Feijter, P.J. de

Failure of CT coronary imaging to identify plaque erosion: A resetting of expectations (Article)

2011-11-01T00:00:00Z

Comparison of the Value of Coronary Calcium Detection to Computed Tomographic Angiography and Exercise Testing in Patients With Chest Pain (Article)

2009-12-01T00:00:00Z

The aim of this study was to investigate the value of coronary calcium detection by computed tomography compared to computed tomographic angiography (CTA) and exercise testing to detect obstructive coronary artery disease (CAD) in patients with stable chest pain. A total of 471 consecutive patients with new stable chest complaints were scheduled to undergo dual-source multislice computed tomography (Siemens, Germany; coronary calcium score [CCS] and coronary CTA) and exercise electrocardiography (XECG). Clinically driven invasive quantitative angiography was performed in 98 patients. Only 3 of 175 patients (2%) with a negative CCS had significant CAD on CT angiogram, with only 1 confirmed by quantitative angiography. In patients with a high calcium score (Agatston score >400), CTA could exclude significant CAD in no more than 4 of 65 patients (6%). In patients with a low-intermediate CCS, CTA more often yielded diagnostic results compared to XECG and could rule out obstructive CAD in 56% of patients. For patients with CAD on CT angiogram, those with abnormal exercise electrocardiographic results more often showed severe CAD (p <0.034). In patients with diagnostic results for all tests, the sensitivity and specificity to detect >50% quantitative angiographic diameter stenosis were 100% and 15% for CCS >0, 82% and 64% for CCS >100, 97% and 36% for CTA, and 70% and 76% for XECG, respectively. In conclusion, nonenhanced computed tomography for calcium detection is a reliable means to exclude obstructive CAD in stable, symptomatic patients. Contrast-enhanced CTA can exclude significant CAD in patients with a low-intermediate CCS but is of limited value in patients with a high CCS.

Computed tomography versus exercise electrocardiography in patients with stable chest complaints: Real-world experiences from a fast-track chest pain clinic (Article)

2009-10-01T00:00:00Z

Objective: To compare the diagnostic performance of CT angiography (CTA) and exercise electrocardiography (XECG) in a symptomatic population with a low-intermediate prevalence of coronary artery disease (CAD). Design: Prospective registry. Setting: Tertiary university hospital. Patients: 471 consecutive ambulatory patients with stable chest pain complaints, mean (SD) age 56 (10), female 227 (48%), pre-test probability for significant CAD >5%. Intervention: All patients were intended to undergo both 64-slice, dual-source CTA and an XECG. Clinically driven quantitative catheter angiography was performed in 98 patients. Main outcome measures: Feasibility and interpretability of, and association between, CTA and XECG, and their diagnostic performance with invasive coronary angiography as reference. Results: CTA and XECG could not be performed in 16 (3.4%) vs 48 (10.2%, p<0.001), and produced nondiagnostic results in 3 (0.7%) vs 140 (33%, p<0.001). CTA showed ≥1 coronary stenosis (≥50%) in 140 patients (30%), XECG was abnormal in 93 patients (33%). Results by CTA and XECG matched for 185 patients (68%, p=0.63). Catheter angiography showed obstructive CAD in 57/98 patients (58%). Sensitivity, specificity, positive and negative predictive value of CTA to identify patients with ≥50% stenosis was 96%, 37%, 67% and 88%, respectively; compared with XECG: 71%, 76%, 80% and 66%, respectively. Quantitative CTA slightly overestimated diameter stenosis: 6 (21)% (R=0.71), compared with QCA. Of the 312 patients (66%) with a negative CTA, 44 (14%) had a positive XECG, but only 2/17 who underwent catheter angiography had significant CAD. Conclusion: CTA is feasible and diagnostic in more patients than XECG. For interpretable studies, CTA has a higher sensitivity, but lower specificity for detection of CAD.

