Abstract
Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by persistent elevation of platelet count due to abnormal proliferation of megakaryocytes. While some cases may be asymptomatic, the condition is associated with an increased risk of complications such as thrombosis and bleeding tendencies, necessitating appropriate management tailored to individual cases. Hemostasis analyzer systems are automated analytical devices designed for comprehensive evaluation of blood coagulation function. These systems enable rapid and accurate measurement of multiple parameters, including coagulation time, platelet function, and fibrin formation, thus facilitating a holistic assessment of hemostatic function. A 76-year-old male patient presented to our hospital. At the age of 65, he received treatment for promyelocytic leukemia and achieved remission. At 75 years, he developed leukocytosis, thrombocytosis, and progressive anemia. A comprehensive examination, including bone marrow biopsy and genetic testing, revealed a JAK2 mutation, leading to the diagnosis of ET. At the age of 76 years, he complained of chest discomfort during exertion. Further investigation revealed severe aortic valve stenosis and two-vessel coronary artery disease. The patient underwent aortic valve replacement and three-vessel coronary artery bypass grafting. A hemostasis analyzer system was used to monitor coagulation function throughout the procedure. Compared with the normal range, his coagulation profile showed a tendency toward hypercoagulability. Intraoperative and postoperative transfusions were performed as required. The patient's postoperative course was uneventful without any complications related to bleeding or thrombosis.