title: Trial participation as a determinant of clinical outcome: differences between trial-participants and Every Day Clinical Care patients in the field of interventional cardiology.
abstract: BACKGROUND
  This study examines differences in clinical outcome between trial-participants and non-participants after percutaneous coronary intervention (PCI).
  
  
  RESULTS
  This study compromised of 11,931 consecutive patients who underwent PCI in a high volume center, during the period 2000 - 2009. Of these patients, 1787 (15%) participated in an interventional clinical trial with a follow-up period of at least six months. The maximum follow-up duration was 11.8 years, with a median of 3.8 years (IQR: 2.6 - 6.5). Baseline and procedural characteristics differed between trial-participants and non-participants. Trial-participants were more often male, were younger, had more cardiovascular risk factors and were treated more often for stable angina pectoris and single vessel disease. Overall mortality at maximum follow-up was lower for trial-participants compared to non-participants (8.1% versus 17.6%, p<0.001, adjusted HR, 0.62, 95% CI: 0.52-0.74). There was no difference in the incidence of non-fatal MI and CABG. Repeat PCI was seen more often in trial-participants (18.1% versus 30.7%, p<0.001, adjusted HR 1.91, 95%CI 1.73-2.10). Consequently, a higher incidence of the composite of mortality, repeat revascularization, and non-fatal MI was seen in the trail-participants (adjusted HR.1.36 95% CI 1.25 - 1.47), but this association was primarily driven by the occurrence of repeat PCI.
  
  
  CONCLUSIONS
  Participants in clinical trials in the field of interventional cardiology with a follow-up of at least six months differed considerably from non-participants in baseline and procedural characteristics. Trial-participants had better survival than non-participants. In contrast, a two-fold higher incidence of repeat PCI was observed in trial-participants.
authors.affiliation: Department of Cardiology, Erasmus MC, Thoraxcenter, Rotterdam, The Netherlands.
authors.forename: Sanneke P M
authors.initials: SP
authors.lastname: de Boer
authors.forename: Maarten A H
authors.initials: MA
authors.lastname: van Leeuwen
authors.forename: Jin M
authors.initials: JM
authors.lastname: Cheng
authors.forename: Rohit M
authors.initials: RM
authors.lastname: Oemrawsingh
authors.forename: Robert-Jan
authors.initials: RJ
authors.lastname: van Geuns
authors.forename: Patrick W J C
authors.initials: PW
authors.lastname: Serruys
authors.forename: Eric
authors.initials: E
authors.lastname: Boersma
authors.forename: Mattie J
authors.initials: MJ
authors.lastname: Lenzen
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery*; D000787:Angina Pectoris / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery*; D002309:Cardiology / Q000379:methods*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery*; D010358:Patient Participation / Q000379:methods*; D062645:Percutaneous Coronary Intervention / Q000379:methods; D016896:Treatment Outcome
keywords: Outcome; Percutaneous coronary intervention; Trial-participation