Late-term clinical outcomes with zotarolimus- and sirolimus-eluting stents. 5-year follow-up of the ENDEAVOR III (A Randomized Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Cypher Sirolimus-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions).

OBJECTIVES

This study sought to compare late safety and efficacy outcomes following percutaneous coronary revascularization with zotarolimus-eluting stents (ZES) and sirolimus-eluting stents (SES).

BACKGROUND

Despite higher late lumen loss and binary restenosis with ZES compared with SES, it is uncertain whether differences in early angiographic measures translate into more disparate late clinical events.

METHODS

Clinical outcomes were prospectively evaluated through 5 years in the ENDEAVOR III (A Randomized Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Cypher Sirolimus-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions) that randomized 436 patients of relatively low anatomic and clinical risk to treatment with ZES (n = 323) or SES (n = 113) and evaluated a primary endpoint of 8-month angiographic late lumen loss.

RESULTS

At 5 years (completeness of follow-up: 95.2%), pre-specified endpoints of all-cause mortality (5.2% vs. 13.0%, p = 0.02), myocardial infarction (1.0% vs. 4.6%, p = 0.03), and the composite event rates of cardiac death/myocardial infarction (1.3% vs. 6.5%, p = 0.009) and major adverse cardiac events (14.0% vs. 22.2%, p = 0.05) were significantly lower among patients treated with ZES. Rates of target lesion (8.1% ZES vs. 6.5% SES, p = 0.68) and target vessel revascularization were similar between treatment groups. Stent thrombosis was infrequent and similar in both groups (0.7% ZES vs. 0.9% SES, p = 1.0). Between 9 months and 5 years, progression of major adverse cardiac events was significantly more common with SES than with ZES (16.7% vs. 7.8%, p = 0.015).

CONCLUSIONS

Despite initially higher angiographic late lumen loss, rates of clinical restenosis beyond the protocol-specified angiographic follow-up period remain stable with ZES compared with the rates for SES, resulting in similar late-term efficacy. Over 5 years, significant differences in death, myocardial infarction, and composite endpoints favored treatment with ZES. (The Medtronic Endeavor III Drug Eluting Coronary Stent System Clinical Trial [ENDEAVOR III]; NCT00217256).