Three-Year Outcome of Sirolimus-Eluting Versus Bare-Metal Stents for the Treatment of ST-Segment Elevation Myocardial Infarction (from the MISSION! Intervention Study)

Abstract

To compare the long-term efficacy and safety of sirolimus-eluting stents (SES) to those of bare-metal stents (BMS) for ST-segment elevation myocardial infarction, outcomes were assessed in 310 patients (mean age age 59 +/- 11 years, 78% men) included in the randomized MISSION! Intervention Study: A Prospective Randomised Controlled Trial to Evaluate the Efficacy of Drug-Eluting Stents Versus Bare-Metal Stents for the Treatment of Acute Myocardial Infarction after a median follow-up period of 38 months. All patients were treated with aspirin (lifelong) and clopidogrel for 1 year after stent implantation. Except for a significant difference between reference vessel diameters (SES 2.76 mm vs BMS 2.92 mm, p = 0.02), there were no significant differences in baseline and angiographic characteristics between the treatment groups (158 SES, 152 BMS). A significant difference between SES and BMS patients for all revascularization end points was found after the first year of follow-up. However, at 3 years of follow-up, although there was still a trend toward better clinical outcomes in SES-treated patients, differences were no longer significant (death 4.4% vs 6.6%, p = 0.41; target vessel-related myocardial infarction 2.5% vs 4.6%, p = 0.32; target vessel revascularization 8.9% vs 15.8%, p = 0.06), target lesion revascularization 6.3% vs 12.5%, p = 0.06; and target vessel failure 12.0% vs 19.7%, p = 0.06). Three cases of very late (definite) stent thrombosis were observed in the SES group (1.9%) versus none in the BMS group (p = 0.14). In conclusion, the significant SES benefit (compared to BMS) in patients with ST-segment elevation myocardial infarctions at 1-year follow-up in terms of target vessel revascularizations decreased to some extent because of more similar target vessel revascularization rates during the 2 subsequent years. Rates of death and nonfatal recurrent MI remained comparable.