The Canadian study of the sirolimus-eluting stent in the treatment of patients with long de novo lesions in small native coronary arteries (C-SIRIUS)

Does the use of paclitaxel or rapamycin-eluting stent decrease further need for coronary-artery bypass grafting when compared with bare-metal stent?

CONTEXT AND OBJECTIVE

The safety and efficacy of drug-eluting stents reduce the need for surgical revascularization. The objective of the present study was to investigate whether paclitaxel or rapamycin-eluting stent are effective in avoiding the need for coronary-artery bypass grafting.

METHODS

This was a systematic review of the literature using the methodology of the Cochrane Collaboration. The type of study considered was controlled randomized trials; the type of intervention was drug-eluting or bare-metal stents; and the main outcome investigated was coronary-artery bypass grafting.

RESULTS

The ten studies included in this systematic review did not show any statistically significant difference between the drug-eluting stents and the bare-metal stents with regard to the outcome of coronary-artery bypass grafting (confidence interval: 0.31 to 1.42).

CONCLUSION

The surgical revascularization rate was not reduced by the use of drug-eluting stents.

Long-term clinical outcomes and thrombosis rates of sirolimus-eluting versus paclitaxel-eluting stents in an unselected population with coronary artery disease (REWARDS registry)

Sirolimus-eluting stents (SESs) and paclitaxel-eluting stents (PESs) significantly decrease the need for repeat interventions compared with bare metal stents. Comparative outcome data from randomized, controlled, head-to-head trials using these systems in a selected group of patients and lesions are conflicting; therefore, we compared clinical outcomes of unselected patients who underwent contemporary percutaneous coronary intervention with SES or PES implantation. In the REWARDS registry, 1-year clinical outcomes of 1,925 patients who received SESs were compared with 844 patients who received PESs. Outcomes at 30 days and 6 months were similar between groups, with a trend toward higher rates of stent thrombosis in the SES group compared with the PES group. Stent thrombosis rate at 12 months was significantly higher in the SES than in the PES group, with cumulative stent thrombosis rates of 1.9% in the SES group and 0.8% in the PES group (p = 0.034). However, overall rates of major adverse cardiac events (MACEs) were similar in the 2 groups at 12 months. After adjusting for significant multivariate predictors of MACEs, the hazard ratio at 1 year was 1.06 (95% confidence interval 0.85 to 1.33, p = 0.607) and the major predictors for MACEs were a history of renal failure, diabetes, previous myocardial infarction, cardiogenic shock, class III or IV heart failure, type C lesions, and saphenous vein grafts. In conclusion, use of SESs and PESs in unrestricted, contemporary practice had comparable outcomes in terms of low rates of revascularization and clinical events. Stent thrombosis continues to be a major concern for SESs and PESs.

Increased Late Mortality After Sirolimus-Eluting Stents Versus Bare-Metal Stents in Diseased Saphenous Vein Grafts

OBJECTIVES

We sought to provide long-term follow-up data of sirolimus-eluting stents (SES) versus bare-metal stents (BMS) in saphenous vein grafts (SVG) from the RRISC (Reduction of Restenosis In Saphenous vein grafts with Cypher) trial.

BACKGROUND

We have previously shown that, in SVG, the use of SES reduces 6-month restenosis and repeated revascularization procedures versus the use of BMS. These data are consistent with trials in native coronary arteries. However, recently published long-term follow-up data of these trials have revealed an increased risk of adverse events (particularly very late stent thrombosis) after SES.

METHODS

A total of 75 patients with 96 SVG lesions were randomized to SES versus BMS. All patients underwent clinical follow-up up to 3 years. Specific outcomes assessed in this secondary post-hoc analysis were all-cause mortality, myocardial infarction, and target vessel revascularization.

RESULTS

Thirty-eight patients received 60 SES for 47 lesions, whereas 37 patients received 54 BMS for 49 lesions. At a median follow-up time of 32 months (interquartile range 26.5 to 36 months), 11 deaths (7 cardiac, of which 1 was caused by very late stent thrombosis and, 3 were sudden) occurred after SES (29% [95% confidence interval (CI) 17% to 45%]) versus 0 after BMS (0% [95% CI 0% to 9%]) with an absolute difference of 29% ([95% CI 14% to 45%], p < 0.001). The rates of myocardial infarction and target vessel revascularization were not different: 18% and 34% after SES, respectively, versus 5% and 38% after BMS, respectively (p = 0.15 and p = 0.74, respectively).

CONCLUSIONS

In this secondary post-hoc analysis, BMS were associated with lower long-term mortality than SES for SVG disease. Also, the 6-month reduction in repeated revascularization procedures with SES was lost at longer-term follow-up. (RRISC Study: Reduction of Restenosis In Saphenous Vein Grafts With Cypher Sirolimus-Eluting Stent; http://clinicaltrials.gov/ct/show/NCT00263263?order=1; NCT00263263).

Diagnostic accuracy of 64-slice CT in the assessment of coronary stents

PURPOSE

The purpose of this study was to assess the diagnostic accuracy of 64-slice computed tomography (64-CT) coronary angiography in the detection of coronary in-stent restenosis.

MATERIALS AND METHODS

Ninety-five patients (72 men and 23 women, mean age 58+/-8 years) with previous percutaneous coronary intervention with stenting and suspected restenosis underwent 64-CT (Sensation 64, Siemens). The mean time between stent deployment and 64-CT was 6.1+/-4.2 months. The scan parameters were: slices 32 x 2, individual detector width 0.6 mm, rotation time 0.33 s, feed 3.84 mm/rotation, 120 kV, 900 mAs. After the intravenous administration of iodinated contrast material (Iomeprol 400 mgI/ml, Iomeron, Bracco) and a bolus chaser (40 ml of saline), the scan was completed in <12 s. All coronary segments with a stent were assessed on 64-CT by two observers in consensus and judged as: patent, with intimal hyperplasia (lumen reduction of <50%), with in-stent restenosis (> or =50%), or with in-stent occlusion (100%). The consensus reading was compared with conventional coronary angiography.

RESULTS

Four patients were excluded because of insufficient image quality. In the remaining 91, we assessed 102 stents (31 RCA; 10 LM; 54 LAD; 7 CX). In 14 (13.7%) stents, in-stent restenosis (n=8) or in-stent occlusion (n=6) was found. Intimal hyperplasia was detected in 11 (10.8%) stents. The sensitivity and negative predictive value of 64-CT for in-stent occlusion were 100% and 100%, respectively, whereas for all stenoses, >50% they were 92.9% and 98.7%, respectively.

