with 10 +/- 8 days in patients with unstable angina (p less than 0.001). Abrupt vessel closure during PTCA occurred only in patients with unstable angina (0% versus 17%, p less than 0.05). The major complication rate was 2.5% in the stable angina group, and 20% in unstable angina group (p less than 0.01). This rate was also significantly higher than the complication rate of 8% observed in 442 procedures that were performed during the same period in patients with the unstable angina and nonocclusive stenosis (p less than 0.01). Patients with unstable angina who undergo PTCA of a totally occluded artery represent a subset of high risk for major complications.

Long-term follow-up after attempted angioplasty of saphenous vein grafts: the Thoraxcenter experience 1981-1988 (Article)

1991-01-01T00:00:00Z

Between 1981 and 1988, 107 percutaneous transluminal coronary angioplasty (PTCA) procedures, including repeat PTCA, were performed in 84 patients with previous coronary artery bypass grafting (CABG). Fifty-nine patients underwent a first angioplasty of the vein graft alone, and 25 underwent a first PTCA of the graft and one or more native vessels. Seventeen patients underwent two procedures, four patients three procedures and one patient four procedures. In 84 first angioplasties, 133 lesions were attempted; 40 lesions in native vessels and 93 graft lesions (28 ostial stenoses, 33 shaft stenoses, and 32 stenoses at the distal anastomosis). Three patients died during their hospital stay. Two patients underwent emergency CABG. Seven patients sustained an acute myocardial infarction (AMI), among whom five underwent a PTCA of an occluded vessel. The clinical primary success rate per patient was 82%. After five years, 70% of patients were alive. At a median follow-up of 2.1 years, 41% of patients were alive and event-free (no AMI, no repeat CABG, no repeat PTCA). Symptomatic improvement was maintained in 36% of patients. Angioplasty of grafts may be an alternative to re-operation in selected patients with previous bypass surgery.

Delayed rupture of right coronary artery after directional atherectomy for bail-out (Article)

1991-01-01T00:00:00Z

The importance of adequate anticoagulation to prevent early thrombosis after stenting of stenosed venous bypass grafts (Article)

1991-01-01T00:00:00Z

Stent implantation in native coronary arteries may be complicated by acute thrombosis, despite the use of stringent anticoagulation. Thrombotic occlusion of stented venous grafts may occur less frequently, possibly because of the larger caliber of these grafts. We report our experience with 46 stents (Wallstent, Medinvent, Lausanne, Switzerland) implanted in 35 lesions of 24 consecutive patients (mean age 64 years, range 43 to 75). Two overlapping stents were implanted in seven patients, and three overlapping stents were positioned in two. After implantation, activated partial thromboplastin time was maintained at two to three times the control level by intravenous administration of heparin (160 to 550 mg daily) until thrombotest values were reduced 5% to 10% by acenocoumarol. Impending thrombotic occlusion was recognized in two suboptimally anticoagulated patients: patient A after implantation of four stents and patient B after anticoagulation therapy was discontinued because of acute upper gastrointestinal bleeding. Coronary artery bypass grafting was performed successfully in both patients. A third patient had a myocardial infarction on day 7 after stent implantation, in spite of adequate anticoagulation and optimal medical drug therapy. It is concluded that stringent anticoagulation therapy appears mandatory to maintain graft patency after stent implantation.

Quantitative angiography after directional coronary atherectomy (Article)

1991-01-01T00:00:00Z

OBJECTIVE: To assess by quantitative analysis the immediate angiographic results of directional coronary atherectomy. To compare the effects of successful atherectomy with those of successful balloon dilatation in a series of patients with matched lesions. DESIGN--Case series. SETTING--Tertiary referral centre. PATIENTS--62 patients in whom directional coronary atherectomy was attempted between 7 September 1989 and 31 December 1990. INTERVENTIONS--Directional coronary atherectomy. MAIN OUTCOME MEASURES--Increase in minimal luminal diameter of coronary artery segment. RESULTS--Angiographic success on the basis of intention to treat was obtained in 54 patients (87%). In four patients the lesion could not be crossed by the atherectomy device; all four had an uneventful conventional balloon angioplasty. Four of the 58 patients who underwent atherectomy were subsequently referred for coronary bypass surgery because of failure or complications; three of them sustained a transmural infarction. In the successful cases, coronary atherectomy resulted in an increase in the minimal luminal diameter from 1.1 mm to 2.5 mm with a concomitant decrease of the diameter stenosis from 62% to 22%. In the subset of 37 patients in which the changes induced were compared with conventional balloon angioplasty atherectomy increased the minimal luminal diameter more than balloon angioplasty (1.6 v 0.8 mm; p less than 0.0001). Conventional histology showed media or adventitia in 26% of the atherectomy specimens. In hospital complications occurred in six patients who had undergone a successful procedure: two transmural infarctions, two subendocardial infarctions, one transient ischaemia attack, and one death due to delayed rupture of the atherectomised vessel. All patients were clinically evaluated at one and six months. One patient had persisting angina (New York Heart Association class II), one patient sustained a myocardial infarction, one patient underwent a percutaneous transluminal coronary angioplasty for early restenosis, and one patient underwent coronary bypass surgery because of a coronary aneurysm formation. At six months 80% (36/47) of the patients were symptom free. CONCLUSIONS--Coronary atherectomy achieved a better immediate angiographic result than balloon angioplasty; however, in view of the complication rate in this preliminary series, which may be related to a learning curve, a randomised study is needed to show whether this procedure is as safe as a conventional balloon angioplasty.

Edge detection versus videodensitometry for quantitative angiographic assessment of directional coronary atherectomy (Article)

1991-01-01T00:00:00Z

Quantitative coronary angiography to measure progression and regression of coronary atherosclerosis. Value, limitations, and implications for clinical trials (Article)

1991-01-01T00:00:00Z

Comparative angiographic quantitative analysis of the immediate efficacy of coronary atherectomy with balloon angioplasty, stenting, and rotational ablation (Article)

1991-01-01T00:00:00Z

Interventional cardiology has branched in two directions: devices that primarily dilate coronary stenoses and those that debulk coronary tissue. Presently the optimum coronary intervention has not been found. While patients are awaiting randomized trials, a comparison based on matched quantitative coronary analysis may be useful to evaluate results of new interventional techniques. Therefore we compared 51 patients undergoing atherectomy with individually matched patients who were undergoing balloon angioplasty and stenting. The lesions were matched according to location of stenosis and reference diameter. Atherectomy and stenting resulted in larger gains in minimal luminal diameter compared with conventional balloon angioplasty. The minimal luminal diameter was increased from 1.2 +/- 0.4 mm to 2.6 +/- 0.4 mm in the atherectomy group and from 1.2 +/- 0.3 mm to 1.9 +/- 0.4 mm in the angioplasty group (p less than 0.00001). Atherectomy and stenting resulted in similar gains in minimum luminal diameter (1.4 mm vs 1.3 mm, p = NS). In addition, atherectomy and stenting appear to be more effective in resisting elastic recoil because of tissue removal and an intrinsic dilating effect, respectively. In matched populations directional atherectomy and stenting appear to be more effective intracoronary interventional devices than balloon angioplasty based on the immediate results. However, atherectomy is limited in smaller coronary vessels because of its larger size.

