A randomized comparison of the Endeavor zotarolimus-eluting stent versus the TAXUS paclitaxel-eluting stent in de novo native coronary lesions 12-month outcomes from the ENDEAVOR IV trial

Zotarolimus-eluting stent versus sirolimus-eluting and paclitaxel-eluting stents for percutaneous coronary intervention: a meta-analysis of randomized trials

BACKGROUND

The zotarolimus-eluting stent (ZES) is a new drug-eluting stent that delivers zotarolimus, a synthetic analogue of sirolimus, through a biocompatible phosphorylcholine polymer coating. ZES has shown promising results compared with bare-metal stents, but its safety and efficacy against sirolimus-eluting (SES) and paclitaxel-eluting (PES) stents is yet to be established.

AIMS

We aimed to summarize current evidence from randomized trials comparing ZES with SES and PES.

METHODS

We searched the Medline, Embase and CENTRAL databases for randomized studies comparing ZES with SES and PES for percutaneous coronary intervention. Relevant clinical and angiographic outcomes were extracted and combined using random and fixed-effect models for heterogeneous and homogenous outcomes, respectively.

RESULTS

Seven randomized trials met the inclusion criteria: ZES group, n=3787; SES group, n=2606; PES group, n=1966. Compared with SES, ZES was associated with significantly higher odds of clinically driven target vessel revascularization (odds ratio [OR] 2.36, 95% confidence interval [CI] 1.78-3.14) and target lesion revascularization (OR 2.46, 95% CI 1.36-4.46). Compared with SES, ZES had higher in-stent restenosis (OR 6.13, 95% CI 3.96-9.50), late lumen loss 'in-stent' (mean difference [MD] 0.39 mm, 95% CI 0.34-0.44) and late lumen loss 'in-segment' (MD 0.18 mm, 95% CI 0.15-0.21). ZES was associated with higher in-stent late lumen loss than PES (MD 0.18 mm, 95% CI 0.07-0.28). There were no differences in mortality, reinfarction or stent thrombosis with ZES compared with SES and PES.

CONCLUSION

ZES is not superior to PES and is inferior to SES in terms of angiographic outcomes and clinically driven revascularization.

In vitro mutagenicity and blood compatibility of paclitaxel and curcumin in poly (DL-lactide-co-glicolide) films

Curcumin is considered to be a potential component for drug-eluting stents due to its anti-inflammatory properties. In this study we compared the mutagenicity and blood compatibility of curcumin to first generation drug eluting stent components: paclitaxel and sirolimus. The Ames test was used to assess mutagenicity. Blood compatibility was tested by measuring platelet activation and fibrinogen adsorption on poly (DL-lactide-co-glycolide, PLGA) films. We discovered that there was no significant increase in the number of revertants/plate following treatment with curcumin (up to 0.5mg/plate) or sirolimus (up to 0.5 μg/plate). However, a significant induction in the frequency of bacterial his(+) revertant colonies by paclitaxel at concentrations of 0.02, 0.05, 0.1, 0.2 and 0.5 μg/plate was observed. We also discovered a significant reduction in platelet activation by PLGA films containing 30% and 50% by weight curcumin. A similar reduction in platelet activation was also observed for PLGA films containing 1% by weight paclitaxel. In addition, we observed an increase of fibrinogen adsorption to PLGA-films containing curcumin. This would compromise the potential use of curcumin as a component of drug-eluting stents. Moreover, our data challenges the current view that paclitaxel does not significantly induce mutagenesis.

Coronary stent choice in patients with acute myocardial infarction

A prompt reperfusion with primary percutaneous coronary intervention represents the current gold standard treatment for patients with acute myocardial infarction. In this setting, coronary stents have been shown to improve outcomes compared to plain angioplasty and are routinely used. However, the stent selection among patients with acute myocardial infarction is still a matter of some debate. An increased risk of very late (>1-year) stent thrombosis has been associated with the use of early-generation drug-eluting stents (DES), leading to concerns regarding the long-term safety of these devices. Newer-generation DES were developed with the aim of addressing this safety issue, and were recently investigated in a few randomized studies in patients with acute myocardial infarction. The objective of the present review is to summarize the accumulated evidence, to guide the stent selection in patients with acute myocardial infarction.

Zotarolimus-eluting vs. sirolimus-eluting coronary stents in patients with and without acute coronary syndromes: a SORT OUT III substudy

OBJECTIVES

To compare clinical outcomes among patients with acute coronary syndrome treated with zotarolimus-eluting and sirolimus-eluting stents in the SORT OUT III trial.

BACKGROUND

Currently, only limited data allow direct comparison of clinical outcomes among patients with acute coronary syndrome treated with a second-generation drug-eluting stent (DES) eluting zotarolimus vs. a first-generation DES eluting sirolimus.

METHODS

Patients with acute coronary syndrome (n=1052) were randomized to treatment with zotarolimus-eluting (n=506) or sirolimus-eluting (n=546) stents and followed for 18 months. The primary composite endpoint, major adverse cardiac events (MACE), was defined as a composite of cardiac death, myocardial infarction or target vessel revascularization.

RESULTS

Zotarolimus-eluting stent treatment compared to sirolimus-eluting stent treatment was associated with increased rates of MACE (8·7% vs. 5·0%; hazard ratio (HR), 1·78; 95% confidence interval (CI), 1·10-2·88; P=0·02) and TVR (6·8% vs. 3·9%; HR, 1·77; 95% CI, 1·03-3·04; P=0·04), while all-cause death, cardiac death, myocardial infarction and definite stent thrombosis did not differ significantly. In the same trial, stable angina pectoris patients (n=1206) were randomized to zotarolimus-eluting (n=614) and sirolimus-eluting (n=592) stents with similar results.

CONCLUSIONS

With and without acute coronary syndromes, patients treated with the sirolimus-eluting stent had better clinical outcomes than those treated with the zotarolimus-eluting stent.

A first-in-man study of sirolimus-eluting, biodegradable polymer coated cobalt chromium stent in real life patients

INTRODUCTION

Despite considerable benefits associated with current drug-eluting stents, continued attention to the safety, efficacy, and deliverability of available drug-eluting stent has led to the development of newer stent.

METHODS

This study was a single-centre, prospective, non-randomized, first-in-man study which included clinical follow-up data was collected at 1, 8 and 12 months after the procedure. The study included 105 patients with de novo native coronary artery lesions including multi-vessel disease treated with Supralimus-Core® stent. Repeat angiography was performed 8 months post-stent implantation.

RESULTS

At quantitative coronary angiography 8-month luminal late loss was 0.39 ± 0.33 mm in-stent and 0.33 ± 0.35 mm in-segment. The incidence of any major adverse cardiac event at 30 days, 8 months and 12 months was 1 (1%), 6 (6%) and 7 (7%) respectively.

CONCLUSION

This study demonstrates that the Supralimus-Core® SES is a safe and effective treatment for patients with obstructive coronary artery disease. ClinicalTrials.gov ID: NCT00811616.

Everolimus-eluting stents in interventional cardiology

Bare metal stents have a proven safety record, but limited long-term efficacy due to in-stent restenosis. First-generation drug-eluting stents successfully countered the restenosis rate, but were hampered by concerns about their long-term safety. Second generation drug-eluting stents have combined the low restenosis rate of the first generation with improved long-term safety. We review the evolution of drug-eluting stents with a focus on the safety, efficacy, and unique characteristics of everolimus-eluting stents.

Short- and long-term outcomes with drug-eluting and bare-metal coronary stents: a mixed-treatment comparison analysis of 117 762 patient-years of follow-up from randomized trials

BACKGROUND

Drug-eluting stents (DES) have been in clinical use for nearly a decade; however, the relative short- and long-term efficacy and safety of DES compared with bare-metal stents (BMS) and among the DES types are less well defined.

METHODS AND RESULTS

PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials, until March 2012, that compared any of the Food and Drug Administration-approved durable stent and polymer DES (sirolimus-eluting stent [SES], paclitaxel-eluting stent [PES], everolimus-eluting stent [EES], zotarolimus-eluting stent [ZES], and ZES-Resolute [ZES-R]) with each other or against BMS for de novo coronary lesions, enrolling at least 100 patients and with follow-up of at least 6 months. Short-term (≤ 1 year) and long-term efficacy (target-vessel revascularization, target-lesion revascularization) and safety (death, myocardial infarction, stent thrombosis) outcomes were evaluated and trial-level data pooled by both mixed-treatment comparison and direct comparison analyses. From 76 randomized clinical trials with 117 762 patient-years of follow-up, compared with BMS, each DES reduced long-term target-vessel revascularization (39%-61%), but the magnitude varied by DES type (EES~SES~ZES-R>PES~ZES>BMS), with a >42% probability that EES had the lowest target-vessel revascularization rate. There was no increase in the risk of any long-term safety outcomes, including stent thrombosis, with any DES (versus BMS). In addition, there was reduction in myocardial infarction (all DES except PES versus BMS) and stent thrombosis (with EES versus BMS: Rate ratio, 0.51; 95% credibility interval, 0.35-0.73). The safest DES appeared to be EES (>86% probability), with reduction in myocardial infarction and stent thrombosis compared with BMS. Short-term outcomes were similar to long-term outcomes, with SES, ZES-R, and everolimus-eluting stent being the most efficacious and EES being the safest stent.

CONCLUSIONS

DES are highly efficacious at reducing the risk of target-vessel revascularization without an increase in any safety outcomes, including stent thrombosis. However, among the DES types, there were considerable differences, such that EES, SES, and ZES-R were the most efficacious and EES was the safest stent.

Outcomes of patients treated with the everolimus-eluting stent versus the zotarolimus eluting stent in a consecutive cohort of patients at a tertiary medical center

Background

In this study we compared the outcomes of the everolimus-eluting stent (EES) versus the zotarolimus-eluting stent (ZES) in patients treated at a tertiary medical center, with up to one year of follow-up.

Methods

Unselected consecutive patients were retrospectively recruited following stenting with the ZES (n = 197) or EES (n = 190). The first 100 consecutive patients in each cohort underwent syntax scoring. The primary endpoint of the study was target vessel failure, defined as the combined endpoint of cardiac death, non-fatal myocardial infarction, or target vessel revascularization. Secondary endpoints included target lesion revascularization, target lesion failure, acute stent thrombosis, total death, cardiac death, and non-fatal myocardial infarction.

Results

The two groups were similar, including for Syntax scores (19.6 ± 12.8 versus 20.6 ± 13.6), number of stents per patient (2.9 ± 1.9 versus 2.9 ± 2.1), and cardiovascular risk factors. By one year, the primary outcome occurred in 20.8% EES versus 26.7% ZES (P = 0.19) patients. The secondary endpoints were as follows: target lesion revascularization (8.9% versus 20.6%, P = 0.003), target vessel revascularization (18.9% versus 25.6%, P = 0.142), definite and probable stent thrombosis (0% versus 2.5%), non-fatal myocardial infarction (2.7% versus 3.6%), and mortality (3.2% versus 5.1%) for the EES versus the ZES, respectively.

Conclusion

EES had similar target vessel failure to ZES, but superior target lesion revascularization and target lesion failure at one year of follow-up in an unselected cohort of patients.

DUrable polymer-based sTent CHallenge of Promus ElemEnt versus ReSolute integrity (DUTCH PEERS): rationale and study design of a randomized multicenter trial in a Dutch all-comers population

BACKGROUND

Drug-eluting stents (DES) are increasingly used for the treatment of coronary artery disease. An optimized DES performance is desirable to successfully treat various challenging coronary lesions in a broad population of patients. In response to this demand, third-generation DES with an improved deliverability were developed. Promus Element (Boston Scientific, Natick, MA) and Resolute Integrity (Medtronic Vascular, Santa Rosa, CA) are 2 novel third-generation DES for which limited clinical data are available. Accordingly, we designed the current multicenter study to investigate in an all-comers population whether the clinical outcome is similar after stenting with Promus Element versus Resolute Integrity.

METHODS

DUTCH PEERS is a multicenter, prospective, single-blinded, randomized trial in a Dutch all-comers population. Patients with all clinical syndromes who require percutaneous coronary interventions with DES implantation are eligible. In these patients, the type of DES implanted will be randomized in a 1:1 ratio between Resolute Integrity versus Promus Element. The trial is powered based on a noninferiority hypothesis. For each stent arm, 894 patients will be enrolled, resulting in a total study population of 1,788 patients. The primary end point is the incidence of target vessel failure at 1-year follow-up.

SUMMARY

DUTCH PEERS is the first randomized multicenter trial with a head-to-head comparison of Promus Element and Resolute Integrity to investigate the safety and efficacy of these third-generation DES.

The Generations of Drug-Eluting Stents and Outcomes in Women

Drug-eluting stents have become one of the mainstays of percutaneous coronary artery revascularization. Since their introduction, there have been many developments in this technology including the optimization of the stent platform, novel polymer coatings, and antiproliferative drugs. Although cardiovascular disease is the leading cause of death in women, the prevalence of obstructive coronary artery disease is lower, and women comprise a minority of patients included in clinical trials assessing the performance of drug-eluting stents. This article reviews the advances in drug-eluting stent technology and the studies reporting outcomes in women after implantation of these stents.

New technologies aimed at percutaneous intervention in the small coronary artery

Percutaneous coronary intervention (PCI) of small vessels can be complicated by technically difficult access to the target lesion, an increased risk of major adverse cardiac events and in-stent restenosis requiring repeat revascularization. Conventional management of such lesions is with drug-eluting stent implantation; however, these have only partly attenuated the problem. In response, several medical device companies are competing to produce new technologies aimed at PCI in small coronary arteries. Such innovations include thin-strutted stents, stent-on-a-wire systems, drug-coated balloons, endothelial progenitor cell-catching stents and biodegradable stent systems. To date, none of these techniques have been sufficiently validated for use in small coronary arteries to justify a change in practice; however, small-vessel coronary artery disease is an increasingly common problem, and PCI of target lesions with reference vessel diameter <3.0 mm is likely to increase, especially in view of the increasing prevalence of diabetes, warranting further well-designed studies. The prospect of mounting a self-expandable biodegradable drug-eluting stent directly onto a guidewire could potentially be an exciting future development.

Stent thrombosis: incidence, predictors and new technologies

Some concerns have been raised regarding the risk of late and very late stent thrombosis (ST) following drug-eluting stent implantation. Despite remaining an uncommon complication of percutaneous coronary intervention, when ST occurs, it can be catastrophic to the individual, commonly presenting as acute ST elevation myocardial infarction or sudden cardiac death. The incidence and predictors of ST have been reported in the literature and the role of dual antiplatelet therapies in the avoidance of such a complication remains vital. Ongoing studies are assessing the role of these therapies including platelet reactivity testing, genetic testing and optimum duration of therapy. In addition, newer polymer-free and bioabsorbable stents are under investigation in the quest to potentially minimise the risk of ST.

Initial clinical experience with an everolimus eluting platinum chromium stent (Promus Element) in unselected patients from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

BACKGROUND

The safety and efficacy of the Promus Element stent have been recently demonstrated in a selected population from one randomized trial. The aim of this study was to describe the initial clinical experience with the everolimus eluting platinum chromium stent (Promus Element) in unselected patients from a real life nationwide registry.

METHODS

The Promus Element DES was compared to all other DES implanted in Sweden (with more than 500 implants) from November 2009 to March 2011. The results were assessed using Cox regression.

RESULTS

A total of 13,577 stents (Promus Element, n=2724, Cypher, n=782; Endeavor, n=747; Taxus Liberté, n=1393, Xience V/Promus, n=4832, Resolute, n=1566, Xience Prime, n=4832) were implanted at 8375 procedures. At one year the restenosis rate in the Promus Element was not significantly different from the overall DES group (2.8% vs. 2.7%, adjusted HR:1.17, 95% CI: 0.75-1.75). A significantly lower restenosis rate was observed in the Promus Element when compared with Endeavor (2.8% vs. 5.8%; adjusted HR: 0.44; 95% CI: 0.26-0.74). The stent thrombosis (ST) rate at one year was not significantly different in the Promus Element as compared with the overall DES group (0.2% vs. 0.5% adjusted HR: 0.59; 95% CI: 025-1.40). ST rate was significantly lower as compared with Endeavor stent (0.2% vs. 0.8%; HR: 0.24; 95% CI: 0.08-0.67).

CONCLUSIONS

In a large unselected population the Promus Element stent appears to be safe and effective with a low risk of restenosis and ST.

Differences in drug-eluting stents used in coronary artery disease

The introduction of drug-eluting stents (DES) has improved the efficacy of percutaneous coronary intervention by addressing the issue of neointimal proliferation, a pathology contributing to restenosis. First-generation stents eluting sirolimus or paclitaxel were joined by second-generation stents, such as the everolimus- and the zotarolimus-eluting stents, promising increased safety and efficacy. As a result, there is a plethora of drug-eluting stents available, with differences in the stent platform, the polymer coating and the eluted drug, which translate into differences in biological markers of efficacy, such as late loss. However, it remains controversial whether these discrepancies have an impact on clinical markers of safety and efficacy, or if the improved efficacy of DES is a class effect. This article reviews the differences between DES by looking into the biological differences and into trials and registries of DES.

Frequency and impact of bleeding in elective coronary stent clinical trials--utility of three commonly used definitions

BACKGROUND

Bleeding events are common after percutaneous coronary intervention (PCI) and have been shown to increase mortality in studies of acute coronary syndrome (ACS) and anti-thrombotic therapy. Despite this evidence, bleeding has not been included as a traditional major endpoint in clinical trials of low-risk populations enrolled in PCI clinical trials. Thus, the impact of specific bleeding definitions has not been evaluated fully among these patients.

METHODS AND RESULTS

Using patient-level pooled data from sirolimus and zotarolimus drug-eluting stent clinical trials, we identified bleeding events using three common definitions of bleeding, ACUITY, TIMI, and GUSTO, and assessed the impact on mortality and MI at 12 months after PCI. The GUSTO, ACUITY, and TIMI classifications identified bleeding rates of 2.3%, 1.9%, and 2.1%, respectively. The GUSTO criteria classified all 118 suspected bleeding events. There were 22 (18.6%) and 8 (6.8%) suspected bleeding events that did not meet ACUITY and TIMI criteria, respectively. The combined endpoint of all-cause death or myocardial infarction (MI) at 12 months was significantly higher for patients with a bleeding event compared with those who did not bleed [hazard ratio 1.95 (95% CI 1.06-3.60)].

CONCLUSION

There is a substantial variability in the utility and inclusiveness of three widely used bleeding definitions in identifying clinically significant bleeding events in clinical trials of low risk patients undergoing PCI with DES. Patients with bleeding after elective PCI have an increased one-year risk of death or MI compared to those patients who do not bleed.

Drug-eluting stent restenosis: effect of drug type, release kinetics, hemodynamics and coating strategy

Restenosis following stent implantation diminishes the procedure's efficacy influencing long-term clinical outcomes. Stent-based drug delivery emerged a decade ago as an effective means of reducing neointimal hyperplasia by providing localized pharmacotherapy during the acute phase of the stent-induced injury and the ensuing pathobiological mechanisms. However, drug-eluting stent (DES) restenosis may still occur especially when stents are used in complex anatomical and clinical scenarios. A DES consists of an intravascular metallic frame and carriers which allow controlled release of active pharmaceutical agents; all these components are critical in determining drug distribution locally and thus anti-restenotic efficacy. Furthermore, dynamic flow phenomena characterizing the vascular environment, and shear stress distribution, are greatly influenced by stent implantation and play a significant role in drug deposition and bioavailability within local vascular tissue. In this review, we discuss the performance of DES and the interaction of the different DES components with the hemodynamic milieu emphasizing on the inhibition of clinical restenosis.

Risk of target lesion failure in relationship to vessel angiographic geometry and stent conformability using the second generation of drug-eluting stents

BACKGROUND

Vessel angulation and large changes in vessel geometry after stent implantation have been associated with an increased risk of target lesion failure (TLF) using bare-metal stents. Second-generation drug-eluting stents (DES)offer superior conformability and inhibition of neointima. The aim of the study is to investigate the relationship between pre and post-implant vessel geometry and the occurrence of TLF at 1 year after treatment with second-generation DES; and to compare the conformability of Resolute and Xience stents.

METHODS

The RESOLUTE All-Comers trial randomized 2292 patients (3366 lesions) to Resolute zotarolimus-DES (Medtronic CardioVascular) or Xience everolimus-DES (Abbott Vascular). At 1 year, 176 lesions (121 patients)presented with TLF; a composite of cardiac death, acute myocardial infarction (AMI) and target lesion revascularization (TLR). Lesions with TLF were matched with 176 lesions (168 patients) without TLF adjusting for clinical and procedural characteristics. The number of bends, vessel curvature and angulation were assessed with quantitative coronary angiography pre and post-implantation. The absolute difference post minus pre-implantation was used as a surrogate of stent conformability.

RESULTS

At pre-implantation, lesions without and with TLF had similar numbers of bends/lesion (1.81 vs 1.74; P = .35), vessel curvature (0.295 cm(-1) vs 0.363 cm(-1); P = .13) and vessel angulation (46.3° vs 43.5°; P = .80), respectively. Lesions without and with TLR also had similar numbers of bends/lesion (1.39 vs 1.39; P = .83), vessel curvature (0.368 cm(-1) vs 0.325 cm(-1); P = .33) and angulation (40.2° vs 37.2°; P = .19). Lesions without and with in-hospital AMI also presented with similar number of bends/lesion (1.69 vs 1.81; P = .48), vessel curvature (0.349 cm(-1) vs 0.345 cm(-1); P = .91) and vessel angulation (43.53° vs 48.45°; P = .38). The absolute difference post- - pre-implantation was similar in lesions without and with TLF, TLR and In-hospital AMI. The absolute difference post- - pre-implantation was similar with both Resolute and Xience in vessel curvature (-0.046 cm(-1) vs -0.047 cm(-1); P = .66) and was smaller in number of bends/lesion (-0.08 vs -0.16; P = .13) and in vessel angulation (-6.0° vs -10.1°; P = .03) with the Resolute.

CONCLUSIONS

Bended, curved, and angulated lesions and changes in the number of bends/lesion, vessel curvature, and angulation from pre to post-implantation have no relation with TLF and TLR at 1 year and have no relation with In-hospital AMI using second-generation of DES. Resolute appears to be more conformable than Xience.

Outcome of sirolimus-eluting versus zotarolimus-eluting coronary stent implantation in patients with and without diabetes mellitus (a SORT OUT III Substudy)

Diabetes is associated with an increased risk of major adverse cardiac events after percutaneous coronary intervention. We compared clinical outcomes in patients with and without diabetes mellitus treated with the second-generation Endeavor zotarolimus-eluting stent (ZES) or the first-generation Cypher Select+ sirolimus-eluting stent (SES). We randomized 2,332 patients to treatment with ZESs (n = 1,162, n = 169 diabetics) or SESs (n = 1,170, n = 168 diabetics) and followed them for 18 months. Randomization was stratified by presence/absence of diabetes. The primary end point was major adverse cardiac events defined as a composite of cardiac death, myocardial infarction, or target vessel revascularization. Secondary end points included these individual end points plus all-cause mortality and target lesion revascularization. In diabetic patients, use of ZES compared to SES was associated with an increased risk of major adverse cardiac events (18.3% vs 4.8%, hazard ratio 4.05, 95% confidence interval 1.86 to 8.82), myocardial infarction (4.7% vs 0.6%, hazard ratio 8.09, 95% confidence interval 1.01 to 64.7), target vessel revascularization (14.2% vs 3.0%, hazard ratio 4.99, 95% confidence interval 1.90 to 13.1), and target lesion revascularization (12.4% vs 1.2%, hazard ratio 11.0, 95% confidence interval 2.59 to 47.1). In patients without diabetes differences in absolute risk decrease were smaller but similarly favored SES. In conclusion, implantation of ZESs compared to SESs is associated with a considerable increased risk of adverse events in patients with diabetes at 18-month follow-up.

Rationale and design of the MASS COMM trial: A randomized trial to compare percutaneous coronary intervention between MASSachusetts hospitals with cardiac surgery on-site and COMMunity hospitals without cardiac surgery on-site

BACKGROUND

Emergency surgery has become an increasingly rare event after percutaneous coronary intervention (PCI). There have been no randomized trials evaluating whether cardiac surgery services on-site are essential for patient safety and optimal outcomes during and after PCI.

STUDY DESIGN

The MASS COMM trial (ClinicalTrials.gov no. NCT01116882) is a randomized trial comparing the safety and effectiveness of nonemergency PCI at hospitals without surgery on-site (SOS) (non-SOS hospitals) and hospitals with SOS (SOS hospitals). A total of 3,690 subjects will be randomized in a 3:1 fashion to undergo PCI at non-SOS and SOS hospitals, with follow-up at hospital discharge, 30 days, and 12 months after PCI. The rate of major adverse cardiac events (all-cause mortality, myocardial infarction, repeat revascularization, and stroke) will serve as the primary safety end point at 30 days and the primary effectiveness end point at 12 months. The design is a 1-way randomized trial with a statistical hypothesis of noninferiority of nonemergency PCI at non-SOS hospitals for both safety and effectiveness end points.

CONCLUSIONS

This multicenter, randomized trial will compare the relative safety and effectiveness of nonemergency PCI at sites with and without cardiac SOS.

Restenosis after PCI. Part 2: prevention and therapy

The techniques and materials used during percutaneous coronary intervention have advanced considerably over the past 3 decades, yet restenosis remains one of the major drawbacks of this procedure. Many innovative technologies, including drug-eluting stents, with or without specific polymers, and fully biodegradable stents have been and continue to be developed in the search for a safe and effective antirestenosis therapy. Remarkable advances in stent design and nanoparticle delivery systems ('nanovehicles') have already fueled revolutionary changes in the prevention and treatment of in-stent restenosis. In this Review we provide an overview of the latest innovations for optimizing outcomes of coronary stenting, and up-to-date information about prevention and treatment of in-stent restenosis.

Sex differences in neointimal hyperplasia following endeavor zotarolimus-eluting stent implantation

Inconsistent results in outcomes have been observed between the genders after drug-eluting stent implantation. The aim of this study was to investigate gender differences in neointimal proliferation for the Endeavor zotarolimus-eluting stent (ZES) and the Driver bare-metal stent (BMS). A total of 476 (n = 391 ZES, n = 85 BMS) patients whose volumetric intravascular ultrasound analyses were available at 8-month follow-up were studied. At 8 months, neointimal obstruction and maximum cross-sectional narrowing (CSN) were significantly lower in women than in men receiving ZES (neointimal obstruction 15.5 ± 9.5% vs 18.2 ± 10.9%, p = 0.025; maximum CSN 30.3 ± 13.2% vs 34.8 ± 15.0%, p = 0.007). Conversely, these parameters tended to be higher in women than in men receiving BMS (neointimal obstruction 36.3 ± 15.9% vs 27.5 ± 17.2%, p = 0.053; maximum CSN 54.3 ± 18.6% vs 45.6 ± 18.3%, p = 0.080). There was a significant interaction between stent type and gender regarding neointimal obstruction (p = 0.001) and maximum CSN (p = 0.003). Multivariate linear regression analysis revealed that female gender was independently associated with lower neointimal obstruction (p = 0.027) and maximum CSN (p = 0.004) for ZES but not for BMS. Compared to BMS, ZES were independently associated with a reduced risk for binary restenosis in both genders (odds ratio for women 0.003, p = 0.001; odds ratio for men 0.191, p <0.001), but the magnitude of this risk reduction with ZES was significantly greater in women than men (p = 0.015). In conclusion, female gender is independently associated with decreased neointimal hyperplasia in patients treated with ZES. The magnitude of risk reduction for binary restenosis with ZES is significantly greater in women than in men.

Second- and third-generation drug-eluting coronary stents: progress and safety

Drug-eluting stents (DES) have revolutionized the treatment of coronary artery disease by reducing the rate of in-stent restenosis from 20-40% with bare-metal stent (BMS) to 6-8% with DES. However, with widespread use of DES, safety concerns have risen due to the observation of late stent thrombosis. With this in mind and better understanding of mechanism and pathophysiology of stent thrombosis, the technological platform, especially innovative anti-restenotic agents, polymeric coatings, and stent platforms, improved with newer DES. Two second-generation DES, the Endeavor zotarolimus-eluting stent (ZES) and the Xience-V everolimus-eluting stent (EES), have provided promising results in both randomized controlled trials (SPIRIT and ENDEAVOR) and registries (E-Five, COMPARE) compared with bare-metal stents (BMS) and first-generation DES. Newer third-generation stent technology, especially biodegradable polymers, polymer-free stents, and biodegradable stents on the basis of poly-L-lactide (PLLA) or magnesium, has been evaluated in preclinical and initial clinical trials. However, despite encouraging initial results, long-term data of large-scale randomized trials as well as registries comparing them to currently approved first- and second-generation DES are still lacking.

Drug-eluting coronary stents - focus on improved patient outcomes

The development of stent has been a major advance in the treatment of obstructive coronary artery disease since the introduction of balloon angioplasty. Subsequently, neointimal hyperplasia within the stent leading to in-stent restenosis emerged as a major obstacle in long-term success of percutaneous coronary intervention. Recent introduction of drug-eluting stents is a major breakthrough to tackle this problem. This review article summarizes stent technology, reviews progress of drug-eluting stents and discusses quality of life, patient satisfaction, and acceptability of percutaneous coronary intervention.

Current and future drug-eluting coronary stent technology

Despite the impressive benefits obtained following the introduction of the drug-eluting stent, safety concerns have been raised over their long-term safety with particular regard to stent thrombosis. Various mechanisms such as delayed endothelialization, local hypersensitivity and endothelial dysfunction owing to the durable polymer coating and/or the drug itself have been suggested as possible causes of this phenomenon. Therefore, to address these concerns, a newer-generation of drug-eluting stents has been developed and they are currently undergoing preclinical and clinical evaluation in order to increase both the safety and biocompatibility by optimizing the three major components of drug-eluting stents: the stent platform, the polymer and the drug. This article critically reviews the key clinical trials and the current status of these new coronary devices as well as preventing future perspectives for their continued development.

Three-year clinical outcome with the Endeavor™ zotarolimus-eluting stent in primary percutaneous coronary intervention for ST elevation myocardial infarction: the Endeavor™ primary PCI study (E-PPCI)

Primary percutaneous coronary intervention (PPCI) is superior to thrombolysis in STEMI (ST segment elevation myocardial infarction) patients. Data on late stent thrombosis (ST) have raised concerns regarding the use of drug-eluting stents during PPCI. We report the first 3-year clinical evaluation of the zotarolimus-eluting stent (ZES) in patients undergoing PPCI for STEMI, a single-center, prospective cohort study of consecutive patients admitted with STEMI. All underwent PPCI within 12 hours of symptoms; each received one or more ZES in one or more target lesions. All patients received aspirin 300 mg, clopidogrel 600 mg, abciximab, and unfractionated heparin. A total of 102 STEMI patients (76 male, mean 62 years) received 162 ZES (mean 1.6 stents/patient). Median call-to-balloon time was 123 (102-152) minutes. Thirty-day combined major adverse cardiovascular event (MACE) rate was 3.9% (n = 4). Subacute ST occurred in 2 patients (1.96%). Combined MACE rates at 12 months and 3 years were 7.8% (n = 8) and 13.7% (n = 14). Late ST occurred in 1 patient (1%) with no occurrence of very late ST. This is the first 3-year report of the use of the ZES in an unselected, consecutive PPCI population. Overall 3-year incidence of MACE and target lesion revascularization (5.9%) was low, and was comparable to that seen with sirolimus- and paclitaxel-eluting stents in randomized controlled trials. At 3 years there was no occurrence of very late ST.

Long-term effectiveness and safety of sirolimus drug-eluting stents

The root cause of coronary artery disease is atherosclerosis, ie, intraluminal narrowing (stenosis) of the arteries that supply blood to tissues of the heart. The introduction of the drug-eluting stent over the past decade has revolutionized the field of interventional cardiology. It is used extensively in clinical practice for the treatment of coronary artery disease. The first drug-eluting stent to receive US Food and Drug Administration approval was the sirolimus-eluting stent. Recently, two other stent analogs of sirolimus were approved, ie, the zotarolimus-eluting stent and the everolimus-eluting stent. However, concern has arisen in recent years about the long-term safety and efficacy of drug-eluting stents, due to the occurrence of late adverse clinical events, such as stent thrombosis. This review focuses on clinical studies that have been performed with the sirolimus-eluting stent or its analogs. We discuss the pharmacology, safety, and various therapeutic options that exist when choosing stents for coronary artery disease. Our aim is to provide a thorough review of the long-term efficacy and safety of sirolimus drug-eluting stents, and also to discuss currently approved and promising investigational drug-eluting stents, in an effort to provide insight into how these stents are currently evolving and generate further investigation in this area.

Comparison of zotarolimus- versus everolimus-eluting stents in the treatment of coronary bifurcation lesions

OBJECTIVES

To compare zotarolimus-eluting stent (Endeavor Sprint®; ZES-S) and the everolimus-eluting stent (Xience V®; EES) in the treatment of coronary bifurcation lesions.

BACKGROUND

Both these stents have demonstrated good outcomes in the treatment of coronary lesions. However, the outcomes with respect to treatment of bifurcation lesions have yet to be conclusively demonstrated.

METHODS

In this single centered, nonrandomized, open label study, we treated, between August 2006 and December 2008, 110 bifurcations with ZES-S and, in a second stage of the study, 129 bifurcations with EES. The primary end point was to compare the rate of major adverse cardiac events (MACE) (death, myocardial infarction, and new target lesion revascularization) in-hospital and at 12 months of follow-up. Provisional T stenting was the strategy used in the majority of cases. Angiographic follow-up was performed only in patients who presented signs or symptoms suggestive of angina or ischemia.

RESULTS

There were no significant differences in in-hospital MACE between the groups (ZES-S: 8.1%; EES: 6.2%; P = 0.5). At 12 months, the ZES-S group had significantly more MACE than the EES group (23.1% vs. 4.5%; P < 0.001) and an elevated index of new revascularization of the bifurcation (17.5% vs. 3.2%; P < 0.001). There were no significant differences in mortality (four patients in ZES-S vs. one in EES; P = 0.14).

CONCLUSION

The treatment of coronary bifurcation lesions using everolimus-eluting stents results in better outcomes at 12 months of follow-up than zotarolimus-eluting stents.

Drug-eluting stents for coronary artery disease: a review

Over the past decade the introduction of drug-eluting stents (DESs) has revolutionised the treatment of coronary artery disease. However, in recent years concern has arisen over the long-term safety and efficacy of DESs due to the occurrence of late adverse clinical events such as stent thrombosis. With this concern in mind, research and development is currently centred on increasing the long-term safety and efficacy of DESs. The aim of this paper is to provide a thorough review of currently approved and promising investigational DESs. With dozens of companies involved in the development of new and innovative anti-restenotic agents, polymeric coatings and stent platforms, it is intended that this review paper will provide a clear indication of how DESs are currently evolving and prove a valuable reference tool for future research in this area.

Long-term clinical outcomes with zotarolimus-eluting versus bare-metal coronary stents

OBJECTIVES

This study sought to evaluate the long-term safety of the zotarolimus-eluting stent (ZES) using a pooled analysis of pivotal trials.

BACKGROUND

Drug-eluting stents, compared with bare-metal stents (BMS), have reduced restenosis; however, individual trials of these stents have not had sufficient power to ascertain long-term safety.

METHODS

We combined patient level data from 6 prospective randomized single-arm multicenter trials involving 2,132 patients treated with ZES and 596 patients treated with a BMS control. The median follow-up was 4.1 years, with 5-year follow-up completed in 1,256 patients (97% of those eligible). The recommended minimum duration of dual antiplatelet therapy in these studies was 3 to 6 months regardless of stent type. An independent events committee adjudicated all events. The 2 treatment groups were compared after adjustment for between trial variation and for individual patient clinical and angiographic characteristics by propensity score.

RESULTS

The cumulative incidence of adverse events at 5 years for ZES and BMS were: death: 5.9% versus 7.6% (adjusted hazard ratio: 0.81, p = 0.34), cardiac death: 2.4 versus 3.7% (0.83, p = 0.57), myocardial infarction: 3.4 versus 4.8% (0.77, p = 0.37), target lesion revascularization: 7.0% vs. 16.5% (0.42, p < 0.001), stent thrombosis (definite or probable): 0.8 versus 1.7% (0.50, p = 0.21). After adjustment for variation in study and patient characteristics, there were no significant differences in stent thrombosis or the clinical safety event rates at 5 years between ZES and BMS.

CONCLUSIONS

Over 5 years, there was no increased risk of death, myocardial infarction, or stent thrombosis, and there was a benefit of prevention of repeat revascularization procedures in ZES compared with BMS.