Predictors of coronary in-stent restenosis: importance of angiotensin-converting enzyme gene polymorphism and treatment with angiotensin-converting enzyme inhibitors

OBJECTIVES: This study aimed to clarify the role of the angiotensin-converting enzyme (ACE) gene polymorphism in the development of in-stent restenosis. BACKGROUND: In-stent restenosis occurs after treatment of coronary artery stenosis in 12% to 32% of coronary interventions with stents. Experimental and clinical studies have suggested that the deletion/insertion (D/I) polymorphism of the ACE gene plays a role in this. METHODS: Quantitative coronary angiography before, immediately after and six months after stent implantation were compared in 369 patients, in whom D/I typing of the ACE gene was performed. RESULTS: At follow-up we found no differences between the three genotypes in minimal lumen diameter (homozygotes with two deletion alleles in the ACE gene [DD], 2.20 mm; heterozygotes with one deletion and one insertion allele in the ACE gene [DI], 2.19 mm; and homozygotes with two insertion alleles in the ACE gene [II], 2.25 mm). The corresponding diameter stenoses were: DD: 25%, DI: 27%, II: 27% (p = NS), and the frequency of restenosis (>50% diameter stenosis) was: DD: 15.7%, DI: 11.0% and II: 16.4% (p = NS). Logistic regression analysis identified diabetes (odds ratio [OR]: 3.0, 95% confidence interval [CI]: 1.0 to 8.7), lesion length (OR: 1.1, 95% CI: 1.01 to 1.30) and minimal lumen diameter immediately after the intervention (OR: 0.3, 95% CI: 0.14 to 0.85) as predictors of in-stent restenosis. In a post hoc analysis of patients treated versus those not treated with an ACE-inhibitor antagonist or an angiotensin receptor antagonist, we found an increased frequency of in-stent restenosis in the DD genotypes (40% vs. 12%, p = 0.006). CONCLUSIONS: The D/I polymorphism is not an independent predictor of coronary in-stent restenosis in general, but it may be of clinical importance in patients treated with ACE inhibitors or angiotensin receptor antagonists.     

ACE gene polymorphism and coronary restenosis.

In humans, circulating levels of angiotensin-converting enzyme (ACE) are linked with an insertion (I)/deletion (D) polymorphism in the ACE gene: DD genotype bearers have higher levels of ACE than either ID or II genotype bearers. Recent studies have suggested that the ACE DD genotype might be associated with a higher risk of coronary artery disease. The aim of this paper is to review studies on the influence of the I/D polymorphism on coronary restenosis. The renin-angiotensin system has been implicated in the pathogenesis of neointimal hyperplasia in experimental models. In humans, the I/D polymorphism is not associated with restenosis after balloon angioplasty, but is strongly associated with restenosis after coronary stent implantation. This may be explained by the fact that the contribution of neointimal hyperplasia to restenosis is much more important after coronary stent implantation than after balloon angioplasty.     

Effect of angiotensin-converting enzyme inhibition on restenosis after coronary stenting

The Plasma level of angiotensin-converting enzyme (ACE) has been identified as a major risk factor for restenosis after coronary stent implantation in selected patients; ACE inhibition may therefore contribute to prevent its occurrence. The effect of oral ACE inhibition at conventional doses was analyzed retrospectively in a series of 897 patients with ischemia who received >or=1 coronary stent on 998 lesions and underwent angiographic follow-up; no exclusion criteria were introduced in this analysis. The restenosis rate in 282 patients (31.4%) taking ACE inhibitors was 36.6% compared with 22.9% in 615 non-ACE-inhibited patients (p = 0.00001, odds ratio [OR] 1.94, 95% confidence interval [CI] 1.45 to 2.59), and the late loss in minimum lumen diameter was 1.25 +/- 0.8 versus 0.96 +/- 0.8 mm, respectively (p = 0.0001). During univariate analysis, a negative effect of the drug on restenosis was observed in all subgroups of patients (i.e., hypertensives, diabetics, women, and patients with previous myocardial infarction). Similar effects were observed independently of the ACE gene insertion/deletion polymorphism. During multivariate analysis, ACE inhibition was confirmed as an independent risk factor for restenosis (OR 1.84, 95% CI 1.35 to 2.51, p = 0.0001). Other predictors were the implantation of multiple stents (OR 2.41, 95% CI 1.60 to 3.64, p <0.0001), diabetes (OR 2.34, 95% CI 1.61 to 3.41, p <0.0001), and vessel reference diameter before angioplasty (OR 0.51, 95% CI 0.38 to 0.69, p <0.0001). Although unexplained and apparently contradictory, our data suggest that the use of conventional oral doses of ACE inhibitors in a "real-world" population who underwent coronary stent implantation increases the incidence of in-stent restenosis. Such a finding does not negate the known clinical benefits of ACE inhibitors, but it may deserve attention when a patient treated with ACE inhibitors becomes a candidate for stent implantation.     

