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

Paclitaxel Versus Sirolimus Stents in Diabetic and Nondiabetic Patients

Background— Drug-eluting stents are more effective in reducing restenosis than bare-metal stents. Less certain is the relative performance of 2 widely used drug-eluting stents—sirolimus- and paclitaxel-eluting stents—in diabetic and nondiabetic patients undergoing percutaneous coronary intervention in routine clinical practice. We therefore studied the long-term effectiveness and safety of sirolimus versus paclitaxel stents overall and stratified by the absence or presence of diabetes.

Methods and Results— We compared sirolimus and paclitaxel stents in a propensity-score matched cohort of 2054 pairs of patients (835 matched pairs of diabetic patients and 1219 matched pairs of nondiabetic patients) undergoing percutaneous coronary intervention in Ontario between December 1, 2003 and March 31, 2006. The cohort was derived from the Cardiac Care Network of Ontario percutaneous coronary intervention registry and linked to population-based administrative health databases. In the overall cohort, there was no difference in rates of target-vessel revascularization ( P =0.47), myocardial infarction ( P =0.71), or death ( P =0.49). As compared with paclitaxel stents, the use of sirolimus stents was associated with a significantly lower 3-year rate of target-vessel revascularization in nondiabetic patients (8.3% versus 10.0%, P =0.01), but not in diabetic patients (12.7% versus 10.3%, P =0.07). Rates of all-cause mortality were similar in patients receiving sirolimus stents versus paclitaxel stents in both the diabetic (8.4% versus 9.2%, P =0.91) and nondiabetic (4.6% versus 3.0%, P =0.22) groups.

Conclusions— In this large observational study, patients receiving paclitaxel and sirolimus stents had similar mortality rates, but nondiabetic patients receiving sirolimus stents were significantly less likely to require repeat revascularization.

Type 2 diabetes and coronary heart disease: focus on myocardial infarction

Individuals with type 2 diabetes are more likely to experience a myocardial infarction and have worse outcomes compared with nondiabetic individuals. The underlying pathophysiology of the atherosclerotic process is accentuated but not significantly different in patients with type 2 diabetes. In addition, the prothrombotic state associated with diabetes may also contribute to the higher incidence of and worse prognosis after myocardial infarction. Difficulties of re-establishing vessel patency by thrombolytic or mechanical means due to diffuse coronary disease, altered vessel structure, and prothrombotic state can contribute to the high morbidity and mortality in these patients. The concurrent metabolic dysfunction contributes to impair compensatory mechanisms, which can increase infarct size and cause more impairment of left ventricular function. Aggressive medical therapy and careful modulation of glucose metabolism in the acute and follow-up phase of a myocardial infarction may favorably influence outcome.

Paclitaxel-eluting stent long-term outcomes in percutaneous saphenous vein graft interventions (PELOPS) study

This study examined the 1-year clinical and angiographic follow-up results of implantation of paclitaxel-eluting stents (PES) in aortocoronary saphenous vein graft (SVG) lesions. Sixty-eight consecutive patients with 90 nonoccluded SVG lesions were treated with PES (Taxus), size ranging from 2.25 to 4.5 mm. Angiographic follow-up was performed on 63 patients (93%) and 83 lesions (92%) at 12 months; major adverse cardiac event (MACE) was recorded in all patients at 1 year. The mean age of patients was 71+/-8 years with predominance of men (75%); the mean graft age was 13+/-4 years. Glycoprotein IIb/ IIIa inhibitors were given in 21 patients (31%); embolic protection devices were used in 54 lesions (60%). On average, patients received 1.4 stents per lesion with a stent size of 3.4+/-0.6 mm and a length of 35.8+/-27.0 mm. Angiographic follow-up revealed a late loss of 0.36+/-0.66 mm with an in-segment binary restenosis rate of 7%. The in-hospital MACE was 7%, which was solely contributed by 5 patients with postprocedure non-Q myocardial infarction; the 1-year MACE was 15%, accounted by 1 noncardiac death and 9 patients with target vessel revascularization. Peripheral vascular disease and the use of glycoprotein IIb/ IIIa inhibitors were the independent predictors of MACE at 1 year. In conclusion, implantation of PES to treat degenerative aortocoronary SVG lesions is safe and associated with low late loss, angiographic restenosis, and MACE at 1-year follow-up.

Meta-analysis comparison (nine trials) of outcomes with drug-eluting stents versus bare metal stents in patients with diabetes mellitus

In patients with diabetes mellitus, outcome after drug-eluting stent (DES) versus bare metal stent (BMS) implantation remains under investigation; although lower reintervention rates were reported, incidence of death and myocardial infarction (MI) during follow-up is not completely characterized. Thus, we performed a meta-analysis of available randomized studies evaluating follow-up events of DESs versus BMSs in patients with diabetes mellitus. Randomized trials reporting outcome of DES versus BMS in diabetic patients with a follow-up > or =6 months were included. Outcomes analyzed were (1) death, (2) MI, (3) in-stent restenosis (ISR) and target lesion revascularization (TLR), and (4) stent thrombosis. Data were extracted by 2 independent reviewers. A total of 9 trials, including 1,141 patients, were found. ISR occurred in 8% of patients with DESs versus 41% of those with BMSs (odds ratio [OR] 0.13, 95 confidence interval [CI] 0.09 to 0.20, p <0.00001) and TLR in 8% versus 27% (OR 0.23, 95% CI 0.16 to 0.33, p <0.00001). There was no difference in the incidence of stent thrombosis (1.1% vs 1.2%, p = 0.98) or death (2.4% vs 2.3%, p = 0.91). MI occurred in 3.5% of patients with DESs versus 7.2% of those with BMSs (52% risk decrease, p = 0.02). Decrease of ISR with DESs was observed in noninsulin-treated (OR 0.17, 95% CI 0.11 to 0.26, p <0.00001) and insulin-treated (OR 0.22, 95% CI 0.13 to 0.37, p <0.00001) patients. In conclusion, diabetic patients receiving DESs have lower risk of ISR and TLR versus those treated with BMSs; use of DESs in patients with diabetes mellitus significantly decreases the incidence of MI during follow-up, without affecting mortality or stent thrombosis.

