A study published in Blood Advances observed a high risk of recurrent thrombotic events in patients with myeloproliferative neoplasms (MPN) with a history of venous thromboembolism (VTE), even among those who received long-term oral anticoagulant treatment.
Researchers conducted a systematic review and meta-analysis of Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science conference proceedings, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform to identify randomized trials and observational studies evaluating anticoagulant and/or antiplatelet therapy, with or without cytoreduction, in patients with MPN and a history of VTE.
No randomized trials were identified; 10 observational studies involving 1,295 patients with MPN were included in the final analysis. Median duration of follow-up among the studies ranged from 2.1 to 10 years. The median age of study participants ranged from 47 to 75 years, and 57% of the overall study population was female. Essential thrombocytopenia was the most prevalent type of MPN (54%), followed by polycythemia vera (37%). Among the full cohort, 87% (n=1,121) had a history of any thrombosis, while 13% did not have a history of thrombosis (n=174).
A total of 623 patients received antiplatelet therapy, most often low-dose aspirin (80 mg). Vitamin K antagonists (VKA) were the most common oral anticoagulant treatment (n=467).
Overall, 23% of patients had an arterial or recurrent venous thrombotic event during follow-up. Recurrence risk was lowest for patients receiving oral anticoagulation plus cytoreduction (16%). In 746 analyzed patients, the risk of recurrent VTE ranged up to 33% (median, 13%) and was low in 63 patients treated with direct oral anticoagulants plus cytoreduction (3.2%). All types of antithrombotic treatments were associated with a lower risk of recurrent VTE when combined with cytoreduction.
Most studies had a high risk of bias, whereas clinical and statistical heterogeneity led to inconsistent and imprecise findings. “Our data suggest that a combination of anticoagulation and cytoreduction may provide the lowest recurrence risk,” the researchers concluded.