Inability of coronary blood flow reserve measurements to assess the efficacy of coronary angioplasty in the first 24 hours in unselected patients (Article)

1991-01-01T00:00:00Z

To determine functional and anatomic changes in the first 24 hours after coronary angioplasty, we studied at random 15 patients (9 men, mean age 60 years) who underwent coronary angioplasty of 16 coronary arteries. Quantitative coronary angiography and coronary flow reserve measurements from digitized coronary angiograms were performed before, immediately after, and 24 hours after coronary angioplasty. Calculated were the minimal luminal diameter, obstruction area, and percentage diameter stenosis from two preferably orthogonal projections. Prior myocardial infarction in the myocardial region of interest was present in four patients. Seven patients had multivessel disease. Collateral vessels supplying the compromised flow region were observed in three patients. Six patients had refractory unstable angina pectoris. After coronary angioplasty, angiographically visible dissection was noted in six patients, whereas side branch occlusion was observed in one. Minimal luminal diameter before, immediately after, and 24 hours after was 0.93 +/- 0.18 mm, 1.53 +/- 28 mm, and 1.53 +/- 0.21 mm, respectively; obstruction area was 0.70 +/- 0.26 mm2, 1.92 +/- 0.69 mm2, and 1.87 +/- 0.51 mm2, respectively; diameter stenosis was 60.4 +/- 8.0%, 36.8 +/- 11.4%, and 37.6 +/- 5.3%, respectively. The coronary flow reserve (lower limit of normal with this technique 3.4) was essentially the same before and immediately after coronary angioplasty (1.26 +/- 0.59 vs 1.30 +/- 0.42, p = NS) with a slight improvement to 1.78 +/- 0.90 (p less than 0.05) 1 day later. Coronary artery dimensions correlated poorly with coronary blood flow reserve before and after angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Tissue plasminogen activator in refractory unstable angina. A randomized double-blind placebo-controlled trial in patients with refractory unstable angina and subsequent angioplasty (Article)

1991-01-01T00:00:00Z

To evaluate the effect of recombinant tissue plasminogen activator (alteplase) on the clinical course, angiographic changes and the outcome of subsequent coronary angioplasty, 36 patients with angina at rest, despite bedrest and medical treatment including heparin, and with concomitant ECG changes, were studied. After diagnostic angiography, patients were randomized to receive either alteplase 100 mg in 3 h (19 patients), or placebo (17 patients). The mean interval between qualifying anginal episode and initial angiography was 10 and 9 h for the alteplase and placebo group, respectively. Angiography was repeated and angioplasty was performed within 24 hours. Between the first and the second angiogram, five patients in the alteplase and seven in the placebo group had recurrent ischaemic episodes, while four alteplase and three placebo patients showed signs of myocardial necrosis (creatine kinase (CK) rise greater than or equal to twice the upper limit for normal). Intracoronary clots were recognized in three alteplase patients and one placebo patient at the first angiogram, while two alteplase patients and one placebo patient showed total occlusion of the ischaemic-related vessel. After infusion, thrombi were present in four alteplase patients and one placebo patient, and total occlusion in three alteplase patients and one placebo patient. Quantitative coronary angiography showed no change in the percentage diameter stenosis of the ischaemia-related segment after drug infusion, (alteplase 67 +/- 16 to 69 +/- 16%; placebo 65 +/- 11 to 63 +/- 12%). Angioplasty was successful in 14 of 19 alteplase and 14 of 16 placebo patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative quantitative angiographic analysis of directional coronary atherectomy and balloon coronary angioplasty (Article)

1991-01-01T00:00:00Z

An attempt to assess the "utility" of directional atherectomy was made using a new quantitative angiographic index. This index can be subdivided into an initial gain component and a restenosis component. The initial gain index is the ratio between the gain in diameter during intervention and the theoretically achievable gain (i.e., reference diameter). The restenosis index is the ratio between the decrease at follow-up and the initial gain during the procedure. The net result at long-term follow-up is characterized by the utility index, which is the ratio between the final gain in diameter at follow-up and what theoretically could have been achieved. For this purpose, 30 coronary artery lesions were selected from a consecutive series of successfully dilated primary angioplasty lesions and were matched with the initial 30 successfully treated primary atherectomy lesions. Matching by location of stenosis and reference diameter resulted in 2 comparable groups with identical preprocedural stenosis characteristics. Atherectomy resulted in an increase in minimal luminal diameter 2 times larger than angioplasty (1.53 vs 0.77 mm; p less than 0.0001). However, at follow-up there was a significant decrease in minimal luminal diameter and a significant increase in percent diameter stenosis in the groups with atherectomy and angioplasty (1.69 +/- 0.58 vs 1.57 +/- 0.58 mm, p = not significant [NS], and 37 +/- 18 vs 47 +/- 18%, p = NS, respectively). The decrease in minimal luminal gain was more pronounced in the group with atherectomy than in that with angioplasty (0.92 +/- 0.69 vs 0.35 +/- 0.51 mm; p = 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement of left ventricular contractility and relaxation with the B1-adrenergic receptor partial agonist in Xamoterol at rest and during exercise in patients with postinfarction left ventricular dysfunction (Article)

1990-01-01T00:00:00Z

A new cardioselective beta 1-adrenergic receptor agonist xamoterol (Corwin) has been developed for the treatment of heart failure. To study the acute hemodynamic effects of xamoterol, 24 patients, 39-70 years old, with mild-to-moderate postinfarction left ventricular dysfunction entered a double-blind, between-patient comparison of a single 5-minute intravenous infusion of xamoterol (0.2 mg/kg) and placebo. The acute hemodynamic effects of xamoterol were measured at rest and during two multistaged symptom-limited supine bicycle exercise tests (Ex-T), a control Ex-T followed by an Ex-T with either xamoterol or placebo. Compared with placebo, xamoterol significantly increased left ventricular contractility (Vmax and positive [+] dP/dt) and enhanced relaxation (dP/dt- and time constant relaxation) at rest and at the 25% and 50% levels of maximum exercise. The heart rate, the frequency and time to onset of anginal symptoms, the magnitude of exercise-induced ST segment depression, the left ventricular end-diastolic and peak systolic pressures, the mean pulmonary artery pressures, the cardiac index, the left ventricular stroke-work index, and the epinephrine and norepinephrine plasma levels at rest and during exercise did not differ significantly between placebo xamoterol groups. Thus, xamoterol can be a useful addition for the treatment of left ventricular dysfunction because of long-term ischemic heart disease.

Acute hemodynamic effects of the B1-adrenoceptor partial agonist xamoterol at rest and during supine exercise in patients with left ventricular dysfunction due to ischaemic heart disease: a double-bline randomized trial (Article)

1990-01-01T00:00:00Z

The effects of xamoterol 0.2 mg kg-1 i.v. and placebo on left ventricular function at rest and on exercise were compared in patients with left ventricular dysfunction due to ischaemic heart disease. Improvements were seen in systolic and diastolic function at rest, and at up to 50% of maximal exercise, without evidence of worsening myocardial ischaemia.

Directionele coronaria-atherectomie; eerste Nederlandse ervaringen met een nieuwe percutane revascularisatiemethode (Article)

1990-01-01T00:00:00Z

Successful multiple segment coronary angioplasty: Effect of completeness of revascularization in single-vessel multilesions and multivessels (Article)

1990-01-01T00:00:00Z

A long-term follow-up study was performed to evaluate the long-term value of performing multiple dilatations according to their procedural (single-vessel multilesion or mutltivessel dilatations) and anatomic types (single-vessel disease with multiple dilatations or multivessel disease dilatations with complete and incomplete revascularization). From 1980 until 1988, 248 patients met the following criteria: (1) at least two lesions dilated (range: 2 to 4) and (2) all attempted lesions successfully dilated. The mean length of follow-up was 33 months. The end points analyzed were death, myocardial infarction, redilatation, and bypass surgery. No differences were found for these events between the single-vessel multilesion group (144 patients) and the multivessel group (104 patients). The 4.5-year probability of event-free survival was 68% and 70%, respectively, for the multilesion group and the multivessel group. In the event-free patients, 57% versus 59% were asymptomatic and 45% versus 46% were not taking antianginal drugs. In the anatomic subgroups, there were less event-free patients in the cohort of incompletely revascularized multivessel disease patients (55% of 55 patients) when compared with the cohort of those who were completely revascularized (84% of 79 patients) or when compared with the single-vessel disease multiple dilatation patients (74% of 107 patients). The 4.5-year event-free survival probability for each group was 44%, 78%, and 74%, respectively. This difference was caused by more infarctions (9% versus 2% versus 4%, respectively) and bypass operations in the multivessel disease, incomplete revascularization group (20% versus 5% versus 10%, respectively). In event-free patients, improvement of angina was similar and was documented in over 85% of patients in each group. Furthermore, the number of asymptomatic patients at follow-up was similar in all groups except that within the incomplete revascularization group, less patients were free of antianginal drugs (21% versus 51% versus 48%). Finally, 48% of the entire cohort performed an exercise test 4.6 months (mean) after dilatation and no difference was found in any of the variables in any group. About 10% of the patients experienced angina and approximately 30% had a positive exercise test for ischemia by ST segment criteria. The functional performance in every group was over 90% of the predicted work load. These results suggest that completeness of revascularization in multivessel disease patients is an important prognostic variable. However, the symptomatic improvement after dilatation is very rewarding in all subsets of patients and argues in favor of the continued use of multiple dilatations as a treatment strategy.

