Long-Term, Low-Intensity Warfarin Therapy for the Prevention of Recurrent Venous Thromboembolism

The standard therapy for idiopathic venous thromboembolism is anticoagulation with heparin followed by 3 to 12 months of warfarin therapy, but after warfarin is discontinued, venous thrombosis may recur. This clinical trial compared long-term, low-intensity warfarin therapy (target international normalized ratio, 1.5 to 2.0) with placebo after completion of standard anticoagulant therapy. Low-intensity warfarin therapy was very effective and was associated with a low risk of bleeding. A new standard for anticoagulation after venous thromboembolism. Therapy for idiopathic venous thromboembolism typically includes a 5-to-10-day course of heparin followed by 3 to 12 months of oral anticoagulation therapy with full-dose warfarin, with adjustment of the dose to achieve an international normalized ratio (INR) between 2.0 and 3.0. 1 – 4 After cessation of anticoagulation therapy, however, recurrent venous thromboembolism is a major clinical problem, with an estimated rate of 6 to 9 percent annually. 5 , 6 Unfortunately, no therapy with an acceptable benefit-to-risk ratio is available for long-term management. In particular, although extended use of full-dose warfarin is associated with reduced rates of recurrent venous thromboembolism, 2 – 4 community-based studies . . .