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 referred to as Pediatric Inflammatory Multisystem Syndrome (PIMS), poses significant challenges in pediatric cardiology due to its complex molecular underpinnings. In this retrospective study of 15 cases managed at a single tertiary care center, we investigated the molecular drivers of myocardial dysfunction, including cytokine storms, endothelial dysfunction, and hypercoagulable states. Transient myocardial involvement was identified in 46.6% of patients, with elevated cardiac biomarkers (median NT-proBNP: 4500 pg/mL; median troponin: 758 ng/L) and complete recovery achieved within 2–4 weeks following treatment. Notably, no coronary artery aneurysms were observed. Furthermore, vaccination was associated with a marked reduction in both the incidence and severity of MIS-C. These findings highlight the critical importance of early, standardized interventions and vaccination strategies in mitigating severe outcomes, and they provide valuable insights into the molecular mechanisms driving myocardial dysfunction in MIS-C.