Echocardiographic Findings and Correlation with Laboratory Values in Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19

Multisystem inflammatory syndrome in children (MIS-C): A nationwide collaborative study in the Greek population

Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe hyperinflammatory condition that may occur following SARS-CoV-2 infection. This retrospective, descriptive study of children hospitalized with multisystem inflammatory syndrome in children (MIS-C) in 12 tertiary care centers from 3/11/2020 to 12/31/2021. Demographics, clinical and laboratory characteristics, treatment and outcomes are described. Among 145 patients (95 males, median age 8.2 years) included, 123 met the WHO criteria for MIS-C, while 112 (77%) had serological evidence of SARS-CoV-2 infection. Fever was present in 99%, gastrointestinal symptoms in 77%, mucocutaneous involvement in 68% and respiratory symptoms in 28%. Fifty-five patients (38%) developed myocarditis, 29 (20%) pericarditis and 19 (13%) coronary aneurysms. Among the above cases 11/55 (20%), 1/29 (3.4%) and 5/19 (26.3%), respectively, cardiac complications had not fully resolved at discharge. Underlying comorbidities were reported in 18%. Median CRP value was 155 mg/l, ferritin 535 ng/ml, PCT 1.6 ng/ml and WBC 14.2 × 109/mm3. Most patients had elevated troponin (41.3%) and/or NT-pro-BNP (49.6%). Intravenous immunoglobulin plus corticosteroids were used in 117/145 (80.6%), monotherapy with IVIG alone in 13/145 (8.9%) and with corticosteroids alone in 2/145 (1.3%). Anti-IL1 treatment was added in 15 patients (10.3%). Thirty-three patients (23%) were admitted to the PICU, 14% developed shock and 1 required ECMO. Mortality rate was 0.68%. The incidence of MIS-C was estimated at 0.69/1000 SARS-CoV-2 infections. Patients who presented with shock had higher levels of NT-pro-BNP compared to those who did not (p < 0.001). Acute kidney injury and/or myocarditis were associated with higher risk of developing shock.

CONCLUSION

MIS-C is a novel, infrequent but serious disease entity. Cardiac manifestations included myocarditis and pericarditis, which resolved in most patients before discharge. Timely initiation of immunomodulatory therapy was shown to be effective. NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. Further research is required to elucidate the pathogenesis, risk factors and optimal management, and long-term outcomes of this clinical entity.

WHAT IS KNOWN

• MIS-C is an infrequent but serious disease entity. • Patients with MIS-C present with multi-organ dysfunction, primarily involving the gastrointestinal and cardiovascular systems.

WHAT IS NEW

• NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. • Acute kidney injury and/or myocarditis were associated with higher risk of developing shock.

Clinical Predictors of Subacute Myocardial Dysfunction in Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19

Multisystem Inflammatory Syndrome in Children (MIS-C) often involves a post-viral myocarditis and associated left ventricular dysfunction. We aimed to assess myocardial function by strain echocardiography after hospital discharge and to identify risk factors for subacute myocardial dysfunction. We conducted a retrospective single-center study of MIS-C patients admitted between 03/2020 and 03/2021. Global longitudinal strain (GLS), 4-chamber longitudinal strain (4C-LS), mid-ventricular circumferential strain (CS), and left atrial strain (LAS) were measured on echocardiograms performed 3-10 weeks after discharge and compared with controls. Among 60 MIS-C patients, hypotension (65%), ICU admission (57%), and vasopressor support (45%) were common, with no mortality. LVEF was abnormal (< 55%) in 29% during hospitalization but only 4% at follow-up. Follow-up strain abnormalities were prevalent (GLS abnormal in 13%, 4C-LS in 18%, CS in 16%, LAS in 5%). Hypotension, ICU admission, ICU and hospital length of stay, and any LVEF < 55% during hospitalization were factors associated with lower strain at follow-up. Higher peak C-reactive protein (CRP) was associated with hypotension, ICU admission, total ICU days, and with lower follow-up GLS (r = - 0.55; p = 0.01) and CS (r = 0.41; p = 0.02). Peak CRP < 18 mg/dL had negative predictive values of 100% and 88% for normal follow-up GLS and CS, respectively. A subset of MIS-C patients demonstrate subclinical systolic and diastolic function abnormalities at subacute follow-up. Peak CRP during hospitalization may be a useful marker for outpatient cardiac risk stratification. MIS-C patients with hypotension, ICU admission, any LVEF < 55% during hospitalization, or a peak CRP > 18 mg/dL may warrant closer monitoring than those without these risk factors.

