The Challenge Ahead

Despite widespread advances in coronary heart disease (CHD) treatment and the growing use of implantable cardioverter-defibrillators (ICDs), sudden cardiac death (SCD) remains a major cause of CHD death in the United States,1 and identification of patients at risk for SCD remains a challenge. Left ventricular ejection fraction (LVEF) has been found to be the strongest independent predictor of SCD among traditional clinical markers,2 and risk of SCD exponentially increases as LVEF decreases.3 Based on data from observational studies, clinical trials were designed to test the hypothesis that ICD therapy would prolong life in patients with clinically recognized left ventricular dysfunction. Although these trials have demonstrated convincing survival benefits,4,5 there continues to be great debate regarding the overall effectiveness, and in particular cost-effectiveness, of the current strategy of allocating ICD therapy on the basis of LVEF.6,7