Direct oral anticoagulants (DOACs) are commonly used to manage valvular atrial fibrillation, but limited evidence is available to guide treatment selection. To address this knowledge gap, researchers compared the effectiveness and safety of DOACs with warfarin in patients who have valvular atrial fibrillation.

After propensity score matching, 28,168 new users of DOACs and 28,168 new users of warfarin who were age 18 or older and had a diagnosis of atrial fibrillation and valvular heart disease were included in the retrospective cohort study. Median follow-up was 134 days for people taking DOACs and 124 days for those receiving warfarin.

During follow-up, 787 users of DOACs had stroke or systemic embolism (3.9 events per 100 person-years) compared with 1,211 users of warfarin (6 events per 100 person-years). The absolute reduction in the probability of stroke or systemic embolism with DOACs compared with warfarin was 0.015 within six months and 0.026 within one year. Results were consistent for individual DOACs. Major bleeding events occurred in 1,465 users of DOACs (7.1 events per 100 person-years) compared with 2,155 users of warfarin (10.6 events per 100 person-years). The absolute reduction in the probability of a major bleeding event with DOACs compared with warfarin was 0.019 within six months and 0.035 within one year. Again, results were consistent for individual DOACs. Subgroup analyses showed generally consistent results across age and other factors, as well as among types and subtypes of valvular heart disease.

The study was limited by a lack of data on lifestyle factors, over-the-counter drug use, and long-term outcomes.

Noting the clinical implications of the study, the authors point out that DOACs provide treatment options for patients with valvular atrial fibrillation who are at risk for poor outcomes and receive suboptimal benefits from warfarin therapy.