Predictors of thrombosis and bleeding in 1613 myelofibrosis patients from the Spanish Registry of Myelofibrosis

Available data have proved insufficient to develop consensus recommendations on the prevention of thrombosis and bleeding in myelofibrosis (MF). We evaluated the incidence and risk factors of vascular complications in 1613 patients from the Spanish Myelofibrosis Registry. Over a total of 6981 patient-years at risk, 6.4% of the study population had at least one thrombotic event after MF diagnosis, amounting to an incidence rate of 1.65 per 100 patient-years. Prior history of thrombosis, the JAK2 mutation, and the intermediate-2/high-risk International Prognostic Scoring System (IPSS) categories conferred an increased thrombotic risk after adjustment for the risk-modifying effect of anti-thrombotic and cytoreductive treatments. History of thrombosis and the JAK2 mutation allowed us to pinpoint a group of patients at higher risk of early thrombosis. No decreased incidence of thrombosis was observed while patients were on anti-thrombotic or cytoreductive treatment. An increased risk of venous thrombosis was found during treatment with immunomodulatory agents. A total of 5.3% of patients had at least one episode of major bleeding, resulting in an incidence rate of 1.5 events per 100 patient-years. Patients in the intermediate-2/high-risk IPSS categories treated with anti-coagulants had an almost sevenfold increased risk of major bleeding. These findings should prove useful for guiding decision-making in clinical practice.

Automated summary

Insufficient data are available to develop consensus recommendations on preventing thrombosis and bleeding in myelofibrosis (MF). Researchers evaluated 1613 patients from the Spanish Myelofibrosis Registry to determine the incidence and risk factors of vascular complications. Prior history of thrombosis, the JAK2 mutation, and the intermediate-2/high-risk International Prognostic Scoring System (IPSS) categories were found to increase the risk of thrombosis. No decrease in thrombosis incidence was observed with anti-thrombotic or cytoreductive treatment. The study also suggested an increased risk of venous thrombosis during treatment with immunomodulatory agents. An incidence rate of 5.3% for major bleeding was observed, with the highest risk seen in patients in the intermediate-2/high-risk IPSS categories who were treated with anti-coagulants.