Predicting the risk of venous thromboembolism recurrence.

Venous thromboembolism (VTE) is a chronic disease with a 30% ten-year recurrence rate. The highest incidence of recurrence is in the first 6 months. Active cancer significantly increases the hazard of early recurrence, and the proportions of time on standard heparin with an APTT ≥ 0.2 anti-X(a) U/mL, and on warfarin with an INR ≥ 2.0, significantly reduce the hazard. The acute treatment duration does not affect recurrence risk after treatment is stopped. Independent predictors of late recurrence include increasing patient age and body mass index, leg paresis, active cancer and other persistent VTE risk factors, idiopathic VTE, antiphospholipid antibody syndrome, antithrombin, protein C or protein S deficiency, hyperhomocysteinemia and a persistently increased plasma fibrin D-dimer. A recommendation for secondary prophylaxis should be individualized based on the risk for recurrent VTE (especially fatal pulmonary embolism) and bleeding. The appropriateness of secondary prophylaxis should be continuously reevaluated, and the prophylaxis stopped if the benefit no longer exceeds the risk.