Changes and Outcome of Cardiac Function in Children with SARS-CoV-2 Multisystem Inflammatory Syndrome

Background: Cardiac involvement has been reported in children with SARS-CoV-2 inflammatory syndrome. The objectives herein were to assess changes in cardiac parameters and compare cardiac pathologies observed in SARS-CoV-2 to Kawasaki-(KW) and myocarditis-(MY). Methods: Patients < 18 years of age, with symptoms of Kawasaki disease (KW group) and/or of acute myocarditis (MY group) from March 1 to May 31 2020 were included. Clinical, laboratory data, and cardiac parameters were recorded upon diagnosis and at several points over two weeks. Results: Sixteen patients (8 males) diagnosed in the context of SARS-CoV-2 pandemic, were included (8 KW, 8 MY); the mean age was 5.9 years (KW 2.7 years, MY 10.2 years; p = 0.0002). Fever was present in all. Conjunctivitis, buccal inflammation, lymphadenopathies, dermatological lesions were more frequent in KW, chest pain, and gastrointestinal symptoms more frequent in MY. C-reactive protein, procalcitonin, and fibrinogen levels were higher in MY. Platelets were higher, and hemoglobin and hematocrit lower in KW. Troponin and NT pro-BNP were higher in MY. Coronary anomalies were observed in KW, and mitral regurgitation and pericarditis in MY. LV systolic function impairment in MY was concomitant to the highest values of troponin, NT-pro-BNP, CRP, ferritin, D-dimers, and lowest value of lymphocytes and platelets. Mean length of intensive care stay was 7.8 days and that of hospital stay was 9.7 days (MY 5.1 days, KW 14.4 days, p = 0.0008). Systolic function was normalized within 15 days. Diastolic dysfunction appeared after normalization of systolic function. Conclusion: Cardiac injury is parallel to biological changes, as evidenced by serial changes of systolic and diastolic myocardial ultrasound parameters.