Sex Differences in Dabigatran Use, Safety, And Effectiveness In a Population-Based Cohort of Patients With Atrial Fibrillation

Abstract

Background-Sex differences were observed with regard to warfarin treatment in patients with atrial fibrillation, with women having a higher risk of stroke compared with men. We aimed to compare sex differences in use, safety, and effectiveness of dabigatran. Methods and Results-We conducted a population-based cohort study of patients with atrial fibrillation using administrative data in Quebec, Canada, 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. The cohort comprised 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 OR, 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 (HR, 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-In real-life practice, women are more frequently treated with low-dose dabigatran, yet a trend toward lower stroke rates in women taking high-dose dabigatran was observed. Men benefit from lower bleeding rates with dabigatran compared with warfarin. (Circ Cardiovasc Qual Outcomes. 2015;8:593-599.

Temporal Trends in the Use and Comparative Effectiveness of Direct Oral Anticoagulant Agents Versus Warfarin for Nonvalvular Atrial Fibrillation: A Canadian Population‐Based Study

“…This study of ≈35 000 nonvalvular AF patients from a complete population shows that treatment with DOACs is associated with reduced risk for a combined end point of all‐cause stroke or death compared with warfarin, even after adjustment for baseline differences. Consistent with the pivotal clinical trials comparing warfarin and DOACs, meta‐analysis of clinical trials data, and other population‐based analyses, the protective effect of DOACs in our study is driven by lower rates of hemorrhagic stroke and death. DOAC treatment is not associated with increased risk of myocardial infarction.…”

Sex Differences in the Use of Oral Anticoagulants for Atrial Fibrillation: A Report From the National Cardiovascular Data Registry (NCDR ® ) PINNACLE Registry

“…For example, women may be more likely to decline OAC therapy, particularly warfarin, due to concerns for bleeding, inconvenience, or lack of social support (ie, transportation for international normalized ratio check) . Additionally, providers may perceive increased frailty or bleeding risk in women compared to men because women have been shown to have higher rates of bleeding while on warfarin and after cardiac interventions . Our finding of greater increases in NOAC use in women compared to men may support the notion that higher bleeding risk contributed to past sex differences in OAC use when therapy options were more limited.…”

“…Second, the development of non–vitamin K oral anticoagulants (NOAC) has expanded treatment options for patients with AF. NOACs have a lower risk of major bleeding and equivalent stroke rates compared to warfarin . Therefore, it is possible that sex differences in OAC use have diminished with the introduction of NOACs.…”

Sex-Specific Comparative Effectiveness of Oral Anticoagulants in Elderly Patients With Newly Diagnosed Atrial Fibrillation

“…However, sex specific outcomes were not reported in these observational studies. A Canadian study 41 , using a propensity matched analysis involving 31,786 women and 31,324 men with AF from administrative data, compared sex specific effectiveness of DABI (110 mg and 150 mg) to Warfarin. The study concluded that DABI use was associated with similar stroke risk compared to Warfarin in both sexes, but was protective against major bleeding only in men.…”