MADIT-II: clinical implications.

The MADIT-II trial showed that in patients with a prior myocardial infarction and ejection fraction </=0.30, prophylactic implantation of a defibrillator improves survival with a 31% reduction in mortality during an average follow-up of 20 months. Electrophysiologic inducibility was positive in 36% of patients at the time of ICD implantation. Inducibility was associated with increased ICD utilization for ventricular tachycardia during long-term follow-up, and decreased utilization for ventricular fibrillation. These preliminary findings raise questions about the clinical usefulness of electrophysiologic testing as a risk stratifier in patients with advanced left ventricular dysfunction.