Implantable Cardioverter-Defibrillators for Primary Prevention of Sudden Cardiac Death

The implantable cardioverter-defibrillator (ICD) has been one of the most significant advances made in sudden cardiac death prevention. Landmark randomized clinical trials convincingly demonstrated survival benefits of ICD therapy in patients 40 days after myocardial infarction with left ventricular ejection fraction (LVEF) of <30%1 and in patients with stable New York Heart Association Class II-III congestive heart failure and LVEF of <35%,2 and subsequent observational studies have confirmed these mortality benefits.3 Results from clinical trials were rapidly incorporated into guidelines,4,5 and the Centers for Medicaid and Medicare Services approved both indications for primary prevention ICDs by 2005. At the same time, the Centers for Medicaid and Medicare Services mandated that data on all patients receiving ICDs be entered into a national registry to track use. Approximately 10 years later, what progress have we made with respect to allocating and disseminating this life-saving technology, and what additional impact can be made with this technology on mortality attributable to sudden cardiac death? The article by Narayanan et al6 in this issue of Circulation highlights these questions.Article see p 1733The authors examined the proportion of sudden cardiac arrest (SCA) victims in the Portland, Oregon metropolitan area who had an ICD implanted for primary prevention before their cardiac arrest from 2003 to 2012. Among individuals in which echocardiogram results were available, only a minority (13%) of victims who met contemporary guidelines for prophylactic ICD implantation had received an ICD. This rate of ICD use is much lower than that for patients enrolled in heart failure registries, in which use rates range from 35% in the inpatient7 to 51% in the outpatient8 settings. Because these registries were specifically designed to evaluate and improve the use of medical therapies among heart failure patients, these use …