Drug-Eluting Stents for Acute Coronary Syndrome: A Meta-Analysis of Randomized Controlled Trials

Background: Drug-eluting stents (DES) are increasingly used for treatment of acute coronary syndrome (ACS). However, clinical efficacy and safety of various types of DES is not well established in these subjects. We therefore evaluated clinical utility of second-generation and first-generation DES in patients with ACS by conducting a meta-analysis. Methods: A search of Medline, Embase, the Cochrane databases, and Web of Science was made. Randomized controlled trials (RCTs) which compared second-generation DES (everolimus-eluting stents [EES] or zotarolimus-eluting stents [ZES]) versus first-generation DES (sirolimus-eluting stents [SES] or paclitaxe-eluting stents [PES]) in patients with ACS and provided data on clinical efficacy or safety endpoints were included. Pooled estimates were calculated using random-effects model. Result: A total of 2,757 participants with ACS in 6 RCTs were included. Compared with first-generation one, second-generation DES trended to be associated with the decreased incidence of definite or probable stent thrombosis in ACS patients (risk ratio [RR] = 0.60, 95% confidence intervals [CI] 0.33 to 1.07, p = 0.09). However, the rate of target lesion revascularization (TLR) significantly increased in second-generation DES (RR = 2.08, 95%CI 1.25 to 3.47, p = 0.005). There were no significant differences in the incidence of major adverse cardiac events (MACEs), all-cause death, cardiac death, and recurrent myocardial infarction between the two arms (all p>0.10). The second-generation EES showed a tendency towards lower risk of MACEs (p = 0.06) and a beneficial effect on reducing stent thrombosis episodes (p = 0.009), while the second-generation ZES presented an increased occurrence of MACEs (p = 0.02) and TLR (p = 0.003). Conclusion: Second-generation DES, especially EES, appeared to present a lower risk of stent thrombosis, whereas second-generation ZES might increase the need for repeat revascularization in ACS patients. During coronary interventional therapy, DES class should be adequately considered in order to maximize clinical benefit of DES implantation in these specific subjects.