Black adult AFib risk linked to higher resting heart rates

In a study of nearly 5,000 Black adults, a relatively higher resting heart rate was associated with increased risk of new-onset atrial fibrillation (commonly called “AFib”), an irregular heartbeat that can have serious consequences. 

The findings were published Oct. 30 in JAMA Network Open. The study’s lead author, Dr. Vid Yogeswaran, is a cardiologist at the University of Washington (UW) School of Medicine. 

“This study is useful because, among Black adults, we know little about risk factors for cardiovascular disease — and specifically for AFib, which can lead to heart failure, stroke, dementia and death,” Yogeswaran said. “Paradoxically, Black adults have a lower reported clinical prevalence of atrial fibrillation than white adults, but have a much higher risk of AFib-associated consequences such as stroke and death.” 

She and colleagues analyzed data from the Jackson Heart Study, a longitudinal research inquiry focused on the cardiovascular health of adult Black patients in Jackson, Mississippi. 

The records of patients who had no AFib diagnosis in the year 2000 were reviewed through 2016 for resting heart rate and new-onset AFib. Among 4,965 participants (average age 55), the average baseline resting heart rate was 65 beats per minute. 

During the follow-up span of almost 14 years, 458 participants experienced AFib events. Each 10 beats-per-minute higher resting heart rate was associated with a 9% higher risk of developing AFib. 

The risk was greater in Black adults without cardiovascular disease and in people not on antiarrhythmic medications. 

The association between resting heart rate and AFib was seen independent of other known AFib risk factors. The researchers found no difference in effect across patients’ age, sex, hypertension status, body mass index or extent of moderate to vigorous physical activity. 

Atrial fibrillation is the most common heart rhythm disorder. It is managed with lifestyle changes, medications and procedures. A paper published in September estimated that at least 10 million Americans live with the condition’s symptoms, which can include palpitations, lightheadedness and fatigue. 

Previous studies of AFib have mostly involved people of European descent, and evidence about the relationship between resting heart rate and the condition has been inconsistent. 

“Some studies say it's only low (resting heart rate that poses risk for AFib). Some studies say it's only high. None of the studies has been powered enough to detect the resting-heart-rate risk among Black adults,” Yogeswaran said. 

“Our paper shows that high resting heart rate is the risk among Black adults.” 

The finding “underscores the importance of resting heart rate as a measure to estimate the risk of AFib in Black adults,” the authors wrote. More research is needed, they added, to determine whether considering a patient's resting heart rate can improve the selection of individuals for AFib screening. 

The paper’s other contributors represent the UW Cardiovascular Health Research Unit and UW School of Public Health, the Inova Heart and Vascular Institute of Virginia, Boston University’s schools of Medicine and Public Health, and the University of Mississippi Medical Center.

Funders for the study included the National Institutes of Health (R01HL092577), the American Heart Association (AHA_18SFRN34110082, HHSN26818HV00006R), the National Heart, Lung, and Blood Institute and the National Institute on Minority Health and Health Disparities (HHSN2682018000131, HHSN2682018000141, HHSN2682018000151, HHSN2682018000101, HHSN2682018000111 and HHSN2682018000121).

The authors’ conflict-of-interest statements are in the published paper, which will be provided upon request.  

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