Acute heart failure in multisystem inflammatory syndrome in children (MIS-C) in the context of global SARS-CoV-2 pandemic

Background: Cardiac injury and myocarditis have been described in adults with COVID-19. SARS-CoV-2 infection in children is typically minimally symptomatic. We report a series of febrile pediatric patients with acute heart failure potentially associated with SARS-CoV-2 infection and the multisystem inflammatory syndrome in children (MIS-C) as defined by the US Centers for Disease Control. Methods: Over a two-month period contemporary with the SARS-CoV-2 pandemic in France and Switzerland, we retrospectively collected clinical, biological, therapeutic, and early outcomes data in children who were admitted to pediatric intensive care units in 14 centers for cardiogenic shock, left ventricular dysfunction and severe inflammatory state. Results: Thirty-five children were identified and included in the study. Median age at admission was 10 years (range 2-16 years). Co-morbidities were present in 28% including asthma and overweight. Gastrointestinal symptoms were prominent. Left ventricular ejection fraction was <30% in one third; 80% required inotropic support with 28% treated with ECMO. Inflammation markers were suggestive of cytokine storm (interleukin 6 median 135 pg/mL) and macrophage activation (D-dimer median 5284 ng/mL). Mean brain natriuretic peptide was elevated (5743 pg/mL). Thirty-one/35 (88%) patients tested positive for SARS-CoV-2 infection by PCR of nasopharyngeal swab or serology. All patients received intravenous immune globulin, with adjunctive steroid therapy used in one third. Left ventricular function was restored in the 25/35 of those discharged from the intensive care unit. No patient died, and all patients treated with ECMO were successfully weaned. Conclusion: Children may experience an acute cardiac decompensation due to severe inflammatory state following SARS-CoV-2 infection (multisystem inflammatory syndrome in children - MIS-C). Treatment with immune globulin appears to be associated with recovery of left ventricular systolic function.