Objectives: To evaluate the recurrence rate after deep calf-vein thrombosis treated with 6 weeks of oral anticoagulation.
Design and subjects: A 2 year follow-up of 126 consecutive patients admitted to the Department of Internal Medicine with venographically verified deep calf-vein thrombosis.
Results: One hundred and twenty-six patients were treated with warfarin for 6 weeks, 18 of them having had a previous episode of venous thrombosis (DVT). Eleven patients (8.7%) suffered a recurrent thromboembolic episode within 2 years, four of which were within the first 3 months. Eight of those without a history of DVT had a recurrence (7.4%). Three of these were activated protein C (APC)-resistant, one was protein C-deficient and one had malignant melanoma. Eight patients (6.3%) reported minor haemorrhagic complications, but no major bleeding was seen.
Conclusion: Our data support the use of a 6 week regimen of secondary oral prophylaxis after a first episode of deep calf-vein thrombosis in patients without a permanent risk factor. Whether individuals with inherited thrombophilia require prolonged treatment remains to be evaluated.