Hypertension and the older diabetic

Hypertension is a common comorbidity in persons with diabetes mellitus, and its prevalence increases with advancing age. Both diabetes mellitus and hypertension are independent risk factors for development in older persons of coronary artery disease, ischemic stroke, peripheral arterial disease, and of congestive heart failure. This article reviews studies addressing the implications of hypertension and the older diabetic.

Leukemia inhibitory factor is upregulated in coronary arteries of Ossabaw miniature swine after stent placement

Leukemia inhibitory factor (LIF), an IL-6 class cytokine, is reported to be antiatherosclerotic. Thus, we hypothesized that LIF expression might be altered during in-stent neointimal hyperplasia. Ossabaw miniature swine, a unique large-animal model of metabolic syndrome and cardiovascular disease, were used for these studies. Bare-metal stents were deployed in the left anterior descending and left circumflex coronary arteries. Stents were expanded to either 1.0 x luminal diameter (in accordance with current clinical practice) or 1.3 x (overexpansion). The development of in-stent neointimal hyperplasia was assessed 28-day postimplantation using intravascular ultrasound. The atherosclerotic coverage of the vessel wall was approximately five-fold higher in 1.0 x stents and approximately nine-fold higher in 1.3 x stents 4 weeks after deployment, compared with the same segments before stenting. LIF mRNA was elevated approximately 11-fold in stented segments, relative to unstented epicardial coronary arteries. LIF expression and the intima : media ratio were strongly correlated in 1.0 x stented vessels. Further studies to investigate the nature of the association between LIF and neointimal hyperplasia revealed that vascular smooth muscle cell proliferation was inhibited by LIF treatment in an in-vitro model of atherosclerosis (coronary artery organ culture). These novel and clinically relevant studies show that elevated LIF gene expression is predictive for in-stent neointimal hyperplasia, and suggest that LIF upregulation may be a compensatory mechanism in this setting.

Coronary artery stents: Part I. Evolution of percutaneous coronary intervention

The subspecialty of interventional cardiology has made significant progress in the management of coronary artery disease over the past three decades with the development of percutaneous coronary transluminal angioplasty, atherectomy, and bare-metal and drug-eluting stents (DES). Bare-metal stents (BMS) maintain vessel lumen diameter by acting as a scaffold and prevent collapse incurred by angioplasty. However, these devices cause neointimal hyperplasia leading to in-stent restenosis and requiring reintervention in more than 20% of patients by 6 mo. DES (sirolimus and paclitaxel) prevent restenosis by inhibiting neointimal hyperplasia. However, DESs also delay endothelialization, causing the stents to remain thrombogenic for an extended, yet unknown, period of time. Late stent thrombosis is associated with a 45% mortality rate. Premature discontinuation of antiplatelet therapy, particularly clopidogrel, is the strongest predictor of stent thrombosis. Sixty percent of patients receive stents for off-label (unapproved) indications, which also increases the frequency of stent thrombosis. Clopidogrel and aspirin are the cornerstone of therapy in the prevention of stent thrombosis in both BMS and DES. Recommendations pertaining to the optimal duration of dual-antiplatelet therapy have been debated. Both the Food and Drug Administration and the American Heart Association/American College of Cardiologists, in association with other major societies, have made recommendations to extend the duration of dual-antiplatelet therapy in patients with DES to 1 yr. The 6-wk duration of dual-antiplatelet therapy in patients with BMS remains unchanged. All patients with coronary stents must remain on life-long aspirin monotherapy. Since the introduction of percutaneous transluminal coronary angioplasty for the treatment of coronary atherosclerosis, the practice of percutaneous coronary intervention has undergone a dramatic transformation from simple balloon dilation catheters to sophisticated mechanical endoprostheses. These advancements have impacted the practice of perioperative medicine. In this series of two articles, in Part I we will review the evolution of percutaneous coronary intervention and discuss the issues associated with percutaneous transluminal coronary angioplasty and coronary stenting; in Part II we will discuss perioperative issues and management strategies of coronary stents during noncardiac surgery.

C-Peptide and atherogenesis: C-Peptide as a mediator of lesion development in patients with type 2 diabetes mellitus?

Patients with insulin resistance and early type 2 diabetes exhibit an increased propensity to develop a diffuse and extensive pattern of arteriosclerosis. Typically, these patients show increased levels of C-peptide and over the last years various groups examined the effect of C-peptide in vascular cells as well as its potential role in lesion development. While some studies demonstrated beneficial effects of C-peptide, for example, by showing an inhibition of smooth muscle cell proliferation, others suggested proatherogenic mechanisms in patients with type 2 diabetes. Among them, C-peptide may facilitate the recruitment of inflammatory cells into early lesions and promote lesion progression by inducing smooth muscle cell proliferation. The following review will summarize the effects of C-peptide in vascular cells and discuss the potential role of C-peptide in atherogenesis in patients with type 2 diabetes.

