title: The prognostic value of the admission and predischarge electrocardiogram in acute coronary syndromes: the GUSTO-IIb ECG Core Laboratory experience.
abstract: BACKGROUND
  Prior research suggests that patients may be entered into clinical trials with different electrocardiographic (ECG) findings than specified by study protocol criteria; the extent and impact of this variability in a large-scale trial have not been previously described.
  
  
  METHODS
  We evaluated the relationship between case report form (CRF) categorization of the admission ECG and a Core Laboratory and subsequent outcome in a retrospective analysis of a trial of patients with acute ischemia and a broad spectrum of ECG changes (the GUSTO-IIb trial).
  
  
  RESULTS
  In 11,037 patients with CRF information and an interpretable ECG, there was agreement in 89.1% of ST-elevation and 81.9% of non-ST-elevation cases. Among patients designated as having no ST elevation on the CRF, 1-year mortality rates were significantly higher in the subgroup of patients with Core Laboratory-determined ST elevation as compared with those where both the CRF and Core Laboratory classification were in agreement (8.8% vs 6.8%, P = .0093). Among patients designated as having ST elevation by the CRF, 1-year mortality rates were similar in both the subgroup of patients with and without Core Laboratory agreement (7.7% vs 8.2%, P = .72).
  
  
  CONCLUSIONS
  These findings have important implications for clinicians in routine practice because even a simple evaluation (presence or absence of ST elevation) on the admission ECG was often discordant and was associated with adverse clinical outcome.
authors.affiliation: The Canadian Heart Research Centre, Division of Cardiology, St. Michael's Hospital, University of Toronto, Toronto, Canada. goodmans@smh.toronto.on.ca
authors.forename: Shaun G
authors.initials: SG
authors.lastname: Goodman
authors.forename: Yuling
authors.initials: Y
authors.lastname: Fu
authors.forename: Anatoly
authors.initials: A
authors.lastname: Langer
authors.forename: Aiala
authors.initials: A
authors.lastname: Barr
authors.forename: Mary
authors.initials: M
authors.lastname: Tan
authors.forename: Galen S
authors.initials: GS
authors.lastname: Wagner
authors.forename: Alejandro
authors.initials: A
authors.lastname: Barbagelata
authors.forename: Elena B
authors.initials: EB
authors.lastname: Sgarbossa
authors.forename: Yochai
authors.initials: Y
authors.lastname: Birnbaum
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Granger
authors.forename: Robert M
authors.initials: RM
authors.lastname: Califf
authors.forename: Frans
authors.initials: F
authors.lastname: Van de Werf
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Topol
authors.forename: Paul W
authors.initials: PW
authors.lastname: Armstrong
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000401:mortality*; D004562:Electrocardiography; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000401:mortality*; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D013577:Syndrome