Left Atrial Strain in Multisystem Inflammatory Syndrome in Children and Associations with Systemic Inflammation and Cardiac Injury

Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury. In this retrospective cohort study, LAS parameters [reservoir (LAS-r), conduit (LAS-cd), and contractile (LAS-ct)] obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP > 500 pg/ml or troponin-I > 0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed. We identified 118 patients with MIS-C and 20 healthy controls. Median LAS parameters were reduced in MIS-C patients compared to controls (LAS-r: 31.8 vs. 43.1%, p < 0.001; LAS-cd: - 28.8 vs. - 34.5%, p = 0.006; LAS-ct: - 5.2 vs. - 9.3%, p < 0.001) and reduced in MIS-C patients with cardiac injury (n = 59) compared to no injury (n = 59) (LAS-r: 29.6 vs. 35.8%, p = 0.001; LAS-cd: - 26.5 vs. - 30.4%, p = 0.036; LAS-ct: - 4.6 vs. - 9.3%, p = 0.008). A discrete LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p < 0.001). Procalcitonin correlated strongly with averaged E/e' (r = 0.55, p = 0.001). Moderate correlations were found for ESR and LAS-ct (r = - 0.41, p = 0.007) as well as BNP and LAS-r (r = - 0.39, p < 0.001) and LAS-ct (r = 0.31, p = 0.023). Troponin-I had only weak correlations. Intra-rater reliability was good for all LAS parameters, and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct. LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.

Baseline Echocardiography and Laboratory Findings in MIS-C and Associations with Clinical Illness Severity

Children with COVID-associated multisystem inflammatory syndrome (MIS-C) may develop severe disease. We explored the association of admission echocardiographic and laboratory parameters with MIS-C disease severity. This retrospective, single center study of consecutive MIS-C patients (4/2020-12/2021) excluded those with preexisting cardiomyopathy, congenital heart disease, or prior cardiotoxic therapy. Our hypothesis was that worse admission echocardiographic and laboratory parameters were associated with more severe disease based on vasoactive medication use. Univariable and multivariable logistic regression models assessed the association between vasoactive medication use and baseline variables. Of 118 MIS-C patients, median age was 7.8 years (IQR 4.6, 11.8), 48% received vasoactive medication. Higher admission brain natriuretic peptide [OR 1.07 (95% CI 1.02,1.14), p = 0.019], C-reactive protein [OR 1.08 (1.03,1.14), p = 0.002], troponin [OR 1.05 (1.02,1.1), p = 0.015]; lower left ventricular ejection fraction [LVEF, OR 0.96 (0.92,1), p = 0.042], and worse left atrial reservoir strain [OR 0.96 (0.92,1), p = 0.04] were associated with vasoactive medication use. Only higher CRP [OR 1.07 (1.01, 1.11), p = 0.034] and lower LVEF [0.91 (0.84,0.98), p = 0.015] remained independently significant. Among those with normal admission LVEF (78%, 92/118), 43% received vasoactive medication and only higher BNP [OR 1.09 (1.02,1.19), p = 0.021 per 100 pg/mL] and higher CRP [OR 1.07 (1.02,1.14), p = 0.013] were associated with use of vasoactive medication. Nearly half of all children admitted for MIS-C subsequently received vasoactive medication, including those admitted with a normal LVEF. Similarly, admission strain parameters were not discriminatory. Laboratory markers of systemic inflammation and cardiac injury may better predict early MIS-C disease severity.

