Abstract 12785: Abnormal Dynamic Remodeling of the 12-Lead Electrocardiogram is a Risk Marker for Sudden Cardiac Death

Abstract

Introduction: The ECG has always been evaluated as static risk factor for sudden cardiac death (SCD). The importance of dynamic ECG remodeling has not been investigated. Hypothesis: Abnormal ECG remodeling over time is associated with increased risk of SCD. Methods: We investigated pre-SCD ECG remodeling in SCD cases from 2 ongoing population-based studies of out-of-hospital SCD in Portland, OR (discovery) and Ventura County, CA (validation). Two archived pre-SCD ECGs performed at least 1 year apart were obtained from lifetime health records. Controls were matched on geographical region, age, sex, and duration between the 2 ECG recordings. Dynamic ECG remodeling was measured as the change in a previously validated cumulative 6-variable ECG electrical risk score (ERS) between the 1st and 2nd ECG. Results: A total of 231 SCD cases (66.5±13.6 years, 61% male), and 234 controls (65.8±11.1 years, 61% male) were included in the discovery cohort, and 203 SCD cases (70.3±14.4 years, 54% male), and 203 controls (68.4±11.8 years, 54% male) in the validation cohort. The mean time between the 2 ECG recordings in SCD cases and controls was 6.0±4.0 years vs 6.2±4.5 years (discovery) and 3.7±2.6 years vs. 3.7±1.6 years (validation), respectively. In both cohorts, SCD cases compared to controls had greater dynamic ECG remodeling over time: Discovery cohort ERS change +1.06 (95% CI +0.89 to +1.24) vs. -0.05 (-0.21 to +0.11; p<0.001) and validation cohort ERS change +0.87 (+0.7 to +1.04) vs. -0.11 (-0.27 to 0.05; p<0.001). In a multivariate model including clinical SCD risk factors, a 1-unit increase in the ERS was an independent risk marker for SCD: Discovery cohort OR 1.89 (95% CI 1.58-2.26; p<0.001), validation cohort OR 2.17 (95% CI 1.63-2.91; p<0.001). Conclusions: SCD cases were observed to have abnormal dynamic ECG remodeling prior to the SCD event, not observed in matched controls. These findings warrant further investigation of dynamic ECG remodeling as a novel risk marker for SCD.