Racial Differences in Heart Age and Impact on Mortality.

BACKGROUND: Heart age is an estimate of the age of a person's cardiovascular system given their cardiovascular disease (CVD) risk factors. The difference between a person's chronological age and heart age (excess heart age) represents their added CVD risk.

OBJECTIVE: To examine racial differences in excess heart age and whether race impacts the association between excess heart age and CVD mortality.

METHODS: This analysis included 5110 participants (2449 non-Hispanic white, 1287 non-Hispanic black, and 1374 Mexican-American) from the NHANES III who were free of CVD. Heart age was calculated using the sex-specific non-laboratory-based Framingham risk prediction functions. Multivariable Cox proportional-hazards regression models were used to evaluate the relationship (overall and by race) between excess heart age and CVD mortality.

RESULTS: Mean excess heart age was greatest in non-Hispanic blacks (13.0 years), followed by Mexican-Americans (10.5 years), and non-Hispanic whites (8.5 years); p < 0.001 for pairwise differences. Over a mean follow-up of 13.0 years, 394 CVD deaths occurred. Each 10 years of excess heart age was associated with 65% increased risk of CVD mortality (HR, 95% CI: 1.65, 1.53-1.78). This association was stronger in non-Hispanic whites (1.83, 1.63-2.02) compared to non-Hispanic blacks (1.50, 1.29-1.72) and Mexican American (1.60, 1.33-1.87), interaction p = 0.065.

CONCLUSIONS: Compared to non-Hispanic whites, non-Hispanic blacks and Mexican Americans have more excess heart age, but the risk of CVD death for the same level of excess heart age appears more pronounced in non-Hispanic whites. Further investigation is needed to show the usefulness of these findings in directing future efforts and resource allocation for reduction of health disparities between ethnic groups.