Cardiac manifestations of multisystem inflammatory syndrome of children after SARS-CoV-2 infection: a systematic review and meta-analysis

This systematic review and meta-analysis were conducted to evaluate the prevalence of cardiac manifestations associated with multisystem inflammatory syndrome in children worldwide. We conducted electronic searches in Ovid MEDLINE, Ovid EMBASE, and the World Health Organization COVID-19 Literature Database from the inception of the SARS-CoV-2 pandemic to 1 January, 2022. Three authors independently screened the abstracts to determine eligibility, assessed methodology in the full texts, and extracted the data.We identified 2848 citations; 94 studies (14,932 patients) were included. The prevalence of vasopressors was 48.2% (95% CI 45.1%, 51.3%), left ventricular systolic dysfunction occurred in 37.2% (95% CI 34.1%, 40.3%), myocarditis in 34.1% (95% CI 30.5%, 37.8%), electrocardiographic dysrhythmias and abnormalities detected in 23.1% (95% CI 18.8%, 27.6%), coronary abnormalities identified in 18% (95% CI 16%, 20%), extracorporeal membrane oxygenation deployed in 2.2% (95% CI 1.7%, 2.8%), and mortality rate of 2.2% (95% CI 1.7%, 2.7%). A sensitivity analysis was performed after removing eleven studies with high bias, and the adjusted prevalence was not different than the original evaluation.In this meta-analysis of the largest cohort of multisystem inflammatory syndrome in children patients to date, we established the most accurate prevalence of the most common cardiac manifestations. Providers will subsequently have more precise data to anticipate patient outcomes and approach discussions concerning the frequency of monitoring outside the acute hospital period.

Efficacy of Biomarkers in Identifying Abnormal Echocardiogram in Multisystem Inflammatory Syndrome in Children

Cardiac involvement in multisystem inflammatory syndrome in children (MIS-C) is common and contributes to significant morbidity and mortality. We evaluated the efficacy of cardiac biomarkers in detection of an abnormal echocardiogram in MIS-C patients. A retrospective chart review of children ≤18 years diagnosed with MIS-C at our hospital was performed. Sensitivity and specificity of high-sensitivity troponin I (hs-TnI) and B-type natriuretic peptide (BNP) were estimated for an abnormal echocardiogram. Of the 83 patients with MIS-C, 33 (39.8%) had an abnormal echocardiogram. While BNP was more sensitive, hs-TnI >50 ng/L was more specific for detecting an abnormal echocardiogram. Compared with children who had normal hs-TnI levels (<17 ng/L), those with hs-TnI >50 ng/L were more likely to have an echocardiographic abnormality (relative risk: 4.9; 95% CI, 2.9-10.9). Children with abnormal BNP and/or troponin (especially greater than 3-fold the upper limit of normal) would benefit from an urgent echocardiogram in the emergency department.

Echocardiographic Findings in Children with Multisystem Inflammatory Syndrome from Initial Presentation to the First Years after Discharge

OBJECTIVE

We aimed to evaluate clinical and echocardiographic features of the children diag- nosed with multisystem inflammatory syndrome related to severe acute respiratory syndrome coronavirus-2 infection and determine early and mid-term cardiovascular outcomes.

MATERIALS AND METHODS

We retrospectively evaluated 38 children who were diagnosed with multisystem inflammatory syndrome in our hospital between November 2020 and November 2021. Cardiovascular evaluations were performed during hospitalization, at the first, the second, and the third months after discharge, and then cardiac evaluation was repeated at 3-month intervals until a median of 24 weeks (range: 9-56 weeks).

RESULTS

The mean age of patients was 9.6 years and 25 patients had cardiovascular involve- ment. Echocardiography showed that there was left ventricular dysfunction in 11 cases and any coronary abnormalities in 11 cases on admission. Cardiovascular involvement was most fre- quently seen in patients older than 10 years and of male sex. Severe clinical courses occurred in half of them. The mortality rate was 2.6% during hospitalization. At discharge, complete recovery was achieved in 30 cases and partial recovery was seen in 6 cases; there were 1 case with ventricular dysfunction and 5 cases with coronary abnormalities. At the last polyclinic visit, there was no case with symptoms or myocardial dysfunction, there was only 1 case with persist- ing coronary aneurysms.

