Molecular Mechanisms and Pathophysiology of Myocardial Disease: Insights from Pediatric Inflammatory Multisystem Syndrome (PIMS) Associated with SARS-CoV-2.

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome (PIMS), presents significant challenges in pediatric cardiology, due to its complex molecular pathophysiology. In this retrospective analysis of 15 cases that were managed at a single tertiary care center, we investigated the molecular contributors to myocardial dysfunction, including cytokine storms, hyperinflammation markers, and hypercoagulable states. Transient myocardial involvement was identified in 46.6% of patients, with complete recovery achieved within 2-4 weeks following treatment. Ferritin, NT-ProBNP, and troponin levels were significantly elevated in patients with ventricular dysfunction compared to those without. The neutrophil-to-lymphocyte ratio (NLR), which was previously identified as a severity marker in acute COVID-19, was also significantly higher in patients with ventricular dysfunction, suggesting its potential as a prognostic indicator in MIS-C. Notably, no coronary artery aneurysms were detected in the cohort. These findings underscore the importance of early, standardized therapeutic interventions in mitigating severe outcomes, and they provide valuable insights into the molecular mechanisms driving myocardial dysfunction in MIS-C. Incorporating NLR and ferritin into the initial diagnostic workup may improve the early triage and identification of high-risk MIS-C patients.