Differentiation of Multi-system Inflammatory Syndrome Associated with COVID-19 Versus Kawasaki Disease Using Cardiac Biomarkers.

ABSTRACT

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) after COVID-19 shares clinical similarities to Kawasaki disease (KD). We sought to determine whether cardiac biomarker levels differentiate MIS-C from KD and their association with cardiac involvement. METHODS: Subjects included 38 MIS-C patients with confirmed prior CoVID-19 and 32 pre-pandemic and 38 contemporaneous KD patients with no evidence of COVID-19. Patient, clinical, echocardiographic, electrocardiographic and laboratory data timed within 72 hours of cardiac biomarker assessment were abstracted. Groups were compared, and regression analyses were used to determine associations between biomarker levels, diagnosis and cardiac involvement, adjusting for clinical factors. RESULTS: MIS-C patients had fewer KD clinical features, with more frequent shock, ICU admission, inotrope requirement, and ventricular dysfunction, with no difference regarding coronary artery involvement. Multivariable regression analysis showed that both higher N-terminal pro-B-type natriuretic peptide (NTproBNP) and cardiac troponin I (TnI) were associated with MIS-C versus KD, after adjusting for significant covariates. Receiver operating characteristic curves for diagnosis showed that any detectable TnI greater than 10 ng/L was predictive of MIS-C versus KD with 91% sensitivity and 76% specificity. NTproBNP >2000 ng/L predicted MIS-C versus KD with 82% sensitivity and 82% specificity. Higher TnI but not NTproBNP was associated with lower LV ejection fraction; neither biomarker was associated with coronary artery involvement. CONCLUSIONS: Positive TnI and higher NTproBNP may differentiate MIS-C from KD, which may become more relevant as evidence of prior COVID-19 becomes more challenging to determine. Cardiac biomarkers may have limited associations with cardiac involvement in this setting.