- Objectives The aim of this study was to compare outcomes among unselected patients undergoing percutaneous coronary intervention (PCI) with either sirolimus-eluting (SES) or paclitaxel-eluting stents (PES). Background Although the benefits of both SES and PES are well-established, studies comparing these stents directly have yielded conflicting results. Methods We used data from the EVENT (Evaluation of Drug Eluting Stents and Ischemic Events) registry to compare in-hospital and 1-year outcomes among unselected patients undergoing nonemergent PCI with either SES or PES implantation. Results Between July 2004 and June 2006, 6,035 patients underwent PCI with either SES (n = 3,443) or PES (n = 2,592) at 47 U.S. centers. Baseline clinical and angiographic characteristics were generally similar for the 2 stent types. At 1-year, there were no differences in the primary end point of cardiac death or myocardial infarction (MI) between the SES and PES groups (9.1% vs. 10.0%, p = 0.11) or in any individual end points including cardiac death, nonfatal MI, or stent thrombosis. In unadjusted analyses, target lesion revascularization (TLR) was slightly more common with SES than with PES (4.4% vs. 3.3%, p = 0.048), but this difference was no longer apparent after adjusting for baseline characteristics as well as site-related factors (adjusted hazard ratio: 1.09, 95% confidence interval: 0.78 to 1.50). Conclusions Among unselected patients undergoing PCI, adjusted rates of both ischemic complications as well as clinically important restenosis were similar for SES and PES. The unexpected finding that TLR was influenced by site characteristics suggests that the correlation between TLR and angiographic restenosis might be weaker than previously described and warrants further study.