Comparison of vascular response to zotarolimus-eluting stent versus sirolimus-eluting stent: Intravascular ultrasound results from ENDEAVOR III

BackgroundThe purpose of this study was to investigate the vascular response of zotarolimus-eluting stent (ZES) and sirolimus-eluting stent (SES) using serial intravascular ultrasound (IVUS).MethodsData were obtained from the Endeavor Drug-Eluting Coronary Stent System Versus the Center Siromlimus-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions (ENDEAVOR) III trial, a randomized study comparing ZES and SES for the treatment of de novo native coronary artery lesions. Serial (baseline and 8-month follow-up) IVUS was available in 258 patients (190 ZES, 68 SES).ResultsAt 8 months, ZES had greater percentage of neointimal volume index (ZES 1.1 ± 0.8 mm3/mm vs SES 0.2 ± 0.1 mm3/mm, P < .01), resulting in smaller lumen volume index (6.0 ± 2.0 mm3/mm vs 7.0 ± 2.1 mm3/mm, P < .05). Zotarolimus-eluting stents showed larger IVUS-detectable neointimal coverage over stent surface (50.2% vs 10.5%, P < .01) and greater mean neointimal thickness (0.19 ± 0.07 mm vs 0.10 ± 0.06 mm, P < .01). Zotarolimus-eluting stents had a significantly lower incidence of late-acquired incomplete stent apposition.ConclusionsZotarolimus-eluting stent is associated with a significantly greater amount of neointimal hyperplasia compared with SES. This amount of hyperplasia in ZES is distributed throughout the stent at 8-month follow-up.