Comparison of costs of percutaneous transluminal coronary angioplasty and coronary bypass surgery for patients with angina pectoris (Article)

1990-01-01T00:00:00Z

To determine the costs of a procedure, the total costs of the department that provides the service must be considered and, in addition, the direct cost of the specific procedure. Applying this principle to the cost accounting of angioplasty and bypass surgery results in a direct, i.e. procedural, cost, including the initial hospital stay, of respectively 8694 Dfl and 20,987 Dfl. A review of the follow-up data for the first year after the original intervention revealed a 2% reintervention rate for bypass surgery, while this percentage was 29% for angioplasty. Adding the first year costs involved with reinterventions to the procedural costs results in a 1-year cost of angioplasty and bypass operation of 13,625 Dfl and 21,363 Dfl, respectively. It is concluded that because of reinterventions in the first year, a mark up of 57% on the procedural cost of angioplasty must be added to cover 1-year costs, while for bypass surgery this is only 1%. Nevertheless, the 1-year cost for angioplasty is still 36% less than for bypass surgery. As reinterventions after PTCA may stay considerably higher than for CABG for several years, the mark-up percentages will be substantially higher for longer time spans. This may tend to equalize the total costs of PTCA and CABG over time spans of perhaps 5-8 years. Sufficient data are not available to verify this statement. Clinicians must realize that choosing the most appropriate procedure is not only a matter of medical assessment but also a matter of cost effectiveness. CABG can be seen as an 'investment decision' while PTCA tends to become a decision with characteristics of 'maintenance planning'!

Recovery of regional myocardial dysfunction after successful coronary angioplasty early after a non-Q wave myocardial infarction (Article)

1990-01-01T00:00:00Z

More aggressive therapy has been suggested for patients who have a non-Q wave myocardial infarction (MI) because of the frequency of subsequent unstable angina, recurrent MI, and high mortality rate compared to patients with Q wave MI. The present study was undertaken to investigate the effect of coronary angioplasty on regional myocardial function of the infarct zone in patients with angina early after a non-Q wave MI. The study population consisted of 36 patients undergoing successful coronary angioplasty within 30 days of a non-Q wave MI, in whom sequential left ventricular angiograms of adequate quality were obtained before the initial procedure and at follow-up angiography. The global ejection fraction increased significantly from 60 +/- 9% to 67 +/- 6% (p = 0.0003). This significant increase in the global ejection fraction was primarily due to a significant improvement in the regional myocardial function of the infarct zone. The results of the present study show not only that ischemic attacks early after a non-Q wave MI may lead to prolonged regional myocardial dysfunction but more important that this depressed myocardium has the potential to achieve normal contraction after successful coronary angioplasty.

Assessment of "silent" restenosis and long-term follow-up after successful angioplasty in single vessel coronary artery disease: the value of quantitative exercise electrocardiography and quantitative coronary angiography (Article)

1990-01-01T00:00:00Z

Exercise electrocardiographic (ECG) testing during follow-up after coronary angioplasty is widely applied to evaluate the efficacy of angioplasty, even in asymptomatic patients. One hundred forty-one asymptomatic patients without previous myocardial infarction underwent quantitative exercise ECG testing and quantitative coronary angiography 1 to 6 months after successful angioplasty in single vessel coronary artery disease to 1) determine the value of exercise ECG testing to detect "silent" restenosis, and 2) assess the long-term prognostic value of exercise ECG testing and coronary angiography. The prevalence of restenosis (defined as greater than or equal to 50% luminal narrowing at the dilation site) was 12% in this selected study group. Of 26 patients with an abnormal exercise ECG (ST segment depression greater than or equal to 0.1 mV), only 4 (15%) showed recurrence of stenosis. Sensitivity and specificity for detection of restenosis were 24% and 82%, respectively. One hundred thirty-four patients (95%) were followed up 1 to 64 months (mean 35) after exercise ECG testing and coronary angiography. Thirty-two patients (24%) experienced a cardiac event: in 25 patients (78%) the initial event was recurrent angina pectoris (New York Heart Association class III or IV) and in 7 patients (22%) it was myocardial infarction, although cardiac death did not occur. The mean interval between exercise ECG testing and the initial cardiac events was 14 months (range 1 to 55), whereas 47% of the initial events took place less than or equal to 6 months after exercise ECG testing.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutane transluminale coronaria-angioplastiek bij patienten ouder dan 70 jaar; korte- en lange-termijnresultaten (Article)

1990-01-01T00:00:00Z

Quantitative angiographic assessment of elastic recoil after percutaneous transluminal coronary angioplasty (Article)

1990-01-01T00:00:00Z

Little is known about the elastic behavior of the coronary vessel wall directly after percutaneous transluminal coronary angioplasty (PTCA). Minimal luminal cross-sectional areas of 151 successfully dilated lesions were studied in 136 patients during balloon inflation and directly after withdrawal of the balloon. The circumvent geometric assumptions about the shape of the stenosis after PTCA, a videodensitometric analysis technique was used for the assessment of vascular cross-sectional areas. Elastic recoil was defined as the difference between balloon cross-sectional area of the largest balloon used at the highest pressure and minimal luminal cross-sectional area after PTCA. Mean balloon cross-sectional area was 5.2 +/- 1.6 mm2 with a mean minimal cross-sectional area of 2.8 +/- 1.4 mm2 immediately after inflation. Oversizing of the balloon (balloon artery ratio greater than 1) led to more recoil (0.8 +/- 0.3 vs 0.6 +/- 0.3 mm, p less than 0.001), suggestive of an elastic phenomenon. A difference in recoil of the 3 main coronary branches was observed: left anterior descending artery 2.7 +/- 1.3 mm2, circumflex artery 2.3 +/- 1.2 mm2 and right coronary artery 1.9 +/- 1.5 mm2 (p less than 0.025). The difference was still statistically significant if adjusted for reference area. Thus, nearly 50% of the theoretically achievable cross-sectional area (i.e., balloon cross-sectional area) is lost shortly after balloon deflation.

Emergency stenting for refractory acute coronary artery occlusion during coronary angioplasty (Article)

1990-01-01T00:00:00Z

Myocardial release of hypoxanthine and lactate during percutaneous transluminal coronary angioplasty (Article)

1989-01-01T00:00:00Z

The response of myocardial lactate and hypoxanthine metabolism during percutaneous transluminal coronary angioplasty was studied in a series of 15 patients undergoing this procedure. A minimum of 4 balloon inflations was performed per patient with an average duration per occlusion of 49 +/- 11 seconds (mean +/- standard deviation) for a total occlusion time of 192 +/- 40 seconds. Thermodilution coronary venous blood flow measured in the great cardiac vein decreased from control values of 72 +/- 4 ml/min (mean +/- standard error of the mean) to 47 +/- 10 ml/min with the fourth coronary occlusion (p less than 0.005). Arteriovenous lactate and hypoxanthine showed peak differences during the reactive hyperemia after the first 2 occlusions which did not increase after subsequent occlusions. Within minutes after the procedure, lactate and hypoxanthine efflux was no longer seen, demonstrating the reversibility of the metabolic disturbances after repeated ischemia. The results of this study indicate that there is no permanent alteration in lactate or hypoxanthine metabolism after percutaneous transluminal coronary angioplasty with 4 coronary occlusions of 40 to 60 seconds' duration, with a total occlusion time of 192 +/- 40 seconds.

Short-, medium-, and long-term follow-up after percutaneous transluminal coronary angioplasty for stable and unstable angina pectoris (Article)

1989-01-01T00:00:00Z

The first 840 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) performed in the same institution were retrospectively assessed at an average follow-up period of 25 months after the initial procedure. The study population consisted of 506 patients with stable angina pectoris (group 1) and 334 patients with unstable angina pectoris (group 2). Clinical end points were death, nonfatal myocardial infarction, recurrent angina pectoris necessitating bypass surgery or repeat PTCA, and event-free survival. The two groups were comparable with respect to age, sex, previous myocardial infarction, ejection fraction, and number of diseased vessels. PTCA was successful in 83.0% of group 1 and 87.1% of group 2. Follow-up rates were expressed as events per attempted PTCA in a patient group. No difference in survival was observed between the two groups, the mortality rate being approximately 2.8% at 25 months. In the group with stable angina pectoris there was a lower incidence of nonfatal myocardial infarction within the first 24 hours after angioplasty; 4.3% vs 9.0% (p less than 0.01). During long-term follow-up the increase in the incidence of nonfatal myocardial infarction was similar, resulting in an overall long-term follow-up infarction rate of 8.3% and 14.2%, respectively (p less than 0.01). A higher event-free survival was observed in group 1 within 24 hours after PTCA: 93.7% vs 84.2% (p less than 0.01). During subsequent follow-up the difference in event-free survival between the two groups was no longer significant: 68.5% vs 61.2%.(ABSTRACT TRUNCATED AT 250 WORDS)

Fracture of a balloon on a wire device during coronary angioplasty (Article)

1989-01-01T00:00:00Z

In a 61-year-old patient with unstable angina an attempt was made to dilate a severe stenosis in a tortuous obtuse marginal branch. The initial attempt with conventional equipment was not successful; although the wire could be advanced distal to the stenosis, a 2.0 balloon did not cross the stenosis. A second attempt with a balloon on a wire device resulted in fracture of this catheter, with the distal 2.8-cm-long fragment looped in the left coronary artery. Immediate bypass surgery was performed and the broken fragment was easily removed from the left coronary ostium. The patient made an uneventful recovery.

