Iglesias JF, Muller O, Heg D, et al. - Researchers compared ultrathin strut biodegradable polymer sirolimus-eluting stents with thin strut durable polymer everolimus-eluting stents in terms of safety and efficacy in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) in the BIOSTEMI trial, which is an investigator-initiated, multicentre, prospective, single-blind, randomised superiority trial conducted at ten hospitals in Switzerland. Eligible patients were those aged 18 years or older and who were referred for primary PCI for acute STEMI. The superiority of biodegradable polymer sirolimus-eluting stents over durable polymer everolimus-eluting stents was revealed by target lesion failure at 1 year, which occurred in 25 (4%) of 649 patients in the former group and 36 (6%) of 651 patients in the latter group. The driver of this difference was reduced ischaemia-driven target lesion revascularisation in patients who received biodegradable polymer sirolimus-eluting stents vs durable polymer everolimus-eluting stents.