Appropriate use of drug-eluting stents: balancing the reduction in restenosis with the concern of late thrombosis

Restenosis is a serious occurrence that can lead not only to recurrent angina and repeat revascularisation but also to acute coronary syndromes. Drug-eluting stents revolutionised interventional cardiology owing to their pronounced ability to reduce restenosis compared with bare-metal stents. Attention has now shifted to safety of these devices because of evidence suggesting an association with late stent thrombosis. Findings of randomised clinical trials have not shown that drug-eluting stents result in excess mortality after 4-5 years of follow-up. Current recommendations are that individuals with a drug-eluting stent should receive at least 12 months of uninterrupted dual antiplatelet treatment; patients must understand the importance of this long-term regimen. Patients' assessment should focus on bleeding abnormalities, pre-existing disorders that need anticoagulation treatment, and possible future surgical procedures, since these factors could all contraindicate use of drug-eluting stents. Many people will do well with a bare-metal stent, whereas for individuals with a high likelihood of restenosis and late thrombosis, medical management or surgical revascularisation might be preferred options.

Coronary in-stent restenosis in diabetic patients after implantation of sirolimus or paclitaxel drug-eluting coronary stents

It is now emerging that, in patients who are at high risk for cardiovascular complications and, in particular, those with diabetes, the occurrence of late restenosis and thrombosis after treatment of coronary artery disease with drug-eluting stents is higher than earlier reports have suggested. Therefore, the aim of this study was to assess the prevalence of in-stent restenosis in a cohort of consecutive patients with diabetes treated for coronary disease in 2005 with drug-eluting stents [either sirolimus (58%) or paclitaxel (42%)]. The duration of follow-up was 9.0+/-3.4 months [mean+/-1 standard deviation (S.D.)]. A total of 154 patients (type 2 diabetes: 91%) were included in the study (age: 66+/-10 years), and the total number of implanted stents was 184. Two subjects died from cardiac causes, while myocardial infarction and (un)stable angina were observed in 3 (2%) and 39 (25%) patients, respectively. In-stent restenosis, appraised by angiography, was observed in 17 individuals (11%) after a mean follow-up of five months. Mean HbA(1c) in patients with restenosis was 7.6+/-1.8%. There was no difference in the rate of restenosis with sirolimus-(n=8) compared with paclitaxel-(n=9) eluting stents. Male gender, oral therapy for diabetes and stent diameter were predictors of in-stent restenosis. In conclusion, even over a medium-term period, in-stent restenosis remains a potential risk for coronary diabetic patients treated with drug-eluting devices.

Influence of diabetes on >10-year outcomes after percutaneous coronary intervention

There are few reports showing the relationship between diabetes and the long-term outcome following percutaneous coronary intervention (PCI) in Asians. As well, the association between glycosylated hemoglobin (HbA1c) level and outcome remains controversial. In this analysis, 748 Japanese patients including 298 with diabetes (DM) and 450 without diabetes (non-DM) who underwent PCI from 1984 to 1992 were evaluated over the long term. The mean follow-up was 12.0 +/- 3.6 years. There were 47 (15.8%) total deaths in DM and 41 (9.1%) in non-DM [hazard ratio (HR) 1.71, 95% confidence interval (CI) 1.11-2.65, P = 0.013] and 28 (9.4%) cardiovascular deaths in DM and 19 (4.2%) in non-DM (HR 2.09, 95% CI 1.14-3.81, P = 0.016). Among DM, increased HbA1c was associated with both total (HR 1.25, 95% CI 1.03-1.53, P = 0.024) and cardiovascular (HR 1.30, 95% CI 1.00-1.69, P = 0.048) mortality. Even in Asians, DM showed an increased mortality following PCI. Among DM, increased HbA1c level was also associated with mortality.

A cardiologist view of vascular disease in diabetes

Diabetes mellitus is a potent risk factor for the development of a wide spectrum of cardiovascular (CV) complications. The complex metabolic milieu accompanying diabetes alters blood rheology, the structure of arteries and disrupts the homeostatic functions of the endothelium. These changes act as the substrate for end-organ damage and the occurrence of CV events. In those who develop acute coronary syndromes, patients with diabetes are more likely to die, both in the acute phase and during follow-up. Patients with diabetes are also more likely to suffer from chronic cardiac failure, independently of the presence of large vessel disease, and also more likely to develop stroke, renal failure and peripheral vascular disease. Preventing vascular events is the primary goal of therapy. Optimal cardiac care for the patient with diabetes should focus on aggressive management of traditional CV risk factors to optimize blood glucose, lipid and blood pressure control. Targeting medical therapy to improve plaque stability and diminish platelet hyper-responsiveness reduces the frequency of events associated with atherosclerotic plaque burden. In patients with critical lesions, revascularization strategies, either percutaneous or surgical, will often be necessary to improve symptoms and prevent vascular events. Improved understanding of the vascular biology will be crucial for the development of new therapeutic agents to prevent CV events and improve outcomes in patients with diabetes.

The effect of drug-eluting stents on intermediate angiographic and clinical outcomes in diabetic patients: insights from randomized clinical trials

OBJECTIVE

Implantation of drug-eluting stents has emerged as the predominant percutaneous revascularization strategy in diabetic patients, despite limited outcomes data. Accordingly, our aim was to conduct a meta-analysis to assess the benefit and safety profile of drug-eluting stents in diabetic patients.

METHODS

We included randomized trials comparing either the paclitaxel- or sirolimus-eluting stent with a bare-metal stent or with each other in diabetic patients during a follow-up of at least 6 months.

