Predictors of survival and cause of death in patients with essential thrombocythemia

ObjectivesStandard risk stratification for overall survival (OS) in patients with essential thrombocythemia (ET) is based on advanced age and history of thrombotic events. Recently, International Prognostic Score for ET (IPSET) incorporated also leukocytosis in prognostic model. The aim of this study was to establish additional risk factors for OS in ET patients. MethodsAfter the median follow-up of 7yr, in 244 consecutive ET patients, 32 deaths were documented (13.2%). The 5- and 10-yr OS was 95.9% and 79.7%, respectively. Considered additional risk factors at diagnosis of ET were the presence of arterial hypertension, diabetes, hyperlipidemia, and smoking attitude. ResultsThe main cause of death in 75% of patients was cardiovascular (CV) comorbidity. Patients with CV risk factors had increased risk of death (HR=2.33). Cox regression model identified age, leukocytosis, presence of CV risk factors, and previous thrombosis as unfavorable predictors of survival. Based on these parameters, four risk groups were defined, with significantly different survivals (P<0.001). Improved prognostic model displayed a better hazard ratio profile compared to the standard risk stratification and IPSET. ConclusionThe addition of CV risk factors allows better prognostic assessment by delineating the intermediate-risk category and improved identification of the high-risk patients.