Review of Cardiac Involvement in Multisystem Inflammatory Syndrome in Children

Cardiovascular post-acute sequelae of SARS-CoV-2 in children and adolescents: cohort study using electronic health records

The risk of cardiovascular outcomes following SARS-CoV-2 infection has been reported in adults, but evidence in children and adolescents is limited. This paper assessed the risk of a multitude of cardiac signs, symptoms, and conditions 28-179 days after infection, with outcomes stratified by the presence of congenital heart defects (CHDs), using electronic health records (EHR) data from 19 children's hospitals and health institutions from the United States within the RECOVER consortium between March 2020 and September 2023. The cohort included 297,920 SARS-CoV-2-positive individuals and 915,402 SARS-CoV-2-negative controls. Every individual had at least a six-month follow-up after cohort entry. Here we show that children and adolescents with prior SARS-CoV-2 infection are at a statistically significant increased risk of various cardiovascular outcomes, including hypertension, ventricular arrhythmias, myocarditis, heart failure, cardiomyopathy, cardiac arrest, thromboembolism, chest pain, and palpitations, compared to uninfected controls. These findings were consistent among patients with and without CHDs. Awareness of the heightened risk of cardiovascular disorders after SARS-CoV-2 infection can lead to timely referrals, diagnostic evaluations, and management to mitigate long-term cardiovascular complications in children and adolescents.

Longitudinal analysis of Covid-19 infection trends and in-hospital mortality across six pandemic waves in Tunisia

BACKGROUND

The global impact of the COVID-19 pandemic was remarkably diverse, unfolding with multiple waves that have touched countries and continents in distinctive ways, leading to varying rates of mortality. The objectives of this study were to examine the characteristics and in-hospital fatality rates of COVID-19 patients hospitalized in the Monastir governorate over two years, with an overall analysis and a wave-specific breakdown throughout the pandemic's progression.

METHODS

We carried out a two-year longitudinal study, enrolling all COVID-19-infected patients admitted to both public and private health facilities in the governorate of Monastir from March 2020 to March 2022. The study covered six complete infection waves. Patients were followed from their first day of admission to their outcome in hospital. The data were collected using a questionnaire manually completed by well-trained residents. The data were globally analyzed across all hospitalized patients and then compared based on the different waves.

RESULTS

Overall, 5176 were hospitalized. The cumulative in-hospital case fatality rate (CFR) over the study period was 21.4%. After the first wave (W1), the in-hospital CFR followed a gradual increase, reaching its peak at 27.5% during W4 (alpha variant). Later, it decreased to 21.8% during W5 (delta variant), and further declined to 19.5% during W6, associated with the Omicron variant (overall p < 0.001). W5 exhibited the highest proportions of infections, hospitalizations, and in-hospital deaths. W6 featured a low hospitalization rate of 2.8% and a decline in severe cases. Nevertheless, there was a significant surge in hospitalizations among both the pediatric (≤ 18 years) and geriatric (≥ 75 years) populations, with a pronounced impact on the elderly with chronic conditions. This surge resulted in an increase in fatalities among the elderly. The length of stay (LoS) decreased throughout the course of the pandemic, declining from 13 days [10;14] in W1 to 4 days [2;9] in W6 with almost half of them had a LoS less than seven days (55.6%).

CONCLUSION

This study underscores the critical interplay of variant-specific disease severity, patient demographics, and evolving healthcare responses in managing COVID-19's impact on hospital outcomes.

Multisystem Inflammatory Syndrome in Children: A Comprehensive Review Over the Past Five Years

Multisystem Inflammatory Syndrome in Children: A Comprehensive Review over the Past Five Years This review explores many facets of Multisystem Inflammatory Syndrome in Children (MIS-C) over the previous 5 years. In the time since the COVID 19 pandemic gripped our medical systems, we can now explore the data that has been collected from the previous years. The literature has allowed us to better understand the impact of COVID 19 and the post illness occurrence of a severe systemic inflammatory disease on our youngest patient populations. This paper will outline the pathophysiology of MIS-C, the treatments utilized, short and long-term patient outcomes including epidemiological factors.

