Risk of Arrhythmic Death in Patients With Nonischemic Cardiomyopathy: JACC Review Topic of the Week.

Nonischemic cardiomyopathy (NICM) is common and patients are at significant risk for early mortality secondary to ventricular arrhythmias. Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy to decrease sudden cardiac death (SCD) in patients with heart failure and reduced left ventricular ejection fraction. However, in randomized clinical trials comprised solely of patients with NICM, primary prevention ICDs did not confer significant mortality benefit. Moreover, left ventricular ejection fraction has limited sensitivity and specificity for predicting SCD. Therefore, precise risk stratification algorithms are needed to define those at the highest risk of SCD. This review examines mechanisms of sudden arrhythmic death in patients with NICM, discusses the role of ICD therapy and treatment of heart failure for prevention of SCD in patients with NICM, examines the role of cardiac magnetic resonance imaging and computational modeling for SCD risk stratification, and proposes new strategies to guide future clinical trials on SCD risk assessment in patients with NICM. [Display omitted] • NICM patients are at increased risk for SCD; however, current guidelines are insufficient in identifying those who may benefit from ICD therapy. • Identifying the underlying cause for the NICM is important in understanding the disease trajectory. CMR imaging adds additional information in understanding the risk for SCD. • Optimizing guideline-directed medical therapy for heart failure, incorporating clinical parameters, and detailed myocardial structural assessment will be critical to personalized decision-making in SCD risk stratification. [ABSTRACT FROM AUTHOR]