A new study from Tulane University challenges the long-held assumption in cardiac care that being female automatically increases the risk of stroke in patients with atrial fibrillation, a common condition in which the heart beats irregularly.
This research JACC: Progressfound that the risk of stroke was not equally increased in all female patients with atrial fibrillation. Rather, the study suggests that being female is something of a risk modifier, with increased stroke risk primarily seen in women over age 75 or with a greater burden of other health conditions.
AFib is the most common heart rhythm disorder and increases the risk of stroke, which is often treated with blood thinners. The findings could change the way we think about how often women are prescribed blood thinners and how they compare to men who have an otherwise similar risk profile.
For many years, female gender was included as a risk factor, along with other factors such as high blood pressure and diabetes, meaning that women were more likely to be prescribed anticoagulants. Our study shows that younger women may not have as much increased risk of stroke as previously thought, but older women, particularly those over 75, appear to have a higher risk that requires close attention. ”
Dr. Amitabh C. Pandey, Co-corresponding author, Director of Translational Cardiovascular Research, Tulane University School of Medicine
To determine whether a patient with atrial fibrillation should be prescribed blood thinners, clinicians typically use a scoring system that assigns points to risk factors such as age, heart failure, diabetes, history of stroke, vascular disease, and hypertension. Under that system, women can earn one point just for having sex.
This could allow women with atrial fibrillation to receive blood thinners sooner or more frequently than men. These drugs can help prevent blood clot-related strokes, but they can also increase the risk of bruising, prolonged bleeding, gastrointestinal bleeding, and other serious complications.
“This common approach stems from the underrepresentation of women in AFib trials and studies, who make up only about one-third of the study population,” said co-author Dr. Han Feng, assistant professor of medicine at Tulane University School of Medicine. “Our study shows that not all women with atrial fibrillation have the same risk profile, and these decisions must be made on an individual basis.”
Tulane researchers analyzed approximately 950,000 AFib patients using TriNetX, a large de-identified electronic health records database, and compared stroke outcomes in male and female patients across three age groups: <65 years, 65-74 years, and 75 years and older. The researchers matched male and female patients based on age, other health problems, and whether they were prescribed anticoagulants to allow for more direct comparisons.
The study found no significant difference in 1-year stroke risk between men and women in patients younger than 75 years. However, among patients over 75 years of age, women showed a small but statistically significant increased risk of stroke compared with men.
Among patients aged 75 years and older with no additional risk factors other than age, women had approximately 1 more stroke per 629 patients than men.
This finding supports the growing interest in a new AFib risk score framework, called the CHA2DS2-VA score, which excludes gender as an independent risk factor. Still, the researchers said additional research is needed and medical guidance remains inconsistent.
“These findings highlight the need for modern tools and approaches that can personalize risk profiles,” Pandey said. “The goal is not to undertreat patients who need stroke prevention, but to better identify who is most likely to benefit from anticoagulation therapy and who may be exposed to unnecessary risks.”
sauce:
Reference magazines:
Female sex is not a uniform risk factor for atrial fibrillation. Journal of the American College of Cardiology. DOI: 10.1016/j.jacadv.2026.102826
