Multisystem inflammatory syndrome in children is a rare, post-infectious complication of SARS-CoV-2 infection in children. We aimed to assess the long-term sequelae, particularly cardiac, in a large, diverse population.

We performed a retrospective cohort study of all children (aged 0–20 years, n = 304) admitted to a tertiary care centre with a diagnosis of multisystem inflammatory syndrome in children from March 1, 2020 to August 31, 2021 and had at least one follow-up visit through December 31, 2021. Data were collected at hospitalisation, 2 weeks, 6 weeks, 3 months, and 1 year after diagnosis, where applicable. Cardiovascular outcomes included left ventricular ejection fraction, presence or absence of pericardial effusion, coronary artery abnormalities, and abnormal electrocardiogram findings.

Population was median age 9 years (IQR 5–12), 62.2% male, 61.8% African American (AA), and 15.8% Hispanic. Hospitalisation findings included abnormal echocardiogram 57.2%, mean worst recorded left ventricular ejection fraction 52.4% ± 12.4%, non-trivial pericardial effusion 13.4%, coronary artery abnormalities 10.6%, and abnormal ECG 19.6%. During follow-up, abnormal echocardiogram significantly decreased to 6.0% at 2 weeks and 4.7% at 6 weeks. Mean left ventricular ejection fraction significantly increased to 65.4% ± 5.6% at 2 weeks and stabilised. Pericardial effusion significantly decreased to 3.2% at 2 weeks and stabilised. Coronary artery abnormalities significantly decreased to 2.0% and abnormal electrocardiograms significantly decreased to 6.4% at 2 weeks and stabilised.

Children with multisystem inflammatory syndrome in children have significant echocardiographic abnormalities during the acute presentation, but these findings typically improve within weeks. However, a small subset of patients may have persistent coronary abnormalities.

Here, we are sharing our second report about children affected by Multisystem Inflammatory Syndrome in Children (MIS-C). The aim of the present study was to update our knowledge about children with MIS-C. Furthermore, we tried to compare clinical manifestations, laboratory features and final outcome of patients based on disease severity, in order to better understanding of the nature of this novel syndrome.

This retrospective study was conducted at Children's Medical Center Hospital, the hub of excellence in paediatrics in Iran, located in Tehran, Iran. We reviewed medical records of children admitted to the hospital with the diagnosis of MIS-C from July 2020 to October 2021.

One hundred and twenty-two patients enrolled the study. Ninety-seven (79.5%) patients had mild to moderate MIS-C (MIS-C without overlap with KD (n = 80); MIS-C overlapping with KD (n = 17)) and 25 (20.5%) patients showed severe MIS-C. The mean age of all patients was 6.4 ± 4.0 years. Nausea and vomiting (53.3%), skin rash (49.6%), abdominal pain (46.7%) and conjunctivitis (41.8%) were also frequently seen Headache, chest pain, tachypnea and respiratory distress were significantly more common in patients with severe MIS-C (P < 0.0001, P = 0.021, P < 0.0001 and P < 0.0001, respectively). Positive anti-N severe acute respiratory syndrome coronavirus 2 IgM and IgG were detected in 14 (33.3%) and 23 (46.9%) tested patients, respectively. Albumin, and vitamin D levels in children with severe MISC were significantly lower than children with mild to moderate MIS-C (P < 0.0001, P = 0.05). Unfortunately, 2 (1.6%) of 122 patients died and both had severe MIS-C.

Patients with MIS-C in our region suffer from wide range of signs and symptoms. Among laboratory parameters, hypoalbuminemia and low vitamin D levels may predict a more severe course of the disease. Coronary artery dilation is frequently seen among all patients, regardless of disease severity.

This study aimed to evaluate electrocardiographic and echocardiographic findings, Holter recordings of the multisystem inflammatory syndrome in children, and to identify prognostic factors for cardiac involvement.

We retrospectively reviewed demographic characteristics, medical data, laboratory findings, electrocardiogram and echocardiographic findings, 24-hour Holter recordings, need for an ICU, and extracorporeal membrane oxygenation in multisystem inflammatory syndrome in children. Acute left ventricular systolic dysfunction was defined as left ventricular ejection fraction (EF) ≤%55 on echocardiography.

