[Idiopathic venous thromboembolic disease. risk factors for recurrence in 2006].

The duration of anticoagulant therapy after a first attack of venous thromboembolic disease (VTE) is related to the risk of recurrence and the iatrogenic complication of bleeding. Recent prospective trials have provided information concerning the clinical and biological profiles of those at greatest risk of recurrence of deep vein thrombosis. The value of ultrasonic investigations and of D-Dimer measurements have also been assessed. The risk of recurrence is not negligible, about 10% in the first year after stopping treatment and 2/3 of recurrences occurring in the first two years. There are several risk factors for recurrence: male gender, past history of renal transplant, presence of malignant disease, proximal site of the initial thrombosis, initial presentation with pulmonary embolism, previous deep vein thrombosis and the co-existence of two thrombophilic factors. On the other hand, age, single deep vein thrombosis and a family history of deep vein thrombosis are not significantly related to increased risk. The presence of a residual thrombus at the end of treatment remains a subject of controversy. The risk of recurrence when the D-Dimers are normal one month after stopping the anticoagulants seems to be low, especially in cases of an associated thrombophilia. Finally, the risk of haemorrhage is related to the duration of oral anticoagulant therapy and the age of the patient. These trials have provided information for the issue of recommendations by consensus conferences and allow better economic evaluation of the duration of treatment after a first episode of deep vein thrombosis with respect to differing clinical situations.