title: Predictive value of T-wave abnormalities at the time of emergency department presentation in patients with potential acute coronary syndromes.
abstract: OBJECTIVE
  T-wave abnormalities on electrocardiograms (ECGs) are common, but their ability to predict 30-day cardiovascular outcomes at the time of emergency department (ED) presentation is unknown. The authors determined the association between T-wave abnormalities on the presenting ECG and cardiovascular outcomes within 30 days of presentation in patients with potential acute coronary syndromes (ACSs).
  
  
  METHODS
  This was a secondary analysis of a prospective cohort study of ED patients that presented with a potential ACS. Patients were excluded if they had a prior myocardial infarction, ST-segment elevation or depressions, right or left bundle branch block, or Q-waves on the initial ECG. Data included demographics, medical and cardiac history, and ECG findings including the presence or absence of T-wave flattening, inversions of 1-5 mm, and inversions >5 mm. Investigators followed the hospital course for admitted patients, and 30-day follow-up was performed on all patients. The main outcome was a composite of death, acute myocardial infarction, revascularization, coronary stenosis greater than 50%, or a stress test with reversible ischemia.
  
  
  RESULTS
  Of 8,298 patient visits, 5,582 met criteria for inclusion: 4,166 (74.6%) had no T-wave abnormalities, 721 (12.9%) had T-wave flattening in two or more leads, 659 (11.8%) had T-wave inversions of 1-5 mm, and 36 (0.64%) had T-wave inversions >5 mm. The composite endpoint was more common in patients with T-wave flattening (8.2% vs. 5.7%; p = 0.0001; relative risk [RR] = 1.4; 95% confidence interval [CI] = 1.1 to 1.9), T-wave inversions 1-5 mm (13.2% vs. 5.7%; p = 0.0001; RR = 2.4; 95% CI = 1.8 to 3.1), and T-wave inversions >5 mm (19.4% vs. 5.7%; p = 0.0001; RR = 3.4; 95% CI = 1.7 to 6.1), or any T-wave abnormality (10.8% vs. 5.7%; p = 0.0001; RR = 1.9; 95% CI = 1.6 to 2.3), even after adjustment for initial troponin. This association also existed in the subset of patients without known coronary artery disease.
  
  
  CONCLUSIONS
  In patients with potential ACS presenting to the ED, T-wave abnormalities are associated with higher rates of 30-day cardiovascular events.
authors.affiliation: Department of Emergency Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA 19104-4283, USA.
authors.forename: Kathy B
authors.initials: KB
authors.lastname: Lin
authors.forename: Frances S
authors.initials: FS
authors.lastname: Shofer
authors.forename: Christine
authors.initials: C
authors.lastname: McCusker
authors.forename: Emily
authors.initials: E
authors.lastname: Meshberg
authors.forename: Judd E
authors.initials: JE
authors.lastname: Hollander
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D016009:Chi-Square Distribution; D004562:Electrocardiography; D004636:Emergency Service, Hospital / Q000458:organization & administration*; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010414:Pennsylvania; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment