The Tasmanian Atrial Fibrillation Study (TAFS): Differences in Stroke Prevention According to Sex

Background: There are limited Australian data on sex differences in oral anticoagulant (OAC) prescribing in atrial fibrillation (AF) and ongoing debate regarding the optimal approach to stroke risk assessment and OAC prescribing in female patients with AF. Objective: The purpose of this study was to investigate sex differences in the prescribing of OACs in patients with AF stratified by stroke risk and in the rate of adverse outcomes. Methods: A retrospective analysis of patients admitted to the Royal Hobart Hospital (Tasmania, Australia) with nonvalvular AF between January 2011 and July 2015 was conducted. Rates of antithrombotic prescribing according to sex and stroke risk were assessed along with a multivariate analysis for predictors of OAC prescribing. Rates of thromboembolism, bleeding, and all-cause mortality were assessed according to sex. Results: A total of 2090 patients were included (44.7% female). Women with a CHA₂DS₂-VA score ≥2 were less likely to receive an OAC compared with men (56.7% vs 62.2%, P = 0.023). Female sex was an independent negative predictor of OAC prescribing (adjusted odds ratio = 0.83; 95% CI = 0.69-0.99; P = 0.041). There were no sex differences in the incidence rates of thromboembolism, bleeding, or all-cause mortality in patients newly commenced on antithrombotic therapy. Conclusion and Relevance: Female patients with a high stroke risk were less likely to receive guideline-recommended treatment. This study provides new information on prescribing trends within the Australian setting and highlights the opportunity to improve the management of female patients with AF and 1 or more additional stroke risk factors.