Timely Cardiac Function Recovery Seen Among Children With COVID-19, MIS

A new 1:1 matched retrospective study between 60 pediatric patients with COVID-19­–related multisystem inflammatory syndrome (MIS) and 60 controls shows that the patient study group did not suffer from long-term cardiac dysfunction, according to results published online today in Journal of the American Heart Association.

Reviewing evaluations performed at 4 time points during this study—acute phase, subacute phase (3 days after initial echocardiography [ECG]), 1-month follow-up, and 3-4 months follow-up—the team from Children’s Hospital of Philadelphia (CHOP) saw initial, and rapid, recovery in the first week after symptom presentation, with return to normal cardiac function by 3 months. All of the children received treatment at CHOP or St. Peter’s University Hospital between April 2020 and January 2021.

Left ventricular global longitudinal strain (GLS), peak left atrial strain (LAS), longitudinal early diastolic strain rate (EDSR_L), and right ventricular free wall strain (RVFWS)—as measures of deformation—were used to gauge recovery within the first week. According to the investigators, strain testing has higher sensitivity for detecting subtle changes in heart function. In addition, a troponin-1 level of > 0.09 ng/mL (>3 times above normal) or a brain-natriuretic peptide level above 800 pg/mL indicated myocardial injury.

MIS is first shown to affect pediatric patients within 4 to 6 weeks of their exposure to COVID-19, with inflammation seen in the heart, lungs, kidneys, and gastrointestinal organs, according to an American Heart Association statement on these study results. “However, there is limited data at this time about how frequently and how long we should monitor heart function during the recovery state of MIS after the child leaves the hospital,” said Anirban Banerjee, MD, senior study author and attending cardiologist with the Cardiac Center at CHOP, in the statement. “Our research team hoped to provide some guidance and reduce the ambiguity on optimal care approaches, especially as it relates to sports participation.”

Comparing outcomes between the diverse study (48%, Black; 27%, White; 15%, Hispanic; 4%, Asian; 23%, unknown) and control (62%, White; 27%, Black; 7%, Hispanic; 3%, Asian; 8%, unknown) populations showed that GLS and LAS typically returned to normal after a median 6 (95% CI, 3-9) days. In addition, for the 70% of patients in the MIS group who initially presented with myocardial injury, short-term outcomes were not adversely affected.

Among the 7% of patients who also had small coronary aneurysms at presentation, resolution of the condition was seen among all via scans at 3 months. And for the 1 patient with residual edema, no cardiac fibrosis was detected through cardiac MRI.

Conventional ECG, speckle-tracking ECG, clinical data interpretation, and cardiovascular MRI were the methods utilized to evaluate cardiac dysfunction, diagnosis, and recovery. Most patients also received intravenous immunoglobulin (90%) and/or systemic steroid (92%) treatment.

Analyses also revealed the following results:

• Left atrial contraction phase normalized in all patients by 3 to 4 months
• EDSR_L normalized in all patients by 3 months
• GLS remained significantly lower at 3 months among the study group, but this difference was not considered clinically relevant because it fell within normal published values
• Left ventricular function normalized within a median 8 (95% CI, 4-13) days
• RVFWS normalized within a median 9 (95% CI, 4-18) days
• No evidence of high-grade atrioventricular block via ECG by 3 months
• GLS and LAS improved quicker between the acute and subacute phases for those with myocardial injury

The authors highlighted the importance of their results on several fronts: The rapid recovery they saw among their study patients adds to similar results seen in other recent studies and their findings are unique because they used both LAS and EDSR_L to gauge left ventricular diastolic function.

“Noninvasive assessment of diastolic dysfunction has not been well established in children,” the wrote. “Conventional parameters used in adult diagnostic algorithms incorrectly classify up to 30% of patients with overt and often severe pediatric cardiomyopathy as having normal diastolic function.”

In addition, their data may support discharging pediatric patients from cardiology care, “if their ECGs and echocardiograms are normal at a 3-month evaluation.”

“These findings may inform early guidelines for outpatient management strategies and recommendations for returning to competitive sports,” the authors concluded. “In addition, the echocardiographic parameters described in this study may form the basis of future long-term follow-up studies.”

Reference

Matsubara D, Chang J, Kauffman HL, et al. Longitudinal assessment of cardian outcomes of multisystem inflammatory sundrome in children associated with COVID-19 infections. J Am Heart Assoc. Published online January 19, 2022. doi:10.1161/JAHA.121.023251