title: Randomized comparison of biodegradable polymer sirolimus-eluting stents versus durable polymer everolimus-eluting stents for percutaneous coronary revascularization: rationale and design of the BIOSCIENCE trial.
abstract: BACKGROUND
  Biodegradable polymers for release of antiproliferative drugs from metallic drug-eluting stents aim to improve long-term vascular healing and efficacy. We designed a large scale clinical trial to compare a novel thin strut, cobalt-chromium drug-eluting stent with silicon carbide-coating releasing sirolimus from a biodegradable polymer (O-SES, Orsiro; Biotronik, Bülach, Switzerland) with the durable polymer-based Xience Prime/Xpedition everolimus-eluting stent (EES) (Xience Prime/Xpedition stent, Abbott Vascular, IL) in an all-comers patient population.
  
  
  METHODS
  The multicenter BIOSCIENCE trial (NCT01443104) randomly assigned 2,119 patients to treatment with biodegradable polymer sirolimus-eluting stents (SES) or durable polymer EES at 9 sites in Switzerland. Patients with chronic stable coronary artery disease or acute coronary syndromes, including non-ST-elevation and ST-elevation myocardial infarction, were eligible for the trial if they had at least 1 lesion with a diameter stenosis >50% appropriate for coronary stent implantation. The primary end point target lesion failure (TLF) is a composite of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization within 12 months. Assuming a TLF rate of 8% at 12 months in both treatment arms and accepting 3.5% as a margin for noninferiority, inclusion of 2,060 patients would provide more than 80% power to detect noninferiority of the biodegradable polymer SES compared with the durable polymer EES at a 1-sided type I error of 0.05. Clinical follow-up will be continued through 5 years.
  
  
  CONCLUSIONS
  The BIOSCIENCE trial will determine whether the biodegradable polymer SES is noninferior to the durable polymer EES with respect to TLF.
authors.affiliation: Department of Cardiology, Swiss Cardiovascular Center, University Hospital, Bern. Electronic address: thomas.pilgrim@insel.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Pilgrim
authors.affiliation: Department of Cardiology, University Hospital, Geneva.
authors.forename: Marco
authors.initials: M
authors.lastname: Roffi
authors.affiliation: Department of Cardiology, Triemlispital, Zurich.
authors.forename: David
authors.initials: D
authors.lastname: Tüller
authors.affiliation: Department of Cardiology, University Hospital, Lausanne.
authors.forename: Olivier
authors.initials: O
authors.lastname: Muller
authors.affiliation: Department of Cardiology, Kantonsspital, Aarau.
authors.forename: André
authors.initials: A
authors.lastname: Vuilliomenet
authors.affiliation: Department of Cardiology, University Hospital, Fribourg.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Cook
authors.affiliation: Department of Cardiology, Kantonsspital, St Gallen.
authors.forename: Daniel
authors.initials: D
authors.lastname: Weilenmann
authors.affiliation: Department of Cardiology, University Hospital, Basel.
authors.forename: Christoph
authors.initials: C
authors.lastname: Kaiser
authors.affiliation: Department of Cardiology, Kantonsspital, Luzern, Switzerland.
authors.forename: Peiman
authors.initials: P
authors.lastname: Jamshidi
authors.affiliation: Institute of Social and Preventive Medicine and Clinical Trials Unit, Bern University Hospital, Bern, Switzerland.
authors.forename: Dik
authors.initials: D
authors.lastname: Heg
authors.affiliation: Institute of Social and Preventive Medicine and Clinical Trials Unit, Bern University Hospital, Bern, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Jüni
authors.affiliation: Department of Cardiology, Swiss Cardiovascular Center, University Hospital, Bern.
authors.forename: Stephan
authors.initials: S
authors.lastname: Windecker
mesh_terms: D020341:Absorbable Implants; D054058:Acute Coronary Syndrome / Q000628:therapy*; D003324:Coronary Artery Disease / Q000628:therapy*; D054855:Drug-Eluting Stents; D000068338:Everolimus; D006801:Humans; D062645:Percutaneous Coronary Intervention; D012107:Research Design; D020123:Sirolimus / Q000008:administration & dosage* / Q000031:analogs & derivatives*
chemical_list: D000068338:Everolimus; D020123:Sirolimus