Should patients with congenital heart disease and a systemic ventricular ejection fraction less than 30% undergo prophylactic implantation of an ICD?

Abstract

Areduced left ventricular (LV) ejection fraction (EF) is established as one of the strongest risk factors for sudden and total cardiac mortality in adults with ischemic and nonischemic heart disease.1,2 Based on the Multicenter Automatic Defibrillator Implantation Trial II and Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) clinical trials, patients with an LVEF <30% are at a significantly increased risk for sudden cardiac death (SCD) and thus warrant an implantable cardioverter defibrillator (ICD).3,4 At the same time, increasing numbers of patients with congenital heart disease (CHD) continue to survive complex repairs or palliations of their heart defects, allowing survival beyond adolescence and into adulthood. However, it is uncertain whether the risks of systemic ventricular dysfunction and the benefits of primary prevention ICDs demonstrated in adult clinical trials extend to patients with CHD. Clarification regarding this issue is important because in the current era, the majority of ICD implantations in patients with CHD are for primary prevention of SCD.5 Response by Triedman see p 307 In this article, we argue that patients with CHD and a systemic ventricular EF <30% should undergo prophylactic implantation of an ICD. Although large-scale randomized clinical ICD trials are unlikely to be performed in these patients, data from adult studies with other forms of heart disease as well as observational and registry studies in CHD patients provide consistent support for the proposal that advanced systemic ventricular dysfunction is a significant risk factor for SCD in CHD patients and thus provides a rational basis for prophylactic implantation of an ICD. Several major randomized clinical trials have been reported regarding the efficacy of ICDs for the primary prevention of SCD in adults with ischemic and nonischemic heart disease and have been the subject of several meta-analyses and reviews.3,4,6–8 These studies include a total …