Percutaneous transluminal angioplasty of a totally occluded venous bypass graft: a challenge that should be resisted (Article)

1989-01-01T00:00:00Z

Haemodynamic observations during percutaneous transluminal coronary angioplasty in the presence of synchronised diastolic coronary sinus retroperfusion (Article)

1988-01-01T00:00:00Z

Animal studies have demonstrated that synchronised coronary sinus retroperfusion with arterial blood can provide effective perfusion of ischaemic myocardium. Preliminary clinical studies have shown that the technique can also be used with safety in human beings, and in the present study its effectiveness was assessed in three patients undergoing repeated coronary artery occlusions during percutaneous transluminal coronary angioplasty. Arterial blood was removed via an 8F catheter positioned in the femoral artery and delivered by a retroperfusion pumping system to a 7F retroperfusion balloon catheter positioned in the anterior cardiac vein. Ischaemia-related indices were monitored both before and during coronary sinus retroperfusion. These indices included high fidelity left ventricular pressure recordings and pressure derived indices (including velocities of isovolumic contraction and relaxation), as well as electrocardiographic changes and symptoms. Analysis of these variables showed that the ischaemic changes induced during coronary artery occlusion were not prevented by this type of coronary sinus retroperfusion. There was no major complication in any of the patients. It may be that adaptation of the technique or the use of alternative end points will establish a benefit, but further modifications of the delivery system are necessary for effective clinical use.

Incidence of restenosis after successful coronary angioplasty: a time-related phenomenon. A quantitative angiographic study in 342 consecutive patients at 1, 2, 3, and 4 months (Article)

1988-01-01T00:00:00Z

Data from experimental, clinical, and pathologic studies have suggested that the process of restenosis begins very early after coronary angioplasty. The present study was performed to determine prospectively the incidence of restenosis with use of the four National Heart, Lung, and Blood Institute and the 50% or greater diameter stenosis criteria, as well as a criterion based on a decrease of 0.72 mm or more in minimal luminal diameter. Patients were recatheterized at 30, 60, 90, or 120 days after successful percutaneous transluminal coronary angioplasty (PTCA). After PTCA all patients received 10 mg nifedipine three to six times a day and aspirin once a day until repeat angiography. Of 400 consecutive patients in whom PTCA was successful (less than 50% diameter stenosis), 342 underwent quantitative angiographic follow-up (86%) by use of an automated edge-detection technique. A wide variation in the incidence of restenosis was found dependent on the criterion applied. The incidence of restenosis proved to be progressive to at least the third month for all except NHLBI criterion II. At 4 months a further increase in the incidence of restenosis was observed when defined as a decrease of 0.72 mm or more in minimal luminal diameter, whereas the criteria based on percentage diameter stenosis showed a variable response. The lack of overlap between the different restenosis criteria applied affirms the arbitrary nature of angiographic definitions currently in use. Restenosis should be assessed by repeat angiography, and preferably ascertained according to the change in absolute quantitative measurements of the luminal diameter.

Percutaneous transluminal coronary angioplasty for angina pectoris after a non-Q-wave acute myocardial infarction (Article)

1988-01-01T00:00:00Z

Despite initially favorable prognosis in patients with non-Q-wave acute myocardial infarction (AMI), long-term mortality in this subset of patients appears to be similar to or even greater than that in patients with Q-wave AMI. The relatively poor late prognosis is primarily due to a high incidence of unstable angina and recurrent AMI. Between January 1982 and January 1987, 114 patients with suitable coronary narrowing underwent percutaneous transluminal coronary angioplasty (PTCA) for angina pectoris (present either at rest or during mild exertion, and despite optimal pharmacologic therapy), a median of 31 (range 2 to 362) days after a non-Q-wave AMI. Success was achieved in dilating the obstructed artery in 98 patients (113 of the 129 dilated arteries). Emergency bypass surgery was performed in 7 patients. Mean clinical follow-up of 20 (range 3 to 59) months was obtained in all patients and revealed no deaths. Of the 98 patients with successful PTCAs, 6 (6%) developed a nonfatal recurrent AMI and 62 (63%) were asymptomatic. However, recurrent angina affected 31 patients (32%) and was treated by repeat PTCA (n = 18), coronary bypass surgery (n = 5) or pharmacologic therapy (n = 8). At follow-up, 74% of the patients (73 of 98) were asymptomatic after a successful PTCA and, if necessary, a repeat PTCA, without incidence of recurrent AMI, coronary bypass surgery or death. The high initial success rate, low incidence of subsequent death and late recurrent AMI and sustained symptomatic benefit suggest that PTCA is an effective initial treatment strategy in these selected patients.

Coronary blood flow velocity during percutaneous transluminal coronary angioplasty as a guide for assessment of the functional result (Article)

1988-01-01T00:00:00Z

To investigate the clinical usefulness of intracoronary Doppler recordings during percutaneous transluminal coronary angioplasty (PTCA), the changes of intracoronary blood flow velocity during PTCA were assessed in 20 patients with single proximal coronary stenosis, using a Doppler probe end-mounted on the tip of a PTCA catheter. A mean of 4 inflations was performed in each patient. Intracoronary velocities were measured before and after each inflation and during peak reactive hyperemia after each transluminal occlusion. Quantitative analysis of the coronary stenosis was assessed before and after PTCA, and the dilatation resulted in an increase in minimal luminal cross-sectional area from 1.1 +/- 0.8 to 2.7 +/- 1.2 mm2. A gradual and significant improvement in velocities was observed after the first 3 dilatations, but in 15 of the 20 patients the resting and hyperemic velocities were not affected by the fourth dilatation. Coronary flow reserve measured during reactive hyperemia after the last dilatation with the PTCA catheter across the lesion was 1.9. This value of coronary flow reserve is compatible with the residual stenosis measured after PTCA when corrected for the presence of the Doppler balloon catheter (0.68 mm2). This application of the Doppler technique may provide a new method of on-line functional monitoring of the PTCA procedure in individual patients, but does not yet allow an accurate prediction of the change in coronary geometry brought about by PTCA.

Coronary vasodilatory action after a single dose of nicorandil (Article)

1988-01-01T00:00:00Z

Coronary hemodynamics and vasodilatory effects on major epicardial arteries were investigated after a single dose of nicorandil in 22 patients undergoing cardiac catheterization for suspected coronary artery disease. Nicorandil, 20 mg, was administered sublingually to 11 consecutive patients and 40 mg to 11 others. Systemic blood pressure decreased significantly without affecting the heart rate. Coronary sinus blood flow did not change significantly. As the mean aortic pressure decreased significantly by 13% after 20 mg and 21% after 40 mg of nicorandil, the calculated coronary vascular resistance decreased but did not reach statistical significance. There was a decrease in myocardial oxygen consumption (-14% and -22%, respectively), and this was consistent with a significant decrease in the calculated pressure-rate product of 19% and 24%, respectively. A total of 103 selected coronary segments, including 17 stenotic segments, were analyzed quantitatively using a computer-assisted coronary angiography analysis system. After 20 or 40 mg of nicorandil, a significant increase of the mean diameter was observed in the proximal (+9% and +7%), midportion (+10% and +11%) and distal (+15% and +13%) parts of the left anterior descending coronary artery. Corresponding values for the proximal (+13% and +10%) and distal (+10% and +15%) segments of the circumflex artery were observed. An increase in the obstruction diameter was also observed in all but 3 of the analyzed stenotic segments. The results demonstrate that nicorandil, in the route and doses used, causes a significant vasodilation in the major epicardial coronary segments, including most stenotic segments, and decreases the myocardial oxygen demand with little effect on the resistance vessels.

