Impact of the Everolimus-Eluting Stent on Stent Thrombosis: A Meta-Analysis of 13 Randomized Trials

Study Questions:

What is the impact of the everolimus-eluting stent (EES) on the frequency of stent thrombosis (ST), target vessel revascularization (TVR), myocardial infarction (MI), and cardiac death in randomized controlled trials comparing the EES to non–everolimus-eluting drug-eluting stents (EE-DES)?


The investigators searched MEDLINE, Scopus, the Cochrane Library, and Internet sources for articles comparing outcomes between EES and non–EE-DES without language or date restriction. Randomized controlled trials reporting the frequency of ST were included. Variables relating to patient and study characteristics and clinical endpoints were extracted. The average effects for the outcomes and 95% confidence intervals (CI) were obtained using a random effects model, as described by DerSimonian and Laird.


The investigators identified 13 randomized trials (n = 17,101) with a weighted mean follow-up of 21.7 months. Compared with non–EE-DES, the EES significantly reduced ST (relative risk [RR], 0.55; 95% confidence interval [CI], 0.38-0.78; p = 0.001), TVR (RR, 0.77; 95% CI, 0.64-0.92; p = 0.004), and MI (RR, 0.78; 95% CI, 0.64-0.96; p = 0.02). There was no difference in cardiac mortality between the groups (RR, 0.92; 95% CI, 0.74-1.16; p = 0.38). The treatment effect was consistent by different follow-up times and duration of clopidogrel use. The treatment effects increased with higher baseline risks of the respective control groups, with the strongest correlation observed for ST (R2 = 0.89, p < 0.001).


The authors concluded that intracoronary implantation of the EES is associated with highly significant reductions in ST with concordant reductions in TVR and MI compared to non–EE-DES.


This meta-analysis, comprising 13 randomized trials and including ~17,000 patients and 184 stent thrombosis (ST) events, suggests that EES is associated with a large and significant reduction in the frequency of Academic Research Consortium (ARC) definite or probable ST compared to other non-EES. There were also analogous reductions in both MI and TVR with the EES, but no differences in cardiac mortality between groups. Longer follow-up studies will provide additional insight on the durability of these results and applicability to other patient populations. For now, EES appears to be the preferred DES platform for patients undergoing PCI.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Stable Ischemic Heart Disease, Chronic Angina

Keywords: Risk, Myocardial Infarction, Follow-Up Studies, Coronary Restenosis, Thrombosis, Drug-Eluting Stents, Ticlopidine, Confidence Intervals, Sirolimus, Angioplasty, MEDLINE

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