Analysis of cardiac manifestation and treatment of multisystem inflammatory syndrome in children related to SARS-CoV-2

Cardiovascular (CV) manifestations are common (35%–100%) in the multisystem inflammatory syndrome in children. Our study aimed to analyze treatment impact and CV involvement in patients with multisystem inflammatory syndrome in children. The retrospective cohort included 81 patients treated between April 2020 and December 2021 (9.3 ± 4.6 years). Elevated cardiac troponin I and pro-B-type natriuretic peptide were observed in 34.2% and 88.5% of patients, respectively. Myocardial dysfunction was observed in 50.6%. Children older than 10 years had a 4-fold increased risk of myocardial dysfunction (odds ratio [OR] 3.6, 95% confidence interval [CI] 1.4–8.9; p ═ 0.006). A moderate negative correlation was proved between left ventricular ejection fraction and C-reactive protein (rr ═ −0.48; p < 0.001). More than one-fifth of the patients presented with shock. Coronary artery dilatation was observed in 6.2% of patients. Mild pericardial effusion was detected in 27.1% of children. On standard electrocardiogram, 52.6% of children had negative T waves in the inferior and/or precordial leads; transient QTc prolongation was registered in 43% of patients. Treatment failure was observed in 19 patients. Patients initially treated with intravenous immunoglobulins had 10-fold higher chances for treatment failure than patients treated with corticosteroids (OR 10.6, 95% CI 3.18–35.35; p < 0.001). CV manifestations were observed in more than half of the patients, with acute myocardial dysfunction being the most common, especially in children older than 10 years. We established a negative association between the degree of elevation of inflammatory markers and left ventricular ejection fraction. Patients treated with intravenous immunoglobulins who had CV manifestations had treatment failures more frequently than patients treated with corticosteroids.