Prophylactic Use of Implanted Cardiac Defibrillators in Patients at High Risk for Ventricular Arrhythmias after Coronary-Artery Bypass Graft Surgery

Background Patients with coronary heart disease, left ventricular dysfunction, and abnormalities on signal-averaged electrocardiograms have an increased risk of sudden death. We evaluated the effect on survival of the prophylactic implantation of cardioverter–defibrillators in such patients at the time of coronary-artery bypass surgery. Methods Over the course of five years, 37 clinical centers screened all patients who were scheduled for elective coronary bypass surgery. Patients were eligible for the trial if they were less than 80 years old, had a left ventricular ejection fraction of less than 0.36, and had abnormalities on signal-averaged electrocardiograms. We identified 1422 eligible patients, enrolled 1055, and randomly assigned 900 to therapy with an implantable cardioverter–defibrillator (446 patients) or to the control group (454 patients). The primary end point of the study was overall mortality, and the two groups were compared in an intention-to-treat analysis. Results The base-line characte...