The Role of Direct Oral Anticoagulants in Antiphospholipid Syndrome

Background

Antiphospholipid Syndrome (APS) is defined by thrombosis and/or pregnancy morbidity in patients with antiphospholipid antibodies (aPL). There remains a pressing need for identification of clinical and laboratory parameters that define patients at most considerable risk for APS-related events on Direct oral anticoagulants (DOACs).

Aims

To demonstrate the efficacy and safety of DOAC (Rivaroxaban) compared with Warfarin (Vitamin K Antagonist) in patients with thrombotic APS.

Methods

A retrospective cohort study of thrombotic APS patients who were started on anticoagulant therapy, either VKA or DOAC, from 2010 -2016.

Results

We investigated 73 patients diagnosed with APS. 83.5% of the patients were female. The age range at diagnosis was between 26-40 (52%). 67% of the cases were diagnosed in the form of DVT while the rest had arterial or unusual site venous thrombosis. 43% of the patients had systemic lupus disease. 28% of the cases had a single-positive aPL profile, 23% had double-positive, and 49% had triple-positive aPL. 68.5% of the cases were treated with warfarin, while 31.5% of the cases were switched from warfarin to Rivaroxaban. 15% of patients had major and clinically relevant non-major bleeding (2 patients had major bleeding in the warfarin group, and four patients in the rivaroxaban group). Recurrence of thrombosis (arterial and venous) was 43% with Rivaroxaban and 30% with warfarin. The average duration from starting Rivaroxaban to development of complications such as bleeding and thromboembolic events was mostly after 1-2 years (70%).

Conclusions

Rivaroxaban should be used with extreme caution in APS patients, especially patients with a full positive aPL profile and arterial thrombosis.