Coronary calcium significantly affects quantitative analysis of coronary ultrasound: Importance for atherosclerosis progression/regression studies (Article)

2009-09-01T00:00:00Z

BACKGROUND: Coronary atherosclerosis is a dynamic process, which progresses differently in coronary segments containing noncalcified or calcified plaques. This may have implications for the study of the effects of therapy on progression/regression. OBJECTIVE: To test this hypothesis, we performed a post-hoc analysis on data of a randomized trial in which perindopril treatment was compared with placebo on progression/regression of atherosclerosis with regard to the degree of calcification. METHODS AND RESULTS: The intracoronary ultrasound data of 118 patients, who were enrolled in the multicentre, double-blinded randomized trial (PERSPECTIVE), were analysed. Vessel, lumen and plaque areas were measured in 711 5-mm-long matched coronary segments (perindopril 360, placebo 351). Each individual intracoronary ultrasound cross-section was binary labelled for the presence of calcium (yes/no), and the degree of calcium was assessed as a percentage of length. The segments were classified into three groups: 0-25, 25-50 and 50-100% (percentage of length) calcification. Coronary plaques with no or little calcium (0-25%) regressed on perindopril and did not change on placebo (-0.33±1.74 vs. -0.03±1.66, respectively; P=0.04). Plaques containing moderate calcium (group 25-50%) did not change and plaques with severe amounts of calcification (group 50-100%) equally progressed. CONCLUSION: Noncalcified plaques may be amenable to regression with ACE inhibitor treatment. The method, which considers the amount of calcium content in a plaque, may lead to new insights for quantitative analysis of the effects of therapy in progression/regression studies of atherosclerosis.

Coronair Atherosclerose: 'Hearts too Young to Die' (Farewell Lecture)

2009-05-13T00:00:00Z

Rede, In verkorte vorm uitgesproken bij het afscheid als hoogleraar In de niet-invasieve diagnostiek van ischemische hartziekten aan het Erasmus MC, faculteit van de Erasmus Universiteit Rotterdam. Op 13 mei 2009. Alhoewel het hart niets anders is dan een holle pomp die het bloed rond pompt blijft het intrigerend orgaan, waar veel meer aan toegekend wordt dan de pompwerking. Het hart is door de eeuwen heen een bron van inspiratie geweest voor kunstenaars, schilders, musici, geliefden, vrienden en wetenschappers. Het hart heeft mij al gedurende mijn studie Geneeskunde aangetrokken, al had ik toen nog het simpele idee dat het hart alleen maar een mechanische motor was, het best vergelijkbaar met de motor van een auto, met pomp, kleppen en elektrische bedrading. Deze wat simpele beschouwing is intussen danig bijgesteld en we zien het hart niet meer als een op zichzelf staande pomp, maar in samenhang met alle regel-systemen van het lichaam om de vraag naar zuurstof te beantwoorden. Wat aanvankelijk simpel leek is oneindig veel ingewikkelder en met name ziekte van de kransvaten, coronair atherosclerose, werd aan het begin van mijn studie nog beschouwd als dichtslibben door lipiden stapeling in de vaatwand, maar wordt nu gezien als een chronisch ontstekingproces, waarbij lipiden accumulatie, immuun systeem, bloedplaatjes en stollingsfactoren een ingewikkelde rol spelen.

A histological "Fly-Through" of a diseased coronary artery (Article)

2009-03-01T00:00:00Z

Three-dimensional and quantitative analysis of atherosclerotic plaque composition by automated differential echogenicity (Article)

2007-12-01T00:00:00Z

Objective: To validate automated and quantitative three-dimensional analysis of coronary plaque composition using intracoronary ultrasound (ICUS). Background: ICUS displays different tissue components based on their acoustic properties in 256 grey-levels. We hypothesised that computer-assisted image analysis (differential echogenicity) would permit automated quantification of several tissue components in atherosclerotic plaques. Methods and Results: Ten 40-mm-long left anterior descending specimens were excised during autopsy of which eight could be successfully imaged by ICUS. Histological sections were taken at 5 mm intervals and analyzed. Since most of the plaques were calcified and having a homogeneous appearance, one specimen with a more heterogeneous composition was further examined: at each interval of 5 mm, 15 additional sections (every 100 μm) were evaluated. Plaques were scored for echogenicity against the adventitia: brighter (hyperechogenic) or less bright (hypoechogenic). Areas of hypoechogenicity correlated with the presence of smooth muscle cells. Areas of hyperechogenicity correlated with presence of collagen, and areas of hyperechogenicity with acoustic shadowing correlated with calcium. None of these comparisons showed statistical significant differences. Conclusion: This ex vivo feasibility study shows that automated three-dimensional differential echogenicity analysis of ICUS images allows identification of different tissue types within atherosclerotic plaques. This technology may play a role as an additional tool in longitudinal studies to trace possible changes in plaque composition.

