Left ventricular hypertrophy and risk reclassification for coronary events in multi-ethnic adults

Abstract

Left ventricular hypertrophy (LVH) has not been evaluated for reclassification improvement in the intermediate Framingham risk category for incident hard coronary events in a large multi ethnic population free of cardiovascular disease at baseline. A post-hoc analysis on the Multi Ethnic Study of Atherosclerosis (MESA) dataset (n = 4921) was performed. LVH was defined as the upper 95 th percentile of cardiac magnetic resonance imaging derived left ventricular mass (LVM) indexed based on body surface area (BSA) and height. Multivariate Cox proportional hazards models were used to assess the independent association between LVH and composite outcomes like all cardiovascular disease (CVDa) and hard coronary heart disease (CHDh) events over a mean follow-up period of 4.5 years. To assess the incremental value of LVH over traditional CV risk factors for CHDh prediction, we compared the discrimination, calibration and net reclassification index (NRI) of models comprising of traditional CV risk factors with and without LVH. LVH derived from LVM indexed by BSA (LVH-BSA) and height(1.7)(LVH-height) showed an independent association with CVDa (LVH-BSA: hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.05-2.20, p = 0.03; LVH-height(1.7): HR 1.58, 95% CI 1.14-2.18, p = 0.012) and CHDh (LVH-BSA: HR 2.36, 95% CI 1.37-4.04, p = 0.002; LVH-height(1.7): HR: 1.95, 95% CI: 1.17-3.26, p = 0.01). Addition of LVH to the model based on traditional CV risk factors demonstrated no significant improvement in NRI for CHDh in either the entire cohort (LVH-BSA: NRI 1.7%, 95% CI: -8.3% to 11.7%, p = 0.74; LVH-height(1.7): NRI 2.7%, 95% CI: -5.8% to 11.3%, p = 0.62) or the intermediate risk group (LVH-BSA: NRI 12.0%, 95% CI: -5.7% to 29.8%, p = 0.19; LVH-height(1.7): NRI 14.5%, 0.1% to 28.8%, p = 0.05). Although an independent predictor of cardiovascular events, LVH does not lead to clinically meaningful reclassification of the overall and intermediate risk population for CHDh.