Thrombin-activatable fibrinolysis inhibitor and the risk for recurrent venous thromboembolism

The impact of fibrinolysis for predicting the risk for recurrent venous thromboembolism (VTE) is low. We prospectively followed up 600 patients with a first VTE and evaluated the thrombin-activatable fibrinolysis inhibitor (TAR) as a risk factor for recurrence. A high TAR level (75th or higher percentile in thrombosis patients) was associated with a 2-fold higher risk for recurrence compared with lower levels. The probability of recurrence 2 Introduction years after anticoagulation was 14.5% (95% confidence interval [Cl], 8.6-20.4) among patients with high TAR levels and 6.8% (95% Cl, 4.3-9.3) among patients with lower levels (P =.006). Our data also support the concept of a linkage between fibrinolysis and the coagulation system. Patients with high TAR levels had significantly higher levels of factors XI, VIII, and IX, and a high risk of recurrence was seen among patients with high TAR levels and high levels of one of these factors. the relative risk (RR) for recurrence was highest among patients with high TAR and high factor XI (RR, 2.9; 95% Cl, 1.3-6.9), high factor VIII (RR, 6.5; 95% Cl, 2.9-114 8), or high factor IX (RR,2.0; 95% Cl, 11.0-3.9) levels compared with patients with low levels of TAR and one of these factors. (C) 2004 by The American Society of Hematology.