This study is planned to assess the use of thrombotic biomarkers in patients with HIT, including thrombin-antithrombin complex, d-dimer, fibrin degradation products and Thrombelastograghy monitoring . These biomarkers are monitored in 5-14 days post-operation to assess the risk of thrombosis in HIT patients. All patients were followed up for 30 days, and clinical outcomes, including new thrombus and death, were recorded during follow-up.