Multisystem Inflammatory Syndrome in US Children

Quick Takes

  • Multisystem inflammatory syndrome in children (MIS-C) is associated with a significant need for critical care, with a high rate of cardiac involvement, and an overall mortality rate of 2%.
  • MIS-C differs from Kawasaki disease in that there is a higher rate of cardiovascular shock prompting need for inotropic/vasopressor support (50%) and a lower rate of coronary artery involvement (8%).
  • Further study is required to understand the long-term cardiac sequelae of MIS-C, including coronary involvement.

Study Questions:

What is the epidemiology and clinical course of multisystem inflammatory syndrome in children (MIS-C) and its temporal association with coronavirus disease 2019 (COVID-19)?

Methods:

A multicenter review was performed at 53 centers between March 15 and May 20, 2020. The case definition required: serious illness leading to hospitalization, an age of <21 years, fever for >24 hours, laboratory evidence of inflammation, multisystem organ involvement, and evidence of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Evidence of SARS-CoV-2 infection included positive reverse-transcriptase polymerase chain reaction (RT-PCR), antibody testing, or exposure to patients with COVID-19 in the past month.

Results:

A total of 186 patients with MIS-C were identified in 26 states. The median age was 8.3 years and 62% were male. Most patients (70%) were positive for SARS-CoV-2 based on RT-PCR or antibody testing, with the remainder having exposure to patients with COVID-19. Gastrointestinal organ system involvement was most common (92%), followed by cardiovascular (80%), hematologic (76%), mucocutaneous (74%), and respiratory (70%). The median duration of hospitalization was 7 days, while 80% of patients required intensive care, 20% received mechanical ventilation, 48% received vasoactive support, and 2% died. Coronary artery aneurysms (z-scores ≥2.5) were seen in 8% of patients. Intravenous immune globulin was used in 77% of patients, glucocorticoids in 49%, and interleukin-6 or 1RA inhibitors in 20%.

Conclusions:

MIS-C in children associated with SARS-CoV-2 led to serious and life-threatening illness in previously healthy children and adolescents.

Perspective:

This is one of two studies published in the New England Journal of Medicine online on June 29, 2020, describing targeted surveillance for MIS-C. Previous smaller studies have described a disease with critical illness, but a relatively high rate of myocardial recovery with treatment with immunomodulating therapies such as intravenous immune globulin. Although MIS-C has some common features with Kawasaki disease, it appears to be a distinct clinical entity with a different spectrum of cardiac involvement. Further study will be required to better understand the link between MIS-C and COVID-19, as well as the long-term cardiac effects of the disease process.

Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, Prevention, Stable Ischemic Heart Disease, Vascular Medicine, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Prevention, Chronic Angina

Keywords: Adolescent, Child, Coronary Aneurysm, Coronary Vessels, Coronavirus, COVID-19, Critical Illness, Glucocorticoids, Immunoglobulins, Intravenous, Inflammation, Interleukin-6, Pediatrics, Primary Prevention, Respiration, Artificial, Reverse Transcriptase Polymerase Chain Reaction, SARS Virus, severe acute respiratory syndrome coronavirus 2


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