Introduction: First generation drug-eluting stents for percutaneous coronary interventions have been associated with an increased risk of stent thrombosis (ST), as compared with bare metal stents (BMS), in particular beyond 1 year after stent implantation.
Aim: The aim of this study was to compare second generation cobalt-chromium everolimus eluting stents (CoCr-EES) with BMS with respect to the timing and risks of ST.
Methods: The study is an individual patient level meta-analysis of five randomized trials including a total of 4,896 patients, allocated to CoCr-EES (n=2452) or BMS (n=2444). Endpoints were definite and definite/probable ST, and classified according to the timing from the index procedure as early (within 30 days), late (from 31 to 365 day), and very late (> 1 year). Subhazard ratios (SHR) with 95% confidence intervals (CI) were calculated considering all-cause mortality as the competing event
Results: Compared with BMS, CoCr-EES use was associated with significant reductions in the incidence of early ST (definite ST: SHR 0.28, 95% CI 0.17- 0.48, p<0.001; definite/probable ST: SHR 0.43, 95% CI 0.33-0.55, p<0.001), and late ST (definite ST: SHR 0.33, 95% CI 0.15-0.72, p=0.005; definite/probable ST: SHR 0.39, 95% CI 0.36-0.43, p<0.001). The incidence of very late ST was not significantly different in the CoCr-EES and BMS groups (definite ST: SHR 1.63, 95% CI 0.77-3.44, p=0.19; definite/probable ST: SHR 0.88, 95% CI, 0.44-1.76, p=0.72).
Conclusions: Compared with BMS, CoCr-EES reduce the risk of early and late thrombotic events and show a similar safety profile beyond 1 year after stent implantation.