A comparison of 3 and 6 weeks' anticoagulation in the treatment of venous thromboembolism.

One hundred hospital in-patients treated for pulmonary embolism (PE) and/or deep vein thrombosis (DVT) were randomly allocated to receive 3 or 6 weeks' anticoagulation with heparin and warfarin. At one year recurrence rates were 12% in the 6 week group and 10% in those treated for 3 weeks. No patient died as a result of recurrence. Our study suggests that 3 weeks' anticoagulation therapy, using intravenous heparin for the first 5 days and warfarin from the third day, is adequate for patients without persisting risk factors.