Reproducible coronary plaque quantification by multislice computed tomography (Article)

2007-05-01T00:00:00Z

Background: The aim of this study was to investigate reproducibility end accuracy of computer-assisted coronary plaque measurements by multislice computed tomography coronary angiography (QMSCT-CA). Methods and Results: Forty-sight patients undergoing MSCT-CA end coronary arteriography for symptomatic coronary artery disease and quantitative intravascular ultrasound (IVUS, QCU) were examined. Two investigators performed the QMSCT-CA twice end e third investigator performed the QCU, all blinded for each other's results. There was no difference found for the matched region of interest (ROI) lengths (QCU 29.4 ± 13 mm vs. QMSCT-CA 29.6 ± 13 mm, P = 0.6; total length = 1,400 mm). The comparison of volumetric measurements showed (lumen QCU 267 ± 139 mm3vs. mean QMSCT-CA 177 ± 91 mm3, P < 0.001; vessel 454 ± 194 mm3vs. 398 ± 187 mm3, P < 0.001; and plaque 189 ± 93 mm3vs. 222 ± 121 mm3; investigator 1, P = 0.02; and investigator 2, P = 0.07) significant differences. Automated lumen detection was also applied for QMSCT-CA (218 ± 112 mm3, P < 0.001 vs. QCU). The Interinvestigator variability measurements for QMSCT-CA showed no significant differences. Conclusion: QMSCT-CA systematically underestimates absolute coronary lumen- and vessel dimensions when compared with QCU. However, repeated measurements of coronary plaque by QMSCT-CA showed no statistically significant differences, although, the outcome showed a scattered result. Automated lumen detection for QMSCT-CA showed improved results when compered with those of human investigators.

Drug-eluting stents show delayed healing: Paclitaxel more pronounced than sirolimus (Article)

2007-04-01T00:00:00Z

Aims: To understand wound healing after drug-eluting stents (DES) placement in humans, we studied the histology of in-stent restenosis (ISR) tissue obtained by atherectomy from bare metal stents (BMS) and DES in comparison with de novo atherosclerosis. Methods and results: The tissue was retrieved from ISR in ten sirolimus-eluting stents (SES) and nine paclitaxel-eluting stents (PES), six BMS, and nine stenotic de novo atherosclerotic lesions and processed for histology and immunocytochemistry. Patients with ISR in PES showed a significantly higher incidence of unstable angina upon presentation for re-intervention (P = 0.046). De novo tissue tended to be more collagen rich, whereas ISR tissue tended to be more proteoglycan rich. In all groups, cell content consisted almost exclusively of smooth muscle cells. Histology showed that fibrinoid in ISR tissue was present only in DES (P = 0.004), as late as 2 years following DES placement, indicating a persistent incomplete healing response. The amount of fibrinoid, given as a percentage of total tissue in each atherectomy specimen, was greater in PES than in SES (17 vs. 5%, P = 0.026). Conclusion: ISR in DES shows incomplete neointimal healing as late as 2 years after implantation. Patients with ISR in PES presented with more unstable angina and showed more pronounced signs of delayed healing than SES.

