Primary Prevention of Sudden Cardiac Death: Implications of Recent Trials

A B S T R A C T Based on the results of randomized multicenter studies, such as the MADIT I, MADIT II, DINAMIT, and SCD-HeFT and DEFINITE trials, patients can be identified who are at high risk for sudden cardiac death (SCD) who demonstrate a reduction in arrhythmic mortality and total mortality with the implantation of an implantable cardioverter defibrillator (ICD). These are patients with coronary artery disease, im paired left ventricular function, spontaneous nonsustained ventricular tachycardia and inducible ventricular tachycardia not suppressed by procainamide. Also patients with coronary artery disease and left ventricular ejection fraction <30% benefit from ICD placement. Based on the SCD-HeFT results, patients with ischemic or nonischemic cardiomyopathy and class II or III congestive heart failure also benefit from the ICD. At the same time, based on the results of the DINAMIT study, it has become apparent that the ICD does not play a role in patients within 45 days of myocardial infarction. The implications of these trials are further analyzed in this overview.