D/D genotype of the gene for angiotensin converting enzyme as a risk factor for post-stent coronary restenosis]

INTRODUCTION: Although intracoronary stenting has decreased restenosis rate compared to percutaneous balloon angioplasty, still a high number of patients develop in-stent restenosis, which is an entity primarily due to tissue proliferation. Experimental studies have indicated that the renin-angiotensin system is involved in neointimal hyperplasia. Plasma and cellular levels of ACE are associated with an I/D polymorphism in the ACE gene. Indeed, DD subjects have the higher ACE levels. The purpose of this study was to explore the possibility that the I/D polymorphism might be related with in-stent restenosis. METHODS: We studied the ACE polymorphism in 48 consecutive patients who underwent successful implantation of an elective coronary stent in native coronary vessels and had a 6 month angiographic follow up. Restenosis (50% of the reference vessel) was observed in 23/48 patients. Patients with or without restenosis did not differ in demographic or clinical variables like diabetes, plasma cholesterol levels or in quantitative angiographic parameters such as vessel reference size or minimal lumen diameter after stent implantation. RESULTS: I/D polymorphism was distributed as follows: 22.9% of the patients were D/D; 14.5% were I/I and 62.5% of the patients were heterozygous I/D. The presence of restenosis was strongly related with the I/D polymorphism: 81.8% of the patients with D/D genotype had restenosis, compared with 40.0% of I/D patients and only 14.2% of the I/I patients (chi 2 p < 0.01). CONCLUSIONS: In this limited cohort, homocygous D/D of the ACE gene was significantly associated with in-stent restenosis, whereas restenosis was infrequent in patients with the I/I genotype.     

Association of a CD18 gene polymorphism with a reduced risk of restenosis after coronary stenting.

Inflammatory mechanisms play an important role in the process of restenosis after percutaneous coronary interventions, with cell adhesion molecules, including Mac-1 (CD11b/CD18), as key mediators. A single nucleotide polymorphism, 1323C/T, located in exon 11 of the CD18 gene has been previously described, but its functional and clinical significances have not yet been studied. We assessed whether an association exists between this polymorphism and restenosis after coronary stenting. Clinical and angiographic measures of restenosis were evaluated over 1 year after coronary stent placement in 1,207 consecutive patients. Angiographic restenosis was defined as a > or =50% diameter stenosis at follow-up angiography. Determination of the CD18 1323C/T genotype was based on the polymerase chain reaction technique. The frequency of the T allele was 0.34 and its presence reduced the 1-year risk of a major adverse cardiac event (death, myocardial infarction, target vessel revascularization) by 29% (p = 0.011). Carriers of the T allele had a significantly lower risk of angiographic restenosis compared with noncarriers (odds ratio 0.71, 95% confidence interval 0.55 to 0.92). The incidence of restenosis decreased as a function of the number of T alleles: 38.1% in patients with genotype CC, 31.7% in patients with genotype CT, and 26.0% in patients with genotype TT (p = 0.004). Thus, the 1323T allele of the CD18 gene is associated, in a gene dose-dependent manner, with a lower incidence of angiographic restenosis after coronary stenting. This finding suggests that Mac-1 is involved in the development of restenosis after coronary stent placement.     

Quinapril prevents restenosis after coronary stenting in patients with angiotensin-converting enzyme D allele.

