Abstract 19577: Race and Sudden Cardiac Death: Findings From the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study
Introduction: Blacks, as compared to whites, have a higher burden of cardiovascular disease (CVD) risk factors and CVD. Recent studies have reported a higher burden of sudden cardiac death (SCD) in blacks; however, it remains unclear whether this elevation in SCD risk is independent of racial differences in risk factor profiles and prevalent CVD.
Methods: We examined the association between black race and SCD in participants with and without a history of CVD at baseline in the REGARDS study, a prospective, longitudinal cohort of 29,695 participants ≥45 years (55% women, 41% black) from across the United States. SCD was defined as sudden pulselessness from a presumed cardiac origin that occurred out of hospital or in the emergency room.
Results: Over a median [IQR] of 6.0 [4.5-7.3] years of follow-up, 388 SCD events occurred. Compared to whites, blacks had less education, lower income and a higher burden of CVD risk factors. In the entire population, the age-adjusted SCD incidence rates per 1000 person-years were 2.6 (95% CI, 2.3-3.0) for blacks versus 1.7 (95% CI, 1.4-1.9) for whites, (HR=1.47; 95% CI 1.20-1.79). This elevated risk was attenuated after controlling for CVD risk factors and became non-significant after controlling for prevalent CVD (Table 1). Among the subgroup of 22,507 participants without CVD at baseline, SCD risk remained elevated in blacks (HR=1.90; 1.35-2.68) even after controlling for CVD risk factors and medication use (Table 1). In contrast, there was no elevation in SCD risk among the participants with prevalent CVD at baseline. The association between black race and SCD was stronger in those without compared to those with a history of CVD (p=0.001).
Conclusions: The higher risk of SCD risk associated with black race, compared to whites, is partially explained by the higher prevalence of CVD and its risk factors in blacks. However, there remains a higher SCD risk associated with black race among those without CVD not explained by standard CVD risk factors.
Author Disclosures: R. Deo: None. Y. Khodneva: None. M.M. Safford: None. S. Judd: None. E.Z. Soliman: None. M.G. Shlipak: None. C.M. Albert: None.
- © 2015 by American Heart Association, Inc.