RESULTS

A total of 16 studies were identified, which included 2951 diabetic patients who were followed up for 6 to 12 months. Target lesion revascularization was less frequently performed in patients who received drug-eluting stents compared with bare-metal stents (risk ratio [RR] 0.35, 95% CI 0.27-0.46, P < .0001). Similar reductions were noted in the incidence of major adverse cardiovascular events (RR 0.42, 95% CI 0.31-0.56, P < .0001), in-segment restenosis (RR 0.31, 95% CI 0.25-0.40, P < .0001), and non-Q-wave myocardial infarction (RR 0.57, 95% CI 0.32-0.99, P = .046). Event rates were similar for Q-wave myocardial infarction (RR 0.72, 95% CI 0.25-2.07, P = .54), death (RR 0.64, 95% CI 0.32-1.28, P = .20), and stent thrombosis (RR 0.41, 95% CI 0.13-1.27, P = .12).

CONCLUSIONS

In conclusion, diabetic patients who receive drug-eluting stents have a significantly lower incidence of target lesion revascularization, in-segment restenosis and myocardial infarction at 6 to 12 months, compared with bare-metal stents. The rates of mortality and stent thrombosis are similar.

Angiographic and clinical outcomes of rosiglitazone in patients with type 2 diabetes mellitus after percutaneous coronary interventions: a single center experience

A beneficial effect of thiazolidinediones includes the reduction of intermediate markers, suggesting a potential for reducing atherosclerosis and restenosis. The objective of this study was to determine if rosiglitazone (RSG) reduced the odds of restenosis and if RSG improved the odds of clinical outcomes after percutaneous coronary intervention (PCI) in type 2 diabetes mellitus (DM) patients. A total of 609 patients with 734 lesions were selected from the period between January 1, 2001 and January 31, 2004. These patients were divided into 2 groups: a "control" group representing patients seen between January 1, 2001 and September 2002 when RSG was not available in our hospital and a "RSG treatment" group representing patients seen between September 2002 and January 31, 2004 when RSG was available in our hospital. Thus, 213 patients with 253 lesions (1.19 L/P) were placed in the RSG group and 396 patients with 481 lesions (1.21 L/P) were placed in the control group. Subgroup analysis based on the PCI received had 88 patients in the RSG arm receiving balloon angioplasty and 125 patients receiving coronary stenting; the control group had 187 and 209 patients, respectively, in the subgroups. Primary endpoint was angiographic restenosis at 6 months, and secondary endpoints were death, myocardial infarction, and target lesion revascularization. More patients in the control group were insulin-requiring, had poorer left ventricular function, but had a larger preprocedural minimal lumen diameter (pre-MLD). At 6 months, restenosis and reocclusion rates were lower in the RSG group (P = .014 and P = .006, respectively). Twenty-nine patients died in the control group versus 1 in the RSG group (P <or= .001). RSG (P = .019), stenting (P = .005), preprocedural reference vessel diameter (P = .017), metformin (P = .022), pre-MLD (P < .001), hyperlipidemia (P = .016), and combined RSG and metformin (P = .020) were predictors of restenosis, while RSG (P = .016) and metformin (P = .029) were predictors of survival. In conclusion, RSG was found safe and well tolerated and was associated with reduced odds of restenosis, reocclusion, and mortality rates in type 2 DM patients independent of glycemic control and PCI performed.

Comparison of bypass surgery with drug‐eluting stents for diabetic patients with multivessel disease

BACKGROUND

This retrospective study of prospectively collected data compared coronary artery bypass graft (CABG) surgery to drug-eluting stenting (DES) in diabetic patients with multivessel coronary artery disease (CAD). Prior randomized trials and clinical studies have suggested that CABG may be the preferred revascularization strategy in diabetic patients with multivessel CAD. Data are limited regarding the impact of DES vs. CABG on clinical outcomes.

METHODS

We included 205 consecutive diabetic patients who underwent either CABG (n=103) or DES (n=102). The primary clinical end points were freedom from major adverse cardiac events (MACE) at 30 days and 1 year.

RESULTS

Baseline characteristics were similar between both groups. At 1 year, the mortality rate was similar in the CABG and DES group (8% vs. 10%, p=0.6) but the MACE rate was lower in the CABG group (12% vs. 27%, p=0.006) due to less repeat revascularization with CABG (3% vs. 20%, p<0.001). Stroke occurred only in the CABG group (4% vs. 0%, p=0.04). Angiographically-documented stent thrombosis after DES occurred in 3%. Presentation with acute myocardial infarction (hazard ratio [HR], 2.26, 95% CI, 1.13 to 4.55) and DES (HR, 2.4, 95% CI, 1.23 to 4.77) were positive independent predictors, whereas therapy with a statin was a negative independent predictor of MACE (HR, 0.40, 95% CI, 0.21 to 0.76).

CONCLUSIONS

Bypass surgery was associated with less MACE primarily due to the higher repeat revascularization rate with DES and is therefore superior to DES despite more extensive CAD in CABG patients.

Pathophysiology of coronary artery in-stent restenosis

In-stent restenosis reflects the interaction of a cascade of molecular and cellular events occurring within the vessel wall. Coronary stenting induces localized injury to the vessel wall, which leads to the release of thrombogenic, vasoactive, and lymphocytes mitogenic factors that result in processes causing re-narrowing at the injured site. Three major processes have been identified that lead to the in-stent restenosis: neointimal hyperplasia, elastic recoil, and negative arterial remodeling. The most important one is intimal hyperplasia. As the time course of neointimal hyperplasia is unknown, a causal relationship between the development of new blood vessels and clinical restenosis cannot be firmly established.

Impact of diabetes mellitus on long-term outcomes in the drug-eluting stent era

BACKGROUND

Diabetes mellitus is associated with an increased risk of restenosis, stent thrombosis, and death after percutaneous coronary interventions. Little is known about the late outcome of patients with diabetes mellitus who receive drug-eluting stents (DES).

METHODS

This study includes a prospective database of 2557 consecutive patients with coronary artery disease who underwent DES implantation in native coronary arteries in 2 German hospitals. The primary end points of the study were mortality and clinical restenosis (target lesion revascularization). Secondary end points were binary angiographic restenosis, stent thrombosis, and the composite of death or myocardial infarction.

