Race/ethnic inequalities in cardiovascular disease: Examining burden mitigation in low-risk black Americans (multi-cohort study)

BackgroundWhile the greater burden of cardiovascular disease (CVD) in black Americans relative to white has persisted for four decades, mitigation of this disparity via clinical and non-clinical intervention is largely untested. We examined the relative impacts of targeting conventional risk factors (e.g., diabetes) and the social determinants of health (e.g., education). MethodsIn this multicohort study, we used baseline ethnicity and risk factor data from the US National Health and Nutrition Examination Survey (NHANES, 10 cohorts initiated 1999-2018) with study member linkage to national registries for cause-specific mortality. Low risk was denoted by individual risk factors and their combination. Cox proportional hazard regression models were used to summarise the association of race/ethnicity with CVD mortality. ResultsAn analytical sample of 50,065 individuals (25,934 women; mean baseline age 53) contributed 473,949 person-years at risk (mean follow-up 9.5 yr), giving rise to 9118 deaths (2908 from CVD). In age- and sex-adjusted analyses, as anticipated, relative to whites, black Americans had a markedly higher burden of CVD (hazard ratio; 95% confidence interval: 1.51; 1.30, 1.77) and other major causes of mortality. Black Americans classified as low-risk based on individual clinical risk indices (e.g., normotensives: 1.58; 1.22, 2.04) and the Framingham algorithm (2.94; 2.04, 4.25) continued to experience higher rates of CVD relative to white individuals. A marked reduction in this disparity was, however, apparent in black versus white Americans who had one (1.09; 0.78, 1.51), two (0.99; 0.67, 1.48), and three or more (1.31; 0.81, 2.12) favourable social determinants. A similar pattern of results was evident for total mortality. ConclusionsWhile disparities in CVD continued to be apparent in black people who had achieved treatment targets for clinical and lifestyle factors, those in favourable social circumstances had disease rates similar to white people with the same characteristics. Key pointsO_ST_ABSQuestionC_ST_ABSWhat is the impact of targeting clinical (e.g., diabetes) and non-clinical risk factors (e.g., education) in mitigating disparities in cardiovascular disease (CVD) between black and white Americans? FindingsIn this national multicohort study comprising 50,065 individuals, black Americans in favourable social circumstances, but not those achieving targets for clinical/lifestyle factors, had CVD rates similar to white people. MeaningReduction of current black-white inequalities in CVD seems to require modification of distal determinants.