Older Women Less Likely Than Men To Get Warfarin For Irregular Heartbeat.

2001 JUN 7 - (NewsRx Network) -- Elderly women - those older than 75 - were half as likely as elderly men to receive the drug warfarin, which treats irregular heartbeats that can increase stroke risk, according to a study in the May 15, 2001, issue of Circulation.

"We found that warfarin -- an effective therapy for the prevention of stroke caused by atrial fibrillation - remains underused, particularly in elderly women," says Karin H. Humphries, DSc, lead author of the study. "Gender differences in coronary artery disease have received considerable attention but few studies have dealt with gender differences in arrhythmias."

Atrial fibrillation (AF) is triggered when the electrical impulses that regulate heart rhythm become disorganized, causing the upper chambers of the heart (the atria) to quiver, rather than contract normally. Thus, blood flow in the atria is slower, allowing blood clots to form. Although changes in heart rhythm caused by AF are not themselves life-threatening, the condition increases the potential for blood clots to form in the circulatory system, thereby heightening the risk of stroke.

AF is the most common sustained cardiac arrhythmia in the general population and its incidence increases with age. Compared with women, men have a higher incidence; however, because there are more women than men in the over 75 age group, the absolute number of men and women with AF is about equal, according to Humphries.

To determine if there were gender differences in diagnosis, treatment, and outcome of AF, investigators at the Canadian Registry of Atrial Fibrillation centers and the Centre for Health Evaluation and Outcome Sciences (HEOS) in Vancouver, British Columbia, studied 339 women and 560 men who had cases of new-onset atrial fibrillation.

Researchers gathered data on symptoms - dizziness, fatigue, nausea, chest pain - and performed standard heart function tests such as electrocardiograms. Women were more likely to be older and to seek medical advice because of symptoms.

Although the overall prevalence of antithrombotic therapy (warfarin or aspirin) did not vary by gender, the choice of therapy did. Women ages 75 and older were 54% less likely to receive warfarin, but twice as likely to receive aspirin than were men ages 75 and older.