A study yesterday in JAMA Pediatrics suggests that even the kids who get most sick from an uncommon but serious condition that affects multiple organ systems after COVID-19 infections recover fully by 6 months after infection.
The retrospective cohort study followed outcomes seen among pediatric patients diagnosed as having multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 infection, one of the most severe outcomes seen during the pandemic.
A total of 1,204 participants treated from March 2020 to January 2022 at 32 North American pediatric hospitals, were followed up for 2 years.
About 60% had myocardial issues
All participants met the 2020 Centers for Disease Control and Prevention case definition of MIS-C. The condition was first seen in pediatric patients early in the pandemic, and resembles both toxic shock syndrome and Kawasaki disease.
Patients develop inflammation in organs and often have severe stomach pain, redness or swelling of the lips and tongue, and swelling of the hands or feet. MIS-C patients also are at risk for cardiovascular complications.
The authors collected data on cardiac and noncardiac outcomes during hospitalization and at 2 weeks, 6 weeks, and 6 months after discharge.
The average age of patients was 9.1 years, and 60.1% were boys. During initial hospitalization for MIS-C, 548 of 1,195 participants (45.9%) required vasoactive support, 17 of 1,195 (1.4%) required extracorporeal membrane oxygenation, and 3 (0.3%) died during hospitalization.
Myocardial involvement occurred in 690 of 1,140 participants (60.5%), the authors said.
Most recover by 2 weeks
Though the children were seriously ill, most recovered by 2 weeks post-hospitalization. A return to greater than 90% of pre–MIS-C health status (energy, sleep, appetite, cognition, and mood) was reported by 711 of 824 participants (86.3%) at 2 weeks, and increased to 548 of 576 (95.1%) at 6 months, the authors said.
The most common symptom experienced at 2 weeks post-hospitalization was fatigue, seen in 15.9% of children. By 6 months, only 3.4% reported fatigue.
"Most patients were critically ill during the acute phase, but 6-month cardiovascular and overall health outcomes were excellent," the authors wrote.
Parent questionnaires also reflected a dramatic change in symptoms, with most all resolved by 6 weeks after hospitalization.
Heart conditions largely resolved by 6 months
Among patients with available echocardiograms, 131 of 322 (42.3%) had left ventricular ejection fraction less than 55% during hospitalization; of those with follow-up, all but 1 normalized by 6 months.
During initial hospitalization, 15 participants had coronary artery z scores of 2.5 or greater at any point; 1 participant had a large/giant aneurysm. Of the 13 participants with z scores of 2.5 or greater during hospitalization, 12 (92.3%) had normalized by 6 months.
Overall, by 6 months after hospital discharge, 99% had normalization of left ventricular systolic function, and 92.3% had normalization of coronary artery dimensions. Over 95% of the total patient population reported being more than 90% back to baseline health status.
"Consistent with prior reports on coronary artery outcomes in MIS-C, we found lower frequency and severity of coronary artery aneurysms, with rarity of large/giant aneurysms, compared with findings seen in Kawasaki disease," the authors noted.
In a commentary on the study, David J, Goldberg, MD, and Anna Costello, MD, from the Children's Hospital of Philadelphia, and Bryan Goldstein, MD, of UPMC Children's Hospital of Pittsburgh, wrote, "These data suggest an encouraging outlook for the long-term health of affected children.
The reassuring reports on midterm outcomes can allow the pediatric community a moment of collective exhale.
"While a more complete pathophysiologic understanding of the MIS-C disease process might provide insights into targeted therapies, useful for the smaller group of patients who may yet develop this COVID-related complication, the decreased frequency of the disease along [with] the reassuring reports on midterm outcomes can allow the pediatric community a moment of collective exhale."