RESULTS

Within a median follow-up period of 2.3 years, stent thrombosis occurred in 14 patients with diabetes versus 17 patients without diabetes: 3-year Kaplan-Meier estimates of stent thrombosis were 2.2% versus 1.0%, with a relative risk of 2.17 (95% CI 1.09-4.33, P = .027). Binary angiographic restenosis was observed in 87 patients with diabetes and 208 patients without diabetes (15.2% vs 13.5%, P = .32). Target lesion revascularization was needed in 93 patients with diabetes and 219 patients without diabetes (12.8% vs 12.0%, P = .56). There were 93 deaths among diabetic patients versus 118 deaths among nondiabetic patients: 3-year Kaplan-Meier estimates of mortality were 17.3% versus 7.8%, with a relative risk of 2.10 (95% CI 1.61-2.74, P < .001). After adjustment in the multivariable analyses, diabetes remained an independent predictor of 3-year mortality with a hazard ratio of 1.63 (95% CI 1.23-2.17, P < .001), but not of angiographic (P = .92) or clinical restenosis (P = .97).

CONCLUSION

Although DES attenuate diabetes-associated excess risk of restenosis, risk of death and thrombotic complications remains higher in patients with diabetes than in nondiabetic patients in the DES era.

Remnant-like lipoprotein particle level and insulin resistance are associated with in-stent restenosis in patients with stable angina

BACKGROUND

The aim of this study was to evaluate the independent effect of serum remnant-like lipoprotein particle level and insulin resistance on in-stent restenosis in nondiabetic patients with stable angina.

METHODS

The study included 64 nondiabetic patients with stable angina who underwent successful coronary stenting. At the time of stenting, we evaluated the patients' lipid profiles including remnant-like lipoprotein particles cholesterol, plasma glucose and insulin levels, and insulin resistance by the homeostasis model assessment.

RESULTS

There was no significant difference in total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels between two patient groups with (n=15) and without (n=49) in-stent restenosis. Plasma remnant-like lipoprotein particles cholesterol level was significantly higher in patients with restenosis than in patients without restenosis (8.2+/-7.0 mg/dl vs. 4.5+/-2.6 mg/dl, P=0.006). Although plasma glucose level was similar between the two groups, insulin level and homeostasis model assessment were significantly higher in patients with restenosis, compared with those without restenosis (11.2+/-12.4 vs. 7.1+/-2.8, P=0.039; and 2.6+/-2.9 vs. 1.7+/-0.7, P=0.040, respectively). In multivariate logistic regression analysis, plasma remnant-like lipoprotein particles cholesterol level (>4.8 mg/dl; the 75th percentile of the distribution of remnant-like lipoprotein particles cholesterol level) was the independent predictor of in-stent restenosis (odds ratio: 8.15; confidence interval: 1.02-65.16; P=0.048).

CONCLUSIONS

Our findings suggest that high serum remnant-like lipoprotein particles cholesterol level, and not insulin resistance may be an independent risk factor on in-stent restenosis in nondiabetic patients with stable angina.

Long-Term Safety and Efficacy of Drug-Eluting Stents

BACKGROUND

The long-term safety and efficacy of drug-eluting stents (DES) have been questioned recently.

METHODS AND RESULTS

Between July 2002 and June 2005, 10,629 patients undergoing elective percutaneous coronary intervention with either DES (n=3064) or bare-metal stents (BMS, n=7565) were enrolled in a prospective registry comprising 13 hospitals. We assessed the cumulative incidence of major adverse cardiac events (death, acute myocardial infarction, and target-vessel revascularization) and angiographic stent thrombosis during 2-year follow-up. A propensity score analysis to adjust for different baseline clinical, angiographic, and procedural characteristics was performed. The 2-year unadjusted cumulative incidence of major adverse cardiac events was 17.8% in the DES group and 21.0% in the BMS group (P=0.003 by log-rank test). Angiographic stent thrombosis was 1.0% in the DES group and 0.6% in the BMS group (P=0.09). After adjustment, the 2-year cumulative incidence of death was 6.8% in the DES group and 7.4% in the BMS group (P=0.35), whereas the rates were 5.3% in DES and 5.8% in BMS for acute myocardial infarction (P=0.46), 9.1% in DES and 12.9% in BMS for target-vessel revascularization (P<0.00001), and 16.9% in DES and 21.8% in BMS for major adverse cardiac events (P<0.0001). Independent predictors of target-vessel revascularization in the DES group were diabetes mellitus (hazard ratio 1.36, 95% confidence interval 1.06 to 1.76), renal failure (hazard ratio 1.69, 95% confidence interval 1.06 to 2.69), and reference vessel diameter (hazard ratio 0.64, 95% confidence interval 0.45 to 0.93).

CONCLUSIONS

In this large real-world population, the beneficial effect of DES in reducing the need for new revascularization compared with BMS extends to 2 years without evidence of a worse safety profile.

Preprocedure hyperglycemia is more strongly associated with restenosis in diabetic patients after percutaneous coronary intervention than is hemoglobin A1C

BACKGROUND

Although more frequent in diabetic patients, restenosis after percutaneous coronary intervention (PCI) is less common in those with good glycemic control. High circulating insulin levels may also be associated with more frequent restenosis.

METHODS

Fasting blood samples were obtained from 162 diabetic patients immediately prior to the PCI and analyzed for glucose, hemoglobin A1C, and insulin. Nine-month follow-up information was obtained in 145 (89.5%) patients. Target vessel revascularization (TVR) was the surrogate for restenosis.

