Sex Differences in Dabigatran Safety and Efficacy in AF

Study Questions:

What are the sex-related differences in use, safety, and effectiveness of dabigatran?

Methods:

The investigators conducted a population-based cohort study of patients with atrial fibrillation using administrative data in Quebec, Canada, from 1999 to 2013. Men and women who filled a prescription for dabigatran (110 and 150 mg bid) were compared with matched warfarin users with respect to their rates of stroke, bleeding, and myocardial infarction events, using propensity score analysis.

Results:

The cohort was comprised of 31,786 women (50.4%) and 31,324 men (49.6%). Women had a higher baseline stroke risk and lower baseline bleeding risk compared with men. Women filled more prescriptions for the lower dabigatran dose compared with men (adjusted odds ratio, 1.35; 95% confidence interval, 1.24-1.48). In multivariable analyses adjusted for propensity scores, dabigatran use was associated with a lower risk of bleeding compared with warfarin in men (p for interaction = 0.008). Dabigatran was associated with a trend toward lower risk of stroke in women treated with the 150 mg dose (hazard ratio, 0.79; 95% confidence interval, 0.56-1.04), but was not associated with a difference in the risk of myocardial infarction compared with warfarin in either sex.

Conclusions:

The authors concluded that women are more frequently treated with low-dose dabigatran, despite a trend toward lower stroke rates in women taking high-dose dabigatran.

Perspective:

This study found different utilization patterns of dabigatran among men and women, with women filling more prescriptions for the lower dabigatran dose compared with men. Furthermore, dabigatran use was associated with lower bleeding rates than with warfarin use, mainly in men, and a trend for women to have a lower incidence of stroke when prescribed dabigatran 150 mg twice daily compared with warfarin. This study highlights sex differences in dose use of dabigatran, and dabigatran safety between men and women, with men having more benefits from dabigatran treatment by having less bleeding events compared with warfarin.

Keywords: Anticoagulants, Arrhythmias, Cardiac, Atrial Fibrillation, Benzimidazoles, beta-Alanine, Hemorrhage, Myocardial Infarction, Sex Characteristics, Stroke, Warfarin, Women


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