Left ventricular hypertrophy and cardiovascular disease risk prediction and reclassification in blacks and whites: The Atherosclerosis Risk in Communities Study

Background Left ventricular hypertrophy (LVH) is a major independent predictor of cardiovascular disease (CVD) survival and is more prevalent in blacks than whites. In a large biracial population, we evaluated the ability of electrocardiography (ECG)-determined LVH (ECG-LVH) to reclassify CVD/coronary heart disease (CHD) events beyond traditional risk factors in blacks and whites. Methods The analysis included 14,489 participants (mean age 54 ± 5.7years; 43.5% men; 26% black) from the ARIC cohort, with baseline (1987-1989) ECG, followed up for 10 years. Predicted risk for incident CVD and CHD were estimated using the 10-year Pooled Cohort and Framingham risk equations (base models 1A/1B), respectively. Models 2A and 2B included respective base model plus LVH by "any" of 10 traditional ECG-LVH criteria. Net reclassification improvement (NRI) was calculated, and the distribution of risk was compared using models 2A and 2B versus models 1A and 1B, respectively. Results There were 792 (5.5%) 10-year Pooled Cohort CVD events and 690 (4.8%) 10-year Framingham CHD events. Left ventricular hypertrophy defined by any criteria was associated with CVD and CHD events (hazard ratio [95% CI] 1.62 [1.38-1.90] and 1.56 [1.32-1.86], respectively]. Left ventricular hypertrophy did not significantly reclassify or improve C statistic in models 2A/B (C statistics 0.767/0.719; NRI=0.001 [ P = not significant]), compared with the base models 1A/B (C statistics 0.770/0.718), respectively. No racial interactions were observed. Conclusions In this large cohort of black and white participants, ECG-LVH was associated with CVD/CHD risk but did not significantly improve CVD and CHD events risk prediction beyond the new Pooled Cohort and most used Framingham risk equations in blacks or whites.