Cardiovascular involvement in multisystem inflammatory syndrome in children and midterm follow-up from a pediatric tertiary center in India

BACKGROUND

In multisystem inflammatory syndrome in children (MIS-C) with coronavirus disease 2019, there was paucity of data from low-income and middle-income countries on cardiovascular involvement and its longitudinal outcomes. We planned to estimate the pattern of cardiovascular involvement among children with MIS-C and its mid-term outcomes.

AIM

To determine association between cardiovascular abnormalities and clinical and laboratory parameters. To study the time-line for resolution of various abnormalities.

METHODS

In this prospective study done in a tertiary care hospital, 270 were recruited from June 2020 to January 2022. Baseline demographic data and clinical presentation were recorded. Laboratory parameters and echocardiography were done at admission. Follow-up was done at 2 weeks, 3 months, 6 months and 1 year after diagnosis. Descriptive statistics were used for parametric and non-parametric data. Risk factors were identified by multivariate regression analysis.

RESULTS

The 211 (78.2%) had cardiac involvement and 102 needed intensive care unit (ICU) admission. Cardiovascular abnormalities observed were shock 123 (45.6%), coronary dilatation 28 (10.4%), coronary aneurysm 77 (28.5%), left ventricular (LV) dysfunction 78 (29.3%), mitral regurgitation (MR) 77 (28.5%) and pericardial effusion 98 (36.3%). Coronary artery aneurysm/dilatation during follow-up at 2 weeks and 1 year were 25.7% and 0.9% respectively. Multivariate regression analysis revealed breathlessness [odds ratio (OR) = 3.91, 95%CI: 1.25-12.21, P = 0.019] and hi-flow nasal cannula (HFNC) support (OR = 8.5, 95%CI: 1.06-68.38, P = 0.044) as predictors of cardiovascular involvement. Higher mean age (OR = 1.16, 95%CI: 1.02-1.32, P = 0.026), breathlessness (OR = 4.99, 95%CI: 2.05-12.20, P < 0.001), gallop (OR = 4.45, 95%CI: 0.41-2.52, P = 0.016), MR (OR = 3.61, 95%CI: 1.53-8.53, P = 0.004) and invasive ventilation (OR = 4.01, 95%CI: 1.28-12.58, P = 0.017) were predictive of LV dysfunction. Altered sensorium (OR = 4.96, 95%CI: 2.23-11.02, P < 0.001), headache (OR = 6.61, 95%CI: 1.46-29.92, P = 0.014), HFNC (OR = 7.03, 95%CI: 2.04-24.29, P = 0.002), non-rebreathing mask usage (OR = 21.13, 95%CI: 9.00-49.61, P < 0.001) and invasive ventilation (OR = 5.64, 95%CI: 1.42-22.45, P = 0.014) were risk factors for shock. Anemia was a risk factor for coronary involvement (OR = 3.09, 95%CI: 1.79- 5.34, P < 0.001).

CONCLUSION

Significant number of children with MIS-C had cardiovascular involvement contributing to higher ICU management. Although shock resolved quickly, resolution of ventricular function and coronary abnormalities were slower, and hence warrants a structured long-term follow-up protocol.

Severity of Pediatric Inflammatory Multisystem Syndrome Temporally Associated with SARS-CoV-2 Diminished During Successive Waves of the COVID-19 Pandemic: Data from a Nationwide German Survey

OBJECTIVE

To elucidate how the clinical presentation of Pediatric Inflammatory Multisystem Syndrome temporally associated with Severe Acute Respiratory Syndrome-related Coronavirus 2 (PIMS-TS) was influenced by the successive variants of concern (VOC) and patient age.

STUDY DESIGN

A nationwide PIMS-TS registry was established in Germany in May 2020, shortly after the first cases were described in the US and United Kingdom. The registry captured information on patient characteristics, clinical course, laboratory findings, imaging, and outcome. All pediatric hospitals in Germany, along with one in Austria, were invited to participate. Between March 18, 2020, and April 30, 2023, 920 cases were reported.

RESULTS

By examining a combination of data on clinical features, laboratory findings, treatment, imaging results, and outcomes, our analysis demonstrated disease severity to have continuously declined over the course of the Wildtype, Alpha, Delta, and Omicron waves. Based on clinical symptoms, laboratory and diagnostic findings, and intensive care unit admission rates, older children, irrespective of the related VOC, were shown to experience more severe, acute PIMS-TS; however, they had lower rates of coronary aneurysm.

CONCLUSIONS

During the course of COVID-19 pandemic, as each new VOC emerged, PIMS-TS lessened in severity. In parallel, older children came to experience more debilitating disease.

An Update on Multi-System Inflammatory Syndrome in Children

PURPOSE

To summarize the latest research on the epidemiology, pathogenesis, diagnosis, and treatment of multisystem inflammatory syndrome in children (MIS-C).

RECENT FINDINGS

The epidemiology of MIS-C has been dynamic since its initial description. The pathogenesis remains poorly understood. Case definitions of MIS-C have evolved over time, and practice patterns for treating MIS-C are variable with generally positive long-term outcomes yet persistent changes noted. MIS-C has become less prevalent and less severe over time, yet racial and ethnic disparities persist, and vaccination against COVID-19 is highly effective in preventing this disease. The link between acute infection and subsequent inflammation is not well understood, with growing evidence describing its immunologic signature. Newer case definitions require excluding other inflammatory conditions, including Kawasaki Disease (KD), before diagnosing MIS-C. Corticosteroid monotherapy may be non-inferior to IVIg alone or combination IVIg plus corticosteroids for initial treatment, distinguishing the approaches to MIS-C and KD. A wide range of biologic therapies have been employed for rescue therapy with general success and no clear benefit of one over another. Despite reports of a high rate of coronary artery abnormality regression and resolution of heart failure, long-term studies suggest persistent changes to cardiac function. The long-term effects of MIS-C continue to be active areas of research.

Inflammatory Heart Disease in Multisystem Inflammatory Syndrome

PURPOSEOF THE REVIEW

In this review article, we aim to provide an overview of the pathophysiology, the clinical features, the therapeutic management and prognosis of patients affected by Multisystemic inflammatory syndrome (MIS) with cardiac involvement, focusing on myocarditis and pericarditis.

RECENT FINDINGS

MIS is a multiorgan hyperinflammatory condition due to a cytokine storm following (within 4-12 weeks) SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) infection. First described in children, it also affects young adults without comorbidities, predominantly males with highly heterogeneous clinical manifestations, including cardiac involvement. Pericardial and myocardial involvement are prevalent among patients affected by MIS leading to different clinical manifestations including myocarditis with arrhythmias, acute heart failure and cardiogenic shock that significantly affect the patient's prognosis. The heterogeneity of its clinical features and the significant overlap with other hyperinflammatory diseases make the diagnosis particularly challenging. Moreover, the evidence on the efficacy of pharmacological treatments targeting the hyperinflammatory response is scarce, as well as data on long-term prognosis.

Nationwide Survey of Multisystem Inflammatory Syndrome in Children Associated with Coronavirus Disease 2019 in Japan

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) presents some clinical overlap with Kawasaki disease (KD). Although KD is common in Japan, the clinical characteristics of MIS-C in Japan remain unknown. Therefore, we aimed to determine the epidemiological and clinical features of MIS-C in Japan.

METHODS

Using a case reporting form, a nationwide registry was created between November 2020 and March 2023, involving 2,080 facilities throughout Japan. We prospectively and retrospectively enrolled patients with MIS-C. The primary outcomes were the number and incidence rates of children with MIS-C. The secondary outcomes included clinical features, such as KD phenotype, organ involvement, shock, intensive care unit admission, and coronary artery lesions.

RESULTS

Among 398 patients registered, central review identified 129 MIS-C cases (mean age: 8·8 ± 3·7 years). The overall incidence rate was estimated to be 1·5 per 100,000 COVID-19 cases, exhibiting a decline as the COVID-19 pandemic progressed, from 12·3 cases (Pre-Delta) to 1·3 cases (Omicron); 80% of MIS-C cases occurred during the Omicron variant predominant period, and 72% of children with MIS-C met the KD criteria. Cardiovascular (88%) and gastrointestinal (90%) involvement were frequent. In Japan, MIS-C cases showed comparatively less severe clinical features, with shock in 29% and admission to the intensive care unit in 12% of cases. Coronary artery lesions were identified in 15 cases (11·6%), irrespective of the presence of shock. No fatalities were reported.

CONCLUSION

The incidence of MIS-C was low in Japan. The clinical features distinctively exhibited a more KD-like phenotype, with less severe clinical features.

Clinical and Laboratory Parameters Associated with PICU Admission in Children with Multisystem Inflammatory Syndrome Associated with COVID-19 (MIS-C)

Background/Objectives: Multisystem Inflammatory Syndrome in children (MIS-C) is a rare but severe post-infectious complication of COVID-19 that often requires admission to the Pediatric Intensive Care Unit (PICU). The present study aimed to compare the demographic, clinical, and laboratory characteristics of children diagnosed with MIS-C who were admitted to the PICU and those who did not require PICU admission. Methods: Children diagnosed with MIS-C from September 2020 to April 2023 were included in this case-control study. Demographic, clinical, and laboratory data were collected from medical records. Results: Fifty children with MIS-C were included in the study [median (IQR) age: 7.5 (4.3, 11.4) years, 28/50 (56%) males]. Twenty-two (22/50, 44%) children required admission to the PICU. In the multivariate regression analysis, hepatic (OR: 12.89, 95%CI: 1.35-123.41, p-value = 0.03) and cardiological involvement (OR: 34.55, 95%CI: 2.2-541.91, p-value = 0.01) were significantly associated with hospitalization at the PICU. Regarding the laboratory and imaging parameters during the first 48 h from admission, D-dimer levels higher than 4 μg/mL and decreased Left Ventricular Ejection Fraction (LVEF) were associated with an increased risk of PICU admission (OR: 7.95, 95%CI: 1.48-42.78, p-value = 0.02 and OR = 1.28, 95%CI: 1.07-1.53, p-value = 0.01). Children who were admitted to the PICU were more likely to develop complications during their hospitalization (10/22, 45.5% vs. 3/28, 10.7%, p-value = 0.005) and were hospitalized for more days than children in the pediatric ward (median length of stay (IQR): 20 (15, 28) days vs. 8.5 (6, 14) days, p-value < 0.001). Conclusions: The findings of this study indicate that cardiovascular and hepatic involvement and increased D-dimer levels in children with MIS-C might be associated with admission to the PICU.

Complications of Multisystem Inflammatory Syndrome Associated with SARS-CoV-2 Infection-Many Facets of One Disease-A Literature Review Based on a Case Report

Multisystem inflammatory syndrome in children (MIS-C) is a disease that made its mark in the early days of the COVID-19 pandemic due to the diverse course and symptoms affecting multiple body systems. It is a condition that develops in pediatric patients about 2-6 weeks after contact with a person infected with the SARS-CoV-2 virus. In many instances, MIS-C has caused multiple organ failure, with particularly severe complications involving the cardiovascular system and manifesting as hypotension, various cardiac arrhythmias, myocarditis or coronary artery lesions resembling those seen in Kawasaki disease. Currently, the incidence of MIS-C is about 1-3 per 1000 children, with a decreasing trend in recent years due to the introduction of immunization against the SARS-CoV-2 virus for children as young as 6 months. In our paper, we present the case of a patient with a severe course of MIS-C with numerous cardiovascular and neurological complications, in whom the symptoms of the disease were managed by administering biological treatment. We also present a review of the literature on the subject, which shows how many different facets this disease can have and that physicians still need to remain alert, as there are cases of severe MIS-C, especially in unvaccinated patients.

Clinical and Laboratory Biomarkers as Predictors of Severity in Pediatric Inflammatory Multisystem Syndrome-temporally Associated With SARS-CoV-2: Data From a Prospective Nationwide Surveillance Study in Switzerland

BACKGROUND

PIMS-TS (pediatric inflammatory multisystem syndrome-temporally associated with SARS-CoV-2) is a rare but serious condition in children following SARS-CoV-2 infection, characterized by a range of clinical symptoms with varying severity. Understanding risk factors for severe PIMS-TS is crucial for appropriate and timely intervention.

OBJECTIVE

To identify factors associated with increased PIMS-TS severity in children.

METHODS

In this nationwide prospective observational study, epidemiological and clinical data was collected from children <18 years of age with suspected or confirmed PIMS-TS from all 29 pediatric hospitals in Switzerland. Children were categorized into 3 groups according to admission to intensive care unit (ICU): non-ICU, ICU-moderate and ICU-severe, defined as requirement of invasive ventilation and/or inotropic support.

RESULTS

A total of 204 children were included; 99 (49%) were categorized as non-ICU, 50 (25%) as ICU-moderate and 55 (27%) as ICU-severe. In ICU-severe cases, respiratory and neurological symptoms were more frequent compared with non-ICU cases: 72% versus 47%, P < 0.001 and 66% versus 41%, P = 0.001, respectively. Compared with the non-ICU group, children in the ICU-severe group had lower lymphocyte counts, higher neutrophil-lymphocyte ratios, lower platelet counts, as well as higher C-reactive protein, N-terminal pro-B-type natriuretic peptide, troponin T and creatinine levels at admission. Lymphopenia and elevated troponin T levels at admission were associated with an increased risk of being in the ICU-severe group.

CONCLUSION

The severity of PIMS-TS may be predicted using clinical symptoms and laboratory biomarkers, which help clinicians in decision-making and management of patients.

Should aortic stiffness parameters be used in MIS-C patient follow-up?

We evaluated the short- and long-term effects of multisystem inflammatory syndrome in children (MIS-C) on their cardiovascular system. The study population consisted of 38 MIS-C patients and 55 control patients. Standard echocardiographic measurements and aortic stiffness parameters were compared between the two groups at different time points. During the standard echocardiographic examination at the time of diagnosis, mitral valve insufficiency was detected in 42% of the cases, left ventricular systolic dysfunction in 36%, aortic valve insufficiency in 3%, tricuspid valve insufficiency in 13%, and coronary artery dilatation in 31%. The ejection fraction, pulse pressure of the experimental group were significantly lower than the control group (p < 0.01, p = 0.045, respectively). When aortic stiffness parameters were compared, it was seen that the parameters increased in the experimental group and the difference was significant for aortic distensibility. (p = 0.105, p = 0.029 respectively). When comparing the experimental group's results at diagnosis and at the sixth month, there was a decrease in aortic stiffness parameters at the sixth month compared to the time of diagnosis, but the difference wasn't significant (p = 0.514, p = 0.334). However, no statistically significant difference was detected when comparing the aortic distensibility results of the experimental group with the control group at the sixth month (p = 0.667). Our results showed that many pathological echocardiographic findings detected at diagnosis in MIS-C patients returned to normal within six months. Therefore, we believe that the cardiovascular follow-up period of MIS-C cases should be at least six months.

Specialty follow -up care after hospital discharge of patients with multisystem inflammatory syndrome in children associated with COVID-19 from a rural tertiary-care hospital

BACKGROUND

The clinical features of Multisystem Inflammatory Syndrome in Children (MIS-C) have been well documented, but there is limited data regarding the short term and longitudinal outcomes of children living in rural areas. We report the demographic and clinical features, as well as the multi-specialty follow-up of patients with MIS-C served by a large tertiary care rural health system.

METHODS

Patients that met the Centers for Disease Control (CDC) case definition of MIS-C admitted between March 1, 2020, and March 31, 2021, were included in this case series. Manual chart review was used to report demographic characteristics, clinical, laboratory and radiologic features during acute hospitalization and multispecialty follow-up, and adherence to follow-up 6-10 weeks after hospital discharge.

RESULTS

Twenty-one patients with MIS-C were admitted at our center during the review period. Ninety percent of the cohort required intensive care during hospitalization. Of 19 patients with measured ejection fractions, 52 % had some degree of left ventricular dysfunction on admission; nine patients had electrocardiogram changes on admission. The majority of patients had elevated inflammatory markers during hospitalization. Most patients had resolution of symptoms, improvement in inflammatory markers, and normal cardiac function at the time of discharge. Follow-up with pediatric cardiology, hematology-oncology and infectious disease was indicated for most patients at discharge. Of these, 100 % of patients kept initial follow-up appointments with pediatric cardiology and infectious disease, while 94 % kept initial follow-up appointments with pediatric hematology-oncology.

CONCLUSION

Though most patients were critically ill during hospitalization, the majority had resolution of cardiac abnormalities and inflammatory markers at discharge and timely follow-up with multiple subspecialists after admission with MIS-C.

Lessons from the Pandemic: Role of Percutaneous ECMO and Balloon Atrial Septostomy in Multi-System Inflammatory Syndrome in Children

Multi-system inflammatory syndrome in children (MIS-C) in the setting of COVID-19 can be associated with severe cardiopulmonary dysfunction. This clinical deterioration may sometimes necessitate veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support. We describe an algorithmic approach including the role of balloon atrial septostomy in this cohort. This is the first reported series of percutaneous VA-ECMO in pediatric patients with MIS-C for better outcomes. The lessons from this approach can be replicated in other pediatric clinical conditions and adds to the armament of multiple pediatric specialties.

