Abstract
OBJECTIVES: The aim of this study was to evaluate racial differences in arterial elastance (Ea), which reflects the arterial afterload faced by the left ventricle, and its associations with cardiac structure and function. The hypothesis under study was that the left ventricle in blacks displays heightened afterload sensitivity compared with whites. BACKGROUND: Chronic increasing in arterial afterload may be an important trigger for left ventricular (LV) remodeling and dysfunction that lead to heart failure. Racial differences in the predisposition to heart failure are well described, but the underlying mechanisms remain unclear. METHODS: In total, 5,727 community-based, older ARIC (Atherosclerosis Risk In Community) study participants (22% black) who underwent echocardiography between 2011 and 2013 were studied. RESULTS: Blacks were younger (mean age 75 ± 5 years vs. 76 ± 5 years), were more frequently female (66% vs. 57%), and had higher prevalence rates of obesity (46% vs. 31%), hypertension (94% vs. 80%), and diabetes mellitus (47% vs. 34%) than whites. Adjusting for these baseline differences, Ea was higher among blacks (1.96 ± 0.01 mm Hg/ml vs. 1.80 ± 0.01 mm Hg/ml). In blacks, Ea was associated with greater LV remodeling (LV mass index, β = 3.21 ± 0.55 g/m(2), p < 0.001) and higher LV filling pressures (E/e' ratio, β = 0.42 ± 0.11, p < 0.001). These relationships were not observed in whites (LV mass, β = 0.16 ± 0.32 g/m(2), p = 0.61, p for interaction <0.001; E/e' ratio, β = -0.32 ± 0.06, p < 0.001, p for interaction <0.001). CONCLUSIONS: These community-based data suggest that black Americans display heightened afterload sensitivity as a stimulus for LV structural and functional remodeling, which may contribute to their greater risk for heart failure compared with white Americans.