Polymer-Based Versus Polymer-Free Stents in High Bleeding Risk Patients: Final 2-Year Results From Onyx ONE

Background: Resolute Onyx polymer-based zotarolimus-eluting stents (ZES) were noninferior in safety and effectiveness to BioFreedom polymer-free biolimus A9-coated stents (DCS) in high-bleeding-risk (HBR) patients treated with 1-month dual antiplatelet therapy (DAPT) followed by single antiplatelet therapy (SAPT) at 1 year. Objectives: This study reports the final 2-year results of the randomized Onyx ONE trial. Methods: The Onyx ONE (A Randomized Controlled Trial With Resolute Onyx in One Month Dual Antiplatelet Therapy (DAPT) for High-Bleeding Risk Patients) trial randomly assigned HBR patients to treatment with ZES or DCS. Following 1-month DAPT, event-free patients received SAPT (either aspirin or a P2Y₁₂ inhibitor at physician discretion). The primary safety endpoint, a composite of cardiac death, myocardial infarction, or stent thrombosis at 1 year, was determined at 1 year. Rates of primary and secondary endpoints were calculated after final follow-up at 2 years. Results: A total of 1,003 patients were randomly allocated to ZES and 993 patients to DCS. Follow-up was complete in 980 (97.7%) ZES patients and 962 (96.9%) DCS patients at 2 years. The primary safety endpoint occurred in 208 (21.2%) patients in the ZES group and 199 (20.7%) patients in the DCS group (risk difference: 0.5%; 95% CI: −3.1% to 4.2%; P = 0.78) at 2 years without significant differences in individual components of the composite endpoint. The secondary effectiveness endpoint occurred in 217 (22.1%) patients in the ZES group and 202 (21.0%) patients in the DCS group (risk difference: 1.1%; 95% CI: −2.5% to 4.8%; P = 0.54). Conclusions: Among patients at HBR treated with 1-month DAPT followed by SAPT, the Resolute Onyx polymer-based ZES had similar 2-year outcomes for the primary safety and secondary effectiveness endpoint compared with the BioFreedom polymer-free DCS.