NT-proBNP course during MIS-C post-COVID-19: an observational study

Multisystem inflammatory syndrome in children (MIS-C or PIMS-TS) is a severe disease. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is used for positive and differential diagnosis, diagnosis of complications and severity, and cardiogenic shock prediction. However, contrasting cut-offs have been suggested. The aims of the present study were to compare NT-proBNP values depending on the time of measurement and to describe the NT-proBNP course during the MIS-C episode. The data from a single-centre cohort observational study on the impact of time to diagnosis, defined as the time from first symptom to diagnosis of MIS-C, were used for the purpose of this study, with an extended period of inclusion from May 2020 to April 2023. The timing and level of all NT-proBNP samples available for each patient were retrospectively collected. Thirty-seven children (18 (49%) females, median age 8.8 years, 14 (38%) with shock) were included. Until diagnosis, NT-proBNP increased with time and was significantly higher at 6 days from first symptoms than at 3 days (median (interquartile range) 32,933 (7773-61,592) versus 1994 (1291-4190) pg/mL, respectively, p = 0.031). From diagnosis, NT-proBNP decreased by at least 50% after 3.0 (2.1-5.3) days (n = 12) when NT-proBNP at diagnosis was low ≤ 11,000 pg/mL versus 1.8 (0.7-3.4) days (n = 16) when NT-proBNP at diagnosis was high (p = 0.040), and after 3.6 (2.4-5.9) days (n = 7) when fever persisted after 48 h versus 1.8 (0.8-3.0) days (n = 21) when fever resolved before 48 h (p = 0.004).  Conclusions: During the MIS-C episode, NT-proBNP increased over time until diagnosis and treatment. It dropped faster thereafter in children with high NT-proBNP at diagnosis > 11,000 pg/mL and slower in case of persistent fever. What is Known: • NT-proBNP is useful in MIS-C for positive and differential diagnosis, diagnosis of complications and severity, and cardiogenic shock prediction. • Contrasting cut-offs for differential diagnosis and severity assessment have been suggested. What is New: • Before diagnosis, NT-proBNP increases with time and is significantly higher at 6 days from first symptoms than at 3 days suggesting different cut-offs depending on the timing of measurement. • From diagnosis and treatment initiation, the 50% NT-proBNP drop occurs earlier in children with high NT-proBNP at diagnosis > 11,000 pg/mL and later in children with persistent fever.

Multisystem inflammatory syndrome in children associated with COVID-19: from pathophysiology to clinical management and outcomes

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome (PIMS), is a new postinfectious illness associated with COVID-19, affecting children after SARS-CoV-2 exposure. The hallmarks of this disorder are hyperinflammation and multisystem involvement, with gastrointestinal, cardiac, mucocutaneous, and hematologic disturbances seen most commonly. Cardiovascular involvement includes cardiogenic shock, ventricular dysfunction, coronary artery abnormalities, and myocarditis. Now entering the fourth year of the pandemic, clinicians have gained some familiarity with the clinical presentation, initial diagnosis, cardiac evaluation, and treatment of MIS-C. This has led to an updated definition from the Centers for Disease Control and Prevention in the USA driven by increased experience and clinical expertise. Furthermore, the available evidence established expert consensus treatment recommendations supporting a combination of immunoglobulin and steroids. However, the pathophysiology of the disorder and answers to what causes this remain under investigation. Fortunately, long-term outcomes continue to look promising, although continued follow-up is still needed. Recently, COVID-19 mRNA vaccination is reported to be associated with reduced risk of MIS-C, while further studies are warranted to understand the impact of COVID-19 vaccines on MIS-C. We review the findings and current literature on MIS-C, including pathophysiology, clinical features, evaluation, management, and medium- to long-term follow-up outcomes.

Multisystem inflammatory syndrome in children (MIS-C) post-COVID-19 in Iran: clinical profile, cardiac features, and outcomes

BACKGROUND

In April 2020, an association between multisystem inflammatory syndromes (MIS-C) was observed in children with severe acute respiratory syndrome coronavirus infection (SARS-CoV-2). Most patients had heart involvement alone, and most patients had pericardial effusion. This study aimed to express and emphasize cardiac involvement in pediatric patients with respiratory symptoms who were diagnosed with COVID-19.

