Relation between the insertion/deletion polymorphism of the angiotensin I converting enzyme gene and restenosis after coronary stenting

BACKGROUND: Observations with intravascular ultrasound demonstrated that neointimal hyperplasia is the predominant factor responsible for in-stent restenosis. Experimental data suggest that angiotensin I converting enzyme (ACE) plays a role in the thickening of neointima after balloon denudation. Insertion/deletion (I/D) polymorphism of the ACE gene is significantly associated with plasma level of ACE and subjects with D/D genotype have significantly higher plasma levels of ACE than normal. OBJECTIVE: To investigate whether this polymorphism influences the risk of restenosis after coronary stenting. METHODS: We genotyped 158 patients who had undergone single-vessel coronary stenting for the ACE I/D polymorphism. RESULTS: Of the 158 patients, 56 (35%) had the D/D genotype, 71 (45%) had the I/D genotype and 31 (20%) had the I/I genotype. Prevalences of genotypes were compatible with Hardy-Weinberg equilibrium and distributions of ACE genotype among patients and 132 healthy controls from the same geographic area did not differ. At follow-up (after a median duration of 5.4 months), overall rates of angiographic restenosis and of revascularization of target lesion (RTL) were 32.3 and 22.8%, respectively. Of 51 patients with angiographic restenosis, 31 (60.8%) had focal and 20 (39.2%) had diffuse patterns of restenosis. Diffuse in-stent restenosis was significantly more prevalent among patients with D/D genotype (P = 0.016). Multiple stepwise logistic regression analysis identified ACE I/D polymorphism as the independent predictor of angiographic restenosis and RTL. Relative risk of angiographic restenosis was 6.29 [95% confidence interval (CI), 1.80-22.05, P = 0.0004] for D/D genotype and 3.88 (95% CI 1.11-13.12, P = 0.029) for I/D genotype, whereas relative risk of RTL was 7.44 (95% CI 1.60-34.58, P = 0.01) for D/D genotype and 3.88 (95% CI 0.083-18.15, P = 0.085) for I/D genotype. CONCLUSIONS: The ACE I/D polymorphism is significantly associated with risk of angiographic and clinical restenosis after coronary stenting. Angiographic pattern of restenosis is also significantly associated with I/D polymorphism, diffuse type being more prevalent among subjects with D/D genotype.     

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。     

Angiotensin I-converting enzyme (ACE) inhibitors and restenosis after coronary artery stenting in patients with the DD genotype of the ACE gene

OBJECTIVES: We tested the hypothesis that patients with the DD genotype of the angiotensin I-converting enzyme (ACE) gene who are treated with ACE inhibitors are at a higher risk of restenosis after coronary stent placement than patients who do not receive ACE inhibitors. BACKGROUND: Two recent studies with a limited series of patients carrying the DD genotype suggested an unfavorable impact of the use of ACE inhibitors on the restenotic process after implantation of stents in coronary arteries. Because these findings may question the use of ACE inhibitors after coronary stenting, we examined this important issue in a large series of patients. METHODS: We determined the ACE gene I/D genotype of 2,222 consecutive patients with symptomatic coronary artery disease who underwent stent implantation. The patients with the DD genotype (n = 612) constituted the study population. The primary end point was in-stent restenosis, which was assessed as angiographic restenosis (> or =50% diameter stenosis at six-month follow-up) and clinical restenosis (need for target vessel revascularization due to symptoms or signs of ischemia in the presence of angiographic restenosis over one year after the intervention). RESULTS: Of the 612 patients with the DD genotype, 403 (65.8%) were treated with ACE inhibitors and 209 (34.2%) did not receive ACE inhibitors. The angiographic and clinical restenosis rates were not significantly different between the group treated with ACE inhibitors and the group not receiving ACE inhibitors (p = 0.55). Continuous measures of restenosis, minimal lumen diameter, diameter stenosis, late lumen loss, and loss index were also similar in both groups (p > or = 0.55). In addition, one-year survival free of myocardial infarction was not significantly different between the two groups (p = 0.27). CONCLUSIONS: In contrast to previous reports, our study provides evidence that patients carrying the DD genotype are not exposed to an increased risk of restenosis after stent placement when treated with ACE inhibitors.     

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.     

