title: Defining the outcomes of risk stratification studies of ED patients with chest pain: the marginal value of adding revascularization to the composite end point.
abstract: OBJECTIVE
  Cardiovascular risk stratification studies use various end points, sometimes including revascularization. We assessed whether adding revascularization to a strictly defined composite end point of death, acute myocardial infarction (AMI), and unstable angina (UA) impacts the likelihood of patients attaining the composite end point.
  
  
  METHODS
  We conducted a secondary analysis of a prospectively collected data set of emergency department patients who received an electrocardiogram for chest pain. Patients were followed daily; discharged patients had 30-day telephone follow-up. The main outcome was a 30-day composite end point of death, AMI, and UA compared with death, AMI, UA, and revascularization.
  
  
  RESULTS
  There were 4492 patients enrolled (mean age, 52 +/- 16 years; men, 41%; African American, 68%). One hundred seventy patients were revascularized (158 had AMI or UA). Overall, the incidence of death/AMI/UA was 20.1% (95% confidence interval, 18.9%-21.2%). With revascularization included, the incidence of the composite end point was 20.3% (95% confidence interval, 19.1%-21.5%).
  
  
  CONCLUSIONS
  When both AMI and UA are strictly defined, there appears to be a limited role for adding revascularization to a composite end point of death, AMI, and UA because most revascularized patients have a diagnosis of AMI or UA.
authors.affiliation: Department of Emergency Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA 19104-4283, USA. esther.chen@uphs.upenn.edu
authors.forename: Esther H
authors.initials: EH
authors.lastname: Chen
authors.forename: Frank
authors.initials: F
authors.lastname: Sites
authors.forename: Frances S
authors.initials: FS
authors.lastname: Shofer
authors.forename: Judd E
authors.initials: JE
authors.lastname: Hollander
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000150:complications / Q000401:mortality / Q000628:therapy; D000789:Angina, Unstable; D003643:Death; D004636:Emergency Service, Hospital; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction; D009204:Myocardial Revascularization; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods; D013577:Syndrome