1-Year Clinical Outcomes of All Comers Treated With 2 Bioresorbable Polymer-Coated Sirolimus-Eluting Stents: Propensity Score–Matched Comparison of the COMBO and Ultrathin-Strut Orsiro Stents

Objectives: The aim of this study was to determine 1-year safety and efficacy after treatment with the COMBO and Orsiro stents. Background: The COMBO stainless-steel stent has an anti-CD34⁺ antibody coating to capture endothelial progenitor cells, thereby promoting faster endothelialization. The Orsiro is an ultrathin-strut cobalt-chromium stent, covered by an extremely thin layer of amorphous silicon carbide to minimize ion leakage. Both devices elute sirolimus from biodegradable polymers. Methods: For this analysis we included European patients from the COMBO collaboration, a patient-level pooling of 2 prospective all-comers registries of COMBO stent implantation (n = 2,775), and all patients randomized to the Orsiro stent (n = 1,169) from the Dutch BIO-RESORT (Comparison of Biodegradable Polymer and Durable Polymer Drug-Eluting Stents in an All Comers Population) randomized trial. The main outcome of interest was 1-year target lesion failure, a composite of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization evaluated using propensity score–matched analysis. Results: At baseline, COMBO patients were older and had more insulin-treated diabetes, renal insufficiency, and other comorbidities. However, Orsiro patients included more current smokers and more acute coronary syndrome presentations. Orsiro patients also received longer stents and had more complex target lesions. After propensity score–matched analysis (n = 862/arm), 1-year target lesion failure occurred in 4.1% of COMBO-treated and 2.7% of Orsiro-treated patients (hazard ratio: 1.55; 95% confidence interval: 0.92 to 2.62; p = 0.10). Definite stent thrombosis occurred in 0.5% of COMBO-treated and 0.5% of Orsiro-treated patients (p = 0.99). Conclusions: A propensity score–matched comparison of all comers treated with the COMBO or Orsiro stent showed no statistically significant differences. Stent thrombosis risk was low and similar between the stents.