Background: Arterial (3-fold) and venous (10-fold) thromboembolism are more common in myeloproliferative neoplasm (MPN) than general population with rates as high as 50% in polycythemia vera (PV) and essential thrombocythemia (ET).1,2 While primary prophylaxis with aspirin is not debated for prevention of arterial and venous thromboembolism, the choice of anticoagulant for secondary prophylaxis and treatment [...]