Comparison of different direct oral anticoagulant regimens in atrial fibrillation patients with high bleeding risk

The optimal dose of Direct oral anticoagulants (DOACs) to prevent ischemic stroke (IS) and systemic thromboembolism (STE) in atrial fibrillation (AF) patients with a predisposing bleeding risk remains unclear. To compare the effectiveness and safety of different DOAC dosage regimens in AF patients with a high bleeding risk but a low thrombosis risk. This retrospective, observational study was conducted with the National Health Insurance claims database in Taiwan to include AF patients aged 20 to <75 years, under DOAC therapy, had a CHA2DS2-VASc score of 1 for male and 2 for female and a HAS-BLED score ≥ 3. The standard-dose regimen was defined as dabigatran 300 mg, rivaroxaban 20 mg, apixaban 10 mg, or edoxaban 60 mg per day. Any other lower dose regimen were defined as the low-dose regimen. The primary outcomes were IS and major bleeding (MB). The secondary outcomes were STE, gastrointestinal bleeding, intracranial hemorrhage and cardiovascular death (CVD). A total of 964 patients were included (52.1% standard-dose regimen). The median score of HAS-BLED was 3 (IQR 3-3). Compared with standard-dose group, patients in low-dose group had a significantly increased risk of IS (aHR=5.13, 95% CI:1.37-19.22) and STE (aHR = 3.14 [1.05-9.37]), but similar risk of MB (aHR=0.45 [0.12-1.67]). The risks of other hemorrhage and CVD were similar between the two dose groups. Among patients with a predominant bleeding risk but relatively low thrombosis risk, the low-dose DOAC regimen is not a more appropriate selection than standard dose regimen.