AFib Doubles Risk of Heart Attack in Women

New research reveals that atrial fibrillation—a well-established risk factor for stroke—also increases the risk for heart attack. In fact, it more than doubles that risk in women and African Americans, according to recent research in JAMA Internal Medicine.¹

“Our results show that AF is bad for all, but it is worse for women and African Americans,” says lead study author Elsayed Z. Soliman, MD, director of the Epidemiological Cardiology Research Center at Wake Forest Baptist in Winston-Salem, N.C. “So although women and African Americans need more education about the higher risk of heart attacks associated with AF, the education is needed for all.” AF, or irregular heartbeat, affects an estimated 2.66 million Americans, and that number is expected to grow to as many as 12 million by 2050.²

These findings add to growing concerns of AF as a public health burden. Soliman and his colleagues examined the association between atrial fibrillation and the risk of myocardial infarction in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a large biracial population-based cohort study. The participants were enrolled between 2003 and 2007, with follow-up through December 2009. Out of the 23,928 patients in the study, the researchers identified 1,631 with AF.

Overall, the increase in risk of heart attack was about 70% in AF patients, even after accounting for other cardiovascular disease risk factors, such as hypertension, high cholesterol, body mass index, and history of stroke and vascular disease. However, when the researchers looked at subgroups, they found that increased risk of heart attack was more than doubled in women and African Americans with AF—but less than 50% for men and whites with AF.

“At this stage, there is no clear explanation for these sex and race differences; however, these findings add to the accumulating evidence of the sex and racial differences in cardiovascular disease,” Soliman says. Further investigation is needed to establish whether genetic background, emerging risk factors, access to health care, awareness, and adherence to medications contribute to these sex and racial differences.

“In our study, we observed that blood thinners that are used typically to prevent the risk of stroke in atrial fibrillation were associated with less risk of heart attacks as well,” Soliman says.

“This suggests that the same strategies to prevent stroke in patients with AF may also work for prevention of heart attacks.” However, Soliman stresses that the study was not designed to investigate preventive strategies. After he and his colleagues replicate their findings in other populations, their next step will be to identify the best strategy to prevent the risk of heart attacks in patients with AF while addressing the risk of stroke.

—Colleen Mullarkey

References

1. Soliman EZ, Safford MM, Muntner P, Khodneva Y, Dawood FZ, Zakai NA, et al. Atrial fibrillation and the risk of myocardial infarction. JAMA Intern Med. doi:10.1001/jamainternmed.2013.11912.

2. Lloyd-Jones D, Adams RJ, Brown TM, Carnethon M, Dai S, De Simone G, et al. Heart disease and stroke statistics—2010 update: a report from the American Heart Association. Circulation. 2010;121:e91.