Electrophysiological, structural, and functional disorders in patients with inflammatory cardiomyopathy secondary to inflammatory myopathy

BACKGROUND: Inflammatory cardiomyopathy (IC) is a syndrome with chronic myocarditis and cardiac remodeling. This study aimed to explore predicting factors of adverse outcomes in patients with IC secondary to idiopathic inflammatory myopathy (IIM-IC). METHODS: By means of a single-center retrospective study, 52 patients with IIM-IC at Peking Union Medical College Hospital were identified from January 1999 to June 2019. Electrocardiogram and echocardiography data were analyzed for the primary outcome (defined as all-cause death) and secondary outcomes (defined as re-hospitalization of heart failure and all-cause death), using regression and survival analysis. RESULTS: The prevalence of atrial fibrillation, ventricular tachycardia, Q-wave abnormality, left ventricular conduction abnormalities, and reduced left ventricular ejection fraction (LVEF) (≤40%) were 65.4%, 67.3%, 67.3%, 61.6%, and 50.5%. After a median follow-up of 2 years (IQR 0.8-3.0), 26 cases were readmitted due to heart failure. Twenty-two deaths were recorded, including 20 cardiogenic deaths. Among the patients with adverse events, the incidence of poor R-wave progression, low-voltage of the limb leads, Q-wave abnormality, QRS duration >130 ms, left ventricular enlargement, and impaired systolic function were higher. Kaplan-Meier analysis showed that Q-wave abnormality, limb leads low-voltage, LVEF ≤40%, and left ventricular end-diastolic dimension >60 mm were correlated with shorter survival. However, multivariate Cox regression analysis revealed that only Q-wave abnormality (HR = 12.315) and LVEF ≤40% (HR = 5.616) were independent risk factors for all-cause death. CONCLUSION: Q-wave abnormality and reduced LVEF are predictive of poor prognosis in patients with IIM-IC.