Comparison of the polymer-free biolimus-coated BioFreedom stent with the thin-strut biodegradable polymer sirolimus-eluting Orsiro stent in an all-comers population treated with percutaneous coronary intervention: Rationale and design of the randomized SORT OUT IX trial

Background In patients with increased bleeding risk during dual antiplatelet therapy, the biolimus A9-coated BioFreedom, a stainless steel drug-coated stent devoid of polymer, has shown superiority compared to a bare-metal stent. The aim of this study was to investigate whether the polymer-free biolimus A9-coated BioFreedom is noninferior to a modern thin-strut biodegradable polymer cobalt-chromium sirolimus-eluting Orsiro stent in an all-comers patient population treated with percutaneous coronary intervention. Methods The multicenter SORT OUT IX trial (NCT02623140) randomly assigned all-comers patients to treatment with the BioFreedom drug-coated stent or the biodegradable polymer Orsiro stent in 4 Danish University Hospitals. The primary end point target lesion failure is a composite of cardiac death, myocardial infarction (not related to other than index lesion), or target lesion revascularization within 12 months. Clinically driven event detection based on Danish registries will be used and continue through 5 years. Assuming an event rate of 4.2% in each stent group, 1,563 patients in each treatment arm will provide 90% power to detect noninferiority of the drug-coated BioFreedom stent with a noninferiority margin of 2.1%. Results A total of 3,150 patients have been randomized and enrolled in the study. Conclusions The SORT OUT IX trial will determine whether the drug-coated BioFreedom stent is noninferior to a modern biodegradable polymer Orsiro stent.