Direct Oral Anticoagulants in Patients with Myeloproliferative Neoplasms: A Single Institution Retrospective Study

Introduction: Myeloproliferative neoplasms (MPN) are associated with an increased risk of venous (VTE) and arterial (ATE) thromboembolic events (TE). Anticoagulation needs to be balanced between the risk of incident and recurrent TE and risk of hemorrhage. While data on outcomes of anticoagulation with warfarin in patients with MPN are available, data on safety and efficacy of direct oral anticoagulants (DOACs) in this subgroup are not. Herein, we present outcomes of use of DOACs in patients with MPN at our institution.

Methods: In this retrospective cohort study, we searched the Mayo Clinic clinical databases for patients meeting the WHO criteria for MPN who had been prescribed a DOAC between 2011 and 2017. The MPN diagnosis had to have predated the DOAC prescription. Medical records of consenting patients meeting study criteria were reviewed and data on demographics, diagnosis of MPN, indication for DOAC prescription, and their efficacy (incident or recurrent TE) and safety (hemorrhagic events) were abstracted.

Results: Over the study period, 19 patients (female = 10) met inclusion criteria. The median age of patients at MPN diagnosis was 67 years (35-83), and 73 years (53-86) at initiation of DOAC. Prescribed DOACs included rivaroxaban (n=12), apixaban (n=6), and dabigatran (n=2) (one patient received rivaroxaban and was switched to apixaban). MPN diagnoses included polycythemia vera (PV) (n=9), essential thrombocythemia and chronic myeloproliferative neoplasm NOS (3 each), chronic myeloid leukemia and myelofibrosis (2 each). Indications for DOAC included thromboembolism (n=13; 68%) (arterial:2 and venous:11), and atrial fibrillation (afib) (n=6; 31%). The median duration of DOAC therapy was 241.5 days (range 13-1879). Five patients were switched from warfarin to rivaroxaban (n=4) and apixaban (n=1) at patient and/or provider preference; the rest were initiated on the DOAC de novo based on provider preference.

Of the 19 patients, one patient each experienced a major hemorrhagic and TE event. One patient with PV who was on rivaroxaban for afib required hospitalization for gastrointestinal hemorrhage due to gastritis; DOAC was discontinued following this episode. One other patient with PV had a non-ST elevation myocardial infarction while on rivaroxaban for afib and prior stroke; DOAC was continued. There were no deaths attributable to DOAC use.

Discussion: Our limited data suggests that use of DOACs in patients with MPN is feasible with an acceptable balance between risk of hemorrhage and recurrent thrombosis. Additional data on long term outcomes of DOACs in MPNs are needed.