Recent primary prevention implantable cardioverter defibrillator trials

Abstract

The aim of this article is to summarize the most relevant findings of recently published trials on prophylactic implantable cardioverter defibrillator therapy. A number of important randomized clinical trials on the efficacy of prophylactic implantable cardioverter defibrillator therapy in patients deemed to be at high risk for ventricular tachyarrhythmias have recently reported their results. Patients with chronic ischemic cardiomyopathy, a long history of heart failure, and an ejection fraction of 0.30 or below benefit from preventive device therapy and are thus candidates for prophylactic defibrillator implantation. For this purpose, a single chamber device appears to be appropriate since there have been no prospective studies showing convincing clinical benefit by adding an atrial lead. Prophylactic implantable cardioverter defibrillator therapy should not be used in patients with recent myocardial infarction. There is convincing evidence from one trial that benefit from the defibrillator in coronary patients accrue after a considerable time has elapsed from the most recent infarct, presumably at least 6 months or perhaps longer. Finally, in patients with chronic dilated non-ischemic cardiomyopathy and a left ventricular ejection fraction of 0.35 or below, there is also benefit from prophylactic implantable cardioverter defibrillator therapy. Taken together, these trials allow an evidence-based approach to primary prevention of sudden cardiac death in patients with both ischemic and non-ischemic cardiomyopathy.