Duration of oral anticoagulant treatment in patients with venous thromboembolism and a deficiency of antithrombin, protein C or protein S - A decision analysis

Patients with a first venous thromboembolic event and a deficiency bf the c oagulation inhibitors antithrombin, protein C or protein S have an: increas ed risk of recurrent venous thromboembolism compared to patients without su ch a deficiency. A decision analysis was performed to assess the effect of continuing treatment with vitamin K antagonists on mortality by a reduction in fatal recurrent pulmonary embolism and an induction of fatal haemorrhag es associated with their use. The treatment decision involves continuation or discontinuation of vitamin K antagonists in patients with a first sponta neous or secondary venous thromboembolism and an antithrombin, protein C or S deficiency. Although the efficiency of oral anticoagulation is high in a ll age groups early-after the first thromboembolic event, it decreases over time. Our analysis indicates that the optimal treatment duration will vary , depending on the type of the initial event (spontaneous or secondary; dee p venous thrombosis or pulmonary embolism), age, and rime passed since the initial thromboembolic episode. Moreover, life-long duration of the prophyl axis seems nor warranted in all patients.