title: External validity of a contemporaneous primary percutaneous coronary intervention trial in patients with acute ST-elevation myocardial infarction: insights from a single-centre investigation.
abstract: OBJECTIVE
  Randomised controlled trials (RCTs) represent the most robust source of evidence-based medicine. However, the generalisability of RCTs is limited by the inclusion of selected populations. We sought to assess the external validity of a contemporary trial including patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).
  
  
  RESULTS
  Patients presenting to Bern University Hospital during the inclusion period of the COMFORTABLE AMI trial were divided into three groups: RCT participants (41%), eligible not included (17.5%), and excluded patients (41.5%). Major adverse cardiac events (MACE) were defined as one-year death and myocardial infarction. RCT participants compared with RCT-eligible patients had comparable baseline characteristics and outcomes; however, excluded patients differed in risk and had higher rates of MACE (HR 3.63, 95% CI: 2.03-6.48, p<0.001), death (HR 6.23, 95% CI: 2.93-13.24, p<0,001) and definite/probable stent thrombosis (HR 3.63, 95% CI: 1.79-7.36, p<0.001). Inability to provide consent was the most frequent exclusion criterion and was independently associated with an increased risk for MACE (HR 6.85, 95% CI: 3.97-11.81, p<0.001).
  
  
  CONCLUSIONS
  In this single-centre investigation, results from the COMFORTABLE AMI trial appeared applicable to a broad representation of RCT-eligible patients. However, patients excluded from the trial represented a higher-risk population with impaired clinical outcomes and a lower adherence to cardiovascular medication.
authors.affiliation: Department of Cardiology, Bern University Hospital, Bern, Switzerland.
authors.forename: Ernest
authors.initials: E
authors.lastname: Spitzer
authors.forename: Susanne
authors.initials: S
authors.lastname: Hadorn
authors.forename: Thomas
authors.initials: T
authors.lastname: Zanchin
authors.forename: Kyohei
authors.initials: K
authors.lastname: Yamaji
authors.forename: Aris
authors.initials: A
authors.lastname: Moschovitis
authors.forename: Thomas
authors.initials: T
authors.lastname: Pilgrim
authors.forename: Stefan
authors.initials: S
authors.lastname: Stortecky
authors.forename: Peter
authors.initials: P
authors.lastname: Jüni
authors.forename: Dik
authors.initials: D
authors.lastname: Heg
authors.forename: Stephan
authors.initials: S
authors.lastname: Windecker
authors.forename: Lorenz
authors.initials: L
authors.lastname: Räber
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D015897:Comorbidity; D004608:Eligibility Determination; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009203:Myocardial Infarction / Q000453:epidemiology; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011182:Postoperative Care; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D051437:Renal Insufficiency / Q000453:epidemiology; D015203:Reproducibility of Results; D000072657:ST Elevation Myocardial Infarction / Q000453:epidemiology / Q000628:therapy*; D055502:Secondary Prevention; D016896:Treatment Outcome
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010975:Platelet Aggregation Inhibitors