Prevalence and Risk Factors of Thromboembolic Events in Dermatomyositis in China: A 10-Year Retrospective Analysis

Objective: Dermatomyositis (DM) is an autoimmune disease characterized by chronic muscle inflammation and weakness. Patients with DM are at an increased risk of thromboembolic events (TEs). This study aimed to investigate the prevalence of TEs in DM and to identify the independent predictors. Methods: A total of 543 patients hospitalized for DM within the past 10 years were analyzed retrospectively and compared with patients with DM with and without TEs for demographic, clinical, and laboratory characteristics. The independent predictors were analyzed using multivariate logistic regression analysis. The diagnostic performance was calculated by a receiver operating curve (ROC). Results: Twenty-two (4.1%) patients with DM had TEs, including 12 (54.5%) with venous thromboembolism and 10 (45.5%) with arterial thromboembolism. Multivariate logistic regression analysis demonstrated that glucocorticoid therapy (odds ratio (OR)=0.003, 95% confidence interval (CI) 0.00-0.03, P<0.001) was a protective factor for the patients with DM developing TEs, whereas increased D-Dimer (OR=1.885, 95% CI 1.21-2.95, P=0.006) was a risk factor. The combined ROC analysis of glucocorticoid therapy and D-Dimer indicated high diagnostic values in distinguishing patients with both DM and TEs from patients without TEs, with 86.4% sensitivity, 98.9% specificity, and 0.983 area under the ROC curve (95% CI 0.962-1.000, P<0.001). Conclusion: Patients with DM who have never received glucocorticoid therapy and have increased D-Dimer (>1.3 mg/L fibrinogen equivalent units) should be screened for TEs.