Increased risk of venous thromboembolism associated with polymyositis and dermatomyositis: a meta-analysis

OBJECTIVE: Polymyositis and dermatomyositis (PM/DM) have been implicated in the development of venous thromboembolism (VTE). Previous studies investigating the association between PM/DM and VTE risk had yielded inconsistent findings. The aim of this study was to precisely estimate this association by meta-analysis of all available publications. METHODS: Two investigators independently performed a comprehensive literature search in databases of PubMed, Embase, and the Cochrane Library for eligible studies. The strength for the association was weighed by pooled odds ratios (ORs) with 95% confidence intervals (95% CIs). Stratified analysis and sensitivity analysis were performed for further analysis. RESULTS: Six studies including 9,045 patients with PM/DM were analyzed. The pooled OR suggested that inflammatory myositis was associated with increased risk of VTE (OR =4.31, 95% CI: 2.55–7.29, P<0.001). Besides, significantly elevated risk of VTE was related with PM and DM, respectively (for PM: OR =6.87, 95% CI: 4.12–11.46, P<0.001; for DM: OR =11.59, 95% CI: 6.54–20.55, P<0.001). In addition, inflammatory myositis could increase the risk of DVT (OR =4.85, 95% CI: 1.38–17.12, P<0.05) and PE (OR =4.74, 95% CI: 2.18–10.30, P<0.05). Sensitivity analysis did not materially alter the pooled results. CONCLUSION: Our study shows strong evidence that patients with inflammatory myositis have an increased risk of VTE.