Comparison of 3 and 6 months of oral anticoagulant therapy after a first episode of proximal deep vein thrombosis or pulmonary embolism and comparison of 6 and 12 weeks of therapy after isolated calf deep vein thrombosis

• Published in: Circulation (New York, N.Y.) N.Y.), 2001-05, Vol.103 (20), p.2453-2460
• Main Authors: PINEDE, Laurent, NINET, Jacques, DUHAUT, Pierre, CHABAUD, Sylvie, DEMOLOMBE-RAGUE, Sylvie, DURIEU, Isabelle, NONY, Patrice, SANSON, Christian, BOISSEL, Jean-Pierre
• Format: Article
• Language: English
• Subjects: Administration, Oral; Anticoagulants - adverse effects; Anticoagulants - therapeutic use; Biological and medical sciences; Blood. Blood coagulation. Reticuloendothelial system; Female; Follow-Up Studies; Hemorrhage - chemically induced; Humans; Male; Medical sciences; Middle Aged; Pharmacology. Drug treatments; Pulmonary Embolism - drug therapy; Recurrence; Thrombophlebitis - drug therapy; Time Factors; Treatment Outcome; Vascular Diseases - drug therapy; Venous Thrombosis - drug therapy
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/01.CIR.103.20.2453

The optimal duration of oral anticoagulant therapy after a first episode of venous thromboembolism remains controversial. We performed an open-label, randomized trial comparing a short oral anticoagulant course (3 months for proximal deep vein thrombosis [P-DVT] and/or pulmonary embolism [PE]; 6 weeks for isolated calf DVT [C-DVT]) with a long course of therapy (6 months for P-DVT/PE; 12 weeks for C-DVT). The outcome events were recurrences and major, minor, or fatal bleeding complications. A total of 736 patients were enrolled. There were 23 recurrences of venous thromboembolism in the short treatment group (6.4%) and 26 in the long treatment group (7.4%); the 2 treatment regimens had an equivalent effect. For the hemorrhage end point, the difference between the short and the long treatment groups was not significant: 15.5% versus 18.4% for all events (P=0.302), 1.7% versus 2.8% (P=0.291) for major events, and 13.9% versus 15.3% for minor bleeding. Subgroup analysis demonstrated that the rate of recurrence was lower for C-DVT than for P-DVT or PE. After isolated C-DVT, 6 weeks of oral anticoagulation is sufficient. For P-DVT or PE, we demonstrated an equivalence between 3 and 6 months of anticoagulant therapy. For patients with temporary risk factors who have a low risk of recurrence, 3 months of treatment seems to be sufficient. For patients with idiopathic venous thromboembolism or permanent risk factors who have a high risk of recurrence, other trials are necessary to assess prolonged therapy beyond 6 months.