Dual direct oral anticoagulant therapy in challenging thrombosis: a case series.

Background: While anticoagulation therapy is highly effective at treating venous thromboembolism, some patients can develop rapidly progressive thrombosis in multiple organs or sites despite therapeutic anticoagulation. Effective strategies to manage life-threatening thrombosis in these patients are elusive. Objectives: We describe our experience using dual direct oral anticoagulant (DOAC) therapy with a factor (F)Xa inhibitor (such as rivaroxaban or apixaban) and a FIIa inhibitor (dabigatran) for refractory cases of thrombosis. Methods: A retrospective chart review of all patients treated with simultaneous dabigatran and an oral FXa inhibitor at our institution was conducted. We included all patients over the age of 18. The study was approved by the University of British Columbia Research Ethics Board (REB number: H23-02575). Results: Eight patients were included. All patients initiated standard therapeutic anticoagulation upon diagnosis of acute venous thromboembolism with a median of 3 breakthrough thrombotic events prior to dual DOAC use. Five patients had a positive heparin-induced thrombocytopenia screen, but only 2 had heparin-induced thrombocytopenia confirmed on serotonin release assay testing. There were no recurrent deep vein thrombosis, pulmonary embolism, or bleeding events during dual DOAC use. Most patients ultimately transitioned to a single oral FXa inhibitor. Conclusion: Dual DOAC therapy may be a useful strategy for managing challenging thrombosis cases resistant to conventional anticoagulation. Further research is warranted to validate these findings and explore the broader applicability of dual DOAC therapy in challenging thrombotic scenarios.