CONCLUSION

Cardiovascular abnormalities in patients with multisystem inflammatory syndrome show rapid resolution within the first month. We recommend long-term follow-up evaluation for coronary arteries.

Left atrial strain in multisystem inflammatory syndrome in children (MIS-C) and associations with systemic inflammation and cardiac injury

Background

Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury.

Methods

In this retrospective cohort study, conventional parameters and LAS (reservoir [LAS-r], conduit [LAS-cd], and contractile [LAS-ct]) obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP >500 pg/ml or troponin-I >0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed.

Results

Median LAS components were reduced in MIS-C patients (n=118) compared to controls (n=20) (LAS-r: 31.8 vs. 43.1%, p<0.001; LAS-cd: -28.8 vs. -34.5%, p=0.006; LAS-ct: -5.2 vs. -9.3%, p<0.001) and reduced in MIS-C patients with cardiac injury (n=59) compared to no injury (n=59) (LAS-r: 29.6 vs. 35.8%, p=0.001; LAS-cd: -26.5 vs. -30.4%, p=0.036; LAS-ct: -4.6 vs. -9.3%, p=0.008). An LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p<0.001). Procalcitonin had strong correlation with averaged E/e' (r=0.55, p=0.001); ESR had moderate correlation with LAS-ct (r=-0.41, p=0.007); BNP had moderate correlation with LAS-r (r=-0.39, p<0.001) and LAS-ct (r=0.31, p=0.023), and troponin-I had only weak correlations. No strain indices were independently associated with cardiac injury on regression analysis. Intra-rater reliability was good for all LAS components; and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct.

Conclusions

LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.

Long-Term Cardiovascular Outcomes of Multisystem Inflammatory Syndrome in Children Associated with COVID-19 Using an Institution Based Algorithm

Cardiovascular involvement is a major cause of inpatient and intensive care unit morbidity related to Multisystem inflammatory syndrome in children (MIS-C). The objective of this study was to identify long-term cardiovascular manifestations of MIS-C. We included 80 consecutive patients admitted to the intensive care unit with MIS-C who were evaluated for a year in our follow-up clinic using an institution protocol. The outcome measures were cardiac biomarkers (troponin and BNP), electrocardiogram changes, echocardiographic findings cardiovascular magnetic resonance (CMR) and graded-exercise stress test (GXT) findings. The cohort included patients aged between 6 months and 17 years (median 9 years; 48.8% females). At the peak of the disease 81.3% had abnormal BNP and 58.8% had troponin leak which reduced to 33.8% and 18.8% respectively at discharge with complete normalization by 6 weeks post-discharge. At admission 33.8% had systolic dysfunction, which improved to 11.3% at discharge with complete resolution by 2 weeks. Coronary artery abnormalities were seen in 17.5% during the illness with complete resolution by 2 weeks post discharge except one (1.9%) with persistent giant aneurysm at 1 year-follow up. CMR was performed at 6 months in 23 patient and demonstrated 4 patients with persistent late gadolinium enhancement (17.4%). Normal exercise capacity with no ectopy was seen in the 31 qualifying patients that underwent a GXT. There is significant heterogeneity in the cardiovascular manifestations of MIS-C. Although majority of the cardiovascular manifestations resolve within 6 weeks, diastolic dysfunction, CAA and myocardial scar may persist in a small subset of patients warranting a structured long-term follow-up strategy.

Longitudinal Assessment of Cardiac Function Following Multisystem Inflammatory Syndrome in Children Associated with COVID-19

