Echocardiographic Predictors of Sudden Cardiac Death : The Atherosclerosis Risk in Communities Study and Cardiovascular Health Study

Abstract

<div class="section"> <a class="named-anchor" id="S1"> <!-- named anchor --> </a> <h5 class="section-title" id="d8483011e257">Background</h5> <p id="P1">This study assessed the echocardiographic predictors of sudden cardiac death (SCD) within two population-based cohorts. </p> </div><div class="section"> <a class="named-anchor" id="S2"> <!-- named anchor --> </a> <h5 class="section-title" id="d8483011e262">Methods and Results</h5> <p id="P2">Echocardiograms were obtained on 2383 participants (1993–95) from the Atherosclerosis Risk in Communities (ARIC) Study (100% African-American) and 5366 participants (1987–89 and 1994–95) from the Cardiovascular Health Study (CHS). The main outcome was physician-adjudicated SCD. We used Cox proportional hazards models with incident coronary heart disease (CHD) and heart failure as time-dependent covariates to assess the association between echocardiographic variables and SCD, adjusting for Framingham risk score (FRS) variables, CHD, and renal function. Cohort-specific results were meta-analyzed. During a median follow-up of 7.3 years and 13.1 years, 44 ARIC Study and 275 CHS participants had SCD, respectively. In the meta-analyzed results, the adjusted hazard ratios (95% confidence intervals) for predictors of SCD were 3.07 (2.29–4.11) for reduced left ventricular ejection fraction (LVEF); 1.85 (1.36–2.52) for mitral annular calcification; 1.64 (1.07–2.51) for mitral E/A &gt;1.5 and 1.52 (1.14–2.02) for mitral E/A &lt;0.7 (vs mitral E/A 0.7–1.5); 1.30 (1.15–1.48) per one standard deviation (SD) increase in left ventricular mass; and 1.15 (1.02–1.30) per one SD increase in left atrial diameter. A receiver-operating characteristic model for prediction of SCD using FRS variables had a c-statistic of 0.61 for ARIC and 0.67 for CHS; the full multivariable model including all echocardiographic variables had a c-statistic of 0.76 for ARIC and 0.74 for CHS. </p> </div><div class="section"> <a class="named-anchor" id="S3"> <!-- named anchor --> </a> <h5 class="section-title" id="d8483011e267">Conclusions</h5> <p id="P3">In addition to reduced LVEF, we identified other echocardiographic-derived variables predictive for SCD that provided incremental value over clinical risk factors. </p> </div>