Some women are at higher risk for developing atrial fibrillation (AFib) than men, according to emerging research.

This finding challenges prior research and emphasizes the importance of clinicians discussing this potential risk with women as well as men.

 

Surprising study results

It's estimated that by 2050, 6 to 12 million individuals worldwide will suffer from AFib, the most common cardiac arrhythmia, worldwide, according to a study published in International Journal of Stroke.

Lippi G, Sanchis-Gomar F, Cervellin G. Global epidemiology of atrial fibrillation: An increasing epidemic and public health challenge. Int J Stroke. 2021;16(2):217–221.

 

Significant sex differences in the incidence of AFib have been reported in the literature, with multiple studies demonstrating that the prevalence of AFib among middle-aged and elderly populations is around twice as high in males as in females, as reported in Circulation.

Magnussen C, Niiranen TJ, Ojeda FM, et al. Sex differences and similarities in atrial fibrillation epidemiology, risk factors, and mortality in community cohorts. Circulation. 2017;136(17):1588–1597.

But emerging research has called such findings into question.

 

In one study, investigators at the Smidt Heart Institute at Cedars-Sinai performed a prospective cohort analysis on 25,119 individuals.

Siddiqi HK, Vinayagamoorthy M, Gencer B, et al. Sex differences in atrial fibrillation risk: The vital rhythm study. JAMA Cardiol. 2022;7(10):1027–1035.

The mean age of study participants was 67 years; 51% of subjects were female. Over a median follow-up period of 5.3 years, investigators monitored subjects for AFib events.

 

“This is the first study to show an actual flip in the risk of atrial fibrillation,” said Christine Albert, MD, MPH, senior author of the study and chair of the Department of Cardiology in the Smidt Heart Institute.

Sex differences and AFib: New study flips conventional wisdom. Cedars Sinai. August 31, 2022.

“In this population of 25,000 individuals without prior heart disease, after adjusting for differences in height, women were at higher risk for developing AF than their male counterparts—upward of 50%.”

 

While previous research has shown that females are at lower risk of developing AFib, this study suggested this is because women tend to be shorter than men. However, in cases where a man and a woman have the same height, the woman is more likely to develop AFib.

Now the question has changed: Instead of why are women protected, now we must seek to understand why women are at a higher risk.

 

Additional risk factors

Increased height has been linked to a greater risk of developing AFib, possibly because taller individuals may have larger cardiac dimensions that make them more susceptible to arrhythmias, as documented in a study published by PLOS Medicine.

Levin MG, Judy R, Gill D, et al. Genetics of height and risk of atrial fibrillation: A Mendelian randomization study. PLoS Med. 2020;17(10):e1003288.

 

Research has demonstrated that for every one-inch increase to average height (identified as five feet, seven inches), an individual's risk of developing AFib increases by roughly 3%, as reported by Medical News Today.

Cohut M. Atrial fibrillation: Height could predict risk. Medical News Today. November 15, 2019.

 

Other than height, obesity and BMI are well-established risk factors for AFib. However, it remains unclear whether there are sex differences in the link between obesity and incidence of AFib.

 

Gaps in treating women

Women with AFib are at higher risk of stroke and death than men with the condition, according to an article published by Docwire News.

Diab A. The gaps in management of women with atrial fibrillation. Docwire News. September 21, 2022.

Studies have also demonstrated that women with AFib experience a longer duration of symptoms and worse quality of life scores compared with males, highlighting the need for better intervention and management strategies for women.

 

While AFib is sometimes managed by attempting to reset the heart’s rhythm back to normal, anticoagulants are also utilized to prevent stroke. However, studies have shown that women do not receive anticoagulation as often as men, with one study finding that 43.9% of men and 50% of women who were candidates for anticoagulation did not receive an anticoagulant, according to the DocWire News article.