Restenosis after coronary artery stent implantation is attributed chiefly to intimal hyperplasia, which is prevented experimentally by angiotensin-converting enzyme (ACE) inhibitors. Therefore, the present study investigated whether the effect of quinapril, a tissue-specific ACE inhibitor, on the prevention of coronary restenosis differs according to ACE polymorphism. One hundred consecutive patients with successful stent implantation were randomly assigned to quinapril and control groups. Both follow-up angiography and ACE polymorphism analysis were obtained from 92 patients (control, 46; quinapril treatment, 46). The prevalence of risk factors did not differ statistically according to quinapril treatment or ACE genotypes. There was no statistically significant difference in the occurrence of restenosis 6 months after stenting between the groups. Quantitative coronary angiography revealed that quinapril treatment resulted in significantly higher minimal lumen diameter and significantly lower percent diameter stenosis (22.9 +/- 22.6 vs 37.1 +/- 19.7% in the control group, p < 0.05) in patients with the D allele although there was no difference in those with the II genotype. In addition, intravascular ultrasound revealed that quinapril treatment significantly prevented the loss of minimal lumen cross-sectional area and the increase in percent area stenosis (34.5 +/- 14.0 vs 53.3 +/- 16.4% in the control group, p < 0.05) in patients with the D allele compared to those with the II genotype. These results suggest that the administration of ACE inhibitors for the attenuation of lumen loss after coronary stent implantation is best for subjects with the D allele of the ACE genotype.     

冠状血管病变特征对支架术后再狭窄的预测价值

目的 :探讨冠状血管病变特征对支架术后再狭窄的影响。方法 :冠状动脉造影 (CAG)随访支架术后患者共 110例 ,定量 (QCA)分析术前、术后即刻和随访时靶血管造影结果 ;比较支架术前靶血管及患者临床资料 ,应用单因素和多因素回归法分析术前靶血管解剖学和临床危险因素与再狭窄的相关性。结果 :再狭窄组中术前甘油三酯有增高趋势 ,但与无再狭窄组比较差异无显著性意义 (P >0 .0 5 )。单因素分析表明 ,再狭窄组血管术前狭窄程度、靶血管最小管腔直径和病变分型与无再狭窄组比较差异显著 (P <0 .0 5 ) ;多因素逐步回归分析表明 ,术前靶血管最小管腔直径和病变分型是再狭窄形成的独立危险因素 ,其OR值分别为 0 .12 0和 2 .6 4 2。结论 :冠状血管病变特征对支架术后再狭窄具重要预测价值。     

ACE基因I/D多态性与冠状动脉支架内再狭窄相关性研究

目的研究冠状动脉内行药物洗脱支架置入术患者,术后支架内再狭窄发生情况与ACE基因I/D多态性的关系。方法所有患者行冠状动脉造影检查,PCR方法测定ACE基因型。根据血管造影结果分为再狭窄组（病变狭窄≥50%）和无再狭窄组（病变狭窄〈50%）。采用SPSS18.0软件比较再狭窄组与无再狭窄组的临床基本特征、冠脉造影资料,以及与ACE基因型的关系。结果此次研究共纳入396名行药物洗脱支架置入术的冠心病患者,支架内再狭窄发生40例,再狭窄率为10.1%。再狭窄组与无再狭窄组的临床基本资料、冠脉造影资料均无显著性差异（P〉0.05）。再狭窄组的ACEDD基因型35.56%、ACEDI基因型16.39%、ACEII基因型3.85%。再狭窄组与ACE基因I/D多态性具有相关性（P〈0.001）。结论冠状动脉内行药物洗脱支架置入术患者术后支架再狭窄发生与ACEDD基因型具有显著相关性。     

Intravascular Ultrasound Predictors of Angiographic Restenosis in Lesions Treated With Palmaz-Schatz Stents

