Medtronic's Zotarolimus-Eluting Stent Shows Improved Late Clinical Safety in ENDEAVOR IV Trial

October 20, 2010—Martin B. Leon, MD, et al have published 3-year follow-up results from the ENDEAVOR IV trial in the Journal of the American College of Cardiology: Cardiovascular Interventions (2010;3:1043–1050). ENDEAVOR IV is a randomized controlled trial comparing the Endeavor zotarolimus-eluting stent (ZES) (Medtronic, Inc., Minneapolis, MN) and the Taxus paclitaxel-eluting stent (PES) (Boston Scientific Corporation, Natick, MA) in patients with coronary artery disease.

According to the investigators, the study seeks to address concerns of the increased frequency of very late (> 1 year) stent thrombosis (VLST) with regard to the safety of the Endeavor sirolimus-eluting stents and Taxus PES. They stated that experimental and preliminary clinical findings with the ZES have suggested a favorable safety profile.

The ENDEAVOR IV trial is a single-blind randomized ZES versus PES clinical trial composed of 1,548 patients with de novo native coronary lesions. The primary endpoint of 9-month target vessel failure was previously reported. The current report describes the 3-year outcomes, and annual clinical follow-up is planned at 5 years.

The investigators reported that ZES compared with PES reduced target vessel failure (12.3% vs 15.9%; hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.58–1; P = .049), myocardial infarction (MI) (2.1% vs 4.9%; HR, 0.44; 95% CI, 0.25–0.8; P = .005), and cardiac death plus MI (3.6% vs 7.1%; HR, 0.52; 95% CI, 0.32–0.82; P = .004). Although the overall 3-year rate of Academic Research Consortium definite/probable stent thrombosis did not differ significantly (1.1% vs 1.7%; HR, 0.67; 95% CI, 0.28–1.64; P = .38), VLST (between 1 and 3 years) was significantly reduced in patients with a ZES compared to a PES (1 event vs 11 events; 0.1% vs 1.6%; HR, 0.09; 95% CI, 0.01–0.71; P = .004). Ischemia-driven target lesion revascularization at 3 years was similar with ZES and PES (6.5% vs 6.1%; HR, 1.1; 95% CI, 0.73–1.65; P = .662).

The investigators concluded that 3-year follow-up results from the ENDEAVOR IV trial indicate similar antirestenosis efficacy but improved clinical safety associated with ZES compared with PES due to significantly fewer periprocedural and remote MIs that were associated with fewer VLST events.