Sex-specific associations of oral anticoagulant use and cardiovascular outcomes in patients with atrial fibrillation

Background--Sex-specific effectiveness of rivaroxaban (RIVA), dabigatran (DABI), and warfarin in reducing myocardial infarction (MI), heart failure (HF), and all-cause mortality among patients with atrial fibrillation are not known. We assessed sex-specific associations of RIVA, DABI, or warfarin use with the risk of MI, HF, and all-cause mortality among patients with atrial fibrillation. Methods and Results--Medicare beneficiaries (men: 65 734 [44.8%], women: 81 135 [55.2%]) with atrial fibrillation who initiated oral anticoagulants formed the study cohort. Inpatient admissions for MI, HF, and all-cause mortality were compared between the 3 drugs separately for men and women using 3-way propensity-matched samples. In men, RIVA use was associated with a reduced risk of MI admissions compared with warfarin use (hazard ratio [95% confidence interval (CI): 0.59 [0.38-0.91]), with a trend towards reduced risk compared with DABI use (0.67 [0.44-1.01]). In women, there were no significant differences in the risk of MI admissions across all 3 anticoagulants. In both sexes, RIVA use and DABI use were associated with reduced risk of HF admissions (men: RIVA; 0.75 [0.63-0.89], DABI; 0.81 [0.69-0.96]) (women: RIVA; 0.64 [0.56-0.74], DABI; 0.73 [0.63-0.83]) and all-cause mortality (men: RIVA; 0.66 [0.53-0.81], DABI; 0.75 [0.61-0.93]) (women: RIVA; 0.76 [0.63-0.91], DABI; 0.77 [0.64-0.93]) compared with warfarin use. Conclusions--RIVA use and DABI use when compared with warfarin use was associated with a reduced risk of HF admissions and all-cause mortality in both sexes. However, reduced risk of MI admissions noted with RIVA use appears to be limited to men.