Objectives. This study sought to evaluate the clinical, procedural, preinterventional and postinterventional quantitative coronary angiographic (QCA) and intravascular ultrasound (IVUS) predictors of restenosis after Palmaz-Schatz stent placement.Background. Although Palmaz-Schatz stent placement reduces restenosis compared with balloon angioplasty, in-stent restenosis remains a major clinical problem.Methods. QCA and IVUS studies were performed before and after intervention (after stent placement and high pressure adjunct balloon angioplasty) in 382 lesions in 291 patients treated with 476 Palmaz-Schatz stents for whom follow-up QCA data were available 5.5 ± 4.8 months (mean ± SD) later. Univariate and multivariate predictors of QCA restenosis (≥50% diameter stenosis at follow-up, follow-up percent diameter stenosis [DS] and follow-up minimal lumen diameter [MLD]) were determined.Results. Three variables were the most consistent predictors of the follow-up angiographic findings: ostial lesion location, IVUS preinterventional lesion site plaque burden (plaque/total arterial area) and IVUS assessment of final lumen dimensions (whether final lumen area or final MLD). All three variables predicted both the primary (binary restenosis) and secondary (follow-up MLD and follow-up DS) end points. In addition, a number of variables predicted one or more but not all the end points: 1) restenosis (IVUS preinterventional lumen and arterial area); 2) follow-up DS (QCA lesion length); and 3) follow-up MLD (QCA lesion length and preinterventional MLD and DS and IVUS preinterventional lumen and arterial area).Conclusions. Ostial lesion location and IVUS preinterventional plaque burden and postinterventional lumen dimensions were the most consistent predictors of angiographic in-stent restenosis.     

Pharmacogenetic analysis of the effect of angiotensin-converting enzyme inhibitor on restenosis after percutaneous transluminal coronary angioplasty.

Angiotensin-converting enzyme (ACE) inhibitors are reported to prevent neointimal formation after balloon injury in animal models, but in most prospective studies in humans, ACE inhibitors failed to prevent restenosis after percutaneous transluminal coronary angioplasty (PTCA). The ACE genotype assigned by an insertion/deletion (I/D) polymorphism is known to affect the potency of ACE inhibitors in several renal diseases. The authors attempted to clarify whether the effect of ACE inhibitors on restenosis might be modified by the ACE genotype. A total of 126 patients was randomly and prospectively assigned to the control group and the imidapril group. In the imidapril group, patients received 5 mg imidapril daily, starting 1 day before PTCA and continuing for 3 to 6 months. Forty-six control (65 vessels) and 32 imidapril patients (43 vessels) completed the study. The minimal lumen diameter before and after the procedure did not differ significantly among the groups with the three genotypes (II, ID, and DD) in both the control and imidapril groups. Late luminal loss during the follow-up period was not related to the ACE genotype in the control group but was significantly related in the imidapril group (II, 0.63+/- 0.19 mm; ID + DD, 1.12+/-0.14 mm, p<0.05). Furthermore, in the II genotype, imidapril significantly reduced late loss and restenosis rate as defined by most of the frequently used definitions. In conclusion the ACE I/D polymorphism may influence the effect of ACE inhibitors in preventing restenosis after PTCA.     

Comparison of coronary restenosis rates in matched patients with versus without diabetes mellitus

Diabetes mellitus (DM) is an established risk factor for stent restenosis, in part as a result of the smaller vessel dimensions and longer lesions. This study compared the magnitude of acute lumen gain and late lumen loss after elective coronary stent implantation in patients with and without DM using a matched-pair analysis. A total of 133 patients with DM and 192 coronary lesions were included in this analysis. A group of 192 lesions in 182 patients without DM were matched in a pairwise fashion, stratifying for reference diameter, minimal luminal diameter, and lesion length. The binary restenosis rate at the 5-month follow-up angiography was 25% in the DM group and 14% in the non-DM group (p <0.01). Acute angiographic lumen gain (1.47 +/- 0.41 vs 1.56 +/- 0.38 mm, p = 0.03) and late lumen loss (0.64 +/- 0.42 vs 0.55 +/- 0.36 mm, p = 0.02) were significantly different between the DM and non-DM groups. In conclusion, suboptimal acute procedural results and an exaggerated neointimal proliferation contributed by about 50% to the lower net lumen gain in the DM group. Patients with DM had a significantly higher restenosis rate even when matched for preprocedural angiographic lesion dimensions. Mechanistically, inferior procedural results, as well as exaggerated neointimal proliferation, are, quantitatively, equally important in this process.     

