Multisystem Inflammatory Syndrome in Children: Two Years' Worth of Learning

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening sequela of SARS-CoV-2 infection. Limited data are available regarding risk-stratification or long-term outcomes in MIS-C. This study sought to determine associations between serologic markers and severity of illness and understand long-term cardiac outcomes. This series includes 46 cases (mean age 8.1 years; 63.0% male) of MIS-C. Pearson's chi-squared analysis showed an erythrocyte sedimentation rate (ESR) greater than 30 mm/h and 50 mm/h were disproportionately associated with pediatric intensive care unit (PICU) admission (χ² = 4.44, P = .04) and use of vasopressors (χ² = 6.06, P = .01), respectively. Ferritin less than 175.6 ng/mL was associated with use of vasopressors (χ² = 5.28, P = .02). There was a negative correlation between ESR and ejection fraction (EF) (r = -0.39, P = .009). Most patients with abnormal echocardiograms had resolution of abnormalities within 30 days. Therefore, inflammatory markers may be helpful in predicting which patients may require specific interventions or experience cardiac dysfunction, but MIS-C does not appear to be associated with complications at 1 year.