CONCLUSIONS

We found that 64-CT has a high diagnostic accuracy for the detection of in-stent restenosis in a selected patient population.

Offsetting Impact of Thrombosis and Restenosis on the Occurrence of Death and Myocardial Infarction After Paclitaxel-Eluting and Bare Metal Stent Implantation

Background— Drug-eluting stents compared with bare metal stents (BMS) may increase late stent thrombosis (ST), although an accompanying increase in the rates of death and myocardial infarction (MI) has not been observed. We hypothesized that the prevention of restenosis-related adverse events by drug-eluting stents might offset some or all of the excess risk from ST.

Methods and Results— We analyzed a pooled patient-level database from 4 prospective, double-blind trials in which 3445 patients were randomized to paclitaxel-eluting stents or BMS. The occurrence of death or MI within 7 days of ST or target lesion revascularization was assessed. With a median follow-up of 3.2 years, ST occurred in 34 patients (1.0%), 31 (91.1%) of whom sustained death or MI within 7 days. Target lesion revascularization was performed in 425 patients (12.3%), 15 (3.5%) of whom died or had MI within 7 days. ST occurred in 14 BMS and 20 paclitaxel-eluting stent patients, resulting in 12 and 19 deaths or MIs within 7 days, respectively. Target lesion revascularization was performed in 290 BMS and 135 paclitaxel-eluting stent patients, resulting in 11 and 4 deaths or MI events within 7 days, respectively. In total, 23 patients in both the BMS and paclitaxel-eluting stents groups died or had an MI event within 7 days of either ST or target lesion revascularization.

Conclusions— ST, although infrequent, results in a high incident rate of death and MI, whereas the more frequent occurrence of target lesion revascularization is associated with a finite but lower rate of death and MI. The marked reduction in restenosis with drug-eluting stents compared with BMS may counterbalance the potential excess risk from late ST with drug-eluting stents.

Myocardial revascularization: surgery or stenting?

There is current debate regarding the relative merits and roles of surgical revascularization and percutaneous revascularization for patients with obstructive coronary artery disease. This article reviews the current literature relating to this subject.

Angiographic and 3D intravascular ultrasound assessment of overlapping bare metal stent and three different formulations of drug-eluting stents in patients with diabetes mellitus

OBJECTIVES

The aim of this study was to examine the impact of overlapping bare-metal stent (BMS) and three different formulations of drug-eluting stent (DES) on intimal hyperplasia (IH) response of patients with diabetes mellitus (DM).

METHODS

Forty-nine DM patients treated with overlapping BMS (19 lesions), sirolimus-eluting stent (SES 12 lesions), paclitaxel-eluting stent (PES 8 lesions) or tacrolimus-eluting stent (TES 10 lesions) were studied. Baseline and 9-month follow-up volumetric intravascular vascular ultrasound (IVUS) and quantitative coronary angiography (QCA) analysis were performed in the entire stented segment and in the overlapped (OL) and non-overlapped (non-OL) subsegments. Clinical outcomes were evaluated at 1-year follow-up.

RESULTS

Post-procedure (PO-) QCA measurements were similar in all stent groups, and between OL and non-OL subsegments in each individual type of stents. Percent IH was lower in SES and PES vs. BMS (p < 0.05). Percent IH was significantly greater in OL subsegment compared with non-OL subsegment in BMS (p < 0.05), but not in all type of DES groups. SES showed significantly less %IH compared with PES and TES in OL and non-OL subsegments. Vessel area at the OL remained unchanged from PO to FU in all type of DES and BMS groups. There were no aneurysm formation and no stent thrombosis up to 1-year follow-up.

CONCLUSIONS

Overlapping BMS is associated with enhanced IH response in diabetic patients, whereas overlapping DES, particularly SES and PES, appear effective to inhibit IH without detectable late vascular adverse effects.

Meta-analysis of randomized trials of drug-eluting stents versus bare metal stents in patients with diabetes mellitus

Diabetes mellitus is a major risk factor for restenosis in patients undergoing percutaneous coronary intervention. Randomized controlled trials comparing drug-eluting stents (DESs) with bare metal stents (BMSs) showed a marked decrease in in-stent restenosis and target lesion revascularization with DESs in the total patient population enrolled in the studies, including patients with diabetes. However, it remains unclear whether the antirestenotic benefit of DESs is preserved in the high-risk diabetic subgroup. MEDLINE, EMBASE, ISI Web of Knowledge, Current Contents, International Pharmaceutical Abstracts, and recent Scientific Sessions databases were searched to identify relevant clinical trials comparing DESs with BMSs. A randomized controlled trial was included if it provided outcome data for patients with diabetes for > or =1 of the following: late lumen loss, in-stent restenosis, or target lesion revascularization. Data were combined using fixed-effects models, and standard tests for heterogeneity were performed. Eight studies with 1,520 patients with diabetes were identified that reported > or =1 outcome of interest. Mean late lumen losses (7 studies) were 0.93 mm (95% confidence interval [CI] 0.510 to 1.348) with BMSs and 0.18 mm (95% CI -0.088 to +0.446) with DESs. For patients receiving a DES, this translated into a marked decrease in in-stent restenosis (7 studies, RR 0.14, 95% CI 0.10 to 0.22, p <0.001) and target lesion revascularization (8 studies, RR 0.34, 95% CI 0.26 to 0.45, p <0.001). DES use is associated with a marked decrease in in-stent restenosis and target lesion revascularization in patients with diabetes. In conclusion, the analysis supports the current widespread use of DESs in these high-risk patients.

Safety and efficacy of the CYPHER Select Sirolimus-eluting stent in the "Real World"--clinical and angiographic results from the China CYPHER Select registry

OBJECTIVE

This post-marketing surveillance registry is aimed at determining the safety and reliability of the CYPHER Select Sirolimus-eluting stent (SES) in routine clinical practice.

BACKGROUND

Little information and angiographic follow-up data in large-scale "real world" registry is available for the CYPHER Select SES, an advanced-generation SES.

METHODS

This was a prospective multicenter (20 centers) registry. 1189 consecutive patients who received at least 1 CYPHER Select SES during daily clinical practice were enrolled. Patients who underwent emergency stenting for acute myocardial infarction were excluded.