RESULTS

Patients were divided into quartiles with regard to their blood levels. Insulin, calculated insulin resistance, and hemoglobin A1C were not associated with increased TVR rates. Glucose level was significantly associated (P=.02). Patients in the two lower quartiles (glucose < or = 128 mg/dl) had a 9-month TVR rate of 12.7% while those in the two higher quartiles (>128 mg/dl) had a rate of 33.8% (P=.005). Level of glucose was independent of hemoglobin A1C. In patients whose A1C level was < or = 7%, the TVR rate was greater in those with a glucose level >128 mg/dl (39.1% vs. 10.6%, P=.009). Similarly, in patients with a hemoglobin A1C level >7%, the TVR rate was lower in patients with a glucose level < or = 128 mg/dl, but this difference did not reach statistical significance (16.6% vs. 31.3%, P=.3).

CONCLUSIONS

Hemoglobin A1C, insulin, and insulin resistance at the time of the PCI are not associated with restenosis. Periprocedural hyperglycemia may promote restenosis in diabetics.

Analysis of 14 trials comparing sirolimus-eluting stents with bare-metal stents

BACKGROUND

The long-term effects of treatment with sirolimus-eluting stents, as compared with bare-metal stents, have not been established.

METHODS

We performed an analysis of individual data on 4958 patients enrolled in 14 randomized trials comparing sirolimus-eluting stents with bare-metal stents (mean follow-up interval, 12.1 to 58.9 months). The primary end point was death from any cause. Other outcomes were stent thrombosis, the composite end point of death or myocardial infarction, and the composite of death, myocardial infarction, or reintervention.

RESULTS

The overall risk of death (hazard ratio, 1.03; 95% confidence interval [CI], 0.80 to 1.30) and the combined risk of death or myocardial infarction (hazard ratio, 0.97; 95% CI, 0.81 to 1.16) were not significantly different for patients receiving sirolimus-eluting stents versus bare-metal stents. There was a significant reduction in the combined risk of death, myocardial infarction, or reintervention (hazard ratio, 0.43; 95% CI, 0.34 to 0.54) associated with the use of sirolimus-eluting stents. There was no significant difference in the overall risk of stent thrombosis with sirolimus-eluting stents versus bare-metal stents (hazard ratio, 1.09; 95% CI, 0.64 to 1.86). However, there was evidence of a slight increase in the risk of stent thrombosis associated with sirolimus-eluting stents after the first year.

CONCLUSIONS

The use of sirolimus-eluting stents does not have a significant effect on overall long-term survival and survival free of myocardial infarction, as compared with bare-metal stents. There is a sustained reduction in the need for reintervention after the use of sirolimus-eluting stents. The risk of stent thrombosis is at least as great as that seen with bare-metal stents.

Thiazolidinediones and risk of repeat target vessel revascularization following percutaneous coronary intervention: a meta-analysis

OBJECTIVE

Thiazolidinediones (TZDs) (rosiglitazone and pioglitazone) are a class of antidiabetes agents that have a high affinity for peroxisome proliferator-activated receptor-gamma. TZDs initiate a multitude of physiologic processes that may elicit benefits as systemic agents for the prevention of restenosis requiring revascularization following percutaneous coronary intervention (PCI). Numerous trials have evaluated the impact of TZDs on repeat target vessel revascularization (TVR) in patients following PCI; however, several limitations (small sample size, inconclusive results, and risk factor stratification) complicate definitive conclusions. A meta-analysis was performed to evaluate the impact of TZDs on repeat TVR following PCI.

RESEARCH DESIGN AND METHODS

Included trials met the following criteria: 1) prospective, randomized controlled trials evaluating available TZDs versus standards of care; 2) well-described protocol; 3) minimum of 6 months of follow-up; and 4) data provided on repeat TVR. Data are presented as relative risks (RRs) with 95% CIs.

RESULTS

Seven clinical trials (n = 608) met the inclusion criteria. Upon meta-analysis, the risk of repeat TVR was significantly reduced in patients who received TZD therapy compared with standards of care (RR 0.35 [95% CI 0.22-0.57]). In studies using rosiglitazone (0.45 [0.25-0.83]) and pioglitazone (0.24 [0.11-0.51]), risk of repeat TVR was significantly reduced. Risk of repeat TVR was also significantly reduced among patients with (0.34 [0.19-0.63]) and without (0.37 [0.18-0.77]) diabetes.

CONCLUSIONS

Results from this meta-analysis suggest that TZDs effectively reduce the risk of repeat TVR following PCI.

Influence of diabetes mellitus on in-hospital mortality in patients with acute myocardial infarction in Japan: a report from TAMIS-II

BACKGROUND

The relation between diabetes mellitus (DM) and mortality among patients with acute myocardial infarction is still controversial. We evaluated the influence of DM on the in-hospital mortality of acute myocardial infarction (AMI) patients using data from the Tokai Acute Myocardial Infarction Study-II, a multi-hospital prospective study performed in Japan.

METHODS

All of the study subjects were patients hospitalized for newly diagnosed AMI at 1 of 13 acute care hospitals between January of 2001 and December of 2003. We abstracted the baseline and procedural characteristics from detailed chart reviews. Multivariate analysis was performed, controlling for the variables found to be significantly different between AMI patients with and without DM by chi-square test or unpaired t-test. We evaluated a total of 940 DM and 2284 non-DM patients.

RESULTS

DM patients had roughly twice the in-hospital mortality rate of non-DM patients, with an unadjusted odds ratio of 1.77 (95% CI, 1.37-2.30). However, according to the multivariate analysis, DM was not identified as an independent predictor of in-hospital death, with an adjusted odds ratio of 5.73 (95% CI, 0.97-33.88).

