The Duration of Oral Anticoagulant Therapy after a Second Episode of Venous Thromboembolism

Oral anticoagulant therapy is routinely given to most patients who have had episodes of venous thromboembolism. Two recent multicenter trials have demonstrated that if the duration of treatment after a first episode of thromboembolism is extended to three to six months, instead of four to six weeks, the rate of recurrence can be reduced, especially among patients with permanent risk factors such as thromboembolism that was idiopathic in nature and venous insufficiency. 1 , 2 The optimal duration of secondary prophylaxis after a second episode of venous thromboembolism is unknown. In one study, patients were stratified according to whether the episode of . . .