RESULTS

The procedure's success rate was 98.3% for CYPHER Select SES implantation, and follow-up rates were 98% with 100% data auditing. Target lesion revascularization (TLR) at 12 months occurred in 60 (5.14%) cases, cardiac death in 13 cases (1.11%), Q wave myocardial infarction (MI) in 5 cases (0.43%), non-Q-MI in 9 cases (0.77%), target vessel revascularization (TVR) in 67 cases (5.74%), and MACE defined as cardiac death, nonfatal MI and TLR in 76 cases (6.51%). MACE-free survival rate at 12 months was 93.7%. Angiographic follow-up at 9 months was performed in 418 (68.3%) lesions treated by CYPHER Select SES. The binary restenosis rate was 4.8% in-stent and 9.6% in-segment. Subgroup analysis showed diabetes, bifurcation lesion and combined use of different stents were independent risk factors of cumulative MACE. In-segment MLD </=2.25 mm at post-procedure and ostial lesion was independent predictors of in-segment restenosis.

CONCLUSIONS

In this registry, the MACE, TLR, angiographic late loss and binary restenosis rates of CYPHER Select SES were similar to those reported in SES randomized trials and "real world" registries. The safety and efficacy of CYPHER Select SES shown in this registry are consistent with those seen in SES studies.

Safety of sirolimus-eluting stenting and its effect on restenosis in patients with unstable angina pectoris (a SIRIUS substudy)

The SIRIUS study was a double-blinded, randomized trial of the sirolimus-eluting stent (SES) to evaluate its effect on the rate of restenosis. The present report is a retrospective analysis of short- and long-term outcomes of SESs compared with bare metal stents (BMSs) in a subgroup of patients with unstable angina enrolled in the trial. Of 1,058 patients randomized in SIRIUS, 533 (50.4%) had unstable angina pectoris and 490 had stable angina. In the unstable angina group, patients treated with SESs and BMSs had similar clinical and angiographic characteristics. The stenting procedure was highly successful in the 2 groups (95.9% and 97.4%, respectively) with similar immediate angiographic results and short-term (in-hospital) clinical event rates. At 1-year follow-up, compared with BMSs, patients with unstable angina treated with SESs had significantly lower rates of target lesion revascularization (5.5% vs 22.3%, p <0.0001), target vessel failure (10.9% vs 26.3%, p <0.0001), and major adverse cardiac events (8.4% vs 24.8%, p <0.0001). Stent thrombosis was a rare event, with only 1 patient (0.4%) in each group during the first 30 days. Late thrombosis occurred in 2 patients (0.7%) in the BMS group but in none of the SES group. In conclusion, in the higher risk subgroup of patients with unstable angina, SESs are as safe as BMSs in decreasing restenosis and the need for repeat revascularization. This is reflected by a significant decrease in major adverse cardiac events and target vessel failure. Patients with unstable angina undergoing percutaneous coronary intervention who meet the entry criteria of the SIRIUS study should be preferentially treated with SESs.

Sirolimus-eluting stent showed better one-year outcomes than paclitaxel-eluting stent in a real life setting of coronary intervention in Koreans

OBJECTIVE

The drug-eluting stent (DES) has been proven its efficacy in randomized trials. But the difference of efficacy between sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in unselected patients is in controversy. Therefore, we investigated the clinical and angiographic outcomes of these two types of the DES.

METHODS

All consecutive patients treated with DES from March 2003 to March 2004 at two centers were analyzed.

RESULTS

We analyzed 440 patients with 519 lesions who were treated with the two types of DES (SES 353 lesions/296 patients, PES 166 lesions/144 patients). PES group had more acute myocardial infarction (AMI) patients. Angiographically, the number of stents per lesion, maximal deployment pressure, stent diameter and the percent residual stenosis after procedure were different between the two groups. Angiographic follow-up was available in 103 patients (71.5%) in the PES group and 208 patients (70.3%) in the SES group. PES showed the higher binary restenosis rate (PES 17.9%, SES 4.5%, p<0.0001) and the larger late loss (PES 0.60x0.83 mm vs. SES 0.16x0.40 mm, p<0.001) than SES. PES was the predictor of binary restenosis at six months (OR 4.67, CI 2.20-9.91). At one year follow-up, PES also had more cardiac events (composites of death of all cause, MI, and target lesion revascularization) than SES (PES 13.9% vs. SES 6.1%, p<0.001). PES was a significant predictor of cardiac events at one year (OR 2.47, CI 1.23-4.95).

CONCLUSION

SES showed better clinical and angiographic outcomes compared to PES in a daily routine practice of coronary intervention in Koreans.

Drug-eluting stent: a review and update

The development of stent has been a major advance in the treatment of obstructive coronary artery disease since the introduction of balloon angioplasty. However, neointimal hyperplasia occurring within the stent leading to in-stent restenosis is a main obstacle in the long-term success of percutaneous coronary intervention (PCI). The recent introduction of drug-eluting stents (DES) contributes a major breakthrough to interventional cardiology. Many large randomized clinical trials using DES have shown a remarkable reduction in angiographic restenosis and target vessel revascularization when compared with bare metal stents. The results of these trials also appear to be supported by evidence from everyday practice and noncontrolled clinical trials. However, the expanded applications of DES, especially in treating complex lesions such as left main trunk, bifurcation, saphenous vein graft lesions, or in-stent restenosis, are still under evaluation with ongoing studies. With the availability of different types of DES in the market, the issue of cost should not be a deterrent and DES will eventually be an economically viable option for all patients. The adoption of DES in all percutaneous coronary intervention may become a reality in the near future. In this review article, we summarize the recent development and progress of DES as well as compare and update the results of clinical trials.

Safety and efficacy of sirolimus- and paclitaxel-eluting coronary stents

BACKGROUND

The safety of drug-eluting stents has been called into question by recent reports of increased stent thrombosis, myocardial infarction, and death. Such studies have been inconclusive because of their insufficient size, the use of historical controls, a limited duration of follow-up, and a lack of access to original source data.

METHODS

We performed a pooled analysis of data from four double-blind trials in which 1748 patients were randomly assigned to receive either sirolimus-eluting stents or bare-metal stents and five double-blind trials in which 3513 patients were randomly assigned to receive either paclitaxel-eluting stents or bare-metal stents; we then analyzed the major clinical end points of the trials.

RESULTS

The 4-year rates of stent thrombosis were 1.2% in the sirolimus-stent group versus 0.6% in the bare-metal-stent group (P=0.20) and 1.3% in the paclitaxel-stent group versus 0.9% in the bare-metal-stent group (P=0.30). However, after 1 year, there were five episodes of stent thrombosis in patients with sirolimus-eluting stents versus none in patients with bare-metal stents (P=0.025) and nine episodes in patients with paclitaxel-eluting stents versus two in patients with bare-metal stents (P=0.028). The 4-year rates of target-lesion revascularization were markedly reduced in both the sirolimus-stent group and the paclitaxel-stent group, as compared with the bare-metal-stent groups. The rates of death or myocardial infarction did not differ significantly between the groups with drug-eluting stents and those with bare-metal stents.

CONCLUSIONS

Stent thrombosis after 1 year was more common with both sirolimus-eluting stents and paclitaxel-eluting stents than with bare-metal stents. Both drug-eluting stents were associated with a marked reduction in target-lesion revascularization. There were no significant differences in the cumulative rates of death or myocardial infarction at 4 years.

A pooled analysis of data comparing sirolimus-eluting stents with bare-metal stents

BACKGROUND

Although randomized studies have shown a beneficial effect of drug-eluting stents in reducing the risk of repeated revascularization, these trials were underpowered to compare rates of death and myocardial infarction. The long-term safety of drug-eluting stents has been questioned recently.

METHODS

We performed a pooled analysis of 1748 patients in four randomized trials evaluating the safety of sirolimus-eluting stents as compared with bare-metal stents. Patient-level data were obtained and analyzed by independent statisticians at two academic institutions. The primary safety end point was survival at 4 years. We tested for heterogeneities in treatment effect in patient subgroups.

RESULTS

The survival rate at 4 years was 93.3% in the sirolimus-stent group, as compared with 94.6% in the bare-metal-stent group (hazard ratio for death, 1.24; 95% confidence interval [CI], 0.84 to 1.83; P=0.28). In the 428 patients with diabetes, a significant difference in the survival rate was observed in favor of the bare-metal-stent group over the sirolimus-stent group (95.6% vs. 87.8%; hazard ratio for death in the sirolimus-stent group, 2.9; 95% CI, 1.38 to 6.10; P=0.008). The lower survival rate among patients with diabetes who were treated with sirolimus-eluting stents was due to increased numbers of deaths from both cardiovascular and noncardiovascular causes. No difference in survival rate was detected among the patients without diabetes. Rates of myocardial infarction and stent thrombosis were similar in the two groups.

CONCLUSIONS

In a pooled analysis of data from four trials comparing sirolimus-eluting stents and bare-metal stents, no significant differences were found between the two treatments in rates of death, myocardial infarction, or stent thrombosis. (ClinicalTrials.gov numbers, NCT00233805 [ClinicalTrials.gov] , NCT00381420 [ClinicalTrials.gov] , NCT00232765 [ClinicalTrials.gov] , and NCT00235144 [ClinicalTrials.gov].)

Stent thrombosis in randomized clinical trials of drug-eluting stents

BACKGROUND

Definitions of stent thrombosis that have been used in clinical trials of drug-eluting stents have been restrictive and have not been used in a uniform manner.

METHODS

We applied a hierarchical classification of stent thrombosis set by the Academic Research Consortium (ARC) across randomized trials involving 878 patients treated with sirolimus-eluting stents, 1400 treated with paclitaxel-eluting stents, and 2267 treated with bare-metal stents. We then pooled 4 years of follow-up data. All events were adjudicated by an independent clinical-events committee.

RESULTS

The cumulative incidence of stent thrombosis according to the original protocol definitions was 1.2% in the sirolimus-stent group versus 0.6% in the bare-metal-stent group (P=0.20; 95% confidence interval [CI], -0.4 to 1.5) and 1.3% in the paclitaxel-stent group versus 0.8% in the bare-metal-stent group (P=0.24; 95% CI, -0.3 to 1.4). The incidence of definite or probable stent thrombosis as defined by the ARC was 1.5% in the sirolimus-stent group versus 1.7% in the bare-metal-stent group (P=0.70; 95% CI, -1.5 to 1.0) and 1.8% in the paclitaxel-stent group versus 1.4% in the bare-metal-stent group (P=0.52; 95% CI, -0.7 to 1.4). The incidence of definite or probable events occurring 1 to 4 years after implantation was 0.9% in the sirolimus-stent group versus 0.4% in the bare-metal-stent group and 0.9% in the paclitaxel-stent group versus 0.6% in the bare-metal-stent group.

CONCLUSIONS

The incidence of stent thrombosis did not differ significantly between patients with drug-eluting stents and those with bare-metal stents in randomized clinical trials, although the power to detect small differences in rates was limited.

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.

Diabetic endovascular disease: role of coronary artery revascularization

This century brings a pandemic of diabetes mellitus, with marked increases in early-accelerated atherosclerosis. When asymptomatic patients with diabetes present for evaluation, they have more extensive coronary atherosclerosis, lower ejection fractions, higher rates of previous cardiac events, and more silent ischemia than the normal population. The challenge faced by clinicians is to accurately identify asymptomatic patients with diabetes who have significant coronary ischemia that would benefit from revascularization. Diabetic endovascular disease has all the high-risk features to promote atherosclerosis and coronary occlusion: hyperglycemia-induced endothelial dysfunction, impaired fibrinolysis, increased platelet aggregation, plaque instability, dysfunctional arterial remodeling, and fibrotic and calcified coronary arteries. The optimal revascularization strategy for patients with diabetes is an ongoing debate. The advent of drug-eluting stents has changed the landscape, and some have suggested that the current role of coronary artery bypass grafting may be reduced by as much as 46%. Unfortunately, there is limited evidence from randomized, controlled trials that reflects current practice and could guide clinicians in making the best choices for patients with diabetes and coronary disease. It is hoped that ongoing trials--including Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D), Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease (FREEDOM), and Coronary Artery Revascularisation in Diabetes (CARDia)--will answer many of the remaining questions. Still, the best treatment includes lifestyle modification and early prevention strategies with global risk reduction.

Clinical impact of in-stent late loss after drug-eluting coronary stent implantation†

AIMS

Controversy exists about the clinical significance of in-stent late loss (ISLL) after drug-eluting stent (DES) implantation. We sought to clarify whether ISLL after DES implantation is related to a potential clinical impact.

METHODS AND RESULTS

We included in a meta-regression analysis 21 trials (8641 patients) that randomly compared DES with bare-metal stents (BMS). We evaluated the relationship between angiographic behaviour of DES and the clinical impact of using DES instead of BMS in each trial using meta-regression techniques, weighting by the number of patients included in each trial. Mean ISLL in patients allocated to DES and DeltaISLL (difference in ISLL in patients allocated to BMS and DES) were used as angiographic parameters of efficacy of DES. The number of patients needed to be treated (NNT) to prevent one target lesion revascularization (TLR) was used to quantify the clinical impact of using DES instead of BMS. There was a significant relationship between mean ISLL in patients allocated to DES and the clinical benefit of using DES instead of BMS, as measured with the NNT for TLR: NNT for TLR = 6.2 + 18.4 [ISLL-DES] (R = 0.62; P = 0.007). Therefore, a 0.1 mm increase in mean ISLL-DES was associated with a 1.8 increase in NNT for TLR. There was also a significant association between the degree of inhibition of neointimal hyperplasia of DES in comparison with BMS with the NNT for TLR: NNT for TLR = 17.1-11.8 [DeltaISLL] (R = 0.61; P = 0.008). Therefore, a 0.1 mm reduction in ISLL by using DES instead of BMS was associated with a 1.2 decrease in mean NNT for TLR.