CONCLUSIONS

DM is not an independent predictor of in-hospital mortality, and that there is a need for additional studies to confirm our conclusion.

Factors predictive of cardiac events and restenosis after sirolimus-eluting stent implantation in small coronary arteries

OBJECTIVES

Predictors of cardiac events and restenosis after sirolimus-eluting stent (SES) implantation in small coronary arteries were evaluated.

BACKGROUND

Although SES implantation has markedly reduced the risk of restenosis, small vessel disease remains a major cause of SES failure.

METHODS

We prospectively investigated the factors predictive of cardiac events and restenosis in 1,092 consecutive patients who received SES implantation for 1,269 lesions in small coronary arteries (< or = 2.8 mm). Follow-up angiography at 6 months was performed in 751 patients with 889 lesions (follow-up rate 70.3%).

RESULTS

Restenosis (diameter stenosis > or = 50%) was angiographically documented in 65 patients with 77 lesions (8.7%): 55 focal (71.4%), 8 diffuse (10.4%), 2 diffuse proliferative (2.6%), and 12 total (15.6%). Lesion length, stent length, reference artery size, and in-stent restenotic lesions were univariate predictors of restenosis. By multivariate analysis, lesion length (OR 1.04; 95% CI 1.02-1.05; P < 0.001) and in-stent restenotic lesions (OR 3.38; 95% CI 1.80-6.35; P < 0.001) were significant independent predictors of restenosis. During follow-up (23.2 +/- 7.9 months), there were 17 deaths (5 cardiac and 12 noncardiac), 5 nonfatal Q-wave myocardial infarctions, and 42 target lesion revascularizations. The cumulative probability of survival without major adverse cardiac events (MACE) was (96.6 +/- 0.6)% at 1 year and (95.1 +/- 0.7)% at 2 years. In multivariate analysis, lesion length (HR 1.04; 95% CI 1.01-1.07; P = 0.004) and in-stent restenotic lesions (HR 3.29; 95% CI 1.58-6.86; P = 0.001) were independently related to MACE.

CONCLUSIONS

SES implantation in small coronary arteries is safe and effective, with lesion length having a major impact on restenosis and MACE.

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.

Outcome of diabetic and non-diabetic patients undergoing successful coronary angioplasty with bare stent of chronic total occlusion

BACKGROUND

The prognosis of patients with diabetes mellitus and chronic coronary total occlusion (CTO) treated with percutaneous coronary angioplasty (PTCA) is poorly investigated.

METHODS

To compare the long-term outcome of patients with CTO, with and without diabetes mellitus and undergoing successful PTCA with bare stent implantation performed in a single centre, 170 consecutive patients (mean age 62 +/- 10 years) with CTO aged > 1 month were analysed. Death, myocardial infarction, repeat angioplasty and coronary artery by-pass were considered as hard events in 167 patients with available long-term follow-up (mean 25 +/- 15 months).

RESULTS

Vessel mean luminal diameter after the procedure and stent length were 2.5 +/- 0.4 mm and 21.9 +/- 9.4 mm, respectively. No differences were found in baseline clinical, angiographic and procedural variables between the groups, categorized on the basis of presence or absence of diabetes. There were 13 (27%) and 25 (21%) events in diabetic and non-diabetic groups, respectively (P = not significant). Multivariate analysis identified final mean luminal diameter (odds ratio = 4.7192, P = 0.0013) and stent length (odds ratio = 1.0655, P = 0.0003) but not diabetes (P = 0.78) as predictors of events at long-term follow-up.

CONCLUSIONS

Patients with and without diabetes undergoing CTO re-opening with stent implantation do not differ at long-term follow-up in terms of death, myocardial infarction and target lesion revascularizations. Final mean luminal diameter and stent length are significant predictors of events during long-term follow-up.

C-Peptide Induces Vascular Smooth Muscle Cell Proliferation

Increased levels of C-peptide, a cleavage product of proinsulin, circulate in patients with insulin resistance and early type 2 diabetes mellitus. Recent data suggest a potential causal role of C-peptide in atherogenesis by promoting monocyte and T-lymphocyte recruitment into the vessel wall. The present study examined the effect of C-peptide on vascular smooth muscle cells (VSMCs) proliferation and evaluated intracellular signaling pathways involved. In early arteriosclerotic lesions of diabetic subjects, C-peptide colocalized with VSMCs in the media. In vitro, stimulation of human or rat VSMCs with C-peptide induced cell proliferation in a concentration-dependent manner with a maximal 2.6±0.8-fold induction at 10 nmol/L human C-peptide ( P <0.05 compared with unstimulated cells; n=9) and a 1.8±0.2-fold induction at 0.5 nmol/L rat C-peptide ( P <0.05 compared with unstimulated cells; n=7), respectively, as shown by [H3]-thymidin incorporation. The proliferative effect of C-peptide on VSMCs was inhibited by Src short interference RNA transfection, PP2, an inhibitor of Src-kinase, LY294002, an inhibitor of PI-3 kinase, and the ERK1/2 inhibitor PD98059. Moreover, C-peptide induced phosphorylation of Src, as well as activation of PI-3 kinase and ERK1/2, suggesting that these signaling molecules are involved in C-peptide–induced VSMC proliferation. Finally, C-peptide induced cyclin D1 expression as well as phosphorylation of Rb in VSMCs. Our results demonstrate that C-peptide induces VSMC proliferation through activation of Src- and PI-3 kinase as well as ERK1/2. These data suggest a novel mechanism how C-peptide may contribute to plaque development and restenosis formation in patients with insulin resistance and early type 2 diabetes mellitus.

