http://repub.eur.nl/res/aut/4499/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/9241/ 2000-01-01T00:00:00Z http://repub.eur.nl/res/pub/4589/ 1994-01-01T00:00:00Z http://repub.eur.nl/res/pub/4522/ 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. http://repub.eur.nl/res/pub/4498/ 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. http://repub.eur.nl/res/pub/4510/ 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. http://repub.eur.nl/res/pub/4520/ 1993-01-01T00:00:00Z Part I of this article reviewed the results of studies investigating the effectiveness of antithrombotic, antiplatelet, antiproliferative, anti-inflammatory, calcium channel blocker and lipid-lowering drugs in preventing or reducing restenosis after angioplasty. However, despite 15 years of clinical experience and research in the field of restenosis prevention, this has not yet resulted in the revelation of unequivocal beneficial effects of any particular drug. Other newer approaches likely to receive more attention in the future include antibodies to growth factors, gene transfer therapy and antisense oligonucleotides. Whether there is a feasible monotherapy, whether we have to focus on a drug combination, or whether we are only searching for 'the Holy Grail' remain to be answered. http://repub.eur.nl/res/pub/4531/ 1993-01-01T00:00:00Z http://repub.eur.nl/res/pub/4532/ 1993-01-01T00:00:00Z Background. The renarrowing process after successful percutaneous transluminal coronary angioplasty (PTCA) is now believed to be caused by a response-to-injury vessel wall reaction. The magnitude of this process can be assessed by the change in minimal lumen diameter (MLD) at follow-up angiography. The aim of the present study was to find independent patient-related, lesion-related, and procedure-related risk factors for this luminal narrowing process. A model that accurately predicts the amount of luminal narrowing could be an aid in patient or lesion selection for the procedure, and it could improve assessment of medium-term (6 months) prognosis. Modification or control of the identified risk factors could reduce overall restenosis rates, and it could assist in the selection of patients at risk for a large loss in lumen diameter. This population could then constitute the target population for pharmacological intervention studies. Methods and Results. Quantitative angiography was performed on 666 successfully dilated lesions at angioplasty and at 6-month follow-up. Multivariate linear regression analysis was performed to obtain variables with an independent contribution to the prediction of the absolute change in minimal lumen diameter. Diabetes mellitus, duration of angina <2.3 months, gain in MLD at angioplasty, pre-PTCA MLD, lesion length 26.8 mm, and thrombus after PTCA were independently predictive of change in MLD. Overall prediction of the model was poor, however, percentage-correct classification for a predicted change between -0.1 to -0.4 mm was approximately 10%. Lesions showing no change or regression (change > -0.1 mm) and lesions showing large progression (< -0.4 mm) were more predictable (correct classification, 59.5% and 49.7%, respectively). Conclusions. Renarrowing after successful PTCA as determined with contrast angiography is a process that cannot be accurately predicted by simple clinical, morphological, and lesion characteristics. http://repub.eur.nl/res/pub/4450/ 1992-01-01T00:00:00Z Because many ongoing clinical restenosis prevention trials are using quantitative angiography to assess whether a drug is capable of reducing the amount of intimal hyperplasia, quantitative angiographic risk factors for angiographic luminal narrowing after balloon angioplasty were determined, including stretch and elastic recoil at the dilatation site. Quantitative analysis was performed on 666 lesions in 575 patients during angioplasty and at 6-month follow-up. Stretch was defined as balloon diameter minus minimal luminal diameter (MLD) before angioplasty/reference diameter, and recoil as balloon diameter minus MLD after angioplasty/reference diameter. Multivariate analysis was used to yield independent risk factors for luminal narrowing at follow-up. Predictors of absolute change in MLD were (1) relative gain at angioplasty (gain in millimeters normalized for reference diameter) and (2) lesion length. To allow risk stratification, logistic regression analysis was applied using the decrease in MLD as a binary outcome variable. A decrease in MLD at follow-up of greater than or equal to 0.72 mm was considered significant. Variables retained in the model were: relative gain greater than 0.3 mm (rate ratio 2.9), relative gain 0.2 to 0.3 (rate ratio 2.1), stenosis length greater than or equal to 6.8 (rate ratio 1.7), and thrombus after angioplasty (rate ratio 2.6). Although stretch was significantly related to luminal narrowing at univariate analysis, it was not retained in the multivariate models. A large gain in lumen diameter at angioplasty, dilation of long lesions, and angiographically determined thrombus after angioplasty were found to be accompanied by more severe luminal narrowing at follow-up. http://repub.eur.nl/res/pub/4452/ 1992-01-01T00:00:00Z http://repub.eur.nl/res/pub/4453/ 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. http://repub.eur.nl/res/pub/4454/ 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. http://repub.eur.nl/res/pub/4470/ 1992-01-01T00:00:00Z BACKGROUND. Cilazapril is a novel angiotensin converting enzyme inhibitor with antiproliferative effects in the rat model after balloon injury. METHODS AND RESULTS. We conducted a randomized, double-blind placebo-controlled trial to assess the effect of cilazapril in angiographic restenosis prevention after percutaneous