Anticoagulation in patients with isolated distal deep vein thrombosis: a meta‐analysis

Abstract

Background The optimal management of patients with isolated distal deep vein thrombosis (IDDVT), concerning both the need for anticoagulation and its duration, is undefined. Objectives We performed a meta-analysis of randomized and cohort studies in patients with IDDVT to assess the clinical benefit of: (i) anticoagulation versus no anticoagulation; and (ii) anticoagulant treatment for 6weeks versus for >6weeks. Methods The primary outcome of this analysis was recurrent venous thromboembolism (proximal propagation, recurrence of deep vein thrombosis, and pulmonary embolism). Data were pooled and compared by the use of odds ratio (OR) and 95% confidence interval (CI). Results A reduction in the rate of recurrent venous thromboembolism was observed in patients who received anticoagulation relative to those who did not receive anticoagulation (either therapeutic or prophylactic) (20 studies, 2936 patients; OR0.50, 95%CI0.31-0.79), without an increase in the risk of major bleeding (OR0.64, 95%CI0.15-2.73). The rate of pulmonary embolism was lower in anticoagulant-treated patients than in controls (15 studies, 1997 patients; OR0.48, 95%CI0.25-0.91). A lower rate of recurrent venous thromboembolism was observed in patients who received >6weeks of anticoagulant therapy than in those who received 6weeks of anticoagulant therapy (four studies, 1136 patients; OR0.39, 95%CI0.17-0.90). Conclusions In patients with IDDVT, anticoagulation (both therapeutic and prophylactic) reduces the rate of recurrent venous thromboembolism and the incidence of pulmonary embolism as compared with no anticoagulation, without an increased risk of major bleeding. Anticoagulation for >6weeks should be preferred over shorter durations.