CONCLUSION

There is a strong and significant association between the degree of inhibition of neointimal formation with the use of DES and the clinical impact of using DES instead of BMS.

Characterizing the spectrum of in-stent restenosis: implications for contemporary treatment

BACKGROUND

Reports addressing treatment of in-stent restenosis (ISR) are principally derived from clinical trials.

OBJECTIVES

To characterize the spectrum of ISR in an unselected population, and to explore clinical and angiographic factors determining management.

METHODS

During a prespecified six-month period before the introduction of drug-eluting stents, consecutive cases of ISR that were identified during clinically driven cardiac catheterization at five hospitals offering all approved treatment modalities for ISR were prospectively registered.

RESULTS

ISR was identified in 363 patients; 301 (84%) had one ISR lesion and 62 (16%) had multiple lesions. Unstable clinical presentations accounted for 51%, including 15% with ST-elevation myocardial infarction. The median interval (25th, 75th percentiles) from stent insertion to angiographic diagnosis of ISR was eight months (Q1,Q3: 4,15), with a median stented length of 18 mm (Q1,Q3: 15,28). The majority of lesions (60%) displayed a diffuse ISR pattern (Mehran types 2 and 3). ISR type was independent of time to re-presentation, diabetes, arterial territory and total stent length. Treatment included percutaneous coronary intervention (PCI) alone (n=139 [38%]), PCI with brachytherapy (n=105 [29%]), medical therapy (n=60 [17%]) and coronary artery bypass graft surgery (n=59 [16%]). Medical therapy was associated with small vessel size and recurrent ISR, and coronary artery bypass graft surgery was associated with multiple lesions, as well as diffuse, occlusive and recurrent ISR. For patients treated percutaneously, PCI treatment alone was more common for focal restenosis and after ST-elevation myocardial infarction, and brachytherapy was the more common treatment for diffuse and recurrent ISR, and stable angina.

CONCLUSIONS

These data provide a benchmark description of the spectrum of ISR with which the impact of drug-eluting stents may be compared and better understood.

A meta-analysis of trials comparing Cypher and Taxus stents in patients with obstructive coronary artery disease

AIMS

Drug-eluting stents have been shown to be superior to bare metal stents in reducing restenosis rates. Recently head-to-head trials comparing sirolimus-eluting stents and paclitaxel-eluting stents have been reported. An early combined analysis of these comparative trials is needed. The present meta-analysis was carried out to compare the effects of sirolimus-eluting stents with paclitaxel-eluting stents on the restenosis rate, major adverse cardiac events and late loss of arterial lumen diameter in patients with obstructive coronary artery disease.

METHODS

Electronic (Medline, Cochrane and Embase) and manual search (Index Medicus and cross references of retrieved articles) were carried out for all the relevant articles up till March 2005. Only randomized trials with adequate data for calculation of odds ratio for restenosis rates and major adverse cardiac events using the method of DerSimonian & Laird and standardized mean difference for late loss of arterial lumen diameter were included.

RESULTS

Four studies were found to be eligible for inclusion in the meta-analysis. Restenosis rate and late loss of arterial lumen diameter were significantly reduced by sirolimus-eluting stents as compared with paclitaxel-eluting stents (OR 0.598, 95% CI 0.400, 0.893, pooled mean difference -0.414, 95% CI -0.492, 0.336, respectively). The incidence of major adverse cardiac events was less with sirolimus-eluting stents as compared with paclitaxel-eluting stents (OR 0.727, 95% CI 0.518-1.018) but the results were not statistically significant.

CONCLUSIONS

Sirolimus-eluting stents are superior to paclitaxel-eluting stents in decreasing restenosis rate and late loss of arterial lumen diameter. However, no statistically significant difference in major adverse cardiac events was noted between the two stents.

Randomized comparative trial of a thin-strut bare metal cobalt-chromium stent versus a sirolimus-eluting stent for coronary revascularization

OBJECTIVES

To see whether use of a sirolimus-eluting stent (SES) is superior to a third-generation thin-strut, cobalt-chromium stent (CCS) in terms of in-segment late loss at 9 months in patients with symptomatic coronary artery disease.

BACKGROUND

Stent-strut thickness has been shown to be strictly related with risk of in-stent restenosis, but available demonstrations of the angiographic efficacy of SES have been based on comparisons with thick-strut bare metal control stents.

METHODS

The primary outcome measure of this single-center, single-blind randomized comparative trial was 9-month in-segment late loss. Eligibility criteria were symptomatic coronary artery disease and target vessel diameter appropriate for implantation a 3-mm stent. Based on a power calculation, 104 patients were randomly assigned to receive a SES (Cypher) or a CCS (Vision).

RESULTS

In-segment late loss was significantly lower in the SES group (0.18 +/- 0.40 mm vs 0.58 +/- 0.51 mm, P < 0.001). Regarding subsidiary outcome measures, in-segment restenosis (at 9 months) was recorded in 10% (5/50) patients treated with SES and 23% (11/48) receiving CCS (P = 0.14). No clinical difference between the two groups was apparent at 12 months. Freedom from target vessel failure at 12 months was 72% for SES patients and 68% for CCS patients (P = 0.65).

CONCLUSIONS

In patients with de-novo coronary lesions at medium risk of restenosis the anti-proliferative effect of SES is greater than that of a thin-strut CCS. Nevertheless, the angiographic results of the CCS were rather good. It remains to be seen whether the angiographic superiority of SES can translate into clinical superiority.

Impact of Stable Versus Unstable Coronary Artery Disease on 1-Year Outcome in Elective Patients Undergoing Multivessel Revascularization With Sirolimus-Eluting Stents

OBJECTIVES

We sought to evaluate the impact of unstable coronary artery disease (CAD) on short- and mid-term outcomes in patients with multivessel disease treated by multiple sirolimus-eluting stents (SES) as part of ARTS II (Arterial Revascularization Therapies Study Part II).

BACKGROUND

The differential safety/efficacy profile of SES when implanted in patients with unstable angina (UA) in comparison with stable angina (SA) undergoing multivessel intervention is largely unknown.

