A meta-analysis of the risk of venous thromboembolism in inflammatory rheumatic diseases

INTRODUCTION We performed a meta-analysis to investigate the risk of deep vein thrombosis (DVT) and/or pulmonary embolisms (PEs) in patients with inflammatory arthritis, vasculitis and connective tissue diseases (CTDs) (systemic lupus erythematosus (SLE), Sjögren's syndrome, inflammatory myositis and systemic sclerosis (SSc)). METHODS PubMed, Embase, the Cochrane databases and MEDLINE were searched to identify full-text English-language publications about adult patients with rheumatologic inflammatory diseases and venous thromboembolisms (VTEs). Data regarding rates of DVTs and PEs were extracted. Using random-effects models, pooled estimates for VTEs in individual and pooled diseases were compared with matched populations where possible. Studies were excluded if VTEs were described in the setting of pregnancy, postoperative outcomes or solely antiphospholipid antibody syndrome. RESULTS Most of the 5,206 studies were excluded because they did not state the rate or incidence of VTEs. In total, 25 studies remained for analysis. Ten studies that included rheumatoid arthritis comprised an aggregate of 5,273,942 patients and 891,530,181 controls with a cumulative VTE incidence of 2.18% (95% confidence interval (CI): 1.82% to 2.54%) and an odds ratio of 2.23 (95% CI: 2.02 to 2.47) compared to age- and sex-matched populations. Ten studies comprised an aggregate of 54,697 SLE patients with a cumulative VTE incidence of 7.29% (95% CI: 5.82% to 8.75%). Four Sjögren's syndrome studies comprising an aggregate of 25,100 patients demonstrated a cumulative VTE incidence of 2.18% (95% CI: 0.79% to 3.57%). Four studies of inflammatory myositis comprising an aggregate of 8,245 patients yielded a cumulative VTE incidence of 4.03% (95% CI: 2.38% to 5.67%). The SSc- and antineutrophil cytoplasmic antibody vasculitis-related cumulative VTE rates (four studies each) were 3.13% and 7.97%, respectively. CONCLUSIONS The inflammatory rheumatologic diseases studied were all associated with high rates of VTEs-more than three times higher than in the general population.