Intensity of anticoagulation in the treatment of thrombosis in the antiphospholipid syndrome: a meta-analysis

Introduction: Discussion about the intensity of warfarin in patients with antiphospholipid syndrome (APS) remains present in our days. Objectives: To evaluate which intensity of anticoagulation with warfarin is associated with a greater reduction of thromboembolic events in the treatment of patients with APS, as well as assess the risk of bleeding in the different treatment modalities. Methodology: A systematic review of the literature was carried out with search from electronic databases: PubMed, LILACS and SciELO, with the use of the key-words: treatment, warfarin, antiphospholipid syndrome, antiphospholipid antibody syndrome and their respective translations into Portuguese, in different combinations. In addition, a meta-analysis with the aid of Review Manager 5.2 software by Cochrane was performed. Results: Only two articles met the inclusion criteria for this study. Regarding the main outcome assessed in this study, the two studies showed similar values, indicating higher frequency of thrombotic events in high-intensity groups. The comparative analysis of the randomized clinical trial evaluated showed an increased thrombotic risk for those patients who received intervention with high-intensity warfarin. Another finding of the meta-analysis was the higher incidence of minor bleeding, also in the experimental group, that received warfarin keeping International Normalized Ratio (INR) > 3. Conclusion: In individuals with APS and prevalence of venous events, the use of moderate intensity (MI) anticoagulation (INR: 2-3) is the most suitable. However, this evidence cannot yet be extended to patients with arterial events, due to the limited representation of this sample of subjects in the two clinical trials included in this meta-analysis. (C) 2014 Elsevier Editora Ltd a. All rights reserved.