Will all postinfarction patients receive defibrillators? Recent trials and expanding indications

Implantable defibrillators have been demonstrated to be the most effective therapy for secondary prevention of sudden cardiac death. Unfortunately, however, many patients succumb to their initial episode of cardiac arrest so that primary prevention strategies are warranted. Several studies have demonstrated the mortality benefit of prophylactic, implantable defibrillators in patients with coronary artery disease depressed ventricular function and nonsustained ventricular tachycardia with inducible ventricular tachycardia during electrophysiologic study. However, widespread application of this approach is limited by the need for invasive risk stratification. The results of the MADIT II study, which demonstrate mortality reduction with prophylactic ICD implantation in patients with previous myocardial infarction and severe left ventricular dysfunction in the absence of invasive risk stratification, have dramatic implications for the management of this high-risk population. This article will review these data and their implications.