Immediate PTCA after successful thrombolysis with intracoronary streptokinase, three years follow-up. A matched pair analysis of the effect of PTCA in the randomized multicentre trial of intracoronary streptokinase, conducted by the Interuniversity Cardiology Institute of The Netherlands (Article)

1988-01-01T00:00:00Z

Immediate PTCA following thrombolysis with streptokinase was performed in 46 out of 533 patients enrolled in a multicentre randomized trial of early reperfusion in patients with acute myocardial infarction. Additional effects of PTCA in patients with a residual diameter stenosis in the infarct-related coronary artery of 70% or more after thrombolysis were compared with successful thrombolysis alone in a matched pair analysis. Thirty six pairs of patients were formed identical with respect to the infarct related coronary artery, presence or absence of previous myocardial infarction, total ST segment elevation on the ECG at admission to the trial, and delay between onset of symptoms and hospital admission. PTCA after thrombolysis did not lead to additional limitation of infarct size, nor to further preservation of left ventricular function. Infarction rate during the three-year follow-up was 14% after PTCA versus 30% after thrombolysis alone (P = 0.05). Similarly, patients had less angina or heart failure after PTCA, since on average 128 out of 156 weeks follow-up were symptom free, while this was only 102 weeks after thrombolysis alone (P = 0.03). Immediate PTCA after thrombolysis with intracoronary streptokinase seems to prevent recurrent ischemia and reinfarction. Further studies should address the proper indication and timing of PTCA after thrombolysis.

Indications for coronary angioplasty in acute myocardial ischemic syndromes (Article)

1988-01-01T00:00:00Z

The role of coronary angioplasty for the treatment of patients with evolving myocardial infarction, unstable angina, and early postinfarction unstable angina is discussed. It has been shown that coronary angioplasty in patients with an evolving myocardial infarction is feasible and can be performed with a high initial success rate. The most beneficial timing of dilatation is still unclear, and acute reocclusion following coronary angioplasty remains a problem. Current data suggest that the left ventricular function is greater improved and peri-infarction ischemia is less with angioplasty when compared with sole thrombolytic treatment. Coronary angioplasty for unstable angina and early post-infarction unstable angina can be performed with a high initial success rate, but at an increased risk of major complications. Thus, coronary angioplasty has nowadays obtained a definitive place in the treatment of acute myocardial ischemic syndromes. Further research is needed to improve the initial and late results of coronary angioplasty, and additional randomized clinical studies are necessary to more accurately define the indications and timing of dilatation in these acutely ill patients.

Change in diameter of coronary artery segments adjacent to stenosis after percutaneous transluminal coronary angioplasty: failure of percent diameter stenosis measurement to reflect morphologic changes induced by balloon dilation (Article)

1988-01-01T00:00:00Z

To determine the changes in stenotic and nonstenotic segments of a dilated coronary artery, detailed quantitative angiographic measurements were performed in 342 patients (398 lesions) immediately after angioplasty and at a predetermined follow-up time of 30, 60, 90 or 120 days after the dilation. Measurements of the stenotic segments were expressed as minimal luminal diameter, and the adjacent nonstenotic segments were expressed as interpolated reference diameter (both in millimeters). A follow-up rate of 86% was achieved. In the patients followed up at 30 and 60 days, there was no significant change in either the mean minimal luminal diameter or the mean reference diameter. However, at 90 and 120 days, there was significant deterioration in both the mean minimal luminal diameter (-0.37 and -0.42 mm, respectively) and the mean reference diameter (-0.17 and -0.26 mm, respectively), all of the changes being highly significant (p less than 0.00001). The reference diameter is involved in the dilation process and may be subject to the same restenosis process that takes place in initially stenotic segments. Percent diameter stenosis measurements, which are conventionally used to express the change in the severity of a stenosis after angioplasty, will tend to underestimate the change when there is a simultaneous reduction in the reference diameter.

Coronary angioplasty for unstable angina: immediate and late results in 200 consecutive patients with identification of risk factors for unfavorable early and late outcome (Article)

1988-01-01T00:00:00Z

Two hundred patients (mean age 56 years, range 36 to 74) with unstable angina (chest pain at rest, associated with ST-T changes) underwent coronary angioplasty. In 65 patients with multivessel disease, only the "culprit" lesion was dilated. The initial success rate was 89.5% (179 of 200 patients). At least one major procedure-related complication occurred in 21 patients (10.5%): (death in 1, myocardial infarction in 16 and urgent surgery in 18). All patients were followed up for 2 years. Five patients died late; 8 had a late nonfatal myocardial infarction and 52 had recurrence of angina pectoris. The restenosis rate was 32% (51 of 158) in the patients with initial successful angioplasty who had repeat angiography. At the 2 year follow-up, after attempted coronary angioplasty in all 200 patients, the total incidence rate of death was 3% (one procedure related; five late deaths), of nonfatal myocardial infarction 12% (16 procedure related and 8 late after angioplasty), and 13% (26 patients) were still symptomatic although they had improved in functional class. Multivariate analysis showed that variables indicating an increased risk 1) for major procedure-related complications were: ST segment elevation, persistent negative T wave and stenosis greater than or equal to 65% (odds ratio 3.7, 3.7 and 3.3, respectively); 2) for angiographic restenosis were: presence of collateral vessels, ST segment depression, multivessel disease, left anterior descending coronary artery stenosis and history of recent onset of symptoms (odds ratio: 2.2, 2.0, 1.9, 1.9 and 0.54, respectively); and 3) for late coronary events (recurrence of angina, late myocardial infarction or late death) were: multivessel disease, total occluded vessel and ST segment elevation (odds ratio 3.7, 2.8 and 0.44, respectively). Thus, coronary angioplasty for unstable angina can be performed with a high initial success rate, but at an increased risk of major complications. The prognosis is favorable after initial successful coronary angioplasty.

Percutaneous balloon valvuloplasty for calcific aortic stenosis. A treatment sine cure? (Article)

1988-01-01T00:00:00Z

Twenty-five elderly patients with calcific aortic stenosis, 12 male (48%) and 13 female (52%), mean age 74.8 +/- 7.6 years, underwent percutaneous aortic balloon valvuloplasty between March 1986 and September 1987. Twenty-two patients (88%) were in class III-IV of the New York Heart Association, 13 (52%) had a history of previous angina and 7 (28%) of syncopal attacks. All patients had been considered either unsuitable or high-risk candidates for aortic-valve replacement because of age or associated diseases. Balloons of increasing size (area ranging from 1.3 to 3.8 cm2 during inflation) were successively passed retrogradely from the femoral artery and manually inflated to 3-7 atmospheres. Inflation duration ranged from 15 to 260 s (mean 40 s). Post-dilatation there were significant changes in left ventricular peak-systolic and end-diastolic pressures (P less than 0.00001 and P less than 0.01, respectively), mean systolic aortic transvalvular gradient (from 73 to 43 mmHg, P less than 0.000001), mean systolic aortic flow (from 176 to 208 ml s-1, P less than 0.0001) and aortic valve area (from 0.47 to 0.72 cm2, P less than 0.000001). Major complications included: in-hospital deaths of two patients (8%) admitted in cardiogenic shock; left haemiplegia (4%); transient haemianopia (8%); development of grade III aortic insufficiency (4%); and persistent complete atrioventricular block (4%). Complications at the puncture-site occurred in 7 patients (28%)--including two femoral pseudoaneurysms and the need for surgical removal of a balloon remnant after rupture in one patient. No local haemorrhagic complications were observed in the latter eight procedures, performed using a 16.5 French 100-cm long arterial introducer. At a mean follow-up of 13.0 +/- 5.0 months, an important functional improvement persisted in 14 patients (56%), no major changes in pre-valvuloplasty symptoms were observed in 3 patients (12%), while five patients (20%) required surgical treatment after a successful valvuloplasty because of recurrence of symptoms (late valve restenosis). Percutaneous aortic balloon valvuloplasty is a possible palliative therapy in elderly patients with calcific aortic stenosis. However, its inherent immediate risk, limited haemodynamic result and the possible development of valve restenosis at medium-term follow-up, suggest that the application of this technique should be limited to poor surgical candidates.

