title: Ultrathin strut biodegradable polymer sirolimus-eluting stent versus durable polymer everolimus-eluting stent for percutaneous coronary revascularisation (BIOSCIENCE): a randomised, single-blind, non-inferiority trial.
abstract: BACKGROUND
  Refinements in stent design affecting strut thickness, surface polymer, and drug release have improved clinical outcomes of drug-eluting stents. We aimed to compare the safety and efficacy of a novel, ultrathin strut cobalt-chromium stent releasing sirolimus from a biodegradable polymer with a thin strut durable polymer everolimus-eluting stent.
  
  
  METHODS
  We did a randomised, single-blind, non-inferiority trial with minimum exclusion criteria at nine hospitals in Switzerland. We randomly assigned (1:1) patients aged 18 years or older with chronic stable coronary artery disease or acute coronary syndromes undergoing percutaneous coronary intervention to treatment with biodegradable polymer sirolimus-eluting stents or durable polymer everolimus-eluting stents. Randomisation was via a central web-based system and stratified by centre and presence of ST segment elevation myocardial infarction. Patients and outcome assessors were masked to treatment allocation, but treating physicians were not. The primary endpoint, target lesion failure, was a composite of cardiac death, target vessel myocardial infarction, and clinically-indicated target lesion revascularisation at 12 months. A margin of 3·5% was defined for non-inferiority of the biodegradable polymer sirolimus-eluting stent compared with the durable polymer everolimus-eluting stent. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT01443104.
  
  
  RESULTS
  Between Feb 24, 2012, and May 22, 2013, we randomly assigned 2119 patients with 3139 lesions to treatment with sirolimus-eluting stents (1063 patients, 1594 lesions) or everolimus-eluting stents (1056 patients, 1545 lesions). 407 (19%) patients presented with ST-segment elevation myocardial infarction. Target lesion failure with biodegradable polymer sirolimus-eluting stents (69 cases; 6·5%) was non-inferior to durable polymer everolimus-eluting stents (70 cases; 6·6%) at 12 months (absolute risk difference -0·14%, upper limit of one-sided 95% CI 1·97%, p for non-inferiority <0·0004). No significant differences were noted in rates of definite stent thrombosis (9 [0·9%] vs 4 [0·4%], rate ratio [RR] 2·26, 95% CI 0·70-7·33, p=0·16). In pre-specified stratified analyses of the primary endpoint, biodegradable polymer sirolimus-eluting stents were associated with improved outcome compared with durable polymer everolimus-eluting stents in the subgroup of patients with ST-segment elevation myocardial infarction (7 [3·3%] vs 17 [8·7%], RR 0·38, 95% CI 0·16-0·91, p=0·024, p for interaction=0·014).
  
  
  CONCLUSIONS
  In a patient population with minimum exclusion criteria and high adherence to dual antiplatelet therapy, biodegradable polymer sirolimus-eluting stents were non-inferior to durable polymer everolimus-eluting stents for the combined safety and efficacy outcome target lesion failure at 12 months. The noted benefit in the subgroup of patients with ST-segment elevation myocardial infarction needs further study.
  
  
  BACKGROUND
  Clinical Trials Unit, University of Bern, and Biotronik, Bülach, Switzerland.
authors.affiliation: Department of Cardiology, Swiss Cardiovascular Center, University Hospital, Bern, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Pilgrim
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: Department of Cardiology, University Hospital, Geneva, Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Roffi
authors.affiliation: Department of Cardiology, Triemlispital, Zurich, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Tüller
authors.affiliation: Department of Cardiology, University Hospital, Lausanne, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Muller
authors.affiliation: Department of Cardiology, Kantonsspital, Aarau, Switzerland.
authors.forename: André
authors.initials: A
authors.lastname: Vuilliomenet
authors.affiliation: Department of Cardiology, University Hospital, Fribourg, Switzerland.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Cook
authors.affiliation: Department of Cardiology, Kantonsspital, St Gallen, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Weilenmann
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland.
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: Department of Cardiology, Swiss Cardiovascular Center, University Hospital, Bern, Switzerland.
authors.forename: Therese
authors.initials: T
authors.lastname: Fahrni
authors.affiliation: Department of Cardiology, Swiss Cardiovascular Center, University Hospital, Bern, Switzerland.
authors.forename: Aris
authors.initials: A
authors.lastname: Moschovitis
authors.affiliation: Department of Cardiology, University Hospital, Geneva, Switzerland.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Noble
authors.affiliation: Department of Cardiology, Triemlispital, Zurich, Switzerland.
authors.forename: Franz R
authors.initials: FR
authors.lastname: Eberli
authors.affiliation: Department of Cardiology, Swiss Cardiovascular Center, University Hospital, Bern, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Wenaweser
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, Switzerland. Electronic address: stephan.windecker@insel.ch.
authors.forename: Stephan
authors.initials: S
authors.lastname: Windecker
mesh_terms: D020341:Absorbable Implants; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D054855:Drug-Eluting Stents; D000068338:Everolimus; D005260:Female; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000601:surgery; D062645:Percutaneous Coronary Intervention / Q000295:instrumentation / Q000379:methods*; D011108:Polymers; D016037:Single-Blind Method; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D011108:Polymers; D000068338:Everolimus; D020123:Sirolimus