Assessing medium term cardiac outcomes in children with multi-system inflammatory syndrome

ABSTRACT

Background and Aim: Multi-system inflammatory syndrome in chil-dren (MIS-C) causes widespread systemic inflammation including a pancarditis in the weeks following a COVID infection. Further coronavirus surges appear inevitable and with vaccination rates lower in young people an understanding of the medium-term car-diac impacts of this condition is important for planning further treatment and understanding the impacts on their health. Method(s) A retrospective single-center study of 67 consecutive patients with MIS-C was performed. Three time points were determined as the point of worst cardiac dysfunction during the acute admission, then at intervals of 6-8 weeks and 6-8 months. Echocardiographic findings were used to evaluate both 2D and 3D measures of cardiac function. Coronary artery measurements were recorded. Corresponding serial ECG findings were evaluated. Result(s) The worst cardiac function arose 6.8 +/- 2.4 days after the onset of fever. The mean M mode-derived FS was 30.9 +/- 8.1% during the acute phase. The mean 3D left ventricle (LV) ejection fraction (EF) was borderline at 50.5 +/- 9.8%. A pancarditis was typ-ically present 46.3% showed cardiac impairment;31.3% had some pericardial effusion;26.8% had moderate (or worse) valvar regur-gitation and;26.8% had coronary dilatation. Cardiac function returned to normal in all patients by 6-8 weeks (mean 3D LV EF 61.3 +/- 4.4%, plt;0.001 compared to admission). Coronary dila-tation normalized in all but one patient who initially developed large aneurysms at presentation;these continued 6 months later. ECG findings mainly featured T-wave changes resolving at fol-low-up. There were a small number of adverse events need for ECMO (2), death as an ECMO-related complication (1), suben-docardial infarction (1), LV thrombus formation (1). Conclusion(s) MIS-C causes a pancarditis with decreased cardiac function and almost a quarter of patients showing coronary changes. In most, discharge from long-term follow-up can be con-sidered as full cardiac recovery is expected by 8 weeks. The excep-tion includes patients with medium sized aneurysms or greater or those with more of a Kawasaki disease phenotype as these require on-going surveillance for persistence of coronary changes.