Balloon angioplasty for the treatment of coronary in-stent restenosis: immediate results and 6-month angiographic recurrent restenosis rate

Objectives. The purpose of this prospective study was to evaluate the immediate results and the 6-month angiographic recurrent restenosis rate after balloon angioplasty for in-stent restenosis.Background. Despite excellent immediate and mid-term results, 20% to 30% of patients with coronary stent implantation will present an angiographic restenosis and may require additional treatment. The optimal treatment for in-stent restenosis is still unclear.Methods. Quantitative coronary angiography (QCA) analyses were performed before and after stent implantation, before and after balloon angioplasty for in-stent restenosis and on a 6-month systematic coronary angiogram to assess the recurrent angiographic restenosis rate.Results. Balloon angioplasty was performed in 52 patients presenting in-stent restenosis. In-stent restenosis was either diffuse (≥ 10 mm) inside the stent (71%) or focal (29%). Mean stent length was 16 ± 7 mm. Balloon diameter of 2.98 ± 0.37 mm and maximal inflation pressure of 10 ± 3 atm were used for balloon angioplasty. Angiographic success rate was 100% without any complication. Acute gain was lower after balloon angioplasty for in-stent restenosis than after stent implantation: 1.19 ± 0.60 mm vs. 1.75 ± 0.68 mm (p = 0.0002). At 6-month follow-up, 60% of patients were asymptomatic and no patient died. Eighteen patients (35%) had repeat target vessel revascularization. Angiographic restenosis rate was 54%. Recurrent restenosis rate was higher when in-stent restenosis was diffuse: 63% vs. 31% when focal, p = 0.046.Conclusions. Although balloon angioplasty for in-stent restenosis can be safely and successfully performed, it leads to less immediate stenosis improvement than at time of stent implantation and carries a high recurrent angiographic restenosis rate at 6 months, in particular in diffuse in-stent restenosis lesions.     

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.     

Intracoronary β-irradiation prevents excessive in-stent neointimal proliferation in de novo lesions of patients with high plasma ACE levels. The BetAce randomized trial

BACKGROUND: This study evaluated vascular brachytherapy (VBT) as a potent antiproliferative treatment to prevent in-stent restenosis (ISR) after coronary angioplasty of de novo lesions in patients carrying the D allele of the I/D polymorphism of the ACE gene and high ACE plasma levels (>34 U/l). METHODS AND MATERIALS: A prospective randomized trial was designed to detect a 30% improvement in the minimal lumen diameter (MLD) of the stenotic artery, as measured by quantitative coronary analysis (QCA), 6 months following VBT at the time of stented angioplasty. All patients were carriers of the D allele of the ACE gene, with plasma ACE levels >34 U/l. RESULTS: Thirty-one patients (33 stenoses) were allocated to stent implantation (control group) and 30 patients (31 stenoses) to VBT and stented angioplasty. After angioplasty, in-stent MLD was similar in the two groups. At 6 months in the control group, in-stent MLD had decreased to 1.74+/-0.8 versus 2.25+/-1.05 mm in the VBT group (P=.04). The mean in-stent diameter was 2.3+/-0.8 mm in the control group versus 2.9+/-1.05 mm after VBT (P=.02), and the restenosis rate was 37.5% versus 17.9%, respectively (P=.08). At 6 months, a higher need for target vessel revascularization (TVR) was observed in the control group: 35.5% versus 13.3% (P=.04). CONCLUSIONS: This randomized study confirms that patients with high plasma ACE concentrations are exposed to an increased risk for ISR after coronary stenting. The preventive use of VBT in these patients reduced neointimal formation by 65% such that the MLD at follow-up was increased by 29% compared with the control group.     

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 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.     

The expression of angiotensin-I converting enzyme in human atherosclerotic plaques is not related to the deletion/insertion polymorphism but to the risk of restenosis after coronary interventions

Plasma and tissue concentrations of the angiotensin-I converting enzyme (ACE) have been shown to be associated with the ACE insertion/deletion (I/D) polymorphism. The purpose of this study was to examine the relation of ACE levels in atherosclerotic plaques to the ACE I/D polymorphism and to restenosis after balloon angioplasty and directional atherectomy (DCA). The study included 104 patients who underwent DCA and received angiographic follow-up at 12 to 18 months. The amount of ACE protein in various morphologically defined plaque components (fibrous, atheromatous, and complicated lesions) of the atherectomy specimens was determined by qualitative and semiquantitative immunohistochemistry. ACE levels were related to the ACE genotype, to plaque morphology and to the risk of restenosis. Sequential staining revealed that pathologic ACE overexpression of the atherosclerotic lesions occurred in intimal smooth muscle cells, fibrocytes/fibroblasts and macrophage/foam cells. The ACE content of the whole plaques and of the single plaque components was not associated with the I/D polymorphism, but with restenosis after coronary interventions. In addition, ACE levels in the atherosclerotic lesions correlated with the severity of vessel wall damage. The ACE phenotype might serve as an indicator for the risk of restenosis after coronary interventions.     

