Abstract 8917: Ankle-Brachial Index and Risk of Sudden Cardiac Death in the Community: The Atherosclerosis Risk in Communities (ARIC) Study

Abstract

Introduction: Sudden cardiac death (SCD) is an important public health problem. About 356,000 people suffer SCD in the U.S., accounting for 15% of all deaths. The ankle-brachial index (ABI) is a simple, non-invasive measure of subclinical atherosclerosis. The aim of this study was to determine the relation between ABI and SCD in a middle-aged biracial general population. Methods: All ARIC (Atherosclerosis Risk in Communities) study subjects with a documented ABI measurement between 1987 and 1989 were included in the study. ABI was categorized as abnormal (≤0.9), borderline (0.9-1), normal [1-1.4], and non-compressible (>1.4). SCD was defined as a sudden pulseless condition presumed to be caused by a ventricular tachyarrhythmia in a previously stable individual. All SCD cases were adjudicated by a committee of cardiac electrophysiologists, cardiologists, and internists. Results: Of the 15,135 participants followed for a median of 23.5 years, 558 (3.7%) developed SCD (1.96 cases per 1000 person-years). Abnormal or borderline ABIs were associated with an elevated risk of SCD (HRs with 95 % CIs 2.27 [1.64-3.14] and 1.52 [1.17-1.96], respectively) in comparison to normal ABI. The association between abnormal ABI and SCD remained significant after adjustment for traditional cardiovascular risk factors, but not for borderline ABI (HR 1.63 [1.15-2.32] and 1.24 [0.94-1.63]) (Table). Conclusions: Abnormal ABI is independently associated with risk of SCD in a biracial general population. ABI could be incorporated into a future risk SCD prediction model.