Effectiveness and Safety of Four Direct Oral Anticoagulants in Asian Patients With Nonvalvular Atrial Fibrillation

Background: Whether four direct oral anticoagulants (DOACs) are superior to warfarin in Asian patients with nonvalvular atrial fibrillation (NVAF) remains unclear. Methods: This nationwide retrospective cohort study was based on data from Taiwan's National Health Insurance Research Database from June 1, 2012, to December 31, 2017, covering patients with NVAF taking edoxaban (n = 4,577), apixaban (n = 9,952), rivaroxaban (n = 33,022), dabigatran (n = 22,371), and warfarin (n = 19,761). Propensity score weighting was used to balance covariates across study groups. Patients were followed up until occurrence of study outcomes or end date of study. Results: Edoxaban, apixaban, and rivaroxaban were associated with a lower risk of ischemic stroke/systemic embolism than warfarin. All DOACs had a lower risk of major bleeding than warfarin. Apixaban was associated with a lower risk of major bleeding than rivaroxaban and dabigatran, whereas the risk of major bleeding was comparable between edoxaban and apixaban. The reduced risks of thromboembolism/major bleeding for the four DOACs persisted in high-risk subgroups, including those with chronic kidney disease, elderly patients (age ≥ 75 years), secondary stroke prevention, or CHA₂DS₂-VASc score (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, previous stroke/transient ischemic attack, vascular disease, age 65-74 years, and female sex) ≥ 4. A total of 2,924 (64%), 6,359 (64%), 31,108 (94%), and 19,821 (89%) patients received low-dose edoxaban (15-30 mg/d), apixaban (2.5 mg bid), rivaroxaban (10-15 mg/d), and dabigatran (110 mg bid), respectively. The effectiveness/safety outcomes with the four low-dose DOACs compared with warfarin were consistent with the main analysis. Conclusions: In the largest real-world practice study among Asian patients with NVAF, four DOACs were associated with a comparable or lower risk of thromboembolism, and a lower risk of bleeding than warfarin. There was consistency even among high-risk subgroups and whether standard-or low-dose regimens were compared.