Challenging conventional wisdom: AFib and the sexes

By Samar Mahmoud, PhD | Medically reviewed by James Beckerman, MD, FACC
Published October 24, 2022

Key Takeaways

  • Traditionally, research has suggested that men are at increased risk of developing atrial fibrillation (AFib). However, emerging research has shown that when height is adjusted for, women are at higher risk of developing AFib than men.

  • Increased height, BMI, and age are additional risk factors for developing AFib.

  • Clinicians should prioritize discussing AFib risk with their female patients.

Emerging research could flip conventional wisdom about women's risk of developing atrial fibrillation (AFib) compared with that of men.

Clinicians should follow this research and make a point of discussing this potential risk with women.

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.[]

By 2060, 17.9 million are projected to have AFib in Europe.

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.[] 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.[] 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.

Strikingly, researchers found that there was a correlation between atrial fibrillation risk in women and height, height and weight, or body surface area.

“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.[] “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."

Christine Albert, MD, MPH

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.[]

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.[]

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.

Age is also a well-known risk factor for AFib, with an increase in the incidence of AFib occurring with advancing age in both men and women.

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.[] 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.

What this means for you

Conventional wisdom has long held that men were at increased risk of developing AFib. However, emerging research has challenged this traditional view by demonstrating that when height is accounted for, women are actually at increased risk of developing AFib. This information, coupled with the gaps in management of AFib for women, emphasizes the need for clinicians to discuss risks of AFib with their women patients.

Read Next: Medical myth-busters: The facts about atrial fibrillation

In our Women's Health Focus feature, we'll offer insights and practical guidance to support you in providing the comprehensive and personalized care that women need throughout their life stages. We invite you to submit any topic you'd like to see covered and let us know if you'd like to be a guest author.

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