Plasminogen activator inhibitor-1, thrombin-antithrombin, and prothrombin fragment F1+2 have higher diagnostic values than D-dimer for venous thromboembolism after TKA.

Objective: To investigate the diagnostic values of D-dimer, plasminogen activator inhibitor-1 (PAI-1), thrombin-antithrombin (TAT), and prothrombin fragment F1 + 2 (F1 + 2) for predicting venous thromboembolism (VTE) after total knee arthroplasty (TKA).

Methods: Ultrasonography and CTPA were performed to diagnose VTE in 252 patients who underwent TKAs. Plasma D-dimer, PAI-1, TAT, and F1 + 2 levels were assessed 1-3 days prior to operation (T1), second hour (T2), first (T3), and third day (T4) after the operation. Receiver-operating characteristic curves (ROC) analysis was conducted and pairwise compared to evaluate the diagnostic value of those biomarkers.

Results: Plasma D-dimer levels differed between patients with and without VTE significantly on T4, PAI-1, TAT, and F1 + 2 levels differed on T3 and T4. The areas under ROC of D-dimer, PAI-1, TAT and F1 + 2 levels were 0.645, 0.773, 0.771 and 0.797, respectively. The most feasible cutoff values of D-dimer, PAI-1, TAT and F1 + 2 in predicting VTE after TKA were 2.24 ug/ml, 35.96 ng/ml, 13.36 ng/mg and 11.1 ng/ml, respectively. Pairwise comparison of ROC curves revealed that D-dimer level had the lowest diagnostic accuracy, whereas PAI-1, TAT and F1 + 2 level had similar diagnostic accuracy. There were significant differences in duration of tourniquet time and duration of anesthesia between patients with and without VTE.

Conclusion: After TKA, using 2.24ug/mL as the threshold value of D-dimer is more accurate than using 0.5ug/mL in the monitoring of VTE, PAI-1, TAT and F1 + 2 are more valuable than D-dimer in predicting VTE. Duration of tourniquet and duration of anesthesia are risk factors for the development of VTE.