Risk of thrombosis, hemorrhage and leukemic transformation in patients with myeloproliferative neoplasms: A nationwide longitudinal cohort study.

There are few large-scale, population-based studies detailing the risks of thrombosis, hemorrhage, leukemic transformation in patients with myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF). We performed a nationwide longitudinal cohort study using the Korean National Health Insurance System (NHIS) database. MPN patients (n = 11,991) and their 1:4 age- and sex-matched controls (n = 47,964) were enrolled. The risk of thrombosis, hemorrhage, leukemic transformation was estimated using a Cox proportional hazards regression, and stratified analyses were performed for related factors. During a median of 7.8 years of follow-up, 30.1 % of MPN patients (3614/11,991) and 19.0 % of the matched controls (9141/47,964) developed arterial thrombosis, 11.6 % of MPN patients (1397/11,991) and 6.4 % of the matched controls (3099/47,964) developed venous thrombosis and 18.7 % of MPN patients (2251/11,991) and 12.1 % of the matched controls (5836/47,964) developed hemorrhage. 4.9 % of MPN patients (597/11,991) and 0.1 % of matched controls (50/47,964) developed leukemia. The overall risk of developing thrombosis, hemorrhage, leukemic transformation was higher in MPN patients (adjusted hazard ratio [aHR] 1.695, 95 % confidence interval [CI]: 1.629–1.765 for arterial thrombosis, aHR 1.963, 95 % CI: 1.838–2.096 for venous thrombosis, and aHR 1.714, 95 % CI: 1.630–1.802 for hemorrhage) than in the controls. Patients with MPNs had a 10-year cumulative incidence of leukemic transformation of 6.2 %. The patients with MPNs have a higher risk of thrombosis, hemorrhage, and leukemic transformation than matched controls. Strategies are warranted to reduce the risk of thrombosis, hemorrhage, and leukemic transformation in MPN patients. • MPN patients had 69.5 % increased risk of arterial thrombosis compared with matched controls. • MPN patients had 96.3 % increased risk of venous thrombosis compared with matched controls. • MPN patients had 71.4 % increased risk of hemorrhage compared with matched controls. • Patients with MPNs had a 10-year cumulative incidence of leukemic transformation of 6.2 %. [ABSTRACT FROM AUTHOR]