METHODS

Between February 2003 and November 2003, 607 patients at 45 participating centers were treated; 221 of them (36%) presented with UA.

RESULTS

At 30 days, the cumulative rate of death, myocardial infarction-defined as any creatine kinase (CK)/CK-myocardial band elevation beyond the upper limit of normal-cerebrovascular accident, and repeat revascularization (i.e., major adverse cardiac and cerebrovascular events [MACCEs]) was 19.9% in both groups. Angiographic subacute stent occlusion was documented in 1 (0.5%) and 4 (1%) patients in the UA and SA groups, respectively. At 1 year, the cumulative incidence of MACCEs was 27.1% in the UA and 24.9% in the SA group (p = 0.56). Two late occlusions occurred, both in the SA group. After adjustment for baseline and procedural characteristics, the presence of UA was not identified as an independent predictor of MACCE (hazard ratio 0.94; 95% confidence interval 0.41 to 2.12; p = 0.88). These findings remained consistent after increasing the CK/CK-myocardial band threshold to define periprocedural myocardial infarction up to at least 3 or 5 times the upper limit of normal.

CONCLUSIONS

In ARTS II, an unstable clinical presentation did not exert a negative impact on short- and mid-term outcome after SES implantation for multivessel disease. (ARTS II Trial; ; NCT00235170).

Drug-Eluting Stents

The introduction of percutaneous transluminal coronary angioplasty has revolutionized the field of cardiology by providing patients with coronary artery disease immediate and effective therapy. Overshadowing the early success of angioplasty was the high rate of angiographic restenosis and recurrent symptoms at 6 months. The use of stents reduced the incidence of restenosis; however, the rise in the number of patients undergoing percutaneous interventions produced a new problem of restenosis occurring within the stent: in-stent restenosis (ISR). Mechanical approaches, including directional and rotational atherectomy and systemic pharmacotherapy, have failed to demonstrate a reduction in ISR in randomized clinical trials. Intravascular brachytherapy is currently the only approved therapy for ISR, although this treatment has numerous unresolved questions and is not effective in a large percent of patients. Drug-eluting stents have reduced the incidence of restenosis by providing localized therapy to the targeted lesion without systemic toxicity. The purpose of this review is to synthesize data from major clinical trials involving the 2 most successful agents used in the prevention of restenosis: sirolimus and paclitaxel. The cellular and molecular mechanisms of both ISR and restenosis postangioplasty derived from animal models will be introduced. Second, an overview of 3 alternate interventions that attempt to reduce the rates of restenosis is presented. Finally, the major randomized, controlled trials involving sirolimus and paclitaxel are described, and their clinical implications and use as a possible solution in the prevention of restenosis is discussed.

Coronary stents: a materials perspective

The objective of this review is to describe the suitability of different biomaterials as coronary stents. This review focuses on the following topics: (1) different materials used for stents, (2) surface characteristics that influence stent-biology interactions, (3) the use of polymers in stents, and (4) drug-eluting stents, especially those that are commercially available.

The cost-effectiveness of drug-eluting stents: a systematic review

BACKGROUND

Drug-eluting stents have been seen as an attractive alternative to bare-metal stents for percutaneous coronary interventions (PCIs) because of the decreased need for revascularization. However, comparative clinical trials have shown no difference in patient outcomes, and drug-eluting stents are considerably more expensive than their bare-metal counterparts. We conducted a systematic review of all published comparative cost-effectiveness analyses to identify the factors contributing to the heterogeneity of their conclusions.

METHODS

We retrieved all articles published between Jan. 1, 2000, and July 31, 2006, in which the cost-effectiveness, from a third-party payer perspective, of drug-eluting stents was compared with that of bare-metal stents for PCI in unrestricted patient populations. Electronic databases, Web sites from health technology assessment groups and references of identified articles were searched. Our outcome variable was whether the study's conclusions favoured widespread use of drug-eluting stents, as assessed by 4 independent reviewers. Study characteristics such as quality, funding source, country and year of publication were extracted. Two-by-2 tables and Fisher's exact test were used to study the association between covariates and the outcome variable. A classification and regression tree (CART) model was used for multivariate analysis.

RESULTS

We identified 19 cost-effectiveness analyses. Ten were in favour of widespread use of drug-eluting stents, and 9 favoured more restrained use. Only 1 of 9 high-quality studies supported widespread use, as compared with 9 of 10 lower quality studies (p < 0.001). All of the 7 sponsored studies argued in favour of widespread use, as compared with 3 of the 12 studies without sponsorship (p = 0.003). Studies from the United States were more likely than those from other countries to endorse unlimited use (p = 0.032). A CART model with 2 covariates--study quality and sponsorship--provided the best fit (error rate 10.5%).

INTERPRETATION

Conclusions drawn by cost-effectiveness analyses of drug-eluting stents for PCI are associated with the study's quality, funding source and country of origin. Vigilance regarding these study characteristics is required when interpreting findings from cost-effectiveness analyses.

Drug-eluting stents and stent thrombosis: a cause for concern?

Drug-eluting stents, most commonly sirolimus-eluting stents and polymer-based paclitaxel-eluting stents, are now widely used during percutaneous coronary interventions, and have largely replaced bare-metal stents to treat a variety of native coronary artery and saphenous vein graft lesions. Stent thrombosis, a complication of both bare-metal and drug-eluting stents, is associated with significant morbidity and mortality including high rates of myocardial infarction and death. Recently, several studies in the literature have raised concern about increased rates of overall stent thrombosis and late stent thrombosis in drug-eluting stents in the so-called 'real world' where off-label uses of drug-eluting stents are common. Hypersensitivity reactions to the polymers used in drug-eluting stents, delayed endothelialization of the stents, and discontinuation of dual antiplatelet therapy have all been implicated in the pathophysiology of drug-eluting stents stent thrombosis. The incidence of total stent thrombosis as well as late stent thrombosis, however, does not seem to be significantly higher in drug-eluting stents than in bare-metal stents. An important risk factor for stent thrombosis in both types of stents appears to be the premature discontinuation of dual antiplatelet therapy, and physicians should educate their patients about the importance of adhering to dual antiplatelet therapy, given the dire clinical consequences of stent thrombosis.

Late thrombosis of drug-eluting stents: a meta-analysis of randomized clinical trials

PURPOSE

Drug-eluting stents are commonly used for percutaneous coronary intervention. Despite excellent clinical efficacy, the association between drug-eluting stents and the risk for late thrombosis remains imprecisely defined.