The 5A/6A polymorphism of the stromelysin-1 gene and restenosis after percutaneous coronary interventions.

AIMS: Matrix metalloproteinase stromelysin-1 has been implicated in the process of exaggerated lumen re-narrowing after primarily successful interventions in coronary arteries. We examined the possibility that the 5A/6A promoter polymorphism of the stromelysin-1 gene is associated with restenosis after stenting or percutaneous transluminal coronary angioplasty (PTCA). METHODS AND RESULTS: The study included 3333 consecutive patients with symptomatic coronary artery disease who were treated with stent implantation (n=2857) or PTCA (n=476). Primary end-point was angiographic restenosis, defined as >/=50% diameter stenosis at 6-month follow-up angiography. Restenosis rates were 28.1%, 27.8%, and 29.5% in carriers of the stromelysin-1 genotypes 5A5A, 5A6A, and 6A6A, respectively (P=0.71). The incidence of death or myocardial infarction and the need for revascularization at the site of the intervention due to symptoms or signs of ischaemia in the presence of angiographic restenosis were not significantly different between the genotype groups at 1 year. Separate analysis of the patients who underwent stenting and the patients who were treated with PTCA did not indicate the existence of a treatment type-related association between the 5A/6A polymorphism and restenosis. CONCLUSION: Our data strongly suggest that the 5A/6A polymorphism of the stromelysin-1 gene is not related to angiographic restenosis or the 1-year clinical outcome after interventions in coronary arteries.     

Diabetes mellitus and the clinical and angiographic outcome after coronary stent placement

Objectives. The objectives of this study were to analyze the clinical and angiographic outcome of diabetic patients with successful coronary stent placement and to compare these results with those achieved after stenting in nondiabetic patients.

Background. The outcome of diabetic patients treated with stent placement due to coronary artery disease has not been assessed comprehensively.

Methods. This study analyzes a consecutive series of patients with successful stent placement comprising 715 patients with diabetes and 2,839 patients without diabetes. Clinical one year follow-up and angiographic control at 6 months were part of the protocol. Death, myocardial infarction and target lesion revascularization were considered as adverse events. An automated edge detection system was used for the angiographic assessment. The primary clinical endpoint was event-free survival at one year. The primary angiographic endpoint was restenosis rate at 6 months (≥50% diameter stenosis).

Results. Event-free survival was significantly lower in diabetic than in nondiabetic patients (73.1 vs. 78.5%, p < 0.001). Survival free of myocardial infarction was also significantly reduced in the diabetic group (89.9 vs. 94.4% in nondiabetics, p < 0.001). The incidence of both restenosis (37.5 vs. 28.3%, p < 0.001) and stent vessel occlusion (5.3 vs. 3.4%, p = 0.037) was significantly higher in diabetic patients. Diabetes was identified as an independent risk factor for adverse clinical events and restenosis in multivariate analyses.

Conclusions. Patients with diabetes mellitus have a less favorable clinical outcome at one year after successful stent placement as compared to the nondiabetic patients. The clinical follow-up was characterized by a higher incidence of death, myocardial infarction and reinterventions. Diabetic patients also demonstrated an increased risk for restenosis.     

Angiotensin-converting enzyme insertion/deletion polymorphism does not influence the restenosis rate after coronary stent implantation

