Sex and Race/Ethnicity Differences in Atrial Fibrillation

Abstract

Atrial fibrillation (AF), a worldwide epidemic, contributes to frequent hospitalizations, stroke, heart failure, disability, mortality, and health-resource consumption (1). AF affects people differently with regard to sex, race, ethnicity, and socioeconomic status, and reviews of these differences have highlighted related care disparities. Accordingly, the American College of Cardiology’s Cardiovascular Disease in Women Committee sought to compare these findings in patients with AF to identify potential interventions that may help to rectify disparities of care. This writing group reviewed >200 English-language papers about these disparities to summarize them and identify important knowledge gaps. The most pertinent findings are presented here with recommendations to decrease these disparities in the future. Globally, it is estimated that 23.1 million women and 23.2 million men had AF (atrial fibrillation and atrial flutter) in 2016, with numbers expected to rise (1). The prevalence of AF in the United States was 5 million in 2010 and is projected to be ∼12 million by 2030; the cost was ∼26 billion U.S. dollars in 2005 (1). Men of European ancestry have a higher incidence and lifetime risk of developing AF. We found publications of racial/ethnic differences compared Non-Hispanic whites to blacks, as well as considerable differences by sex and socioeconomic status. Differences in sex and race/ethnicity of patients with AF exist in: 1) epidemiology; 2) lifetime stroke risk; 3) mortality; 4) symptoms and quality of life; and 5) treatment. After adjustment for risk factors, compared with their white counterparts, other races/ethnicities had lower incidence rates of AF: blacks (hazard ratio [HR]: 0.84; 95% confidence interval [CI]: 0.82 to 0.85), Hispanics (HR: 0.78; 95% CI: 0.77 to 0.79), and Asians (HR: 0.78; 95% CI: 0.77 to 0.79; all p < 0.001) (2). The overall lifetime risk of AF comparing sexes appears similar, yet AF does not affect women and men similarly at any given age. The lifetime risk and age-adjusted incidence rates vary by sex, race/ethnicity, and risk factor burden. The lifetime risk of AF according to risk factor burden, after adjustment for competing risk of death at age 55 years, is higher in men compared with women (optimal risk factor burden: men 29.8%, women 20.5%; borderline risk factor burden: men 39.7%, women 28.0%; elevated risk factor burden: men 43.3%, women 34.6%) (3). Whites have a higher incidence than blacks, and white men have a higher incidence than white women for all levels of risk factor burden, including smoking, alcohol consumption, body mass index, blood pressure, and diabetes (2,4). In patients with the elevated risk factor burden, the incidence rate of AF (mean age 54.2 years) per 1,000 person-years adjusted for age was higher in whites compared with blacks (white men 9.1, black men 6.0, white women 6.0, black women 4.1) (4). In the ARIC (Atherosclerosis Risk In Communities) cohort, the lifetime AF risk varied by sex in whites but not in blacks among people age 45 to 55 years (5). White men had a 36% lifetime risk of developing AF versus 30% in white women. Black women had a 22% lifetime risk of developing AF versus 21% in black men (5). The Framingham Heart Study (European ancestry) suggested that at age 55 years, the lifetime risk of AF varied by sex, as well as by the presence and burden of AF risk factors, as summarized in Figure 1 (3). Also, white men and women have a higher lifetime risk of developing AF versus their black counterparts (5).