Drug-eluting stents versus coronary artery bypass grafting in patients with diabetes mellitus

BACKGROUND

Reduction of restenosis and reinterventions was recently reported with percutaneous interventions (PCI) with drug-eluting stents (Cypher). This study compares results of Cypher (Cordis, Miami Lakes, FL) stenting and surgical revascularization in diabetic patients.

METHODS

From January 2002 to January 2005, 518 consecutive diabetic patients underwent myocardial revascularization; 176 by PCI incorporating Cyphers and 342 treated surgically. Single-vessel patients in the surgical group were treated with the left internal thoracic artery (ITA) and most multivessel patients were treated with two ITAs. After matching for age, sex, right system revascularization, and extent of coronary disease, two groups (86 patients each) were used to compare the two revascularization modalities.

RESULTS

Both groups were similar; however, left main, poor ejection fraction, total occlusion, and bifurcation lesions were more prevalent in the surgical group, and in-stent restenosis in the PCI group. The mean number of coronary vessels treated was higher in the surgical group (2.05 vs 1.6, p < 0.001). Mean follow-up was 18 months. Overall mortality (early and late) was 2.3% and 3.5% in the Cypher and surgical groups, respectively (p = 0.65). Angina returned in 39.5% of the Cypher group and 15.1% of the surgical group, p < 0.001. There were 25 reinterventions in the Cypher group compared with five in the surgical group (p = 0.010). The Cox proportional hazard model revealed assignment to the Cypher group to be the only independent predictor of reangina (odds ratio [OR] 3.26, 95% confidence interval [CI] 1.63 to 6.53) and reintervention (OR 4.17, 95% CI 1.92 to 20.83).

CONCLUSIONS

Despite improved results of PCI with Cyphers, midterm clinical outcome of diabetic patients treated surgically is better.

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.

Coronary artery restenosis: vascular biology and emerging therapeutic strategies

Percutaneous coronary intervention with drug-eluting stents is currently the preferred approach to the treatment of obstructive coronary stenoses. Large, randomized trials have demonstrated a significant reduction in the incidence of restenosis after drug-eluting stent placement compared with balloon angioplasty or bare metal stents across a wide range of lesions. Furthermore, these stents have appeared to be effective in maintaining the luminal patency at follow up for up to 2-4 years. Concerns regarding the potential adverse effects of drug-eluting stents, such as aneurysm formation in arteries secondary to drug toxicity or hypersensitivity, as well as the overdependence on antiplatelet therapy for a protracted period to prevent subacute thrombosis, have been raised. However, evidence from large studies has not demonstrated any significant increase in the incidence of such adverse events. Future approaches to treating coronary stenoses involve technical modifications, such as direct stenting, accelerating endothelialization with gene delivery of nitric oxide donors, smooth muscle cell growth inhibitors after stent placement, biodegradable stents and concurrent use of local molecule delivery and oral chemotherapy. Ongoing large-scale postmarketing surveillance studies are expected to provide credible answers to the concerns regarding the safety of these stents.

A double-blind, randomized, placebo-controlled multicenter clinical trial to evaluate the effects of the angiotensin II receptor blocker candesartan cilexetil on intimal hyperplasia after coronary stent implantation

BACKGROUND

Preclinical data suggest beneficial effects of angiotensin II receptor blockers (ARBs) on neointima formation after vascular injury. Preliminary clinical data, however, revealed conflicting results. The AACHEN trial was a double-blind, randomized, placebo-controlled clinical multicenter trial to evaluate the effects of candesartan cilexetil on intimal hyperplasia after coronary stent implantation.

METHODS

A total of 120 patients (61 +/- 9 years, 83% male) were randomized to receive either 32 mg candesartan cilexetil (active) or placebo starting 7 to 14 days before elective coronary stent implantation. A follow-up angiography including intravascular ultrasound assessment of the target lesion was performed 24 +/- 2 weeks after stent implantation. The primary end point was defined as the difference in neointimal area between groups as assessed by intravascular ultrasound. Secondary end points included differences in angiographic parameters (ie, restenosis rate) and incidence of major cardiac events.

RESULTS

The mean stent length measured 15.0 +/- 4.9 mm in the active and 14.6 +/- 5.7 mm in the placebo group (P = .81). There was no significant difference in neointimal area between groups (2.1 +/- 1.0 vs 2.1 +/- 1.5 mm2, P = 1.00), nor were there differences in angiographic end point parameters. Major cardiac event rates were not significantly different between treatment groups (8% vs 11%, P = .75).

CONCLUSIONS

High-dose candesartan cilexetil therapy in patients with symptomatic coronary artery disease undergoing coronary stent implantation does not reduce clinical event rates, restenosis rates, or neointimal proliferation after elective stent implantation.

Changing scenario in chronic ischemic heart disease: therapeutic implications

Over the last 30 years, considerable progress has been made in drug therapy for chronic ischemic heart disease (IHD). Most pharmacologic therapies act by reducing myocardial oxygen consumption, increasing coronary blood flow, improving ventricular relaxation, dilating collateral vessels, and reducing peripheral resistances. Despite "optimal" medical therapy, a large fraction of patients continue to present with angina and myocardial ischemia. Coronary angioplasty (percutaneous transluminal coronary angioplasty) may improve symptoms, but several subgroups of patients, including the elderly, or those who have diabetes mellitus or heart failure, represent high-risk populations that do not always benefit from coronary revascularization. Epidemiologic studies show that life expectancy is longer compared with previous decades and that the prevalence of diabetes is increasing sharply worldwide. In addition, the prevalence of heart failure is growing because of the decreased death rate from acute myocardial infarction and improved survival of patients who have undergone coronary revascularization. We focus on this changing scenario of chronic IHD and propose an innovative approach to the treatment of angina in this context.