METHODS

We performed a meta-analysis on 14 contemporary clinical trials that randomized 6675 patients to drug-eluting stents (paclitaxel or sirolimus) compared with bare metal stents. Eight of these trials have reported more than a year of clinical follow-up.

RESULTS

The incidence of very late thrombosis (>1 year after the index procedure) was 5.0 events per 1000 drug-eluting stent patients, with no events in bare metal stent patients (risk ratio [RR]=5.02, 95% confidence interval [CI], 1.29 to 19.52, P=.02). Among sirolimus trials, the incidence of very late thrombosis was 3.6 events per 1000 sirolimus stent patients, with no events in bare metal stent patients (RR=3.99, 95% CI, .45 to 35.62, P=.22). The median time of late sirolimus stent thrombosis was 15.5 months, whereas with bare metal stents it was 4 months. Among paclitaxel trials, the incidence of very late thrombosis was 5.9 events per 1000 paclitaxel stent patients, with no events in bare metal stent patients (RR=5.72, 95% CI, 1.08 to 32.45, P=.049). The median time of late paclitaxel stent thrombosis was 18 months, whereas it was 3.5 months in bare metal stent patients.

CONCLUSIONS

Although the incidence of very late stent thrombosis more than 1 year after coronary revascularization is low, drug-eluting stents appear to increase the risk for late thrombosis. Although more of this risk was seen with paclitaxel stents, it remains possible that sirolimus stents similarly increase the risk for late thrombosis compared with bare metal stents.

From randomized trials to routine clinical practice: an evidence-based approach for the use of drug-eluting stents

The availability of drug-eluting stents has resulted in a paradigm shift in the management of patients with coronary artery disease with a substantial increase in the percentage of patients being revascularized percutaneously rather than surgically. Since its introduction, there has been a tremendous increase in the use of drug-eluting stents with nearly 90% of patients in the US who undergo percutaneous interventions receiving drug-eluting stents. The promising results of several randomized trials that demonstrated a profound reduction in restenosis rates compared with bare-metal stents, underscores the unprecedented enthusiasm among the cardiology community to adopt this new technology swiftly. Data regarding the safety and superiority of drug-eluting stents abound, and it is imperative for the practicing clinician to review and apply them in appropriate clinical settings. In this review, we present general concepts of drug-eluting stents, and attempt to summarize the available data on the approved drug-eluting stents in a variety of patient and lesion subsets. In addition, we share some insights regarding the potential limitations, and issues specific to drug-eluting stents.

Safety and efficacy of the 2.25-mm sirolimus-eluting Bx Velocity stent in the treatment of patients with de novo native coronary artery lesions: the SIRIUS 2.25 trial

Smaller reference vessel diameter is a recognized determinant of in-stent restenosis. The SIRIUS 2.25 trial was a prospective, nonrandomized study including 100 patients (mean age 63.4 years; 64% men, 40% with diabetes mellitus) assessing the safety and efficacy of the 2.25-mm sirolimus-eluting Bx Velocity stent in patients with de novo native coronary lesions. Using propensity score matching for gender, diabetes mellitus, left anterior descending artery target vessel, lesion length, and reference vessel diameter, the outcomes were compared with historical control groups (angioplasty and Palmaz-Schatz stent arms from the STRESS/BENESTENT I/II trials and the Bx Velocity bare metal stent arm from the RAVEL and SIRIUS trials having a reference vessel diameter <3 mm). Use of the 2.25-mm sirolimus-eluting Bx Velocity stent was associated with a high rate of procedural success (97%) and a low rate of in-hospital major adverse cardiac events (2%). The primary end point, 6-month in-lesion binary angiographic restenosis, occurred less frequently in patients treated with the 2.25-mm sirolimus-eluting Bx Velocity stent than in each of 3 historical controls (16.9% vs 30.6%, p = 0.12; 36.5%, p <0.001; 45.9%, p <0.001, respectively). This translated into lower rates of 6-month target lesion revascularization in the 2.25-mm sirolimus-eluting Bx Velocity stent group (4.0% vs 15.0% in each of 3 control groups, p = 0.01 to <0.001). By multivariate analysis, in-lesion binary restenosis was predicted by multiple implanted stents (odds ratio 10.4, p = 0.002). Four of 13 patients who developed restenosis (30.8%) had a diffuse pattern of restenosis. In the long lesion tertile (mean lesion length 19.5 mm), the in-lesion binary restenosis rate was 27.6%. In conclusion, use of the 2.25-mm sirolimus-eluting Bx Velocity stent was safe and provided favorable 6-month clinical outcomes. Use of multiple stents (in longer lesions) was an independent predictor of in-lesion restenosis.

Randomized Double-Blind Comparison of Sirolimus-Eluting Stent Versus Bare-Metal Stent Implantation in Diseased Saphenous Vein Grafts

OBJECTIVES

We sought to compare, in a randomized fashion, sirolimus-eluting stents (SES) versus bare-metal stents (BMS) in saphenous vein grafts (SVGs).

BACKGROUND

Sirolimus-eluting stents reduce restenosis and repeated revascularization in native coronary arteries compared with BMS. However, randomized data in SVG are absent.

METHODS

Patients with SVG lesions were randomized to SES or BMS. All were scheduled to undergo 6-month coronary angiography. The primary end point was 6-month angiographic in-stent late lumen loss. Secondary end points included binary angiographic restenosis, neointimal volume by intravascular ultrasound and major adverse clinical events (death, myocardial infarction, target lesion, and vessel revascularization).

RESULTS

A total of 75 patients with 96 lesions localized in 80 diseased SVGs were included: 38 patients received 60 SES for 47 lesions, whereas 37 patients received 54 BMS for 49 lesions. In-stent late loss was significantly reduced in SES (0.38 +/- 0.51 mm vs. 0.79 +/- 0.66 mm in BMS, p = 0.001). Binary in-stent and in-segment restenosis were reduced, 11.3% versus 30.6% (relative risk [RR] 0.37; 95% confidence interval [CI] 0.15 to 0.97, p = 0.024) and 13.6% versus 32.6% (RR 0.42; 95% CI 0.18 to 0.97, p = 0.031), respectively. Median neointimal volume was 1 mm(3) (interquartile range 0 to 13) in SES versus 24 (interquartile range 8 to 34) in BMS (p < 0.001). Target lesion and vessel revascularization rates were significantly reduced, 5.3% versus 21.6% (RR 0.24; 95% CI 0.05 to 1.0, p = 0.047) and 5.3% versus 27% (RR 0.19; 95% CI 0.05 to 0.83, p = 0.012), respectively. Death and myocardial infarction rates were not different.

