Correlation of Clinical and Laboratory Features of Multisystem Inflammatory Syndrome in Children with Echocardiographic Findings.

Background and Objectives: The aim of this study was to identify clinical features and laboratory findings that correlate with and predict pathological echocardiographic findings in children diagnosed with Multisystem Inflammatory Syndrome. Materials and Methods: Retrospective study included all patients aged 0-18 diagnosed with Multisystem Inflammatory Syndrome and hospitalized at our clinic from July 2020 to December 2022. The clinical and laboratory data of 61 patients were studied and compared between two subgroups (normal/abnormal echocardiography). Results: Elevated values of high-sensitivity troponin I were observed in 65.57% patients with MIS-C. The mean high-sensitivity troponin I value in the whole sample was 400.89 ± 1989.31 pg/mL. In patients with pathological echocardiographic findings, the mean value was 1240.24 ± 3609 pg/mL, while in patients with normal echocardiographic findings, it was 52.87 ± 71.86 pg/mL. Even though mean value was higher in the group of patients with abnormal echocardiography, no statistically significant difference was observed between high-sensitivity troponin I values in patients with and without pathological echocardiographic findings. Troponin levels were not in good correlation with pathological echocardiographic findings (point-biserial correlation; rpb = 0.25, p = 0.054) and were not good predictors of pathological echocardiographic findings (logistic regression; Chi2 = 3.77, p = 0.052). Logistic regression showed significant positive correlation of blood urea nitrogen levels and the degree of fever with abnormal echocardiographic findings (Chi2 = 10.04, p 0.002/Chi2 = 6.10, p = 0.013, respectively). Conclusions: Only blood urea nitrogen levels and high fever showed statistically significant correlation and predictive value for abnormal echocardiographic findings in children with Multisystem Inflammatory Syndrome. High sensitive troponin I had no significant power to discriminate between normal and abnormal echocardiographic findings.