Clinical introduction of the Tandemheart, a percutaneous left ventricular assist device, for circulatory support during high-risk percutaneous coronary intervention. (Article)

2003-03-01T00:00:00Z

Abstract BACKGROUND: In patients with poor left ventricular function and high-risk coronary lesions, prolonged ischemia during percutaneous coronary intervention (PCI) may have major hemodynamic consequences. The Tandemheart is a percutaneous left ventricular assist device intended for short-term circulatory support. METHODS AND RESULTS: The Tandem-heart incorporates 9-17 F. arterial cannulae and a unique 21 F. transseptal cannula and centrifugal bloodpump. Operating at 7500 rpm, the pump withdraws oxygenated blood from the left atrium and delivers up to 4 liters/min to the arterial circulation. As of May 2001, the Tandem-heart was electively employed in three male patients (ages 52, 54 and 56) scheduled for high-risk PCI. The mean time to initial circulatory support was less than 30 minutes. Systemic hemodynamics significantly improved prior to PCI in two patients. Pump flow after one hour ranged from 2.43 to 3.8 liters/min (mean 3.17 liters/min) and duration of support from 23 to 49 hours (mean 33 hours). Procedural success was 100%, with no significant hemolysis or bleeding. Successful weaning was completed in all patients, who have remained free of major cardiac events up to seven months post-PCI. CONCLUSIONS: In this first clinical experience of elective use of Tandem-heart for circulatory support during high-risk PCI, the device was easily inserted and preserved hemodynamic stability, regardless of the intrinsic cardiac function, creating optimism for more widespread use for this and other indications.

Niet-invasieve beeldvorming van de kransvaten: een open oog en een groot hart (Inaugural Lecture)

2003-01-31T00:00:00Z

Coronary restenosis elimination with a sirolimus eluting stent: first European human experience with 6-month angiographic and intravascular ultrasonic follow-up. (Article)

2001-12-08T00:00:00Z

AIMS: Coronary stenting is limited by a 10%-60% restenosis rate due to neointimal hyperplasia. Sirolimus is a macrocyclic lactone agent that interacts with cell-cycle regulating proteins and inhibits cell division between phases G1 and S1. The hypothesis tested in this study is that local delivery of sirolimus with an eluting stent can prevent restenosis. METHODS AND RESULTS: Fifteen patients were treated with 18 mm sirolimus eluting BX VELOCITY stents. Quantitative angiography and three-dimensional quantitative intravascular ultrasound were performed at implantation and at the 6 months follow-up. All stent implantations were successful. One patient died on day 2, of cerebral haemorrhage and one patient suffered a subacute stent occlusion due to edge dissection (re-PTCA, CKMB 42). At 9 months no further adverse events had occurred and all patients were angina free. Quantitative coronary angiography revealed no change in minimal lumen diameter and percent diameter stenosis and hence no in-lesion or in-stent restenosis. Quantitative intravascular ultrasound showed that intimal hyperplasia volume and percent obstruction volume at follow-up were negligible at 5.3 mm(3)and 1.8%, respectively. No edge effect was observed in the segments proximal and distal to the stents. CONCLUSION: Implantation of a sirolimus-eluting stent seems to effectively prevent intimal hyperplasia.

Real-time quantification and display of skin radiation during coronary angiography and intervention (Article)

2001-01-01T00:00:00Z

BACKGROUND: Radiographically guided investigations may be associated with excessive radiation exposure, which may cause skin injuries. The purpose of this study was to develop and test a system that measures in real time the dose applied to each 1-cm(2) area of skin, taking into account the movement of the x-ray source and changes in the beam characteristics. The goal of such a system is to help prevent high doses that might cause skin injury. METHODS AND RESULTS: The entrance point, beam size, and dose at the skin of the patient were calculated by use of the geometrical settings of gantry, investigation table, and x-ray beam and an ionization chamber. The data are displayed graphically. Three hundred twenty-two sequential cardiac investigations in adult patients were analyzed. The mean peak entrance dose per investigation was 0.475 Gy to a mean skin area of 8.2 cm(2). The cumulative KERMA-area product per investigation was 52.2 Gy/cm(2) (25.4 to 99.2 Gy/cm(2)), and the mean entrance beam size at the skin was 49.2 cm(2). Twenty-eight percent of the patients (90/322) received a maximum dose of <1 Gy to a small skin area ( approximately 6 cm(2)), and 13.5% of the patients (42/322) received a maximum dose of >2 Gy. CONCLUSIONS: Monitoring of the dose distribution at the skin will alert the operator to the development of high-dose areas; by use of other gantry settings with nonoverlapping entrance fields, different generator settings, and extra collimation, skin lesion can be avoided.