The importance of cardiovascular risk factors for thrombosis prediction in patients with essential thrombocythemia

Abstract

The current widely accepted stratification defined by age and previous thrombosis in patients with essential thrombocythemia (ET) probably deserves deeper analysis. The aim of our study was to identify additional factors at the time of diagnosis, which have an impact on the thrombosis prediction. We conducted a study of 244 consecutive ET patients with median follow-up of 83 months. We analyzed the influence of age, gender, laboratory parameters, history of previous thrombosis, spleen size, JAK2 mutation as well as cardiovascular (CV) risk factors including arterial hypertension, diabetes, active tobacco use and hyperlipidemia in the terms of thrombosis. The most important predictors of thrombosis in multivariate Cox regression model were the presence of CV risk factors (p=0.004) and previous thrombosis (p=0.038). Accordingly, we assigned risk scores based on multivariable analysis-derived hazard ratios (HR) to the presence of 1 CV risk factor (HR=3.5; 1 point), >1 CV risk factors (HR=8.3; 2 points) and previous thrombosis (HR=2.0; 1 point). A final three-tiered prognostic model for thrombosis prediction was developed as low (score 0), intermediate (score 1 or 2) and high risk (score 3) (p<0.001). The hazard of thrombosis was 3.8% in low-risk group, 16.7% in the intermediate-risk group and 60% in the high-risk group (p<0.001). Patients with thrombotic complications during the follow-up had a significantly shorter survival (p=0.018). The new score based on CV risk factors and previous thrombotic events allows a better patient selection within prognostic-risk groups and improved identification of the high-risk patients for thrombosis.

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

“…It is well known that the presence of at least one CV risk factor at diagnosis is associated with significantly higher risk of thrombosis in ET, including global thrombosis and arterial thrombosis confirmed by multivariate model (23)(24)(25).…”

Application of prognostic score IPSET-thrombosis in patients with essential thrombocythemia of a Brazilian public service

“…[17][18][19] Additionally, in agreement with other authors, we found a significant association between splenomegaly and venous thrombosis, and cardiovascular risk factors and a high WBC with arterial thrombosis. 1,7,8,10,16 Interestingly, age ≥ 60 years in our cohort of patients was not a significant risk factor for thrombosis. The lack of correlation between older age and thrombosis was also seen in other recent studies such as those of Lekovic et al 1 and Montanaro et al 20 The presence of JAK2 mutation was not significantly associated with thrombosis in our study, contrary to information well-established in the literature.…”

“…1,7,8,10,16 Interestingly, age ≥ 60 years in our cohort of patients was not a significant risk factor for thrombosis. The lack of correlation between older age and thrombosis was also seen in other recent studies such as those of Lekovic et al 1 and Montanaro et al 20 The presence of JAK2 mutation was not significantly associated with thrombosis in our study, contrary to information well-established in the literature. 14,16,[20][21][22] We believe that our small sample size may explain why we found no correlation between thrombosis risk and the presence of JAK2 mutation.…”

“…Therefore, attempts to improve current risk estimation algorithms include additional variables with potential prognostic impact such as the presence of JAK2 mutation and cardiovascular risk factors. 1,10 As a result, a new model was recently proposed and called IPSET--thrombosis score.…”

“…1 ET diagnosis requires a sustained increase in platelet count (≥ 450 x 103/mm 3 ) and megakaryocytic hyperplasia. Furthermore, to diagnose ET, there should not be any clinical, pathological or molecular evidence to support the diagnosis of polycythemia vera, myelofibrosis, chronic myelogenous leukemia, myelodysplastic syndrome or reactive thrombocytosis.…”