A randomised open-label trial in high-risk patients with antiphospholipid syndrome and a history of thrombosis has shown an increased risk of recurrent thrombotic events in those treated with rivaroxaban compared with those given warfarin. Thromboembolic events occurred in 12% of patients assigned to receive rivaroxaban and in no patients assigned to receive warfarin.
There have been no completed clinical trials of the other DOACs (apixaban, dabigatran and edoxaban) in patients with antiphospholipid syndrome. However, available data suggest these agents may be associated with a similarly increased risk.
The MHRA has therefore advised that DOACs are not recommended in patients with antiphospholipid syndrome, particularly high-risk patients (those who test positive for all 3 antiphospholipid tests — lupus anticoagulant, anticardiolipin antibodies, and anti-beta 2 glycoprotein I antibodies).
Prescribers should review whether continued treatment with a DOAC is appropriate for patients diagnosed with antiphospholipid syndrome, particularly high-risk patients, and consider switching to a vitamin K antagonist such as warfarin.