Management of venous thromboembolism in myeloproliferative neoplasms

Venous thromboembolism is frequent in chronic myeloproliferative neoplasms (MPN). The current strategy for its management includes cytoreductive therapy and antithrombotic prophylaxis, but many issues remain uncertain. In this review, the risk factors and prevention of recurrences will be discussed.

Around one-third of patients with polycythemia vera and essential thrombocythemia experience a major thrombosis at diagnosis or during follow-up. According to the European Leukemia Net guidelines, these patients must be included in the high-risk group for thrombotic recurrence and should be treated with cytoreduction and antiplatelet or anticoagulant drugs in the presence of arterial or venous thrombosis, respectively. Despite this treatment, the annual incidence of recurrence after the first venous thrombosis varies from 4.2 to 6.5% on vitamin K-antagonists and is doubled after discontinuation. The highest incidence of recurrence occurs after cerebral and hepatic vein thrombosis (8.8 and 8 per 100 pt-years, respectively). The occurrence of major bleeding on vitamin K-antagonists is similar to a non-MPN population and accounts for a rate of 1.8-2.4 per 100 pt-years.

After venous thrombosis, the incidence of recurrence in MPN remains elevated, which suggested there was a need to review the current recommendations of primary and secondary prophylaxis.