Role of vessel size as a predictor for the occurrence of in-stent restenosis in patients with diabetes mellitus

Intracoronary stents have been shown to reduce the rate of restenosis when compared with balloon angioplasty, but in-stent restenosis continues to be an important clinical problem. It was therefore the aim of this registry to identify procedural and angiographic predictors for the occurrence of in-stent restenosis. We analyzed 368 patients with 421 lesions who underwent coronary stent implantation between January 1998 and February 2000. Indications for the placement of a coronary stent were severe dissections (37%), suboptimal angiographic results (38%), restenotic lesions (20%), and graft lesions (4%). Angiographic follow-up was obtained in 270 patients (73%) with 293 lesions after 6 months. Clinical and angiographic variables were analyzed by univariate and multivariate models for the ability to predict the occurrence of in-stent restenosis, defined as a diameter stenosis >50%. In-stent restenosis was angiographically documented in 67 patients and 68 lesions (23%). Under all tested variables the reference luminal diameter before stent implantation (p = 0.006) and diabetes mellitus (p = 0.023) were identified as independent predictors for the occurrence of in-stent restenosis. The comparison of diabetic and nondiabetic patients according to vessel size revealed a 2 times higher rate of in-stent restenosis in small vessels (44% vs 23%, p = 0.002), whereas in vessels >3.0 mm the rate of in-stent restenosis was not significantly different between the 2 groups. In this registry, the clinical variable diabetes and the procedural variable reference vessel size were independent predictors for the occurrence of in-stent restenosis. In these patients, the rate of in-stent restenosis was as high as 45%.     

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.     

双源CT对冠状动脉支架靶血管再狭窄的诊断价值

目的:探讨双源CT（DSCT）对冠状动脉支架置入靶血管再狭窄的诊断价值。方法:对我院69例冠状动脉支架置入患者（共111枚支架）进行DSCT,评价支架图像质量得分与靶血管级别的相关性;并对部分患者同期进行冠状动脉造影（CAG）检查,对比分析DSCT对冠状动脉支架置入靶血管病变的真实性。结果:DSCT支架图像质量得分与靶血管级别正相关;DSCT对支架靶血管再狭窄诊断的灵敏度82%、特异度98%、和准确度95%;DSCT与CAG对不同直径支架的靶血管再狭窄检出率差异无统计学意义,但DSCT对直径≥3.0 mm支架靶血管再狭窄检出的特异度和准确度明显高于直径＜3.0 mm支架靶血管的相应指标（均P＜0.05）,而灵敏度的差异未达到显著水平。结论:DSCT可清晰的显示冠状动脉支架靶血管的病变情况,能较准确地评价冠状动脉支架靶血管再狭窄的发生,具有临床应用价值。     

Recurrent in-stent restenosis is not associated with the angiotensin-converting enzyme D/I, angiotensinogen Thr174Met and Met235Thr, and the angiotensin-II receptor 1 A1166C polymorphism

Although great progress has been made in reducing renarrowing of the lumen after stenting of coronary arteries, a considerable number of patients develop recurrent in-stent stenosis. Several studies suggest that neointimal proliferation is the crucial pathophysiological process underlying restenosis after stenting. The renin-angiotensin-aldosterone system (RAS) has been implicated in the development of neointimal hyperplasia. We tested the hypothesis that polymorphisms of the RAS genes are associated with recurrent in-stent restenosis (ISR). Coronary stent implantation was performed in 272 patients with clinical symptoms or objective signs of ischemia. At follow-up angiography 6 months after stenting, 81 patients (29.8%) revealed in-stent restenosis. These patients underwent balloon angioplasty and were scheduled for a further 6 months of follow up. One year after initial stenting of the coronary artery, 39 patients displayed no significant angiographic ISR, whereas 42 patients developed recurrent in-stent restenosis (RISR). The survey of specific functional polymorphisms of the RAS, namely the angiotensin-I converting enzyme (ACE) D/I, the angiotensinogen (AGT) T174M and M235T, and A1166C of the angiotensin-II receptor 1 (AGTR1), revealed that the incidence RISR in the high-risk cohort was not associated with any of the polymorphisms examined in this study.     

