Fibrin-related markers for diagnosing acute-, subclinical-, and pre-venous thromboembolism in patients with major orthopedic surgery

Venous thromboembolism (VTE) is a common complication in patients who have undergone major orthopedic surgery, but there are few predictors of VTE after major orthopedic surgery treated with an anticoagulant. We measured levels of fibrin-related markers (FRMs), such as d-dimer, soluble fibrin (SF), and fibrinogen and fibrin degradation products (FDPs) in 66 patients with acute-phase VTE, and 367 patients undergoing major orthopedic surgery. Plasma FDP, d-dimer, and SF levels were significantly higher in patients with acute VTE, but only FDP and d-dimer levels were significantly higher in subclinical VTE. Adequate cut-off levels of d-dimer were 2.2 μg/ml for diagnosing acute VTE and 1.5 μg/ml for diagnosing subclinical VTE. d-dimer of less than 1.9 or 0.7 μg/ml ruled out acute VTE or subclinical VTE. d-dimer of more than 1.3 μg/ml preoperatively showed a moderate risk for postoperative VTE. Measurement of FRMs is useful for evaluating the risk of subclinical or postoperative VTE in patients with major orthopedic surgery. In particular, FDP is the most valuable marker for diagnosing acute VTE, whereas d-dimer is the most valuable for diagnosing subclinical VTE or predicting VTE.