BACKGROUND: Experimental studies have shown an activation of the angiotensin-converting enzyme (ACE) system as a response to endothelial injury. Recent publications have elucidated the hypothesis that the ACE gene polymorphism may influence the level of late luminal loss after coronary stent implantation. It is still unclear whether the polymorphism of the angiotensin gene is a major predictor of the extent of neointimal hyperplasia. In this multicenter study, we therefore tested the relationship between the ACE gene polymorphism and the restenosis rate after coronary stent implantation. METHODS: As a substudy of the optimization with intracoronary ultrasound (ICUS) to reduce stent restenosis (OPTICUS) study, we analyzed ACE serum levels and the ACE gene polymorphism in 154 patients at 9 different centers. All patients underwent elective coronary stent implantation in a stenosis of a major coronary vessel. Balloon inflations were repeated until a satisfactory result was achieved in on-line quantitative coronary angiography or ICUS fulfilling the OPTICUS study criteria. After follow-up of 6 months, all patients underwent reangiography under identical projections as the baseline procedure. A blinded quantitative analysis of the initial procedure as well as the follow-up examinations were performed by an independent core laboratory. ACE gene polymorphism and ACE serum activity were measured at the 6-month follow-up in a double-blinded setting. RESULTS: With respect to the ACE gene polymorphism, there were three subgroups: DD genotype (48 patients), ID (83 patients) and II (23 patients). The subgroups did not differ in regard to age, gender, extent of coronary artery disease, stenosis length, initial degree of stenosis or degree of stenosis after stent implantation. In all, 39 patients (25.3%) had significant restenosis: 12 DD patients (25.0%), 18 ID patients (21.7%) and 9 II patients (39.1%) (odds ratio 2.164, 95% confidence interval 0.853-5.493). We obtained the following results for ACE serum levels: 0.53 micromol/l/s in the DD subgroup, 0.29 micromol/l/s in the ID subgroup and 0.09 micromol/l/s in the II subgroup (p < 0.001). Multivariate logistic regression analysis of the influence of ACE gene polymorphism on the restenosis rate after coronary stent implantation adjusted for lesion length (>12 mm), ACE inhibitor or hydroxymethylglutaryl coenzyme A reductase (CSE) inhibitor treatment, age, male gender, diabetes mellitus, hypertension, high cholesterol, family history, smoking and three-vessel disease did not uncover any statistic significance. CONCLUSIONS: In contrast to other study groups, we were unable to disclose that the DD polymorphism of the ACE gene was associated with a higher rate of restenosis after coronary stent implantation in this multicenter study. In addition, patients with higher ACE serum levels did not show a higher restenosis rate in this trial. We conclude that the pathogenesis of restenosis is a multifactorial process involving various genetic and nongenetic factors.     

Effect of statin therapy on restenosis after coronary stent implantation

The effect of statins on the development of restenosis and clinical outcome after coronary stent implantation was assessed in a retrospective analysis of 525 consecutive patients. Baseline clinical, angiographic, and procedural characteristics did not differ between 258 patients with and 267 patients without statin therapy. Statin therapy was associated with a significantly (p<0.04) improved survival free of myocardial infarction and a significant reduction in repeat target vessel revascularization procedures (27.9% vs. 36.7%, p<0.05) during 6-month follow-up. Minimal lumen diameter was significantly larger (1.98+/-0.88 vs. 1.78+/-0.88 mm, p = 0.01), late lumen loss was significantly less (0.64+/-0.8 vs. 0.8+/-0.8 mm, p = 0.032), and net gain significantly increased (1.2+/-0.88 vs. 0.98+/- 0.92 mm, p = 0. 009) in patients receiving statin therapy. Dichotomous angiographic restenosis (> or =50%) rates were significantly lower, with 25.4% in the statin group compared with 38% in the no-statin group (p<0.005). Multivariate analysis identified statin therapy (p = 0.005), minimal lumen diameter immediately after stenting (p = 0.02), and stent length (p = 0.02) as independent predictors for subsequent restenosis development. Thus, statin therapy is associated with reduced recurrence rates and improved clinical outcome after coronary stent implantation.     

Clinical restenosis after coronary stenting: perspectives from multicenter clinical trials

OBJECTIVES: We sought to evaluate clinical restenosis in a large population of patients who had undergone coronary stent placement. BACKGROUND: One-year success after coronary stenting is limited mainly by restenosis of and requirement for repeat revascularization of the treated lesion.We studied 6,186 patients (6,219 lesions) pooled from several recently completed coronary stent trials. Clinical restenosis was defined using three different definitions: target lesion revascularization (TLR) beyond 30 days, target vessel revascularization (TVR) beyond 30 days, and target vessel failure (TVF), defined as TVR, any death, or myocardial infarction (MI) of the target vessel territory after hospital discharge. RESULTS: By one year, 638 (12.2%) patients had TLR, 748 (14.3%) had TVR, and 848 (16.0%) had TVF, more than two-thirds higher than the rate of these end points at six months. The severity of angiographic restenosis (> or =50% follow-up diameter stenosis [DS]) in 419 of 1,437 (29%) patients undergoing routine angiographic follow-up correlated directly with the likelihood of TLR (73% vs. 26% for >70% DS compared with <60% DS). Smaller pretreatment minimum lumen diameter (MLD), smaller final MLD, longer stent length, diabetes mellitus, unstable angina, and hypertension were independent predictors of TLR. Prior MI and current smoking were negative predictors. CONCLUSIONS: At one year after stenting, most clinical restenosis reflected TLR, which was predicted by the same variables previously associated with an increased risk of angiographic restenosis. The lower absolute rate of clinical restenosis relative to angiographic restenosis was due to infrequent TLR in lesions with less severe (<60% DS) angiographic renarrowing.     