Ace D/I polymorphism and incidence of post-PTCA restenosis: a prospective, angiography-based evaluation

Early restenosis is the major complication of percutaneous transluminal coronary angioplasty (PTCA), occurring in approximately 30% of all initially successful procedures. The D/I polymorphism of the ACE gene, which has variably been reported to represent a risk factor for manifestations of ischemic heart disease, has recently been implicated in the pathophysiology of restenosis after PTCA by some investigators but not by others. All studies conducted thus far involved relatively small sample sizes. We investigated the possible association of ACE D/I genotype and post-PTCA restenosis in a large, prospective sample of patients followed by quantitative coronary angiography. The ACE D/I gene polymorphism was characterized in a cohort of 779 patients, of whom 342 (cases) had developed restenosis (as defined by >50% loss of lumen compared with immediate postprocedure results) at repeat quantitative coronary angiography at 6 months after PTCA. Allele frequencies for the ACE D and I: alleles were 0.58 and 0.42 in cases and 0.58 and 0.42 in control subjects. All observed genotype frequencies were in Hardy-Weinberg equilibrium. There was no evidence for an association between genotype and restenosis or degree of lumen loss. The data from this largest study of its kind conducted so far provide no evidence for an association of the ACE D/I allelic polymorphism with incidence of restenosis after PTCA. On the basis of the power of this study, we conclude that in a general population, the ACE D/I polymorphism is not a useful marker to assess risk of post-PTCA restenosis.     

The relationship between angiotensin converting enzyme gene polymorphism, coronary artery disease, and stent restenosis: the role of angiotensin converting enzyme inhibitors in stent restenosis in patients with diabetes mellitus

Patients with diabetes mellitus (DM) have advanced atherosclerosis compared with nondiabetics. Restenosis after intracoronary stent implantation occurs frequently in diabetic patients. Angiotensin II is an important growth factor for the development of neointimal hyperplasia after vascular injury. The aim of our study was to evaluate the relationships between angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and coronary artery disease (CAD) and stent restonosis in diabetic patients. One hundred and thirty consecutive patients with CAD and 47 consecutive patients (14 males, mean age, 58.0 +/- 10.0) without CAD were enrolled in the study. All patients had type 2 (noninsulin dependent) DM. The patients with CAD underwent percutaneous transluminal coronary angioplasty (PTCA) and stenting. Ninety-four (59 males, mean age, 60.3 +/- 9.8) underwent control coronary angiography at the end of the follow-up period (mean duration, 9.1 +/- 2.9 months). ACE gene I/D genotyping was identified in all patients. No significant difference was found among patients with and without CAD with respect to ACE gene I/D polymorphism (P = 0.460). In the control coronary angiography, stent restenosis and new lesion development were comparable in each genotyping subgroup. However, a significant relationship was observed between restenosis and the use of ACE inhibitors (ACEI) in patients with D allele (ACEI ratio, 43.5% in the restenosis group and 56.5% in non-restenotic group, P < 0.05). We did not find any relationship between ACE gene I/D polymorphism and CAD and stent restenosis and new lesion development in diabetic patients. On the other hand, ACEI treatment may reduce stent restenosis in type 2 diabetic patients with D allele (DD or ID).     

Angiographic and clinical outcome following sirolimus-eluting stent (Cypher) implantation. A single center experience

OBJECTIVES: To investigate the late outcomes of sirolimus-eluting stent implantation in patients with coronary artery disease. BACKGROUND: Drug-eluting stents reduce intimal hyperplasia, which is the main cause of in-stent restenosis. Sirolimus-eluting stents significantly reduce clinical and angiographic restenosis and improve event-free survival. METHODS: The study population consisted of 207 patients (273 stents) who had undergone coronary Cypher stent implantation. Patients were eligible for enrollment if there was symptomatic coronary artery disease or positive exercise testing, and angiographic evidence of single or multivessel disease with a target lesion stenosis of > or = 70% in a > or = 2.25 mm vessel. Follow-up coronary angiography was performed 18 months after stent deployment. Patients were followed-up for a mean of 24.7 +/- 7.4 months. RESULTS: All patients survived after stent implantation, but 5 (2.4%) patients experienced acute ST elevation myocardial infarction and 4 (1.9%) patients developed non-Q wave myocardial infarction following angioplasty. Recurrent angina pectoris was observed in 16 (7.7%) patients (11 stable angina pectoris and 5 unstable angina pectoris). Angiographic evidence of restenosis was observed in these 20 (9.66%) patients. The 5 other patients had noncritical angiographic restenosis. Eleven (5.3%) patients underwent angioplasty because of restenosis, and coronary artery bypass grafting was conducted in the other 9 (4.3%) patients. CONCLUSION: The results of the present study indicate that Cypher stents could be implanted with a very high success rate and have encouraging long-term angiographic and clinical results.     

