Polymer-free biolimus-coated stents versus ultrathin-strut biodegradable polymer sirolimus-eluting stents: two-year outcomes of the randomised SORT OUT IX trial

Background: For patients with high bleeding risk, the BioFreedom stent is safer and more effective than a bare metal stent. However, at the one-year follow-up of the SORT OUT IX trial, the BioFreedom stent did not meet the criteria for non-inferiority for target lesion failure (TLF) when compared with the Orsiro stent and had a higher incidence of target lesion revascularisation (TLR).

Aims: The aim of the study was to compare the two-year outcomes following coronary implantation of the BioFreedom or the Orsiro stents in all-comer patients.

Methods: The Scandinavian Organization for Randomized Trials with Clinical Outcome (SORT OUT) IX trial is a prospective, multicentre, randomised clinical trial comparing the BioFreedom and the Orsiro stents. The primary endpoint, TLF, was a composite of cardiac death, myocardial infarction (MI; not related to other lesions) and TLR.

Results: A total of 1,572 patients were randomised to treatment with the BioFreedom stent and 1,579 patients with the Orsiro stent. At two-year follow-up, TLF was 7.8% in the BioFreedom and 6.3% in the Orsiro stent groups (rate ratio [RR] 1.23, 95% confidence interval [CI]: 0.94-1.61). Risks of cardiac death, MI and definite stent thrombosis did not differ significantly between the groups, whereas more patients in the BioFreedom group had TLR (5.1% vs 2.6%; RR 1.98, 95% CI: 1.26-2.89) attributable to a higher risk of TLR within the first year (3.5% vs 1.3%; RR 2.77, 95% CI: 1.66-4.62).

Conclusions: At two years, there were no significant differences between the BioFreedom and Orsiro stents for TLF. TLR was significantly higher with the BioFreedom stent due to higher risk of TLR within the first year.