Intravascular ultrasonic predictors of angiographic restenosis after long coronary stenting

The intravascular ultrasound (IVUS) criteria for stent optimization have not been determined in stenting long lesions. We evaluated the predictors of angiographic restenosis and compared it with stent lumen cross-sectional area (CSA) and stent length between short (stent length <20 mm) and long (> or =20 mm) coronary stenting. IVUS-guided coronary stenting was successfully performed in 285 consecutive patients with 304 native coronary lesions. Six-month follow-up angiogram was performed in 236 patients (82.8%) with 246 lesions (80.9%). Results were evaluated using conventional (clinical, angiographic, and IVUS) methods. The overall angiographic restenosis rate was 22.8% (56 of 246 lesions) (short stent 17.6% vs. long stent 32.2%, p = 0.009). Using multivariate logistic regression analysis, the independent predictors of angiographic restenosis were the IVUS stent lumen CSA (odds ratio 1.51, 95% confidence intervals 1.18 to 1.92, p = 0.001) and stent length (odds ratio 0.95, 95% confidence intervals 0.91 to 1.00, p = 0.039). The angiographic restenosis rate was 54.8% for stent lumen CSA of <5.0 mm2 (short stent 37.5% vs. long stent 73.3%, p = 0.049), 27.4% for CSA between 5.0 and 7.0 mm2 (short stent 24.1% vs. long stent 31.7%, p = 0.409), 10.5% for CSA between 7.0 and 9.0 mm2 (short stent 10.0% vs. long stent 12.5%, p = 0.772), and 11.4% for stent lumen CSA of > or =9.0 mm2 (short stent 10.4% vs. long stent 13.3%, p = 0.767) (p = 0.001). Compared with short coronary stenting, long coronary stenting is effective treatment modality to cover long lesions with comparable long-term clinical outcomes in cases of stent lumen CSA of > or =7.0 mm2. Regardless of the stent length, the most important factor determining angiographic restenosis was the IVUS stent lumen CSA in relatively large coronary artery lesions.     

Angiographic and clinical outcome of intracoronary stenting: immediate and long-term results from a large single-center experience.

OBJECTIVES. The purpose of this study was to determine the immediate and long-term angiographic and clinical results of coronary stenting. BACKGROUND. Although preliminary trials of endovascular stenting have demonstrated promising results, lack of long-term follow-up has limited the critical evaluation of the role of coronary stenting in the treatment of obstructive coronary artery disease. METHODS. A total of 250 procedures using the Palmaz-Schatz stent, performed in 220 patients between June 1988 and July 1991, were examined. Minimal lumen diameter of the treated segments was measured on angiograms obtained before, after and 6 months after intervention. RESULTS. Stent placement was successful in 246 (98%) of 250 lesions, reducing diameter stenosis from 77% to -2.5%. There were no deaths or Q wave myocardial infarctions. One patient (0.4%) required emergency bypass surgery and one (0.4%) developed subacute thrombosis. Femoral vascular complications occurred in 36 patients (16%). Six-month angiographic follow-up was obtained in 91% of eligible patients. The overall angiographic restenosis rate (stenosis greater than or equal to 50%) was 25%. By univariable analysis, the rate of restenosis was significantly higher for stents in the left anterior descending versus the right coronary artery (44% vs. 12%; p = 0.002); in diabetic patients (56% vs. 20%; p = 0.006), and in vessels with post-stent lumen diameter less than 3.31 mm (34% vs. 16%; p = 0.05). Stenting of the left anterior descending artery was the strongest predictor (p = 0.01) of restenosis in a multivariable model. Total survival was 97% and event-free survival (freedom from death, myocardial infarction or revascularization) was 70% at 36 months. CONCLUSIONS. Palmaz-Schatz stents can be placed successfully with a low incidence of major complications. The angiographic restenosis rate was 25%, and 70% of patients remained free of cardiovascular events at 3 years. Diabetes, small postprocedure lumen diameter and stenting of the left anterior descending artery are associated with higher rates of restenosis.     

