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According to study of a cluster of patients in France and Switzerland, children may experience an acute cardiac decompensation from the severe inflammatory state following SARS-CoV-2 infection, termed multisystem inflammatory syndrome in children (MIS-C). Treatment with immunoglobulin appears to be associated with recovery of left ventricular systolic function.
“The pediatric and cardiology communities should be acutely aware of this new disease probably related to SARS-CoV-2 infection (MIS-C), that shares similarities with Kawasaki disease but has specificities in its presentation,” researchers led by Zahra Belhadjer, MD, of Necker-Enfants Malades Hospital in Paris, wrote in a cases series report published online in Circulation. “Early diagnosis and management appear to lead to favorable outcome using classical therapies. Elucidating the immune mechanisms of this disease will afford further insights for treatment and potential global prevention of severe forms.”
Over a 2-month period that coincided with the SARS-CoV-2 pandemic in France and Switzerland, the researchers retrospectively collected clinical, biological, therapeutic, and early-outcomes data in 35 children who were admitted to pediatric ICUs in 14 centers for cardiogenic shock, left ventricular dysfunction, and severe inflammatory state. Their median age was 10 years, all presented with a fever, 80% had gastrointestinal symptoms of abdominal pain, vomiting, or diarrhea, and 28% had comorbidities that included body mass index of greater than 25 kg/m2 (17%), asthma (9%), and lupus (3%), and overweight. Only 17% presented with chest pain. The researchers observed that left ventricular ejection fraction was less than 30% in 28% of patients, and 80% required inotropic support with 28% treated with extracorporeal membrane oxygenation (ECMO). All patients presented with a severe inflammatory state evidenced by elevated C-reactive protein and d-dimer. Interleukin 6 was elevated to a median of 135 pg/mL in 13 of the patients. Elevation of troponin I was constant but mild to moderate, and NT-proBNP or BNP elevation was present in all children.
Nearly all patients 35 (88%) patients tested positive for SARS-CoV-2 infection by polymerase chain reaction of nasopharyngeal swab or serology. Most patients (80%) received IV inotropic support, 71% received first-line IV immunoglobulin, 65% received anticoagulation with heparin, 34% received IV steroids having been considered high-risk patients with symptoms similar to an incomplete form of Kawasaki disease, and 8% received treatment with an interleukin-1 receptor antagonist because of a persistent severe inflammatory state. Left ventricular function was restored in 71% of those discharged from the intensive care unit. No patient died, and all patients treated with ECMO were successfully weaned after a median of 4.5 days.
“Some aspects of this emerging pediatric disease (MIS-C) are similar to those of Kawasaki disease: prolonged fever, multisystem inflammation with skin rash, lymphadenopathy, diarrhea, meningism, and high levels of inflammatory biomarkers,” the researchers wrote. “But differences are important and raise the question as to whether this syndrome is Kawasaki disease with SARS-CoV-2 as the triggering agent, or represents a different syndrome (MIS-C). Kawasaki disease predominantly affects young children younger than 5 years, whereas the median age in our series is 10 years. Incomplete forms of Kawasaki disease occur in infants who may have fever as the sole clinical finding, whereas older patients are more prone to exhibit the complete form.”
They went on to note that the overlapping features between MIS-C and Kawasaki disease “may be due to similar pathophysiology. The etiologic agent of Kawasaki disease is unknown but likely to be ubiquitous, causing asymptomatic childhood infection but triggering the immunologic cascade of Kawasaki disease in genetically susceptible individuals. Please note that infection with a novel RNA virus that enters through the upper respiratory tract has been proposed to be the cause of the disease (see PLoS One. 2008;3:e1582 and J Infect Dis. 2011;203:1021-30).”
Based on the work of authors, it appears that a high index of suspicion for MIS-C is important for children who develop Kawasaki-like symptoms, David J. Goldberg, MD, said in an interview. “Although children have largely been spared from the acute respiratory presentation of the SARS-CoV-2 pandemic, the recognition and understanding of what appears to be a postviral inflammatory response is a critical first step in developing treatment algorithms for this disease process,” said Dr. Goldberg, a board-certified attending cardiologist in the cardiac center and fetal heart program at Children’s Hospital of Philadelphia. “If inflammatory markers are elevated, particularly if there are accompanying gastrointestinal symptoms, the possibility of cardiac involvement suggests the utility of screening echocardiography. Given the potential need for inotropic or mechanical circulatory support, the presence of myocardial dysfunction dictates care in an intensive care unit capable of providing advanced therapies. While the evidence from Dr. Belhadjer’s cohort suggests that full recovery is probable, there is still much to be learned about this unique inflammatory syndrome and the alarm has rightly been sounded.”
The researchers and Dr. Goldberg reported having no disclosures.
Circulation. Published May 17, 2020. Abstract