[Clinical evaluation of the revised International Prognostic Score of Thrombosis for essential thrombocythemia (IPSET-thrombosis) in a cohort of 746 Chinese adult patients].

Objective: To evaluate the role of the revised International Prognostic Score of Thrombosis (IPSET-thrombosis) in predicting the occurrence of thrombotic events in Chinese patients with essential thrombocythemia (ET) and to develop a thrombosis predicting model more applicable to Chinese ET patients. Methods: Medical records of 746 adult patients with an initial diagnosis of ET were retrospectively analyzed. Results: The median age at diagnosis was 52 (18-87) years, with 305 males and 441 females. According to the revised IPSET-thrombosis model, the number of very low-, low-, intermediate-, and high-risk patients were 271 (36.3%) , 223 (29.9%) , 63 (8.4%) and 189 (25.3%) , respectively. The four groups exhibited significantly different thrombosis-free survival (χ(2)=72.301, P<0.001) . Thirty-six patients were reclassified as intermediate-risk according to the revised IPSET-thrombosis instead of low-risk as per the original IPSET-thrombosis. Nineteen intermediate-risk patients as per the original IPSET-thrombosis were upgraded to high-risk according to the revised IPSET-thrombosis. Fifty-one high-risk patients as per the original IPSET-thrombosis were reclassified as low-risk in the revised IPSET-thrombosis. It suggests that the revised IPSET-thrombosis potentially avoids over- or under-treatment. In low-risk patients as per the revised IPSET-thrombosis, the rate of thrombosis in patients with cardiovascular risk factors (CVF) was higher than that in those without (16.3% vs 5.2%, χ(2)=5.264, P=0.022) , and comparable with intermediate-risk patients as per the revised IPSET-thrombosis (16.3% vs 14.3%, χ(2)=0.089, P=0.765) . As a result, a new revised IPSET-thrombosis model more applicable to Chinese ET patients was developed in which patients with CVF in the low-risk group as per the revised IPSET-thrombosis were reclassified as intermediate-risk group. Conclusion: For predicting the occurrence of thrombotic events, the revised IPSET-thrombosis model was better than the original IPSET-thrombosis model. The revised IPSET-thrombosis was optimized and a new revised IPSET-thrombosis model more applicable to Chinese ET patients was developed, and the new evidence for risk stratification and treatment of ET in Chinese was provided.