Children with MIS-C warrant cardiology follow-up, study findings suggest

Key takeaways:

• Cardiovascular involvement occurs in up to 80% of MIS-C cases.
• At follow up, 54% had evidence of myocardial injury during their acute illness.

Patients recovering from multisystem inflammatory syndrome in children should receive a cardiology follow-up, study findings reported in Pediatrics suggest.

The CDC defines multisystem inflammatory syndrome in children (MIS-C) as an illness occurring in a patient aged 20 years or younger that meets a certain combination of clinical and laboratory or epidemiological criteria, including either a positive COVID-19 test or close contact with a confirmed or probable COVID-19 case up to 60 days before or during hospitalization.

“Cardiovascular involvement is common in MIS-C, occurring in up to 80% of cases,” Dayna Zimmerman, MD, a researcher in the division of pediatric cardiology at Children’s Hospital Los Angeles and co-author of the study, told Healio.

“As we began to see patients who had been treated for MIS-C in the pediatric cardiology clinic at Children’s Hospital Los Angeles, questions arose regarding how best to approach follow-up and cardiovascular surveillance for these patients, given the novelty of the disease and the lack of long-term data,” she said.

Zimmerman and colleagues began by recommending all patients recovering from MIS-C for a cardiac MRI, ambulatory rhythm monitoring and cardiopulmonary exercise stress test, if they were able to undergo the testing.

“With this study, we sought to assess the prevalence of residual cardiovascular pathology in patients who were treated for MIS-C to begin to understand the natural history and inform our approach to follow-up for these patients,” Zimmerman said.

The retrospective study included all patients who had at least one cardiac follow-up, with options including cardiac MRI, ambulatory rhythm monitor, or cardiopulmonary exercise stress test. These tests were performed at Children’s Hospital Los Angeles between October 2020 and June 2022.

“We assessed the prevalence of abnormal findings for each of the testing modalities, which was the primary objective of the study,” Zimmerman said. “A secondary objective of our study was to compare the prevalence of abnormal findings between patients who had evidence of myocardial injury during acute illness vs. those who did not have evidence of acute myocardial injury. We defined myocardial injury as either an elevated troponin or reduced left ventricular function by echocardiography at any point during hospitalization.”

Among 153 patients included in the study, 69 had one or more follow-ups. Of those patients, 54% had evidence of myocardial injury during acute illness, whereas 46% of patients had at least one abnormal cardiac MRI finding in parameters that can reflect myocardial inflammation or fibrosis, the researchers reported. A further 9% had an abnormal ambulatory rhythm monitor result, and 78% had reduced functional capacity on exercise stress test.

Zimmerman said they were surprised “by the high prevalence of abnormal findings, particularly given that most patients appear to make a full clinical recovery, and most were asymptomatic at the time of follow-up.”

“We were also surprised to find that there was no statistically significant difference in the prevalence of abnormal findings on any of the testing modalities between patients who had evidence of myocardial injury during acute illness vs. those who did not, as we expected a higher prevalence of abnormal findings in the group with myocardial injury,” Zimmerman said. “This led us to conclude that all patients treated for MIS-C warrant cardiology follow-up after hospital discharge.”

Although residual and subclinical cardiovascular pathology is common among patients who have been treated for MIS-C, it is unclear whether the findings will persist long term, Zimmerman said.

“Pediatricians should have a low threshold to refer for further cardiology evaluation and workup in patients who report cardiovascular symptoms after treatment for MIS-C,” she said. “We plan to pursue further studies to assess longer term follow-up of patients treated for MIS-C to determine whether findings of residual cardiovascular pathology persist or ultimately resolve. This will be essential information in determining optimal approaches to follow-up and surveillance in patients treated for MIS-C, as well as in providing counseling to patients and families regarding longer term expectations.”

Published by: