Clinical Experiences Using Everolimus-Eluting Stents in Patients with Coronary Artery Disease

Drug-eluting stents versus bare-metal stents for acute coronary syndrome

BACKGROUND

Approximately 3.7 million people died from acute coronary syndrome worldwide in 2012. Acute coronary syndrome, also known as myocardial infarction or unstable angina pectoris, is caused by a sudden blockage of the blood supplied to the heart muscle. Percutaneous coronary intervention is often used for acute coronary syndrome, but previous systematic reviews on the effects of drug-eluting stents compared with bare-metal stents have shown conflicting results with regard to myocardial infarction; have not fully taken account of the risk of random and systematic errors; and have not included all relevant randomised clinical trials.

OBJECTIVES

To assess the benefits and harms of drug-eluting stents versus bare-metal stents in people with acute coronary syndrome.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, SCI-EXPANDED, and BIOSIS from their inception to January 2017. We also searched two clinical trials registers, the European Medicines Agency and the US Food and Drug Administration databases, and pharmaceutical company websites. In addition, we searched the reference lists of review articles and relevant trials.

SELECTION CRITERIA

Randomised clinical trials assessing the effects of drug-eluting stents versus bare-metal stents for acute coronary syndrome. We included trials irrespective of publication type, status, date, or language.

DATA COLLECTION AND ANALYSIS

We followed our published protocol and the methodological recommendations of Cochrane. Two review authors independently extracted data. We assessed the risks of systematic error by bias domains. We conducted Trial Sequential Analyses to control the risks of random errors. Our primary outcomes were all-cause mortality, major cardiovascular events, serious adverse events, and quality of life. Our secondary outcomes were angina, cardiovascular mortality, and myocardial infarction. Our primary assessment time point was at maximum follow-up. We assessed the quality of the evidence by the GRADE approach.

MAIN RESULTS

We included 25 trials randomising a total of 12,503 participants. All trials were at high risk of bias, and the quality of evidence according to GRADE was low to very low. We included 22 trials where the participants presented with ST-elevation myocardial infarction, 1 trial where participants presented with non-ST-elevation myocardial infarction, and 2 trials where participants presented with a mix of acute coronary syndromes.Meta-analyses at maximum follow-up showed no evidence of a difference when comparing drug-eluting stents with bare-metal stents on the risk of all-cause mortality or major cardiovascular events. The absolute risk of death was 6.97% in the drug-eluting stents group compared with 7.74% in the bare-metal stents group based on the risk ratio (RR) of 0.90 (95% confidence interval (CI) 0.78 to 1.03, 11,250 participants, 21 trials/22 comparisons, low-quality evidence). The absolute risk of a major cardiovascular event was 6.36% in the drug-eluting stents group compared with 6.63% in the bare-metal stents group based on the RR of 0.96 (95% CI 0.83 to 1.11, 10,939 participants, 19 trials/20 comparisons, very low-quality evidence). The results of Trial Sequential Analysis showed that we did not have sufficient information to confirm or reject our anticipated risk ratio reduction of 10% on either all-cause mortality or major cardiovascular events at maximum follow-up.Meta-analyses at maximum follow-up showed evidence of a benefit when comparing drug-eluting stents with bare-metal stents on the risk of a serious adverse event. The absolute risk of a serious adverse event was 18.04% in the drug-eluting stents group compared with 23.01% in the bare-metal stents group based on the RR of 0.80 (95% CI 0.74 to 0.86, 11,724 participants, 22 trials/23 comparisons, low-quality evidence), and Trial Sequential Analysis confirmed this result. When assessing each specific type of adverse event included in the serious adverse event outcome separately, the majority of the events were target vessel revascularisation. When target vessel revascularisation was analysed separately, meta-analysis showed evidence of a benefit of drug-eluting stents, and Trial Sequential Analysis confirmed this result.Meta-analyses at maximum follow-up showed no evidence of a difference when comparing drug-eluting stents with bare-metal stents on the risk of cardiovascular mortality (RR 0.91, 95% CI 0.76 to 1.09, 9248 participants, 14 trials/15 comparisons, very low-quality evidence) or myocardial infarction (RR 0.98, 95% CI 0.82 to 1.18, 10,217 participants, 18 trials/19 comparisons, very low-quality evidence). The results of the Trial Sequential Analysis showed that we had insufficient information to confirm or reject our anticipated risk ratio reduction of 10% on cardiovascular mortality and myocardial infarction.No trials reported results on quality of life or angina.

AUTHORS' CONCLUSIONS

The current evidence suggests that drug-eluting stents may lead to fewer serious adverse events compared with bare-metal stents without increasing the risk of all-cause mortality or major cardiovascular events. However, our Trial Sequential Analysis showed that there currently was not enough information to assess a risk ratio reduction of 10% for all-cause mortality, major cardiovascular events, cardiovascular mortality, or myocardial infarction, and there were no data on quality of life or angina. The evidence in this review was of low to very low quality, and the true result may depart substantially from the results presented in this review.More randomised clinical trials with low risk of bias and low risks of random errors are needed if the benefits and harms of drug-eluting stents for acute coronary syndrome are to be assessed properly. More data are needed on the outcomes all-cause mortality, major cardiovascular events, quality of life, and angina to reduce the risk of random error.