Multisystem inflammatory syndrome in children (MIS-C) after COVID-19 is commonly associated with cardiac involvement. Studies found myocardial dysfunction, as measured by decreased ejection fraction and abnormal strain, to be common early in illness. However, there is limited data on longitudinal cardiac outcomes. We aim to describe the evolution of cardiac findings in pediatric MIS-C from acute illness through at least 2-month follow-up. A retrospective single-center review of 36 patients admitted with MIS-C from April 2020 through September 2021 was performed. Echocardiographic data including cardiac function and global longitudinal strain (GLS) were analyzed at initial presentation, discharge, 2-4-week follow-up, and at least 2-month follow-up. Patients with mild and severe disease, normal and abnormal left ventricular ejection fraction (LVEF), and normal and abnormal GLS at presentation were compared. On presentation, 42% of patients with MIS-C had decreased LVEF < 55%. In patients in whom GLS was obtained (N = 18), 44% were abnormal (GLS < |- 18|%). Of patients with normal LVEF, 22% had abnormal GLS. There were no significant differences in troponin or brain natriuretic peptide between those with normal and abnormal LVEF. In most MIS-C patients with initial LVEF < 55% (90%), LVEF normalized upon discharge. At 2-month follow-up, all patients had normal LVEF with 21% having persistently abnormal GLS. Myocardial systolic dysfunction and abnormal deformation were common findings in MIS-C at presentation. While EF often normalized by 2 months, persistently abnormal GLS was more common, suggesting ongoing subclinical dysfunction. Our study offers an optimistic outlook for recovery in patients with MIS-C and carditis, however ongoing investigation for longitudinal effects is warranted.

Cardiac Assessment in Children with MIS-C: Late Magnetic Resonance Imaging Features

Multisystem Inflammatory Syndrome (MIS-C) is a new entity that emerges 2-4 weeks after the SARS-CoV-2 infection in children. MIS-C can affect all systems, the most severe of which is cardiac involvement. The duration of the cardiac symptoms is still uncertain and may be persistent or prolonged. The American College of Rheumatology Clinical Guidelines recommends cardiac magnetic resonance imaging (MRI) 2-6 months after the diagnosis of MIS-C in patients presenting with significant transient left ventricular (LV) dysfunction in the acute phase of illness (LV ejection fraction 50%) or persistent LV dysfunction. There are a few studies investigating cardiac MRI findings in MIS-C patients. In this study, we aimed to evaluate cardiac MRI findings, at the earliest 3 months after diagnosis, and compare these findings with the echocardiograms in children with MIS-C. A retrospective study including 34 MIS-C patients was conducted at a tertiary-level University Hospital between June 2020 and July 2021. Centers for Disease Control and Prevention criteria were used in the diagnosis of MIS-C. Cardiac MRI was performed at least 3 months after MIS-C diagnosis. The study included 17 (50%) boys and 17 (50%) girls with a mean age of 9.31 ± 4.72 years. Initial echocardiographic evaluation revealed cardiac abnormality in 13 (38.2) patients; 4 (11.8%) pericardial effusion, 4 (11.8%) left ventricular ejection fraction (LVEF) < 55%, and 5 (14.7%) coronary artery dilatation. Echocardiography showed normal LV systolic function in all patients during follow-up; coronary dilatation persisted in 2 of 5 (40%) patients at the 6th-month visit. Cardiac MRI was performed in 31 (91.2%) patients, and myocardial hyperemia was not detected in any patients (T1 relaxation time was < 1044 ms in all children). However, 9 (29%) patients' MRI showed isolated elevated T2 levels, and 19 (61.3%) revealed at least one of the following findings: pericardial effusion, right ventricular dysfunction, or LVEF abnormality. In patients with MIS-C, a high rate of cardiac involvement, particularly pericardial effusion was determined by cardiac MRI performed at the earliest 2-6 months after diagnosis. Even if echocardiography does not reveal any abnormality in the initial phase, cardiac MRI should be suggested in MIS-C patients in the late period. This is the first study reporting cardiac MRI findings in the late period of MIS-C patients.

Management of Multisystem Inflammatory Syndrome in Children (MIS-C) in resource limited settings: The Kenyan Experience

BACKGROUND

Since the onset of the recent COVID-19 pandemic, there have been growing concerns regarding multisystem inflammatory syndrome in children (MIS-C). This study aims to describe the clinico-epidemiological profile and challenges in management of MIS-C in low-middle income countries by highlighting the Kenyan experience.

