Ab1630 risk factors for cardiac involvement in idiopathic inflammatory myopathies

Background Idiopathic inflammatory myopathies (IIMs) are heterogenous systemic autoimmune disorders that mainly affect the skin, muscles, and lungs. Whereas cardiac involvement is considered to be rare, it causes cardiac inflammation and fibrosis leading to severe morbidity and mortality. However, little is known about clinical characteristics and risk factors for cardiac involvement in patients with IIMs. Objectives The aim of this study was to clarify the frequency and clinical characteristics of cardiac involvement and its risk factors in patients with IIMs. Methods We retrospectively reviewed consecutive patients with IIMs who visited Keio University Hospital from 2002 to 2022. We divided patients into two groups according to the presence or absence of symptomatic cardiac involvement and compared their clinical characteristics and autoantibodies between the two groups. We defined symptomatic cardiac involvement as the presence of chest pain, palpitation, cardiogenic leg edema, or respiratory distress accompanied by abnormal findings of cardiac examinations such as electrocardiography, echocardiography, and/or cardiac magnetic resonance imaging (MRI). Results We included 145 patients with IIMs in the analysis. The mean age at IIMs diagnosis was 55 years old, and 71.7% were female. Forty patients (27.6%) were polymyositis, 53 (36.6%) were dermatomyositis, 44 (30.3%) were amyopathic dermatomyositis, and 8 (5.5%) were immune-mediated necrotizing myopathy. Among them, 52 patients (35.9%) had abnormal findings on electrocardiography, echocardiography, and/or cardiac MRI, and 17 (11.7%) were diagnosed with symptomatic cardiac involvement at the mean age of 65 years during the mean observation period of 20.0 years. Comparison of clinical characteristics identified no difference in the mean age, sex distribution, and duration from IIM diagnosis to symptomatic cardiac involvement between the two groups. Also, no significant difference was found in the positivity of anti-amynoacyl tRNA synthetase antibody, anti-MDA5 antibody, and anti-SS-A antibody, IIMs subtypes, presence of skin rash, malignancy, interstitial lung disease, history of cyclophosphamide use, and maximum levels of CK, aldolase, CK-MB, troponin T, and CRP. However, the presence of Raynaud’s phenomenon and neutrophil/lymphocyte ratio at diagnosis were significantly higher in the cardiac involved group compared to the non-cardiac involved group (53.85% vs 15.24%, p=0.0009; 56.25% vs 18.25%, p=0.0006). Multivariable analysis identified Raynaud’s phenomenon (odds ratio [OR] 8.42, 95% confidence interval [CI] 2.10-33.8, p=0.0026) and elevated neutrophil/lymphocyte ratio (OR 6.92, 95% CI 1.73-27.6, p=0.0061) as independent risk factors for symptomatic cardiac involvement. One patient in the cardiac involved group died of cardiac failure during the observation period. Conclusion Abnormal findings in cardiac examinations and symptomatic cardiac involvement are frequent in patients with IIMs. Evaluating cardiac involvement is important, especially in patients with Raynaud’s phenomenon and elevated neutrophil/lymphocyte ratio at diagnosis. Reference [1]Lilleker JB, Vencovsky J, Wang G, et al. The EuroMyositis registry: an international collaborative tool to facilitate myositis research. Ann Rheum Dis. 2018;77: 30–39. Figure 1. Risk factors for cardiac involvement in inflammatory myopathies Acknowledgements: NIL. Disclosure of Interests None Declared.