Risk factors for recurrent thrombosis and comparison of DOACs vs VKA in selected thrombotic antiphospholipid syndrome

Introduction : Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of autoantibodies (anti-cardiolipin, anti-β2GP1, and lupus anticoagulant) associated with arterial, venous, or microcirculatory thrombotic events and/or obstetrical events (miscarriages, fetal death, and preterm deliveries). The treatment of thrombotic events is based on long-term anticoagulant therapy with vitamin K antagonist (VKA). Direct oral anticoagulants (DOACs) are not recommended by international guidelines as first-line therapy because of an increased risk of recurrent thrombosis observed in several randomized trials. This study aimed to report a cohort of patients with thrombotic antiphospholipid syndrome (TAPS) to identify risk factors associated with recurrent thrombosis and to identify differences between patients treated with VKA and patients treated with DOACs. Materials and methods : We collected data from 207 patients with TAPS from an initial population of 655 patients identified by automated screening software. Results : This retrospective longitudinal analysis based on real-life data confirmed previously identified risk factors for thrombotic recurrence, such as the absence of antithrombotic treatment following the initial thrombotic event, treatment with antiplatelet treatment alone following the initial thrombotic event. No difference between patients treated with VKA (n=123) or DOACs (n=50) were observed on the risk of recurrent thrombosis. Patients with VKA versus DOACs had more frequently triple APL positivity, presence of lupus anticoagulant and absence of an initial venous thrombotic event. Conclusions : This results suggest a potential use of DOACs in the treatment of TAPS for patients with a primary VTE event and a single APL positivity profile, although its retrospective design prevents firm recommendations.