Abstract 16938: Epicardial Adipose Tissue on the Risk of Lethal Ventricular Arrhythmias in Patients With Nonischemic Cardiomyopathy Receiving Implantable Cardioverter-Defibrillator

Abstract

Background: The arrhythmic risk stratification in patients with nonischemic cardiomyopathy (NICM) remains challenging. The implication of epicardial adipose tissue (EAT) on incident sudden cardiac death (SCD) is unclear. Objectives: To assess the relationship between EAT and SCD in NICM patients receiving implantable cardioverter-defibrillators (ICD) and compare this risk to patients with ischemic cardiomyopathy (ICM). Methods: A total of 421 patients scheduled for primary or secondary prevention ICD implantation underwent CMR at 1.5 or 3T, including cine and late gadolinium enhancement (LGE) imaging. EAT volume surrounding both ventricles was quantified with manual delineation on cine short-axis images and calculated by summation of EAT volume of each slice using the modified Simpson rule. LGE was semiautomatically quantified by adjusting a grayscale threshold. The primary endpoint was a composite of ICD therapy, including anti-tachycardia pacing and SCD. Results: We identified 265 NICM patients (mean age 54 years, 73% men), with LGE present in 152 patients (57%), including 85 patients (32%) with secondary prevention ICD. During the median follow-up of 2.9 years, 42 patients (16%) experienced the endpoint. Low EAT was associated with an increased risk of SCD in NICM patients (HR ad per 10ml decrease, 1.54; 95%CI, 1.19-1.96, p<0.001), even after adjustment for other relevant disease variables. A continuous relationship was evident between EAT and subsequent ICD therapies (p=0.001). Even when considering 85 patients with secondary prevention ICD as theoretically having an SCD event, the risk of EAT in predicting SCD remained essentially unchanged. In contrast, EAT was not associated with increased SCD risk in ICM patients. Conclusions: Low EAT was associated with increased SCD risk in NICM patients receiving ICD implantation, especially primary prevention ICD. These data suggest a potential role of EAT in identifying NICM patients at risk of SCD.