Implantable Cardioverter Defibrillator for the Primary Prevention of Sudden Cardiac Death in Patients With Nonischemic Cardiomyopathy

Objectives: The benefit of implanting patients with nonischemic cardiomyopathy (NICMP) with an implantable cardioverter defibrillator (ICD) for primary prevention has not been demonstrated in any randomized controlled trial. This also holds true for the most recent study on the subject. This systematic review and meta-analysis aims to examine the effectiveness of primary prevention using an ICD in the NICMP population. Methods: We searched the literature for randomized controlled trials examining the effectiveness of ICD in reducing all-cause mortality in patients with NICMP. The primary outcome of our analysis was all-cause mortality. A fixed-effects model was used for the primary analysis. Results: A total of 5 randomized controlled trials focused on primary prevention of sudden cardiac death for patients with NICMP that met our inclusion and exclusion criteria. They have individually failed to consistently show a benefit for the use of an ICD in this population. However, the cumulative effect of ICD implantation in patients with NICMP demonstrated a 21% relative risk reduction in mortality (Relative risk [RR]: 0.79; confidence interval: 0.66-0.95). Conclusion: There is a decrease in mortality with the use of ICD for primary prevention in patients with NICMP having left ventricular ejection fraction <35%.