Six month follow-up of patients with multi-system inflammatory syndrome in children

Abstract

BACKGROUND AND OBJECTIVES: Myocardial dysfunction and coronary abnormalities are prominent features of multisystem inflammatory syndrome in children (MIS-C). In this study we aim to evaluate the early and midterm outcomes of MIS-C. METHODS: This is a longitudinal 6-month cohort study of all children admitted and treated for MIS-C fromApril 17 to June 20, 2020. Patientswere followed ~2 weeks, 8 weeks, and 6months postadmission,with thosewith coronary aneurysms evaluatedmore frequently. RESULTS: Acutely, 31 (62%) patients required intensive carewith vasoactive support, 26 (52%) had left ventricular (LV) systolic dysfunction, 16 (32%) had LV diastolic dysfunction, 8 (16%) had coronary aneurysms (z score$2.5), and 4 (8%) had coronary dilation (z score<2.5).Atotal of 48 patients (96%) received immunomodulatory treatment.At 2weeks, therewas persistentmild LVsystolic dysfunction in 1 patient, coronary aneurysms in 2, and dilated coronary artery in 1.By 8weeks through 6months, all patients returned to functional baselinewith normal LV systolic function and resolution of coronary abnormalities. CardiacMRI performed during recovery in select patients revealed nomyocardial edema or fibrosis. Some patients demonstrated persistent diastolic dysfunction at 2weeks (5, 11%), 8weeks (4, 9%), and 6 months (1, 4%). CONCLUSIONS: Childrenwith MIS-C treatedwith immunomodulators have favorable early outcomes with nomortality, normalization of LV systolic function, recovery of coronary abnormalities, and no inflammation or scarring on cardiacMRI. Persistence of diastolic dysfunction is of uncertain significance and indicates need for larger studies to improve understanding ofMIS-C. These findingsmay help guide clinical management, outpatient monitoring, and considerations for sports clearance.