Patients with myeloproliferative neoplasms (MPN) are predisposed to have an increased thrombotic and hemorrhagic risk and, in this context, the use of newly approved direct oral anticoagulants (DOACs) may have improved bleeding risk compared to warfarin use. However, the published experience is very limited and does not allow any conclusion. In the cohort of patients with MPN and venous thromboembolism (VTE) of European Leukemia-net, only 3.3% of patients had been treated with DOACs. Similarly, in a recent publication of a series of 760 patients with single-center MPN, only 25 (3.3%) were treated with a DOAC (13 for atrial fibrillation and 12 for thrombotic events).

While it is known that the risk of thrombotic recurrence and haemorrhagic event during warfarin treatment is about 30% at 5 years from the first event, the actual risk of such events in MPN patients is not known.

The aim of the present study is therefore to obtain information on patients with MPN treated with DOAC for atrial fibrillation (AF) and VTE. This is an international multi-center retrospective survey aimed at describing the efficacy / safety of DOAC in the prevention of:

• cardioembolic stroke in patients with MPN with AF
• recurrent thrombosis in patients with MPN with VTE
• major bleeding in all patients with MPN.

The results will allow to design future prospective studies that evaluate the benefit / risk profile of DOAC compared to warfarin in these pathologies characterized by high risk of thrombosis and, in some subgroups, of bleeding.

Inclusion Criteria:

• diagnosis of Philadelphia-negative MPN according to World Health Organization (WHO) 2008 and/or 2016 criteria until 31/12/2018;
• diagnosis of atrial fibrillation (AF) and/or diagnosis of venous thromboembolism (VTE) including thrombosis of deep veins of the limbs and the abdomen, cerebral and splanchnic veins (hepatic, portal, mesenteric, and splenic veins) and pulmonary embolism;
• treatment with DOACs.

Exclusion Criteria:

• Administration of DOAC for any medical reason other than AF and/or VTE (excluding superficial vein thrombosis)

Patients with MPN treated with any DOAC for AF or VTE