Utility of current risk stratification tests for predicting major arrhythmic events after myocardial infarction

Objectives We surveyed the literature to estimate prediction values for fiv e 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 st udy (EPS) as the final test. Background Improved approaches are needed for identifying those patients at highest risk for subsequent MAE and candidates for implantable cardioverte r-defibrillators. Methods We located 44 reports for which values of MAE incidence and predict ive accuracy could be inferred: signal-averaged electrocardiography; heart rate variability severe ventricular arrhythmia on ambulatory electrocardiog raphy; left ventricular ejection fraction; and EPS. A meta-analysis of repo rts used receiver-operating characteristic curves to estimate mean values f or sensitivity and specificity for each test and 95% confidence limits. We then simulated a clinical situation in which risk was estimated by combinin g tests in three stages. Results Test sensitivities ranged from 42.8% to 62.4%; specificities from 7 7.4% 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% r isk) 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 relativ ely similar. No one test was satisfactory alone for predicting risk. Combin ations of tests in stages allowed us to stratify 91.8% of patients as eithe r high-risk or low-risk. These data suggest that a large prospective study to develop a robust prediction model is feasible and desirable. (J Am Coll Cardiol 2001; 38:1902-11) (C) 2001 by the American College of Cardiology.