WITHDRAWN: Drug-eluting stents versus bare metal stents for angina or acute coronary syndromes

This review 'topic' has been included in work being carried out as part of a Health Technology Assessment commissioned by the National Institute for Clinical Excellence in England and Wales. Details of this research is available via www.nice.org.uk.

The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the HTA programme, NICE, NIHR, NHS or the Department of Health.

The review has been split into 2 reviews that will be published as "Drug‐eluting stents versus bare‐metal stents for stable ischaemic heart disease" and "Drug‐eluting stents versus bare‐metal stents for acute coronary syndrome".

The editorial group responsible for this previously published document have withdrawn it from publication.

Endovascular versus medical therapy for atherosclerotic renovascular disease

The diagnosis of renal artery stenosis (RAS) has become increasingly common in part due to greater awareness of ischemic renal disease and increased use of diagnostic techniques. Over 90 % of RAS cases are caused by atherosclerotic renovascular disease (ARVD). Patients with ARVD are at high risk for fatal and nonfatal cardiovascular and renal events. The mortality rate in patients with ARVD is high, especially with other cardiovascular or renal comorbidities. Recent clinical studies have provided substantial evidence concerning medical therapy and endovascular interventional therapeutic approaches for ARVD. Despite previous randomized clinical trials, the optimal therapy for ARVD remained uncertain until the results of the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial were released recently. CORAL demonstrated that optimal medical therapy was equally effective to endovascular therapy in the treatment of ARVD. Clinicians can now practice with more evidence-based medicine to treat ARVD and potentially decrease mortality in patients with ARVD using optimal medical therapy.

Update on drug-eluting coronary stents

The introduction of drug-eluting stents (DES) to interventional cardiology practice has resulted in a significant improvement in the long-term efficacy of percutaneous coronary interventions. DES successfully combine mechanical benefits of bare-metal stents and stabilizing the lumen, with direct delivery and the controlled elution of a pharmacologic agent to the injured vessel wall to suppress further neointimal proliferation. The dramatic reduction in restenosis has resulted in the implementation of DES in clinical practice, and has rapidly expanded the whole spectrum of successfully treatable coronary conditions, particularly in high-risk patients and complex lesions. In this review the authors present current data on DES. Currently, two types of DES are available in the USA: sirolimus-eluting stents (SES) CYPHER (Cordis Corp., FL, USA) and paclitaxel-eluting stents (PES) TAXUS (Boston Scientific, MA, USA), and many more are on the way to approval. In addition to sirolimus and paclitaxel, several other drugs have been successfully used in DES. Everolimus and ABT-578 are both analogs of sirolimus that also have immunosuppressive and antiproliferative properties. Another approach in the development of DES is to use drugs that can accelerate re-endothelialization and restore normal endothelial function following vascular injury. Recent advances in vascular gene transfer have also demonstrated potential new treatment modalities for cardiovascular disease, particularly in the treatment of vascular restenosis.

XIENCE V everolimus-eluting coronary stent system: a novel second generation drug-eluting stent

Drug-eluting stents (DES) have been shown to be safe and significantly reduce clinical events and angiographic restenosis in the percutaneous treatment of coronary artery disease. Currently, three DES have been approved in Europe and Northern America: the sirolimus-eluting stent (SES), the paclitaxel-eluting stent (PES) and the zotarolimus-eluting stent (ZES). Everolimus, an analog of sirolimus, is an immunosuppressive and antiproliferative agent. In three studies, the SPIRIT I, FUTURE I and II, the everolimus-eluting stent has proven to be safe, well-tolerated and has shown very favorable clinical and angiographic results. Compared with earlier-generation DES, the XIENCE V everolimus-eluting coronary stent system (Advanced Cardiovascular Systems Inc., an Abbott Vascular Company, CA, USA) may provide enhanced deliverability, radiopacity with thinner strut filaments and, owing to a durable polymer, sustained drug elution and vascular compatibility.

Drug-eluting stents versus bare metal stents for angina or acute coronary syndromes

BACKGROUND

Coronary artery stents are tiny tubular devices used to 'scaffold' vessels open during percutaneous transluminal coronary angioplasty (PTCA). Restenosis (re-narrowing) of vessels treated with stents is a problem; in order to reduce restenosis, stents that elute drugs over time are now available. However these drug-eluting stents are more expensive and there is a need to assess their clinical benefits prior to recommending their use.

OBJECTIVES

To examine evidence from randomised controlled trials (RCTs) to assess the impact of drug eluting stents (DES) compared to bare metal stents (BMS) in the reduction of cardiac events.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 4), MEDLINE (1990 - April 2009) and EMBASE (1980 - January 2009) were searched. We carried out handsearching (electronic and manual) up to January 2008.

SELECTION CRITERIA

We included RCTs comparing DES with BMS used in conjunction with PTCA techniques in the review. Participants were adults with stable angina or acute coronary syndrome (ACS). We considered published and unpublished sources and included them if they reported outcome data of interest.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, assessed trial quality assessment and checked decisions within the group. Data extraction included composite event rates (major adverse cardiac event, target vessel failure); death; acute myocardial infarction (AMI); target lesion revascularisation (TLR); target vessel revascularisation (TVR) and thrombosis. Data synthesis included meta-analysis of composite event rate, death, AMI and revascularisation rates, presented as odds ratios with 95% confidence intervals (CI) using a fixed-effect model. We assessed heterogeneity between trials.

MAIN RESULTS

We included more than 14,500 patients in 47 RCTs. There were no statistically significant differences in death, AMI or thrombosis between DES and BMS. For composite events, TLR and TVR reductions were evident with use of sirolimus, paclitaxel, everolimus, dexamethasone, zotarolimus and (to a limited extent) tacrolimus-eluting stents. These effects are demonstrated in the longer term follow up. Subgroup analyses (e.g. diabetics) largely mirrored these findings.

AUTHORS' CONCLUSIONS

Drug-eluting stents releasing sirolimus, paclitaxel, dexamethasone and zotarolimus reduce composite cardiac events. However, this reduction is due largely to reductions in repeat revascularisation rates as there is no evidence of a significant effect on rates of death, MI or thrombosis. The increased cost of drug-eluting stents and lack of evidence of their cost-effectiveness means that various health funding agencies are having to limit or regulate their use in relation to price premium.

Review of randomized clinical trials of drug-eluting stents for the prevention of in-stent restenosis

Drug-eluting stents (DESs) have shown significant promise at reducing rates of restenosis and subsequent revascularization compared with bare metal stents (BMSs). The purpose of this report is to provide a systematic review of the randomized clinical trials that have evaluated the efficacy and safety of DESs. A total of 28 randomized clinical trials were identified: 21 comparing a DES (sirolimus, paclitaxel, ABT-578, actinomycin, everolimus, or 7-hexanoyltaxol) with a BMS and 7 comparing a DES with another DES (sirolimus vs paclitaxel). Early sirolimus and polymeric paclitaxel studies in low-risk populations demonstrated marked reductions in restenosis according to angiographic and clinical parameters, compared with BMSs. These promising findings led to the more recent evaluations of DESs in higher risk patients in controlled and head-to-head comparisons. In these subsequent trials, sirolimus and paclitaxel DESs continued to exceed the therapeutic potential of BMSs, with a slight but consistent angiographic advantage being observed with the sirolimus DESs.

Drug-Eluting Stents in the Treatment of Intermediate Lesions

OBJECTIVES

To address the safety and efficacy of drug-eluting stents (DES) in the treatment of intermediate lesions, we performed a pooled analysis of four randomized DES versus bare-metal stent (BMS) trials and assessed outcomes among patients with intermediate lesions.

BACKGROUND

Before the introduction of DES, intermediate coronary lesions were commonly managed based on physiologic or anatomic assessment of lesion severity. The DES may challenge this paradigm.

METHODS

The study population involved 167 of 2,478 randomized patients (6.7%) with intermediate lesions (diameter stenosis <50% [mean 44%] by quantitative coronary angiography) from the Sirolimus-coated Bx Velocity Balloon Expandable Stent in the Treatment of Patients with De Novo Coronary Artery Lesions (SIRIUS), TAXUS-IV, and the First and Second First Use to Underscore Restenosis Reduction with Everolimus (FUTURE-I and -II) trials. End points examined included early (in-hospital and 30-day) and late (1-year) major adverse cardiac events (MACE), including cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis, and follow-up angiographic restenosis.

RESULTS

Patients with intermediate lesions randomized to DES versus BMS had low rates of 30-day MACE (1.1% vs. 4.0% respectively; p = 0.22). At one-year follow-up, patients treated with DES versus BMS had similar rates of cardiac death (0% vs. 2.7%, respectively; p = 0.11) and MI (3.4% vs. 5.4%; p = 0.49) but markedly lower rates of TVR (3.4% vs. 20.3%; p = 0.0004), MACE (5.6% vs. 25.4%; p = 0.0003), and binary angiographic restenosis (1.8% vs. 34.0%; p < 0.0001). No patient in either group developed stent thrombosis.

CONCLUSIONS

Compared with BMS, treatment of intermediate lesions with DES appears safe and results in a marked reduction in clinical and angiographic restenosis. The efficacy of DES may require a reevaluation of current treatment paradigms for intermediate lesions.