Coronary angioplasty in patients with unstable angina pectoris: is there a role for thrombolysis? (Article)

1988-01-01T00:00:00Z

Management of unstable angina has evolved progressively, and coronary angioplasty has recently been shown to be an effective treatment strategy for unstable angina. However, the procedure-related major complication rate is higher when compared with that for angioplasty in stable angina. The underlying pathophysiology may explain this higher complication rate. Rupture of an atherosclerotic plaque associated with thrombus formation is frequent in the pathogenesis of unstable angina. These processes lead to a critical reduction in myocardial blood supply, and coronary angioplasty may effectively interrupt this process. In contrast, coronary angioplasty itself may cause further injury of the already ulcerated intima, have the potential to intensify the ongoing thrombogenic process and lead to an increased frequency of abrupt closure of the artery during the procedure. Therefore, intracoronary streptokinase was used in the procedure in those patients with abrupt closure of the artery immediately after dilation to attempt to improve the immediate result. Coronary angioplasty was attempted in 200 consecutive patients with unstable angina. Initial success in crossing the obstructed artery was achieved in 196 patients; however, an abrupt closure immediately after dilation occurred in 21 of these patients. Of these 21 patients, 12 were also treated with intracoronary streptokinase, and successful dilation was achieved in 9 patients without evidence of necrosis or the need for emergency bypass surgery. Of the remaining nine patients, four successfully underwent redilation with a larger-sized balloon, four underwent urgent surgery (one death postoperatively) and one was treated conventionally. Final success was achieved in 188 patients (94%) without death, the need for emergency surgery or evidence of myocardial necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequential dilatation of septal and left anterior descending artery: single guiding catheter and double guide wire technique (Article)

1987-01-01T00:00:00Z

A new technique was used to dilate sequentially a bifurcation lesion involving the left anterior descending artery and the origin of a large septal branch. Two steerable long guide wires (300 cm) were advanced through a single guiding catheter and placed across each lesion. The balloon catheters were introduced into the target arteries for angioplasty one at a time over the pre-positioned guide wires. After the septal branch had been successfully dilated, the balloon catheter was completely withdrawn from the manifold and a second balloon catheter positioned in the left anterior descending artery over the guide wire already placed across the stenosis. Such a technique is feasible and safe, and overcomes the potential risks of the conventional kissing balloon technique.

Regional cardioprotection by subselective intracoronary nifedipine is not due to enhanced collateral flow during coronary angioplasty (Article)

1987-01-01T00:00:00Z

Twelve patients with proximal stenosis of the left anterior descending artery, normal myocardial wall motion but without angiographically demonstrable collateral circulation, were studied during transluminal occlusion. Prior to the first transluminal occlusion before crossing the lesion with the balloon, patients were randomly given 0.2 mg nifedipine or its solvent in the left mainstem. The same dose was repeated via the balloon catheter, positioned across the lesion, immediately prior to the second transluminal occlusion. In all patients great cardiac venous flow and ST-elevation were monitored during and after each transluminal occlusion. The lactate extraction ratio A-GCV/A (A = arterial, GCV = great cardiac vein) was determined prior to the angioplasty procedure, 10-15 seconds after each transluminal occlusion and 10 minutes after the third transluminal occlusion. Great cardiac venous flow rose significantly to an average of 160% of basal flow when nifedipine was administered into the mainstem before the angioplasty procedure while its solvent had no effect. During each transluminal occlusion, great cardiac venous flow diminished on average by 30% in those who received nifedipine and by 28% in those who received only its solvent. This difference was statistically not significant. After angioplasty great cardiac venous flow was slightly, but not significantly, increased in both groups with respect to basal flow (104% resp. 120% of control). Patients who received nifedipine in the post-stenotic area just before the second transluminal occlusion, had significantly lower lactate production, measured immediately after the transluminal occlusion compared with the patients who received only its solvent (P less than 0.01). The ST-elevation during the second transluminal occlusion was significantly lower in the nifedipine group (0.1 mm in nifedipine group versus 1.4 mm in solvent group; P less than 0.05, unpaired t-test). Nifedipine given intracoronary in the post-stenotic area just before coronary angioplasty reduces lactate release and electrocardiographic signs of myocardial ischemic injury. This regional cardioprotective effect seems not due to an enhanced collateral flow, but to a regional cardioplegic effect, which precedes the ischemic event.

Percutane transluminale ballonvalvuloplastiek bij oudere patienten met een verworven aortaklepstenose (Article)

1987-01-01T00:00:00Z

Intracoronary thrombolysis in patients with acute myocardial infarction: The Netherlands randomized trial and current status (Article)

1987-01-01T00:00:00Z

Coronary angioplasty early after diagnosis of unstable angina (Article)

1987-01-01T00:00:00Z

Coronary angioplasty (PTCA) was performed early after diagnosis of unstable angina in 71 patients who responded favorably with initial pharmacologic treatment and who also had persistent exertional angina. The patients selected for PTCA had predominantly single-vessel disease and a normal or slightly abnormal left ventricular function. PTCA was successful in 87% (62/71) of the patients and unsuccessful in 13% (9/71). There were no deaths related to PTCA. The incidence of myocardial infarction during the procedure was 10% (seven of the 71 patients). Urgent bypass surgery was necessary in 11% (eight of 71 patients) of the patients. All patients were followed up for 12 months. There was one late death and one late nonfatal myocardial infarction. During 12 months of follow-up there was recurrence of angina pectoris in 25% of the patients (14/62). The restenosis rate was 25% (13/52) in the patients with an initial successful PTCA who underwent repeat angiography. Improved cardiac functional status after sustained successful PTCA was demonstrated by the normal exercise capacity on bicycle exercise testing and the absence of ischemia on thallium 201 scintigraphy studies in 70% of the patients. At the 1-year follow-up visit after attempted coronary angioplasty in all 71 patients, the total incidence of deaths was 1.5% (one patient), myocardial infarction 11% (eight patients), and the need for revascularization 25% (emergency surgery eight patients, late surgery three patients, and repeat PTCA seven patients); 91% (64 of 70 patients) were symptom free. It is concluded that PTCA in selected patients with unstable angina initially stabilized with medical treatment is an effective treatment with an acceptable complication rate and an excellent 1-year prognosis.

Value of immediate coronary angioplasty following intracoronary thrombolysis in acute myocardial infarction (Article)

1987-01-01T00:00:00Z

A total of 533 patients with acute myocardial infarction of less than 4-h duration were enrolled in the multicenter randomized trial of intracoronary thrombolysis compared to conventional treatment. In two of the five participating centers, an additional coronary angioplasty immediately after thrombolysis was attempted in 46 patients. According to the treatment allocation and early and late patency of the infarct related vessel, patients were subdivided into three groups: conventionally treated (group A); successful coronary angioplasty following thrombolysis with persistent patent infarct related vessel (group B); and late patency of the infarct related vessel postthrombolytic therapy without angioplasty (group C). The highest global ejection fractions were observed in group B (54% +/- 10%) and group C (55% +/- 13%), while the lowest ejection fraction was found in group A (47% +/- 14%). The sequential changes in global ejection fraction from the acute to the chronic stage was + 4% (p = 0.05) in group B, while no significant changes could be demonstrated in group C. Furthermore, in the group successfully treated by angioplasty, the improvement in global ejection fraction was more pronounced and persisted up to three months after the intervention. This was supported by analysis of regional myocardial function of the infarct zone (+ 16% improvement, p = 0.01). The long-term clinical follow-up (median 24 months) of the patients successfully treated by combined procedure of thrombolysis and angioplasty (group B) was most favourable with a lower incidence of re-infarction (6%), and late coronary bypass surgery (13%) and/or (re)-percutaneous transluminal coronary angioplasty (3%) was performed less frequently. These results suggest that reperfusion may need to be supplemented by additional revascularization procedures in order to optimize the changes of obtaining full functional recovery and so to improve the prognosis.

Vélicités intracoronaires en cours d'angioplastie (Article)

1987-01-01T00:00:00Z

Percutaneous aortic balloon dilatation for cacific aortic stenosis in elderly patients: immediate haemodynamic results and short term follow up (Article)

1987-01-01T00:00:00Z

Eight elderly patients (mean (SD) age 72.6 (8.5) years) with severe calcified stenosis of the aortic valve were considered for transluminal balloon dilatation in the Thoraxcenter between March and November 1986. In one patient the procedure could not be performed because of technical difficulties. Balloons of increasing diameter (13-25 mm) were successively passed retrogradely from the femoral artery and manually inflated with pressures of 400-600 kPa (4-6 atmospheres). Post-dilatation, there were significant changes in left ventricular pressures (from 237/21 to 204/13 mm Hg), mean systolic gradient (from 66 to 41 mm Hg, systolic aortic flow (from 172 to 202 ml/s, and aortic valve area (from 0.47 to 0.74 cm2); the cardiac index did not increase significantly (from 2.4 to 2.5 l/min/m2). One patient developed a pseudoaneurysm at the site of the femoral artery puncture that required surgical repair two months after the procedure; one patient experienced an acute left hemianopia during the procedure but had almost completely recovered at discharge. Five patients maintained a clinical improvement at a mean follow up time of 4.5 months after the procedure; two patients underwent aortic valve replacement, one because of minimal haemodynamic improvement after aortic balloon dilatation and persistence of severe dyspnoea and the other because of late recurrence of symptoms caused by restenosis after a successful procedure. Aortic balloon dilatation provides an alternative treatment for patients who are poor surgical candidates for cardiac or extracardiac reasons. At this stage the limited haemodynamic improvements suggest that the treatment can only be regarded as palliative, although proposed technical advances may achieve better immediate results in the future. Long term follow up is needed to evaluate the usefulness of this technique.

