Long-term clinical outcomes with zotarolimus-eluting versus bare-metal coronary stents.

OBJECTIVES: This study sought to evaluate the long-term safety of the zotarolimus-eluting stent (ZES) using a pooled analysis of pivotal trials. BACKGROUND: Drug-eluting stents, compared with bare-metal stents (BMS), have reduced restenosis; however, individual trials of these stents have not had sufficient power to ascertain long-term safety. METHODS: We combined patient level data from 6 prospective randomized single-arm multicenter trials involving 2,132 patients treated with ZES and 596 patients treated with a BMS control. The median follow-up was 4.1 years, with 5-year follow-up completed in 1,256 patients (97% of those eligible). The recommended minimum duration of dual antiplatelet therapy in these studies was 3 to 6 months regardless of stent type. An independent events committee adjudicated all events. The 2 treatment groups were compared after adjustment for between trial variation and for individual patient clinical and angiographic characteristics by propensity score. RESULTS: The cumulative incidence of adverse events at 5 years for ZES and BMS were: death: 5.9% versus 7.6% (adjusted hazard ratio: 0.81, p = 0.34), cardiac death: 2.4 versus 3.7% (0.83, p = 0.57), myocardial infarction: 3.4 versus 4.8% (0.77, p = 0.37), target lesion revascularization: 7.0% vs. 16.5% (0.42, p < 0.001), stent thrombosis (definite or probable): 0.8 versus 1.7% (0.50, p = 0.21). After adjustment for variation in study and patient characteristics, there were no significant differences in stent thrombosis or the clinical safety event rates at 5 years between ZES and BMS. CONCLUSIONS: Over 5 years, there was no increased risk of death, myocardial infarction, or stent thrombosis, and there was a benefit of prevention of repeat revascularization procedures in ZES compared with BMS.