Practice patterns and outcomes of direct oral anticoagulant use in myeloproliferative neoplasm patients.

Myeloproliferative neoplasms (MPNs) are characterized by an increased risk of thrombosis and bleeding. Vitamin K antagonists (VKAs) are the historic anticoagulant recommended for use in MPNs. Direct oral anticoagulants (DOACs) are being increasingly used in general and cancer populations. However, DOAC safety and efficacy in MPN patients remains unclear. We characterized real-world practice patterns of DOAC use in MPN patients and evaluated thrombosis and bleeding risk. We conducted a retrospective cohort study of 133 MPN patients prescribed DOACs for venous thromboembolism (VTE), atrial fibrillation, or arterial thromboembolism (ATE). Practice patterns including duration of anticoagulation, dosing, and concomitant use of antiplatelet/cytoreductive agents, were heterogeneous among MPN patients. The 1-year cumulative incidence of thrombosis and bleeding on DOAC was 5.5% (1.5-9.5%) and 12.3% (6.4-18.2%) respectively. In comparison, reported bleeding rates in MPN patients on DOAC and VKAs are 1-3%. On multivariable analysis, prior history of thrombosis, use of dabigatran or edoxaban, and younger age were significantly associated with a higher risk of recurrent thrombosis, while leukocytosis was associated with a higher risk of bleeding on DOAC. The higher-than-expected bleeding rate found in our study indicates the continued need for rigorous evaluation of DOACs in this population.