Duration Of Anticoagulant Therapy After Venous Thromboembolism: A Meta-Ananlysis

Objective: To evaluate the duration of anticoagulant in patients with venous thromboembolism (VTE).Methods: Chinese Conference Data, Chinese Biomedical Database, VIP Database, Wanfang Data, Cochrane Library, PubMed were searched up to March 2011, and the studies as references of eligible articles were also searched.Included studies were randomized controlled trials and evaluating the duration of anticoagulation in patients with VTE. According to including criteria, articles were evaluated by "bias risk assessment" tool which Cochrane Handbook 5.0 recommended. Software RevMan 5.0 was used to examine the heterogeneity of trials, and analysis the data using fixed or random effect model to pool the Odds Ratio and 95%CI, The funnel plot was used to discuss the publication bias.Results: 6 trials met all eligible criteria. This Meta-analysis indicated that compared with three months, six months or longer anticoagulation therapy in patients with VTE doesn't reduce the risk of recurrent VTE[OR 0.78, 95%CI(0.49, 1.24); P=0.30]. The risk of bleeding with long- vs short-term therapy was similar [OR 2.79, 95%CI(0.93, 8.36); P=0.07]. Subgroup analysis: The risk of recurrent VTE with twelve months or longer anticoagulation therapy versus three months in patients with idiopathic VTE was also not reduced[OR 0.26, 95%CI(0.01, 5.77); P=0.39]. The risk of bleeding with long- vs short-term therapy in patients with idiopathic VTE was increased [OR 4.64, 95%CI(1.31, 16.35); P=0.02].Conclusions: The patients with VTE receiving long-term therapy not only didn't benefit from extended anticoagulation, who maybe receive three months anticoagulation therapy enough, but also had to face the increasing risk of bleeding.