The α2-Plasmin Inhibitor-Plasmin Complex is a Potential Biomarker of Venous Thromboembolism in Orthopedic Trauma Patients

BACKGROUND Venous thromboembolism (VTE) is a common complication in orthopedic trauma patients. Accurate prediction of individual thrombosis risk is important in determining whether prophylactic treatment with anticoagulants is necessary. In this study, we screened for biomarkers that could be used as predictors of VTE risk and evaluated their efficacy and benefit in treating orthopedic traumatic patients. METHODS A total of 683 patients with orthopedic trauma were consecutively enrolled between January 2017 and June 2018 at Renmin Hospital of Wuhan University. Demographic and clinical information was collected, and VTE risk was assessed using the Caprini risk assessment score. The concentrations of PIC, coagulation parameters and other routine biochemical markers were quantified. The Mann-Whitney U test was used to identify potential biomarkers which were significantly different between patients who developed VTE and those who did not. Correlation between individual parameters was assessed using Pearson's correlation. A nomogram model was constructed to predict VTE risk using a combination of biomarkers, and a decision curve analysis was performed to assess the net benefit of using each biomarker. RESULTS Patients with VTE had significantly higher levels of PIC (p = 0.037) and DD (p = 0.042) than those without, even after adjusting for confounding factors. PIC and DD levels increased in a stepwise fashion with increasing VTE risk and were the markers most strongly associated with Caprini score (PIC, r = 0.408; DD, r = 0.474; p < 0.001). In decision curve analysis, PIC levels provided greater net benefit than the Caprini score or DD level across patients with various bleeding risks. CONCLUSIONS Plasma PIC levels are a useful biomarker of VTE risk and can be used to determine whether pharmaco-prophylaxis is needed in orthopedic trauma patients.