Effects of successful percutaneous transluminal coronary angioplasty on global and regional left ventricular function in unstable angina pectoris (Article)

1987-01-01T00:00:00Z

Sixty-eight patients (58 men, 10 women, mean age 56.3 years, range 31 to 72) with unstable angina pectoris, either initially stabilized with or refractory to optimal pharmacologic treatment, were studied to determine whether regional dysfunction due to stunning of the myocardium caused by attacks of chest pain at rest could be improved with percutaneous transluminal coronary angioplasty (PTCA). Patients were included in the study if they had successful 1-vessel PTCA, no angiographic restenosis, no reocclusion or late myocardial infarction and 2 serial left ventriculograms of sufficient quality to allow automated contour analysis before and after PTCA. Global ejection fraction increased significantly (from 56% to 60%, p less than 0.05) only after successful dilatation of a stenosis of the left anterior descending coronary artery. Analysis of regional wall displacement showed significant improvement of regional wall motion in the areas supplied by the dilated vessel of either the left anterior descending, the left circumflex or the right coronary artery. Thus, regional myocardial dysfunction due to stunning of the myocardium in patients with unstable angina improves after successful PTCA.

Hoe heroperatie te voorkomen bij een reeds bestaande bypass op een coronaire bypass (Article)

1986-01-01T00:00:00Z

Coronary angioplasty of the unstable angina related vessel in patients with multivessel disease (Article)

1986-01-01T00:00:00Z

This study is a retrospective analysis of the efficacy of percutaneous transluminal coronary angioplasty of the ischaemia-related vessel in patients with unstable angina. Forty-three patients had multivessel disease with dilatation of the ischaemia-related vessel only (group I; partial revascularization) while 111 patients had single vessel disease only (group II; total revascularization). The initial success rate in both groups was identical (88 versus 88%). The need for emergency coronary artery bypass surgery was similar in the two groups (group I 12% versus group II 9%; NS). The total post PTCA myocardial infarction rate (despite urgent CABG) was also similar in the two groups (group I 9% versus group II 10%; NS). The results of electrocardiographic exercise testing and Thallium-201 scintigraphy provide objective evidence for incomplete revascularization in group I. The maximum workload achieved was lower, and the frequency of exercise induced angina, ST-segment depression and reversible perfusion defect was higher than in group II. Moreover, at 6 months follow-up the recurrence rate of angina pectoris rate was higher in group I than in group II (29% versus 16% P less than 0.05). It is concluded that dilatation of the ischaemia related vessel only in patients with unstable angina and multivessel disease is as effective in the management of the acute phase of unstable angina as is dilatation of the ischaemia related vessel in patients with single vessel disease. However, due to only partial revascularization the recurrence rate of angina pectoris is higher.

Coronary angioplasty for early postinfarction unstable angina (Article)

1986-01-01T00:00:00Z

Coronary angioplasty was performed in 53 patients in whom unstable angina had reoccurred after 48 hr and within 30 days after sustained myocardial infarction. Single-vessel disease was present in 64% of the patients and multivessel disease in 36%. The preceding myocardial infarction had been small to moderate in size in the majority of the patients. The left ventricular ejection fraction was more than 50% in 80% of the patients. Forty-five patients were refractory to pharmacologic treatment; eight were initially stabilized but once again became symptomatic with light exertion. Angioplasty was performed in 35 patients 2 to 14 days and in 18 patients 15 to 30 days after infarction (average 12 +/- 7 days after infarction). The initial success rate was 89% (47/53). The success rate of the patients treated at 2 to 14 days was lower (29/35, 83%) than that of patients treated at 14 to 30 days (18/18, 100%) but did not reach statistical significance (p less than .06). There were no deaths related to the procedure. In four of the six failures, emergency bypass surgery was performed and two patients sustained a myocardial infarction. Furthermore, a myocardial infarction complicated the angioplasty procedure in two other patients; thus the overall procedure-related myocardial infarction rate was 8% (4/53). At 6 months follow-up 26% (14/53) of all the patients who underwent angioplasty had recurrence of angina, which was successfully treated with repeat angioplasty, bypass surgery, or medical therapy. There were no late deaths. Late myocardial infarction occurred in two patients. Thus the total myocardial infarction rate after angioplasty at 6 months was 11% (6/53 patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Maintenance of increased coronary blood flow in excess of demand by nisoldipine administered as an intravenous infusion (Article)

1986-01-01T00:00:00Z

Systemic and hemodynamic effects of nisoldipine, administered as a 4.5-micrograms/kg intravenous bolus over 3 minutes followed immediately by an infusion of 0.2 microgram/kg/min over 30 minutes, were studied in 13 patients undergoing diagnostic catheterization for suspected coronary artery disease or follow-up catheterization after coronary angioplasty. Responses to the drug tended to be exaggerated in the first 8 minutes of the infusion, but thereafter produced a steady state, with heart rate increased by 14 +/- 3% at 16 minutes and by 15 +/- 3% at 24 minutes (p less than 0.05), mean aortic pressure decreased 12 +/- 2% and 13 +/- 3% at the same times (p less than 0.05) and coronary venous blood flow increased by 31 +/- 5% and 34 +/- 6% (p less than 0.05). Myocardial oxygen consumption and the heart rate-systolic aortic pressure product were unchanged and cardiac output and stroke volume were significantly increased. Study during matched coronary sinus pacing produced similar trends. Nisoldipine is a potent coronary and peripheral vasodilator that maintains an increase in myocardial oxygen supply in excess of demand when given as an intravenous infusion.

Coronary and systemic hemodynamic effects of intravenous nisoldipine (Article)

1986-01-01T00:00:00Z

Systemic and coronary hemodynamic effects of the new dihydropyridine calcium antagonist nisoldipine were studied over a 30-minute period in 12 patients with angina pectoris. Previously instituted beta-blocker therapy was continued. Nisoldipine was administered in an intravenous bolus of 6 micrograms/kg over 3 minutes. Heart rate increased as mean aortic pressure and systemic vascular resistance decreased in all patients. Cardiac output increased significantly, from 5.8 +/- 0.3 to 7.9 +/- 0.5 liters/min, 10 minutes after nisoldipine infusion. These trends were maintained over the 30-minute observation period. Coronary sinus blood flow increased from 103 +/- 11 to 139 +/- 13 ml/min immediately after nisoldipine, but had returned to the control level by 30 minutes, as had the reduction in coronary vascular resistance. Myocardial oxygen consumption and heart rate-systolic blood pressure product did not change significantly. Nisoldipine is a potent peripheral and coronary vasodilator free of major myocardial depressant effects after acute intravenous administration. The systemic vasodilatory effects appear to outlast the coronary effects over 30 minutes.

Predictive value of early maximal exercise test and thallium scintigraphy after successful percutaneous transluminal coronary angioplasty (Article)

1985-01-01T00:00:00Z

Restenosis of the dilated vessel after percutaneous transluminal coronary angioplasty can be detected by non-invasive procedures but their ability to predict later restenosis soon after a successful angioplasty as well as recurrence of angina has not been assessed. A maximal exercise test and myocardial thallium perfusion scintigraphy were, therefore, performed in 91 asymptomatic patients a median of 5 weeks after they had undergone a technically successful angioplasty. Primary success of the procedure was confirmed by the decrease in percentage diameter stenosis from 64(12)% to 30(13)% as measured from the coronary angiograms and in the trans-stenotic pressure gradient (normalised for mean aortic pressure) from 0.61(0.16) to 0.17(0.09). A clinical follow up examination (8.6(4.9) months later) was carried out in all patients and a late coronary angiogram obtained in 77. The thallium perfusion scintigram showing the presence or absence of a reversible defect was highly predictive for restenosis whereas the exercise test was not. The positive predictive value of an abnormal scintigram was 82% compared with 60% for the exercise test (ST segment depression/or angina or both at peak workload). Angina or a new myocardial infarction occurred in 60% of patients with abnormal and in 21% of patients with normal scintigrams.