METHODS

A retrospective study at the Aga Khan University Hospital Nairobi, Avenue Hospital Kisumu and Kapsabet County Referral Hospital was undertaken to identify cases of MIS-C. A detailed chart review using the World Health Organization (WHO) data collection tool was adapted to incorporate information on socio-demographic details and treatment regimens.

FINDINGS

Twenty children with MIS-C were identified across the three facilities between August 1st 2020 and August 31st 2021. Seventy percent of the children were male (14 of 20). COVID-19 PCR testing was done for five children and only one was positive. The commonest clinical symptoms were fever (90%), tachycardia (80%), prolonged capillary refill (80%), oral mucosal changes (65%) and peripheral cutaneous inflammation (50%). Four children required admission into the critical care unit for ventilation support and inotropic support. Cardiac evaluation was available for six patients four of whom had myocardial dysfunction, three had valvulitis and one had pericarditis. Immunoglobulin therapy was availed to two children and systemic steroids provided for three children. There were no documented mortalities.

INTERPRETATION

We describe the first case series of MIS-C in East and Central Africa. Majority of suspected cases of MIS-C did not have access to timely COVID-19 testing and other appropriate evaluations which highlights the iniquity in access to diagnostics and treatment.

Cardiovascular Manifestations in Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19 According to Age

Cardiac involvement in multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus-19 disease is often observed with a high risk of heart failure. The aim is to describe cardiovascular involvement, management and early outcome in MIS-C by comparing cardiovascular manifestations in children younger and older than 6 years old. This retrospective observational study included 25 children with MIS-C, admitted to a single pediatric center between March 2020 and September 2021. The median age was 5 years (13 patients under 6 years and 12 over 6 years); coronary artery abnormalities were observed in 77% of preschoolers, with small and medium aneurysms in half of the cases and two cases of mild ventricular dysfunction. School-age children presented myopericardial involvement with mild to moderate ventricular dysfunction in 67% of cases, and two cases of transient coronary dilatation. There was a significant NT-pro-BNP and inflammatory markers increase in 25 of the patients, and mild elevation of troponin I in 9. All patients were treated with intravenous immunoglobulin and corticosteroids, and 8 with anakinra. None of the patients needed inotropes or intensive care unit admission. Our study shows the frequent cardiovascular involvement in MIS-C with a peculiar distribution, according to different age group: coronary artery anomalies were more frequent in the younger group, and myopericardial disease in the older one. A prompt multitarget, anti-inflammatory therapy could probably contribute to a favorable outcome.

CXCL10/IP10 as a Biomarker Linking Multisystem Inflammatory Syndrome and Left Ventricular Dysfunction in Children with SARS-CoV-2

Background: To investigate the diagnostic accuracy of CXCL10/IP10 for left ventricular (LV) dysfunction in multisystemic inflammatory syndrome (MIS-C). Methods: This cross-sectional, longitudinal study included 36 patients with MIS-C. Patients were classified as follows: (1) patients presenting with Kawasaki-like features (group I = 11); (2) patients presenting with LV systolic dysfunction (group II = 9); and (3) other presentations (group III = 3). CXCL10/IP10 levels were measured upon admission and on days 3 and 7 of treatment. Results: Twenty patients were male and 16 were female. The median age of patients at diagnosis was 7.5 (1.5–17) years. All patients had a fever lasting for a median of 4 (2–7) days. Ten patients had LV systolic dysfunction. The duration of hospitalization was longer in group II. Lymphocyte and platelet counts were lower, whereas NT-pro-BNP, troponin-I, D-dimer, and CXCL10/IP10 levels were higher in group II. Baseline levels of CXCL10/IP10 were weakly negatively correlated with ejection fraction (r = −0.387, p = 0.022). Receiver operator characteristic curve analysis yielded a cutoff value of CXCL10/IP10 to discriminate patients with LV dysfunction was 1839 pg/mL with sensitivity 88% and specificity 68% (Area under curve (AUC) = 0.827, 95% CI 0.682–0.972, p = 0.003). Conclusion: Having a good correlation with cardiac function, CXCL10/IP10 is a potential biomarker to predict LV dysfunction in MIS-C patients.