Income, education, traditional factors may confer sudden cardiac death risk in black adults
Black adults, particularly women, have a much higher risk for out-of-hospital sudden cardiac death compared with white adults, with income, education and traditional factors likely explaining much of the racial differences, according to findings published in Circulation.
Di Zhao, PhD, of the departments of epidemiology and medicine and the Welch Center for Prevention, Epidemiology and Clinical Research at Johns Hopkins University Bloomberg School of Public Health, and colleagues examined a cohort study of 3,832 black participants and 11,237 white participants in the ARIC study to estimate the lifetime cumulative risk for sudden cardiac death.
“The association between race and [sudden cardiac death] has been further examined in clinical studies of participants with pre-existing conditions, such as hypertension,” Zhao and colleagues wrote. “Nevertheless, the racial differences in the cumulative risk of [sudden cardiac death] and the reasons for these differences have not been assessed in large-scale community-based cohorts.”
Potential mediators were demographic and socioeconomic factors, CV risk factors, presence of CHD and electrocardiographic parameters as time-varying factors, the researchers wrote.
Mean age was 54 years for black and white participants, and median follow-up was 27.4 years, researchers wrote.
During follow-up, 215 black participants and 332 white participants experienced sudden cardiac death. The lifetime cumulative incidence of sudden cardiac death at age 85 years was 9.6% for black men, 6.6% for black women, 6.5% for white men and 2.3% for white women.
After adjustment for sex, black participants had greater risk for sudden cardiac death compared with white participants (HR = 2.12; 95% CI, 1.79-2.51). According to Zhao and colleagues, the association was attenuated but still statistically significant in fully adjusted models (HR = 1.38; 95% CI, 1.11-1.71).
Known factors explained 65% (95% CI, 37.9-92.8) of excess sudden cardiac death risk when comparing black participants with white participants in mediation analysis.
According to the researchers, important factors were income (50.5%), education (19.1%), hypertension (22.1%) and diabetes (19.6%).
“Low income and education are associated with unhealthy behaviors, low disease awareness and limited access to care, which could all contribute to poor outcomes,” Eliseo Guallar, MD, DrPh, from the departments of epidemiology and medicine and the Welch Center for Prevention, Epidemiology and Clinical Research at Johns Hopkins University Bloomberg School of Public Health, said in a press release. “However, our understanding of the mechanisms for racial differences in sudden cardiac death is still incomplete and additional research is needed.”
Racial differences were evident in both sexes but stronger in women than in men, the researchers wrote, and further studies are needed to explain the underlying cause of increased sudden cardiac death risk in black adults and to determine whether targeted clinical practice that takes race into account can provide a better approach for risk-stratified prevention and therapy for sudden cardiac disease.
“The high burden of [sudden cardiac death] and the racial-gender disparities observed in our study represent a major public health and clinical problem,” Zhao and colleagues wrote. – by Earl Holland Jr.
Disclosures: The authors report no relevant financial disclosures.