Early detection of restenosis after successful percutaneous transluminal coronary angioplasty by exercise-redistribution Thallium scintigraphy (Article)

1985-01-01T00:00:00Z

The value of exercise testing and thallium scintigraphy in predicting recurrence of angina pectoris and restenosis after a primary successful transluminal coronary angioplasty (PTCA) was prospectively evaluated. In 89 patients, a symptom-limited exercise electrocardiogram (ECG) and thallium scintigraphy were performed 4 weeks after they had undergone successful PTCA. Thereafter, the patients were followed for 6.4 +/- 2.5 months (mean +/- standard deviation) or until recurrence of angina. They all underwent a repeat coronary angiography at 6 months or earlier if symptoms recurred. PTCA was considered successful if the patients had no symptoms and if the stenosis was reduced to less than 50% of the luminal diameter. Restenosis was defined as an increase of the stenosis to more than 50% luminal diameter. The ability of the thallium scintigram (presence of a reversible defect) to predict recurrence of angina was 66%, vs 38% for the exercise ECG (ST-segment depression or angina at peak workload). Restenosis was predicted in 74% of patients by thallium scintigraphy, but only in 50% of patients by the exercise ECG. Thus, thallium scintigraphy was highly predictive but the exercise ECG was not (p less than 0.005). These results suggest that restenosis had occurred to some extent already at 4 weeks after the PTCA in most patients in whom it was going to occur.

Elective PTCA of totally occluded coronary arteries not associated with acute myocardial infarction; short-term and long-term results (Article)

1985-01-01T00:00:00Z

Of 652 consecutive patients referred for coronary angioplasty between September 1980 and March 1984, 49 patients presented with total or functional 'occlusion' of the involved vessel. Total vessel occlusion was defined as absent anterograde filling beyond the lesion. Functional occlusion was defined as faint, late anterograde opacification of the distal segment in the absence of a discernible luminal continuity. In 39 patients, the total or functional occlusion represented a progression, without acute myocardial infarction, of a previously diagnosed stenotic lesion. The maximal potential duration of occlusion was estimated to be 4 weeks or less in 21 patients, more than 4 to 8 weeks in 12, and more than 8 weeks in 16. Dilation of the occluded artery was attempted in the left anterior descending coronary artery in 30 patients, in the right coronary artery in 8, in the circumflex coronary in 7 and in 4 jumpgrafts. For the whole group, angioplasty was successful in 28 patients (57%). The primary success rate with the functionally occluded vessel (81%) was significantly higher than with the total occlusion (45%). In 33 patients with an occlusion estimated to be of 8 weeks or less, angioplasty was successful in 65%. In the 16 patients with an occlusion estimated to be of 8 weeks or less, angioplasty was successful in 65%. In the 16 patients with an occlusion estimated to be of more than 8 weeks duration, dilation was successful in 44%. Of the 21 patients in whom angioplasty was unsuccessful, 11 required surgery (1 urgent with persistent pain and ST elevation and 10 elective). Ten patients were maintained on medical treatment. Of the 28 patients in whom angioplasty was successful, 10 patients had recurrence of symptoms during follow-up (1-42 months). Four were kept on medical therapy, three required bypass surgery and three underwent repeat percutaneous transluminal coronary angioplasty (PTCA). After primary success, late angiographic studies obtained in 20 out of 28 patients showed reocclusion in 8. In conclusion, elective PTCA of totally occluded coronary arteries is feasible but the primary success rate is lower (57%) than that associated with conventional lesions. The long-term clinical results following successful angioplasty are satisfactory (64%), but the incidence of reocclusion is higher (40%).

Comparison of preoperative, operative and postoperative variables in asymptomatic or minimally symptomatic patients to severely symptomatic patients three years after coronary artery bypass grafting: analysis of 423 patients (Article)

1985-01-01T00:00:00Z

During a follow-up period of 3 years, among a consecutive series of 423 patients who gave informed consent for recatheterization both 1 and 3 years after coronary artery bypass grafting, the incidence of severely symptomatic patients with New York Heart Association class III or IV was 19% (79 of 423). The predictive value of approximately 80 clinical, angiographic and perioperative variables was too low to be of clinical value. Adverse clinical outcome was associated with a high closure rate of the grafts. Forty-six percent of the patients could not undergo reoperation because of unsuitable coronary anatomy. With intensive medical therapy half of these patients improved to functional class I or II, while of those patients who were reoperable 32% improved to class I or II with intensive pharmacologic treatment instead of reoperation. The nonresponders underwent reoperation, which resulted in improvement of symptoms to functional class I or II in most (83%).

Emergency coronary angioplasty in refractory unstable angina (Article)

1985-01-01T00:00:00Z

We performed percutaneous transluminal coronary angioplasty as an emergency procedure in 60 patients with unstable angina pectoris that was refractory to treatment with maximally tolerated doses of beta-blockers, calcium antagonists, and intravenous nitroglycerin. The initial success rate for angioplasty was 93 per cent (56 patients). There were no deaths related to the procedure, although total occlusion occurred in four patients. Despite emergency bypass grafting, all four sustained a myocardial infarction. All the patients were followed for at least six months. Late cardiac death occurred in one patient, whereas eight had recurrent angina pectoris. There was no progression to myocardial infarction. The restenosis rate was 28 per cent (13 of 46) in the patients with initially successful coronary angioplasty who had repeat angiography. Improved cardiac functional status after sustained successful coronary angioplasty was demonstrated by an almost normal capacity on bicycle exercise testing and the absence of ischemia during thallium isotope studies in 80 per cent. We conclude that emergency percutaneous transluminal coronary angioplasty may be useful for the treatment of selected patients with unstable angina pectoris who are unresponsive to intensive pharmacologic treatment.

Early angiography after myocardial infarction: what have we learned? (Article)

1985-01-01T00:00:00Z

Effect of intracoronary thrombolytic therapy on global and regional left ventricular function. A three year experience with randomization (Article)

1985-01-01T00:00:00Z

The effect of myocardial reperfusion on regional left ventricular function has been quantitated by analysis of segmental wall motion in 185 patients enrolled in a randomized trial comparing thrombolysis with conventional treatment in patients with acute myocardial infarction. When analyzing the hemodynamic data on an "intention to treat" basis we found a significant preservation of left ventricular function after thrombolytic therapy when compared to conventional treatment. In addition, the wall motion analysis showed that a significant improvement of regional function in the "infarct zone" was observed in inferior infarction as well as in anterior infarction, although significant changes in regional function of the remote "non infarct zone" were observed at the acute as well as at the chronic stage. However, our follow-up data indicate that as yet it has not been resolved whether this method of treatment does indeed improve prognosis in patients with acute myocardial infarction. Accordingly, we maintain the view that such invasive treatment should not be generally applied until more follow-up data become available from larger randomized trials.

Values and limitations of transstenotic pressure gradients measured during percutaneous coronary angioplasty (Article)

1985-01-01T00:00:00Z

The pressure gradient across coronary stenoses is measured routinely during angioplasty. Due to the finite size of the angioplasty catheter within the stenotic cross section, the remaining luminal area is further reduced and the transstenotic gradient may be overestimating the "true" pressure drop. This "true" pressure gradient can be approximated from the mean coronary blood flow and the stenosis geometry from theoretical models. Goal of this study was to assess the values and limitations of the in vivo measurements of the pressure gradient versus the calculated values. Therefore, flow in the great cardiac vein was measured in 13 patients before and/or after angioplasty of a proximal left anterior descending stenosis, not filled by collaterals. The Poiseuille and turbulent contributions to flow resistance were determined from stenosis geometry assessed by quantitative coronary angiography. A fourfold increase in the luminal area (from 0.7 mm2 pre- to 2.8 mm2 post angioplasty) was associated with a fourfold decrease in the in vivo measured transstenotic gradient (from 59 mm Hg pre- to 13 mm Hg post angioplasty). The occlusion area and the measured gradient were linearly correlated: gradient = 69-17 X occlusion area (r = 0.76). However, as expected, the transstenotic gradient systematically overestimated the theoretical gradient calculated from the laws of fluid dynamics. A nonlinear relation was found between the calculated gradient P and the occlusion area As: P = 15 X As-2 (r = 0.87).

Thrombolysis of acute total occlusion of the left main coronary artery in evolving myocardial infarction (Article)

1984-01-01T00:00:00Z