PO-03-230 LEFT VENTRICULAR FUNCTION IN SUDDEN CARDIAC DEATH DUE TO ISCHEMIC AND NONISCHEMIC HEART DISEASE

Abstract

Sudden cardiac death (SCD) remains a major public health problem. Severe left ventricular (LV) dysfunction (EF ≤ 35%) increases the risk of SCD and is the most important indication for prophylactic implantable cardioverter defibrillator (ICD). Previous studies have shown that subjects with EF ≤ 35% represent a minority of all SCD cases. However, it has been unclear whether ischemic and nonischemic cardiac diseases present with different LVEF prior to SCD. We sought to evaluate the spectrum of LVEF among SCD victims with ischemic and nonischemic etiologies. Our study population is drawn from the Fingesture study, which has prospectively collected autopsy and clinical data from consecutive SCD victims from Northern Finland between 1998 and 2017. The cause of death was verified to be of cardiac origin in a medicolegal autopsy in all cases. Cases with ischemic SCD had evidence of coronary artery disease and ischemic cardiomyopathy at autopsy. Electronic health records were examined to identify subjects who underwent evaluation for LV function before SCD. LV function was categorized by quantitative assessment of LVEF as normal (EF ≥ 50%), reduced (50% > EF > 35%), and severely reduced (EF ≤ 35%). In all cases, echocardiography was unrelated to the SCD event. Left ventricular assessment was available in 717 SCD victims. The majority of subjects (n=449, 62.7%) had normal LVEF prior to SCD. The prevalence of reduced LVEF was 21.9%, while severely reduced LVEF was found only in 110 subjects (15.4%). Men were more likely to have LV dysfunction than women (45.9% vs 29.6%; p<0.001). In addition, LVEF was found to be severely reduced more commonly in men compared to women (17.4% vs 10.9% respectively; p<0.001). In SCD victims with ischemic and nonischemic heart disease, LV dysfunction was equally common (37.7% vs 36% respectively; p=0.72). The prevalence of severely reduced LVEF was also similar between ischemic SCD and nonischemic SCD (15.1% vs. 16.3%, respectively; p=0.72). Only one third of SCD cases had ventricular dysfunction and only one in seven had severely reduced LVEF prior to their SCD event, suggesting that only a minority of SCD victims meet the current criteria for primary prevention ICD. We found no difference in the spectrum of LVEF between ischemic and nonischemic heart diseases. However, women were found to have preserved LV function more often than men, highlighting the importance of developing novel SCD risk stratification tools beyond LVEF.