Influence of lesion length on restenosis after coronary stent placement

The length of a coronary lesion is a significant predictor of restenosis after balloon angioplasty. The influence of lesion length has not comprehensively been assessed after coronary stent placement. This study includes 2,736 consecutive patients with coronary stent placement. Only patients with recent or chronic occlusions before the intervention were excluded. Patients were divided in 2 groups: 573 patients with long lesions (≥15 mm) and 2,163 patients with short lesions (<15 mm). There were no significant differences between the groups with respect to the procedural success rate and incidence of subacute thrombosis. One-year event-free survival was lower in patients with long lesions (73.3% vs 80.0%, p = 0.001). Six-month angiography was performed in 82.5% of the eligible patients. The incidence of binary restenosis (≥50% diameter stenosis) was higher in patients with long lesions (36.9% vs 27.9%, p <0.001). Similarly, patients with long lesions presented more late lumen loss than those with short lesions (1.29 ± 0.89 vs 1.07 ± 0.77 mm, p <0.001). Multivariate models for both binary restenosis and late lumen loss demonstrated that lesion length was an independent risk factor for restenosis. The risk was further increased by multiple stent placement and overlapping stents that were also independent risk factors of restenosis. Stented segment length did not show any independent effect. Therefore, long lesions represent an independent risk factor for restenosis after coronary stent placement. The results of this study suggest that a possible way to reduce the risk is to cover the lesion with a minimal number of nonoverlapping stents.     

Coronary intervention in the diabetic patient: improved outcome following stent implantation compared with balloon angioplasty

BACKGROUND: Diabetic patients undergoing coronary interventional procedures are at increased risk of restenosis and adverse clinical events. The relative impact of stents compared with balloon angioplasty on the outcome of percutaneous intervention in diabetics remains controversial. HYPOTHESIS: The goal of this study was to determine whether stent placement was superior to balloon angioplasty in reducing restenosis of diabetic patients undergoing coronary intervention. METHODS: The STRESS Trial was a prospective randomized comparison of stent placement and balloon angioplasty in the treatment of new native coronary lesions. Of 594 randomized patients. 92 (16%) were diabetic. In this substudy analysis of the STRESS Trial, the outcomes after stenting and balloon angioplasty in diabetic patients were compared. The primary endpoint was restenosis as determined by angiography at 6 months. Clinical outcomes at 1 year were assessed. RESULTS: Procedural success was achieved in 82% of diabetic patients assigned to angioplasty and in 100% assigned to stenting (p < 0.01). Compared with angioplasty, stenting resulted in a larger postprocedural lumen diameter (2.34 +/- 0.44 vs. 1.87 +/- 0.52 mm, p < 0.001) and greater acute luminal gain (1.61 +/- 0.47 vs. 1.06 +/- 0.46 mm, p < 0.001). At 6 months, stenting conferred a larger lumen (1.69 +/- 0.57 vs. 1.38 +/- 0.60 mm, p = 0.03) and greater net luminal gain (0.97 +/- 0.55 vs. 0.52 +/- 0.52 mm, p < 0.001). Restenosis occurred in 60% of the angioplasty group and in 24% of the stent group (p < 0.01). This was accompanied by a lower need for repeat target vessel revascularization after stenting (31 vs. 13%, p < 0.03). CONCLUSIONS: Compared with balloon angioplasty, stent placement in diabetic patients with focal de novo lesions resulted in superior procedural results, reduced restenosis, and improved clinical outcome with fewer repeat revascularization procedures.