Sixty-seven children were included in the study. 24-hour Holters were recorded in 61.2% of the patients and 49.2% were normal. On echocardiographic examination, 14.9% of the patients had systolic dysfunction (EF ≤ 55%). While 32.8% of patients had mild mitral regurgitation, 3% had moderate mitral regurgitation, and 6% had mild aortic regurgitation. There was no statistically significant difference in EF values between the group with arrhythmia in Holter and the group with normal Holter results (p ≥ 0.05). B-type natriuretic peptide was positively correlated with C-reactive protein, ferritin, and fibrinogen. Significant effectivity of the B-type natriuretic peptide value was observed in the differentiation of those with EF ≤ and > 55%. Extracorporeal membrane oxygenation support was needed for three (4.5%) patients. One patient who died had systemic juvenile idiopathic arthritis.

Neutrophil/lymphocyte ratio, C-reactive protein, D-dimer, ferritin, troponin, and B-type natriuretic peptide were found to be significantly higher in patients with systolic dysfunction. Also, the cut-off value of 1700 pg/ml for B-type natriuretic peptide was significantly effective. These parameters may indicate the severity of the disease but should be supported by prospective studies.

The aim of the study was to evaluate the early myocardial dysfunction detected by strain echocardiography in children with multisystem inflammatory syndrome related to SARS-CoV-2 infection.

This cross-sectional study was conducted with 47 patients diagnosed with MIS-C and 32 healthy age- and gender-matched children. All patients underwent two-dimensional, colour, pulsed, and tissue Doppler, and 2D speckle tracking echocardiography examination at admission, 2 weeks, and 2 months after discharge. The MIS-C patient group was compared with the control group. Echocardiographic changes in MIS-C patients during follow-up were evaluated.

Of 47 patients, 30 (63.8%) were male and 17 (36.2%) were female. The mean age at diagnosis was 9.1 ± 4.3 (1.25–17) years. At admission, 25 patients had abnormal findings on conventional echocardiography. Among them, eight patients had left ventricular systolic dysfunction. Ejection fraction and fractional shortening were significantly lower in the patient group at admission compared to controls (p = 0.013, p = 0.010, respectively). While the ejection fraction was <55% in eight patients, and global longitudinal strain was lower than −2SD in 29 patients at admission. Global longitudinal strain z-score <−2SD persisted in 13 patients at 2-month follow-up. Ejection fraction increased above 55% in 3.42 ± 0.53 days in 7 of 8 patients with left ventricular systolic dysfunction, ejection fraction was 51% at discharge in one patient, and left ventricular systolic dysfunction persisted at the 6-month of follow-up.

These results confirmed that speckle tracking echocardiography is more likely to detect subclinical myocardial damage compared to conventional echocardiography. In addition, it is a valuable method for follow-up in this patient group.

Paediatric ICUs have shared the burden of the COVID-19 pandemic, including subspecialty cardiac ICUs. We sought to address knowledge gaps regarding patient characteristics, acuity, and sequelae of COVID-19 in the paediatric cardiac ICU setting.

Retrospective review of paediatric cardiac ICU admissions with COVID-19-related disease.

Single centre tertiary care paediatric cardiac ICU.

All patients with PCR/antibody evidence of primary COVID-19 infection, and/or Multisystem Inflammatory Syndrome in Children, were admitted between 26 March, 2020 and 31 March, 2021.

None.

Patient-level demographics, pre-existing conditions, clinical symptoms, and outcomes related to ICU admission were captured from medical records.

Among 1064 patients hospitalised with COVID-19/Multisystem Inflammatory Syndrome in Children, 102 patients (9.5%) were admitted to cardiac ICU, 76 of which were symptomatic (median age 12.5 years [IQR 7.5–16.0]). The primary system involved at presentation was cardiovascular in 48 (63%). Vasoactive infusions were required in 62% (n = 47), with eight patients (11%) requiring VA ECMO. Severity of disease was categorised as mild/moderate in 16 (21%) and severe/critical in 60 patients (79%). On univariate analysis, African-American race, presentation with gastrointestinal symptoms or elevated inflammatory markers were associated with risk for severe disease. All-cause death was observed in five patients (7%, n = 5/72) with four patients remaining hospitalised at the time of data query.

COVID-19 and its cardiovascular sequelae were associated with important morbidity and significant mortality in a notable minority of paediatric patients admitted to a paediatric cardiac ICU. Further study is required to quantify the risk of morbidity and mortality for COVID-19 and sequelae.