transluminal coronary angioplasty (PTCA). Patients received cilazapril 2.5 mg in the evening after successful PTCA and 5 mg b.i.d. for 6 months or matched placebo. In addition, all patients received aspirin for 6 months. Coronary angiograms before PTCA, after PTCA, and at 6-month follow-up were quantitatively analyzed. In 94% of 735 recruited patients, PTCA was successful and all inclusion and exclusion criteria were met. For the per-protocol analysis, quantitative angiography after PTCA and at follow-up was available in 595 patients who complied with the treatment regimen (309 control, 286 cilazapril). The mean difference in minimal coronary lumen diameter between post-PTCA and follow-up angiogram (primary end point) was -0.29 +/- 0.49 mm in the control group and - 0.27 +/- 0.51 mm in the cilazapril group. Clinical events during 6- month follow-up, analyzed on an intention-to-treat basis, were ranked according to the most serious clinical event ranging from death (control, two; cilazapril, three), nonfatal myocardial infarction (control, eight; cilazapril, 5), coronary revascularization (control, 51; cilazapril, 53), or recurrent angina requiring medical therapy (control, 67; cilazapril, 68) to none of the above (control, 224; cilazapril, 212). There were no significant differences in ranking. CONCLUSIONS. Long-term angiotensin converting enzyme inhibition with cilazapril in a dose of 5 mg b.i.d. does not prevent restenosis and does not favorably influence the overall clinical outcome after PTCA. http://repub.eur.nl/res/pub/4480/ 1992-01-01T00:00:00Z OBJECTIVES: The objective of this study was to examine the relation between an angiographically visible coronary dissection immediately after successful coronary balloon angioplasty and a subsequent restenosis and long-term clinical outcome. BACKGROUND. The study population comprised all 693 patients who participated in the MERCATOR trial (randomized, double-blind, placebo-controlled restenosis prevention trial of cilazapril, 5 mg two times a day). METHODS. Cineangiographic films were processed and analyzed at a central angiographic core laboratory, without knowledge of clinical data, with use of an automated interpolated edge detection technique. Dissection was judged according to the National Heart, Lung, and Blood Institute classification. Angiographic follow-up was obtained in 94% of patients with 778 lesions. Two approaches were used to assess the restenosis phenomenon: 1) categoric, using the traditional cutoff criterion of greater than 50% diameter stenosis at follow-up, and 2) continuous, defined as absolute change in minimal lumen diameter (mm) between the postcoronary angioplasty and follow-up, adjusted for the vessel size (relative loss). Clinical outcome was ranked according to the most serious adverse clinical event per patient during the 6-month follow-up period, ranging from death, nonfatal myocardial infarction, coronary revascularization and recurrent angina requiring medical therapy to none of these. RESULTS. Dissection was present in 247 (32%) of the 778 dilated lesions. The restenosis rate was 29% in lesions with and 30% in lesions without dissection (relative risk 0.97; 95% confidence interval 0.77 to 1.23). The relative loss in both groups was 0.10 (mean difference 0; 95% confidence interval -0.03 to 0.03). Clinical outcome ranged from death in 4 patients (0.9%) without dissection and 1 patient (0.4%) with dissection; nonfatal myocardial infarction in 4 (0.9%) without and 8 (3.2%) with dissection; coronary revascularization in 73 (16.6%) without and 32 (12.7%) with dissection; recurrent angina requiring medical therapy in 88 (20%) without and 47 (18.7%) with dissection to no serious adverse event in 272 (61.7%) without and 114 (65.1%) with dissection. CONCLUSIONS. These data indicate that a successfully dilated coronary lesion with an angiographically visible dissection is no more likely to develop restenosis, and is not associated with a worse clinical outcome, at 6-month follow-up than is a dilated lesion without visible dissection on the post-balloon angioplasty angiogram. http://repub.eur.nl/res/pub/4417/ 1991-01-01T00:00:00Z The immediate result of percutaneous transluminal coronary angioplasty is influenced by both plastic and elastic changes of the vessel wall. To evaluate the amount of elastic recoil after coronary balloon angioplasty, the minimal luminal cross-sectional area of the largest balloon used at highest inflation pressure was compared with the minimal luminal vessel cross-sectional area directly after final balloon deflation in 607 lesions (526 patients). Elastic recoil was defined as the difference between balloon cross-sectional area and minimal luminal cross-sectional area of the dilated coronary segment immediately after balloon withdrawal. A videodensitometric analysis technique was used to avoid geometric assumptions on stenosis morphology directly after angioplasty. Mean balloon cross-sectional area was 5.3 +/- 1.6 mm2 and minimal luminal cross-sectional area after angioplasty was 2.8 +/- 1.4 mm2. Reference areas before and after angioplasty did not differ (6.0 +/- 2.6 and 6.2 +/- 2.6 mm2, respectively). Univariate analysis revealed that asymmetric lesions, lesions located in less angulated parts of the artery and lesions with a low plaque content showed more elastic recoil. Lesions located in distal parts of the coronary tree were also associated with more elastic recoil probably related to relative balloon oversizing in these distal lesions. http://repub.eur.nl/res/pub/4432/ 1991-01-01T00:00:00Z -- http://repub.eur.nl/res/pub/4442/ 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) http://repub.eur.nl/res/pub/4393/ 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.