Actionable Insights Newsletter

Translating research to power whole health

Issue 11 |    April 2025

Recent findings offer hope
for children with multisystem inflammatory 
syndrome (MIS-C)

While most children hospitalized for MIS-C during the acute COVID-19 phase were critically ill, the vast majority experienced excellent recovery in both cardiac and overall health outcomes within six months.  

Domain(s): cardiovascular

Summary

Background
Multisystem inflammatory syndrome in children (MIS-C) is one of the most serious complications of COVID-19 infection in children. Many publications have focused on immediate treatment and short-term outcomes, but there have been few studies looking at the longer-term health impact of MIS-C.

Objective
The long-terM oUtcomes after the Multisystem Inflammatory Syndrome In Children (MUSIC) study seeks to understand how often and how long cardiac and non-cardiac after-effects last in children who had MIS-C, which have not been well understood to date.


Methods
MUSIC was a multicenter observational cohort study that included 1,204 patients hospitalized from March 2020 to January 2022 across 32 North American centers who met the Centers for Disease Control and Prevention (CDC) 2020 case definition of MIS-C. Information about the study participants was collected at hospital admission and discharge, then 2 weeks, 6 weeks, and 6 months post-hospital discharge, and then annually until 2 years after MIS-C diagnosis. Patient characteristics, sociodemographic information, past medical history, hospital course including length of hospital stay, cardiac and other organ system involvement, echocardiograms, quality of life, and return to pre-MIS-C health status were collected.


Results
Researchers found that most patients diagnosed with MIS-C were critically ill during the acute phase of their illness. All participants were hospitalized for MIS-C, and most participants (62.4%) were hospitalized in the intensive care unit (ICU) for an average of 3 days, with 40.7% needing oxygen during their hospital stay. Three participants died during hospitalization, and one underwent a heart transplant. Myocardial involvement was seen in 60.5% of participants, and decreased cardiac function was seen in 40.8% of study participants. Two weeks after hospitalization, the most reported symptoms included fatigue (16%), low energy (9%), gastrointestinal symptoms (5%), palpitations (2%), severe headaches (1%), and chest pain (1%). After six months, >99% of study participants that had decreased heart function during hospitalization returned to normal, and >95% of participants reported a return to >90% of baseline in energy, sleep, appetite, cognition, and mood. Lasting symptoms six months after discharge were rare in study participants.


Key takeaways

• Researchers found that most patients diagnosed with MIS-C were critically ill during the acute phase of their illness, but six months following discharge, cardiovascular and overall health outcomes were excellent.

• Most children and young adults with MIS-C recover quickly with few lasting side effects.

• Future studies should look at risk factors for the rare cases of children who experience lasting side effects and/or lasting abnormal laboratory and echocardiographic findings.

Publications

• Dongngan T. Truong, MD, Felicia L. Trachtenberg, PhD, Chenwei Hu, Gail D. Pearson MD, ScD, Kevin Friedman, MD, Arash A. Sabati MD, Audrey Dionne, MD, Matthew E. Oster, MD, MPH, Brett R. Anderson, MD, Joseph Block, MD, Tamara T. Bradford, MD, M. Jay Campbell, MD, Lara D'Addese, MD, Kristen B. Drummer, MD, Matthew D. Elias, MD, Daniel Forsha, MD, Olukayode D. Garuba, Keren Hasbani, MD, Kerri Hayes, Pe-Ni Jone, MD, Anita Krishnan, MD, Sean Lang, MD, Brian W. McCrindle, MD, Kimberly E. McHugh, MD, Elizabeth C. Mitchell, MD, Tonia Morrison, Juan Carlos Muniz, MD, R. Mark Payne, MD, Michael A. Portman, MD, Mark W. Russell, MD, Yamuna Sanil, MD, Divya Shakti, MD, Kavita Sharma, MD, J. Ryan Shea, MD, Michelle Sykes MD, PhD, Lara S. Shekerdemian, MD, MHA, Jacqueline Szmuszkovicz, MD, Deepika Tacker, MD, and Jane W. Newburger MD, on behalf of the MUSIC Study Investigators. Cardiac and Non-Cardiac Outcomes Through Six Months in the Long-terM OUtcomes after the Multisystem Inflammatory Syndrome In Children (MUSIC) Study. In press: JAMA Pediatrics accepted 9/26/2024.

Carelon Research project team: Felicia Trachtenberg, Kerri Hayes, Chenwei Hu

For more information on a specific study or to connect with the Actionable Insights Committee,
contact us at [email protected].

Sponsor: Carelon Research, Inc., a subsidiary of Elevance Health, serves as the Data Coordinating Center for this study. This study was funded by the Pediatric Heart Network, through a grant from the National Heart, Blood, and Lung Institute.

Dissemination and sharing of the Newsletter is limited to Elevance Health and its subsidiaries, and included findings and implications are for Elevance Health and its affiliates’ internal use only.