Multisystem Inflammatory Syndrome in Children (MIS-C): Reduced Exercise Duration and Capacity at Six Month Follow-Up

Daniel McAree; Garett J Griffith; Nazia Husain; Peter Koenig; Michael Carr; Kendra Ward

doi:10.1007/s00246-023-03217-7

Multisystem Inflammatory Syndrome in Children (MIS-C): Reduced Exercise Duration and Capacity at Six Month Follow-Up

Pediatr Cardiol. 2023 Oct;44(7):1605-1612. doi: 10.1007/s00246-023-03217-7. Epub 2023 Jun 21.

Authors

Daniel McAree¹, Garett J Griffith², Nazia Husain³, Peter Koenig³, Michael Carr³, Kendra Ward³

Affiliations

¹ Department of Pediatric Cardiology, Northwestern University, Ann & Robert H. Lurie Children's Hospital, 225 E. Chicago Ave, Chicago, IL, 60611, USA. dmcaree@luriechildrens.org.
² Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, USA.
³ Department of Pediatric Cardiology, Northwestern University, Ann & Robert H. Lurie Children's Hospital, 225 E. Chicago Ave, Chicago, IL, 60611, USA.

PMID: 37344558
DOI: 10.1007/s00246-023-03217-7

Abstract

Myocarditis is common in Multisystem Inflammatory Syndrome in Children (MIS-C), and the mechanism may differ from idiopathic/viral myocarditis as MIS-C involves a hyper-inflammatory state weeks after COVID-19. We sought to evaluate exercise stress testing (EST) in these patients as EST may help guide return-to-play recommendations. Retrospective cohort study evaluating ESTs (standard Bruce treadmill protocol) from MIS-C patients from 2020 to 2022, compared to myocarditis patients and age, sex, and weight matched controls from 2005 to 2019. ESTs included 22 MIS-C patients (mean age 11.9 years) with 14 cardiopulmonary and 8 cardiovascular tests, 33 myocarditis (15.5 years), and 44 controls (12.0 years). Percent-predicted peak VO₂ was abnormal (< 80% predicted) in 11/14 (79%) MIS-C patients, 13/33 (39%) myocarditis, and 17/44 (39%) controls (p = 0.04). Exercise duration was shorter in MIS-C than myocarditis or control cohorts (p = 0.01). Isolated atrial or ventricular ectopy was seen in 8/22 (36%) MIS-C, 9/33 (27%) myocarditis, and 5/44 (11%) controls (p = 0.049). No arrhythmias/complex ectopy or evidence of ischemia were noted, though non-specific ST/T wave abnormalities occurred in 4/22 (18%) MIS-C, 5/33 (15%) myocarditis, and 3/44 (7%) controls. Exercise duration and percent-predicted peak VO₂ were significantly reduced in MIS-C at mean 6-month follow-up compared to pre-COVID era idiopathic/viral myocarditis and control cohorts. This may be secondary to deconditioning during the pandemic and/or chronic cardiopulmonary or autonomic effects of COVID/MIS-C. Although there were no exercise-induced arrhythmias in our MIS-C patients, larger cohort studies are warranted. EST in MIS-C follow-up may help evaluate safety and timing of return to play and potentially mitigate further deconditioning.

Keywords: COVID-19; Exercise Stress Testing; Exercise Tolerance; Multisystem Inflammatory Syndrome in Children (MIS-C); Myocarditis.

MeSH terms

COVID-19*
Child
Follow-Up Studies
Humans
Myocarditis*
Retrospective Studies
Systemic Inflammatory Response Syndrome / diagnosis

Supplementary concepts

pediatric multisystem inflammatory disease, COVID-19 related