A-Fib May Be Bigger Threat to Women's Brains Than Men's

MONDAY, June 26, 2023 (HealthDay News) -- A new study finds that women with a common form of irregular heartbeat may be at greater risk for cognitive decline than men.

Atrial fibrillation, or a-fib, is linked with a higher risk for mental decline and dementia, possibly because it also more than doubles a person's risk for mini-strokes. These episodes, which often go unnoticed, can lead to impaired brain function. In addition, women with a-fib are less often prescribed blood thinners to prevent stroke than men, according to researchers.

"Women tend to be diagnosed later with a-fib than men, so they already have additional risk factors for cognitive decline, such as [high blood pressure], heart valve disease or heart failure," said lead researcher Kathryn Wood, an associate professor in the School of Nursing at Emory University in Atlanta.

She said women also have a higher risk of stroke and death once a-fib is diagnosed. When strokes do occur, women have double the risk of severe, disabling or fatal stroke compared to men.

People with a-fib have a fivefold increased risk of stroke compared with those without the condition, so having patients take blood thinners to prevent stroke is a key to treating a-fib, Woods said.

Women with a-fib, however, are significantly less likely to receive blood thinners than men, adding to their risk for the silent mini-strokes that may lead to gradual cognitive decline, she said.

"Because some studies have shown that patients with a-fib who are on blood thinners develop cognitive disease less frequently, patients with a-fib should discuss use of blood thinners with their doctor," Wood said.

For the study, Wood's team collected data on more than 43,600 men and women in the National Alzheimer’s Coordinating Center database. Of these, nearly 4,600 had a-fib.

Researchers found that women with a-fib were three times more likely to have mild mental impairment and dementia than women without a-fib. The link between a-fib and dementia among men was not statistically significant, they noted.

Over a median follow-up of four years, 30% of participants progressed to a worse stage of cognitive impairment and 21% developed dementia. Women with a-fib had a higher risk of worsening mental impairment than women without a-fib.

Women with a-fib were more likely to progress from normal cognition to mild impairment and from mild impairment to dementia, Woods said.

"There is an underutilization of anticoagulation for everybody with a-fib," said Dr. Laurence Epstein, system director of electrophysiology at Northwell Health’s Sandra Atlas Bass Heart Hospital in Manhasset, N.Y.

Anticoagulants are medications to prevent blood clots.

"Only about 50% of people with a-fib are anticoagulated, and there is data that suggest there's also a gap between men and women and it's not a very tiny trivial difference," said Epstein, who was not involved in the study.

Epstein said a-fib can also be a sign of other heart issues that can lead to dementia like high blood pressure and hardening of the arteries (atherosclerosis). These conditions aren't always treated as aggressively in women as they are in men, he pointed out.

"There's lots of things we don't understand and there may be things about female physiology and hormones and clotting factors that put them at higher risk," Epstein said.

Simply put: Anyone with a-fib should be receiving blood thinners, he said.

"We have plenty of data that by doing so you dramatically reduced your risk of a major disabling or life-threatening stroke," Epstein said. "That alone should be enough."

It's not clear if people with a-fib are having mini-strokes that affect their mental functioning and lead to dementia, he said.

"Whether that's true or not, I don't know, but there are good enough reasons to be anticoagulated," Epstein said.

The findings were published June 23 in the journal Alzheimer's and Dementia to coincide with presentation of the findings at a meeting of the European Society of Cardiology in Edinburgh, Scotland.

More information

For more on atrial fibrillation, visit the American Foundation for Women's Health's Stop A-Fib.

SOURCES: Kathryn Wood, PhD, associate professor, nursing, Emory University, Atlanta; Laurence Epstein, MD, system director, electrophysiology, Northwell Health Sandra Atlas Bass Heart Hospital, Manhasset, N.Y.; Alzheimer's and Dementia, June 23, 2023; presentation, European Society of Cardiology meeting, Edinburgh, Scotland, June 23, 2023