Valsartan for prevention of restenosis after stenting of type B2/C lesions: the VAL-PREST trial

The following study was performed to evaluate the effects of chronic 6-month administration of the angiotensin I receptor antagonist valsartan on restenosis rate after stenting of type B2/C lesions in comparison to placebo. Despite encouraging results of the BENESTENT and STRESS trials, stenting of complex coronary lesions leads to an in-stent restenosis rate of up to 40%. Several attempts at systematic medical therapy (e.g., ACE inhibitors) have not improved these results. Because of the important role of angiotensin in endothelial function, the hypothesis that angiotensin I receptor antagonists after stent implantation lead to a reduction of the in-stent restenosis rate should be tested in a single-center trial. Two hundred and fifty patients with type B2/C coronary lesions were randomized in an open-label study with respect to age, gender, lesion type and indication of percutaneous coronary intervention to a chronic administration of 80 mg valsartan or placebo (beta-blocking agents and/or ACE inhibitors). In-stent restenosis rate according to quantitative coronary angiography (QCA) and need for reintervention as primary and secondary endpoints were analyzed after a repeat angiogram at 6 months in 99 patients with 80 mg valsartan and 101 patients with placebo. Chronic administration of 80 mg valsartan reduced the in-stent restenosis rate to 19.2% (n = 19/99) in comparison to placebo with an in-stent restenosis rate of 38.6% (n = 39/101) (p < 0.005). Reintervention rate was 28.7% (n = 29/101) in the placebo group and only 12.1% (n = 12) in the valsartan group (p < 0.005). QCA analysis of stented coronary segments disclosed no differences in reference vessel diameter (2.68 +/- 0.26 mm in the valsartan group versus 2.71 +/- 0.24 mm in the placebo group) but significant differences in stented vessel diameter (2.17 +/- 0.27 mm in the valsartan group and 1.60 +/- 0.20 mm in the placebo group) (p < 0.000001).     

Post-interventional homocysteine levels: failure as a predictive biomarker of in-stent restenosis

OBJECTIVES: Purpose of our study was to determine if homocysteine plasma levels are related to the risk of in-stent restenosis after percutaneous coronary stent implantation in de novo lesions. BACKGROUND: The putative role of homocysteine as a predictive cardiovascular biomarker of coronary artery disease is well established. The impact of homocysteine levels in the development of in-stent restenosis, however, is controversially discussed. METHODS: A total of 177 patients with stable angina pectoris undergoing stent implantation in coronary de novo lesions were included. Laboratory determination comprised blood sample evaluation for homocysteine and other conventional risk factors before baseline coronary intervention and prior to six months control catheterization. Binary restenosis, late lumen loss, and late loss index after six months were assessed by quantitative coronary angiography. Endpoints included target lesion and target vessel failure, homocysteine levels as well as major adverse cardiac events. RESULTS: There was a significant correlation between the length of the implanted stent (p<0.006), the percentage of stenosis (p<0.003) and the pre-interventional luminal diameter (p<0.0001) with late loss index. Linear regression analysis demonstrated no significant impact of the initial or six months homocysteine levels on angiographic restenosis, late lumen loss, or late loss index. CONCLUSIONS: In contrast to homocysteine levels, luminal diameter, stent length and percentage of stenosis correlated with the appearance of restenosis. Taking our data into consideration, we hypothesise that homocysteine may not serve as a safe and independent biomarker of in-stent restenosis after a six months period following percutaneous coronary stenting.     

A randomized comparison of sirolimus-eluting stent implantation with zotarolimus-eluting stent implantation for the treatment of total coronary occlusions: rationale and design of the PRImary Stenting of Occluded Native coronary arteries III (PRISON III) study

Primary intracoronary drug-eluting stent placement after the successful crossing of total coronary occlusions decreases restenosis rate at long-term follow-up compared with bare-metal stent implantation. The PRISON II trial was the first randomized study to show the safety and efficacy of sirolimus-eluting stents in patients with totally occluded native coronary arteries. The sirolimus-eluting stent is superior to the bare-metal stent in treating patients with total coronary occlusions, with significant reduction in angiographic binary in-stent and in-segment restenosis resulting in significantly reduced need for target lesion and target vessel revascularization. Whether sirolimus-eluting stents are superior to other drug-eluting stents in total coronary occlusions is unknown. In this prospective, randomized trial, sirolimus-eluting stent implantation will be compared with zotarolimus-eluting stent implantation for the treatment of total coronary occlusions. A total of 300 patients will be followed for up to 5 years with angiographic follow-up at 8 months. Quantitative coronary analysis will be performed by an independent core laboratory. The primary end point will be in-segment late luminal loss at 8 months angiographic follow-up.