Antiplatelet therapy in the management of myeloproliferative neoplasms.

Low-dose acetylsalicylic acid (ASA) is given to most patients with polycythemia vera (PV) and essential thrombocythemia (ET) although some uncertainties encompass this clinical practice. In patients with history of thrombosis, the use of ASA is supported on the results observed in the general population showing a substantial net benefit of this treatment in preventing thrombosis. In the European collaboration study on low-dose aspirin in polycythemia vera (ECLAP), ASA reduced the risk of thrombosis without increasing the risk of major bleeding when compared with placebo, supporting the primary prevention of thrombosis in PV. In ET, the efficacy of low-dose ASA has not been tested in randomized clinical trials. Two retrospective studies have shown that low-dose ASA could benefit ET patients older than 60 years when combined with cytoreduction, whereas in young, low-risk patients, ASA benefits to particular subgroups of patients. In spite of the fact that in primary myelofibrosis the incidence of thrombosis is increased, the use of ASA is not clearly recommended.