Safety and efficacy of the next generation Resolute Onyx zotarolimus-eluting stent: Primary outcome of the RESOLUTE ONYX core trial

Objectives: To assess the safety and efficacy of the novel Resolute (R-) Onyx drug-eluting stent (DES). Background: The R-Onyx DES consists of a composite wire with an outer shell of cobalt chromium alloy and a platinum-iridium inner core to enhance radiopacity, with thinner, swaged struts and modified stent geometry compared with the predicate Resolute DES, resulting in a slightly lower total drug load in most sizes. Methods: This was a prospective, single-arm non-inferiority trial compared with a historical control. Patients with stable angina/ischemia and up to 2 de novo target lesions ≤35 mm long with reference vessel diameter (RVD) of 2.25–4.2 mm were enrolled. The primary endpoint was late lumen loss at 8-month follow-up. Propensity-score adjusted outcomes from the single-arm RESOLUTE-US trial served as the control. Results: Seventy-five patients (85 lesions) were enrolled. Mean patient age was 66 ± 9 years, 73% were male, and 32% had diabetes. Mean lesion length was 14.28 ± 6.68 mm, mean RVD was 2.57 ± 0.48 mm, and 86% of lesions were class B2/C. In-stent late lumen loss at 8 months was 0.24 ± 0.39 mm with R-Onyx DES compared with 0.36 ± 0.52 mm with Resolute DES (P < 0.001 for noninferiority, P = 0.029 for superiority). At 8 months, clinically driven target lesion revascularization occurred in 3 patients (4.0%) and target lesion failure occurred in 5 patients (6.7%). Conclusions: In-stent late lumen loss is non-inferior, and appears to be superior, with the thin-strut novel composite wire R-Onyx DES compared with Resolute DES. Continued evolution of stent design can improve angiographic outcomes in complex lesions, even in the current era of next-generation DES.