CONCLUSIONS

Sirolimus-eluting stents significantly reduce late loss in SVG as opposed to BMS. This is associated with a reduction in restenosis rate and repeated target lesion and vessel revascularization procedures. (The RRISC Study; http://clinicaltrials.gov/ct/show; NCT00263263).

Angioscopic evaluation of neointima coverage: sirolimus drug-eluting stent versus bare metal stent

BACKGROUND

The process of neointima formation after bare metal stent (BMS) implantation has been previously elucidated by angioscopic observations; however, that after drug-eluting stent (DES) implantation has not been clarified. Therefore, we compared the angioscopic appearance of neointima over DESs with that over BMSs 6 months after implantation.

METHODS AND RESULTS

Patients who received an implantation of a BMS (n = 13) or a sirolimus DES (n = 24) were included in this study. Angiographic and angioscopic examinations were performed at 6 months. The color of the stented lesion (white or yellow), coverage of stent by neointima (not covered, covered by a thin layer, or buried under neointima), and thrombus at the stented lesion (presence or absence) were angioscopically evaluated. Of the 24 lesions in which a DES was implanted, 11 (46%) had a part where the stent strut had no coverage, 21 (88%) had a part where it was covered by a thin layer, and 11 (46%) had a part where it was buried under neointima. Of the 13 lesions in which a BMS was implanted, 1 (8%) lesion had a part where the stent strut had no coverage, 4 (31%) lesions had a part where it was covered by a thin layer, and 13 (100%) lesions had a part where it was buried under neointima. The prevalence of a stent buried under neointima (46% vs 100%, P = .001) was lower and that of thrombus (42% vs 8%, P = .03) was higher in DES-implanted lesions as compared with BMS-implanted lesions. The prevalence of thrombus (64% vs 17%, P = .005) was higher in the yellow area than in the white area when a DES was implanted.

CONCLUSION

Sirolimus DESs, as compared with BMSs, were poorly covered by neointima and were accompanied by thrombus especially when there was a yellow plaque under the stents. Thus, the thrombogenic potential in DES-implanted lesions may be sustained by the inhibition of neointima formation over thrombogenic plaques.

New Developments in Coronary Stent Technology

Coronary stent technology has rapidly evolved from a mechanical solution to abrupt vessel closure and elastic recoil following plain balloon angioplasty, to become a vector for local drug delivery and modification of coronary plaque pathophysiology. The advent of drug-eluting stents (DES) has significantly reduced restenosis, although there is increasing concern over the risk of late stent thrombosis, particularly following cessation of antiplatelet therapy. Here we consider the limitations of the current generation of DES, and review recent advances in platform, carrier, and pharmacological technology, and their place in future clinical practice.

Comparison of zotarolimus-eluting and sirolimus-eluting stents in patients with native coronary artery disease: a randomized controlled trial

OBJECTIVES

This trial examined the relative clinical efficacy, angiographic outcomes, and safety of zotarolimus-eluting coronary stents (ZES) with a phosphorylcholine polymer versus sirolimus-eluting stents (SES).

BACKGROUND

Whether a cobalt-based alloy stent coated with the novel antiproliferative agent, zotarolimus, and a phosphorylcholine polymer may provide similar angiographic and clinical benefit compared with SES is undetermined.

METHODS

A prospective, multicenter, 3:1 randomized trial was conducted to evaluate the safety and efficacy of ZES (n = 323) relative to SES (n = 113) in 436 patients undergoing elective percutaneous revascularization of de novo native coronary lesions with reference vessel diameters between 2.5 mm and 3.5 mm and lesion length > or =14 mm and < or =27 mm. The primary end point was 8-month angiographic in-segment late lumen loss.

RESULTS

Angiographic in-segment late lumen loss was significantly higher among patients treated with ZES compared with SES (0.34 +/- 0.44 mm vs. 0.13 +/- 0.32 mm, respectively; p < 0.001). In-hospital major adverse cardiac events were significantly lower among patients treated with ZES (0.6% vs. 3.5%, p = 0.04). In-segment binary angiographic restenosis was also higher in the ZES cohort (11.7% vs. 4.3%, p = 0.04). Total (clinically and non-clinically driven) target lesion revascularization rates at 9 months were 9.8% and 3.5% for the ZES and SES groups, respectively (p = 0.04). However, neither clinically driven target lesion revascularization (6.3% zotarolimus vs. 3.5% sirolimus, p = 0.34) nor target vessel failure (12.0% zotarolimus vs. 11.5% sirolimus, p = 1.0) differed significantly.

CONCLUSIONS

Compared with SES, treatment with a phosphorylcholine polymer-based ZES is associated with significantly higher late lumen loss and binary restenosis at 8-month angiographic follow-up. (The Endeavor III CR; http://clinicaltrials.gov/ct/show/NCT00265668?order=1?).

Efficacy and Safety of Drug-Eluting Stents: Current Best Available Evidence

The development of drug-eluting coronary stents has proved to be a quantum advance in interventional cardiology, rivaling the impact of stenting itself. Drug-eluting coronary stents deliver effective local concentrations of antiproliferative drugs (thus avoiding systemic toxicities), without substantially modifying the technique of percutaneous coronary intervention. Studies involving several different stent platforms and antiproliferative drug coatings have recently demonstrated dramatic reductions in restenosis rates, compared to conventional bare metal stents. Although the clinical benefits of drug-eluting stents are increasingly evident, important concerns about their long-term safety and costs have been raised. Furthermore, drug-eluting stents are being claimed to replace coronary artery bypass surgery in the near future. This review article evaluates the current best available evidence on the efficacy and safety of drug-eluting stents with a focus on the impact of this "revolutionary" new technology on the practice of coronary artery bypass surgery.

Clinical Benefits of Drug-Eluting Stents

Drug-eluting stents have revolutionized interventional cardiology by incorporating drug and device therapy to reduce rates of restenosis. Early trials have addressed the safety and efficacy of drug-eluting stents. Recent studies have evaluated the use of drug-eluting stents in high-risk populations that were not initially randomized in the early trials. These stents have shown promising outcomes in diabetes, in-stent restenosis, and multivessel disease. The clinical benefits of these stents have been systematically quantified across multiple trials; however, there is a growing debate regarding restenosis and late-stent thrombosis after implantation. Given the expanding indications for drug-eluting stents, the American Heart Association identified it as one of the Top 10 Research Advances for 2005. The purpose of this article is to summarize the current debate surrounding late-stent thrombosis, examine the evidence from leading stent trials, and outline the clinical benefits of drug-eluting stents.