title: Utility of current risk stratification tests for predicting major arrhythmic events after myocardial infarction.
abstract: OBJECTIVE
  We surveyed the literature to estimate prediction values for five common tests for risk of major arrhythmic events (MAEs) after myocardial infarction. We then determined feasibility of a staged risk stratification using combinations of noninvasive tests, reserving an electrophysiologic study (EPS) as the final test.
  
  
  BACKGROUND
  Improved approaches are needed for identifying those patients at highest risk for subsequent MAE and candidates for implantable cardioverter-defibrillators.
  
  
  METHODS
  We located 44 reports for which values of MAE incidence and predictive accuracy could be inferred: signal-averaged electrocardiography; heart rate variability; severe ventricular arrhythmia on ambulatory electrocardiography; left ventricular ejection fraction; and EPS. A meta-analysis of reports used receiver-operating characteristic curves to estimate mean values for sensitivity and specificity for each test and 95% confidence limits. We then simulated a clinical situation in which risk was estimated by combining tests in three stages.
  
  
  RESULTS
  Test sensitivities ranged from 42.8% to 62.4%; specificities from 77.4% to 85.8%. A three-stage stratification yielded a low-risk group (80.0% with a two-year MAE risk of 2.9%), a high-risk group (11.8% with a 41.4% risk) and an unstratified group (8.2% with an 8.9% risk equivalent to a two-year incidence of 7.9%).
  
  
  CONCLUSIONS
  Sensitivities and specificities for the five tests were relatively similar. No one test was satisfactory alone for predicting risk. Combinations of tests in stages allowed us to stratify 91.8% of patients as either high-risk or low-risk. These data suggest that a large prospective study to develop a robust prediction model is feasible and desirable.
authors.affiliation: Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892-5620, USA. jjbailey@helix.nih.gov
authors.forename: J J
authors.initials: JJ
authors.lastname: Bailey
authors.forename: A S
authors.initials: AS
authors.lastname: Berson
authors.forename: H
authors.initials: H
authors.lastname: Handelsman
authors.forename: M
authors.initials: M
authors.lastname: Hodges
mesh_terms: D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control; D017147:Defibrillators, Implantable; D015716:Electrocardiography, Ambulatory; D006801:Humans; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D011237:Predictive Value of Tests; D012372:ROC Curve; D018570:Risk Assessment; D012815:Signal Processing, Computer-Assisted; D013318:Stroke Volume; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology