Electrophysiologic testing to identify patients with coronary artery disease who are at risk for sudden death

Background: The mortality rate among patients with coronary artery disease, abnormal ventricular function, and unsustained ventricular tachycardia is high. The usefulness of electrophysiologic testing for risk stratification in these patients is unclear. Methods: We performed electrophysiologic testing in patients who had corona ry artery disease, a left ventricular ejection fraction of 40 percent or le ss, and asymptomatic, unsustained ventricular tachycardia. Patients in whom sustained ventricular tachyarrhythmias could be induced were randomly assi gned to receive either antiarrhythmic therapy guided by electrophysiologic testing or no antiarrhythmic therapy. The primary end point was cardiac arr est or death from arrhythmia. Patients without inducible tachyarrhythmias w ere followed in a registry. We compared the outcomes of 1397 patients in th e registry with those of 353 patients with inducible tachyarrhythmias who w ere randomly assigned to receive no antiarrhythmic therapy in order to asse ss the prognostic value of electrophysiologic testing. Results: Patients were followed for a median of 39 months. In a Kaplan-Meie r analysis, two-year and five-year rates of cardiac arrest or death due to arrhythmia were 12 and 24 percent, respectively, among the patients in the registry, as compared with 18 and 32 percent among the patients with induci ble tachyarrhythmias who were assigned to no antiarrhythmic therapy (adjust ed P < 0.001). Overall mortality after five years was 48 percent among the patients with inducible tachyarrhythmias, as compared with 44 percent among the patients in the registry (adjusted P = 0.005). Deaths among patients w ithout inducible tachyarrhythmias were less likely to be classified as due to arrhythmia than those among patients with inducible tachyarrhythmias (45 and 54 percent, respectively; P = 0.06). Conclusions: Patients with coronary artery disease, left ventricular dysfun ction, and asymptomatic, unsustained ventricular tachycardia in whom sustai ned ventricular tachyarrhythmias cannot be induced have a significantly low er risk of sudden death or cardiac arrest and lower overall mortality than similar patients with inducible sustained tachyarrhythmias. (N Engl J Med 2 000;342:1937-45.) (C)2000, Massachusetts Medical Society.