DURATION OF ANTICOAGULANT TREATMENT IN VE NOUS THROMBOEMBOLIC DISEASE

The necessity for anticoagulant treatment after pulmonary embolism or deep vein thrombosis has been demonstrated. The modalities of this tre atment have been established, especially the value of initial heparin relayed by oral antivitamin K therapy with a target INR value between 2 and 3. The last question remaining in this protocol is that of the d uration of anticoagulant treatment. The choice of duration of anticoag ulation should take into consideration two potential complications : h aemorrhage due to over-anticoagulation and excessive duration of thera py, and recurrent thromboembolism which could result from an inadequat e duration of therapy. several trials have addressed this question and have led to a consensus of opinion : therefore, secondary venous thro mbo-embolic disease, occurring under known, special circumstances, the cause of which has been treated, should be given 4 to 6 weeks anticoa gulant therapy. In the other cases, so-called idiopathic venous thromb oembolism (the proportion of which is on the increase), recent studies are inadequate to reach a consensus. These ''idiopathic'' farms are c haracterised by a higher incidence of recurrent thromboembolism, of '' secondary'' cancer and coagulation abnormalities. The search for the o ptimal duration of anticoagulant therapy in these forms requires prosp ective trials taking their features into account and should lead to fu rther therapeutic options. The evaluation of longer treatment protocol s with less intensive degrees of anticoagulation and of alternatives t o oral vitamin K antagonists is justified.