Direct oral anticoagulants versus warfarin in patients with single antibody-positive anti-phospholipid syndrome

Background: The role of direct oral anticoagulants (DOACs) among patients with antiphospholipid syndrome (APLS) remains unclear. Warfarin has been shown to be superior to DOACs among high-risk APLS patients (particularly those with triple-positive APLS). However, it remains unknown whether DOACs may be appropriate for lower-risk patients such as those with single-positive APLS. Methods: We conducted a retrospective study comparing the risk of recurrent thrombosis among single-positive APLS patients treated with DOACs (apixaban or rivaroxaban), and those treated with warfarin. Results: One-hundred-forty-three single-positive APLS patients, newly started on anticoagulation following a first thrombotic event, were included. Median follow-up was 54 months (IQR 29–73 months). Ninety-one patients (64%) received warfarin and 52 patients (36%) received a DOAC. Six patients (6.6%) who received warfarin experienced a recurrent thrombotic event compared with 3 of 52 (5.8%) patients who received a DOAC (p =.845). There was no difference in event-free survival between groups (HR DOAC:Warfarin = 0.952, 95% CI 0.232 – 3.908). Major bleeding was similar in both groups. Conclusions: These findings suggest that DOACs may be a safe and effective option for patients with single-positive APLS. Prospective studies are needed to confirm these findings.