Early signs of myocardial remodeling in children with multisystem inflammatory syndrome associated with COVID-19 and cardiac involvement

ABSTRACT

Background and Aim: Multisystem Inflammatory Syndrome in Children (MIS-C) associate with Coronavirus disease-19 is a life-threatening clinical condition in which cardiovascular system is frequently affected. Shock, cardiac arrhythmias, myocarditis, reduced left ventricular ejection fraction (LVEF), pericardial effu-sion, and coronary artery dilatation are amongst the most common cardiac complications. In this study, we aim to assess myocardial status in patient with cardiac involvement in MIS-C. Method(s) Over a 14-month period, we retrospectively collected clinical, biological, echocardiographic data in children who were admitted to our hospital with a diagnosis of MIS-C and cardiac involvement. WHO criteria for clinical case definition of MIS-C were adopted. Elevation in brain-natriuretic-peptide and troponin-I, electrocardiographic abnormalities, echocardio-graphic evidence of pericarditis, myocarditis, reduced LVEF, valvular disease, and coronary artery dilatation were including cri-teria. LV indexed end-diastolic (EDVi), end-systolic (ESVi), stroke volumes were measured with Cardiac Magnetic Resonance (CMR). T2 mapping, Cine-RM and late gadolinium enhance-ment studies were performed. Result(s) 14 children were identified and included in the study, 71% of which were male. Median age at disease onset was 7 years old (IQR 5 to 9 years). All patients underwent cardiological evaluation in the first 48 hours of hospital staying. LVEF was lt;45% in 28.6% and lt;35% in 14.3% of patients. Myocarditis was detected in 78.6%, pericarditis in 28.6%, valvular damage in 35.7%, coronary abnormalities in 42.9%. All patients underwent CMR after on average 4 months (median 3.87, IQR 2 to 4) from disease onset, after full clinical and biological recovery. ESVi and stroke volumes resulted within normal range in 100%. CMR abnormalities were observed in 21%. Particularly, left ventricular EDVi resulted elevated in 7%, delayed washout in T2 was described in 7%, and increased T2 mapping in 7%. Conclusion(s) Despite complete clinical and biological resolution, increased EDVi, delayed washout in T2 and increased T2 mapping at follow-up CMR in patient with cardiac involvement due to MIS-C may be signs of myocardial remodeling.