METHODS

This study was conducted in July 2021 in Kerman province, Southeastern Iran, during a notable surge in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. The study included 904 pediatric patients diagnosed with COVID-19. Data collection involved a comprehensive assessment of clinical symptoms and manifestations. Patients with fever lasting more than five days were admitted to the hospital. Echocardiography was utilized for cardiac involvement diagnosis, with 47 patients undergoing this diagnostic procedure.

RESULTS

Of the 904 patients, most of them had high fevers (74%). Fifty-five patients had a fever for more than five days and were hospitalized. Of the 47 patients who underwent echocardiography, 45 (81%) had heart involvement. In 75% of patients, pericardial effusion was the only cardiac involvement. Patients with pericardial effusion were treated with dexamethasone up to 3 mg every 8 h for 72 h.

CONCLUSIONS

MIS-C has a wide range of clinical symptoms. In cases where the fever is prolonged and there are gastrointestinal symptoms, physicians have clinical suspicion to diagnose this syndrome. Most cases of pericardial effusion are alone and improve with treatment with glucocorticosteroids.

SARS-CoV-2 induced vascular endothelial dysfunction: direct or indirect effects?

Clinical evidence reveals that manifestations of endothelial dysfunction are widely observed in COVID-19 and long-COVID patients. However, whether these detrimental effects are caused by direct infection of the endothelium or are indirectly mediated by systemic inflammation has been a matter of debate. It has been well acknowledged that endothelial cells (ECs) of the cardiovascular system ubiquitously express the SARS-CoV-2 entry receptor angiotensin-converting enzyme 2 (ACE2), yet accumulating evidence suggests that it is more predominantly expressed by pericytes and vascular smooth muscle cells of the mammalian blood vessel. Besides, replicative infection of ECs by SARS-CoV-2 has yet to be demonstrated both in vitro and in vivo. In this study, we review latest research on endothelial ACE2 expression in different vascular beds, and the heterogeneity in various EC subsets with differential ACE2 expression in response to SARS-CoV-2. We also discuss ACE2-independent alternative mechanisms underlying endothelial activation in COVID-19, and the clinical manifestations of SARS-CoV-2-induced endothelial dysfunction. Altogether, understanding ACE2-dependent and ACE2-independent mechanisms driving SARS-CoV-2-induced vascular dysfunction would shed light on strategies of more effective therapies targeting cardiovascular complications associated with COVID-19.

Cardiac Involvement in Patients With Multisystem Inflammatory Syndrome in Adults

Multisystemic inflammatory syndrome in adults is a hyperinflammatory condition following (within 4-12 weeks) SARS-CoV-2 infection. Here, the dysregulation of the immune system leads to a multiorgan involvement often affecting the heart. Cardiac involvement in multisystemic inflammatory syndrome in adults has been described mainly in young men without other comorbidities and may present with different clinical scenarios, including acute heart failure, life-threatening arrhythmias, pericarditis, and myocarditis, with a nonnegligible risk of mortality (up to 7% of all cases). The heterogeneity of its clinical features and the absence of a clear case definition make the differential diagnosis with other postinfectious (eg, infective myocarditis) and hyperinflammatory diseases (eg, adult Still disease and macrophage activation syndrome) challenging. Moreover, the evidence on the efficacy of specific treatments targeting the hyperinflammatory response underlying this clinical condition (eg, glucocorticoids, immunoglobulins, and other immunomodulatory agents) is sparse and not supported by randomized clinical trials. In this review article, we aim to provide an overview of the clinical features and the diagnostic workup of multisystemic inflammatory syndrome in adults with cardiac involvement, highlighting the possible pathogenetic mechanisms and the therapeutic management, along with remaining knowledge gaps in this field.

Assessing autonomic activity and prognostic risk factors comparing multisystem inflammatory syndrome and isolated viral myocarditis/myopericarditis

INTRODUCTION AND AIM

In pediatric multisystem inflammatory syndrome and isolated viral myocarditis/myopericarditis, autonomic nervous system function can be evaluated by a non-invasive method called heart rate variability. This study aims to evaluate heart rate variability in these two groups by comparing them with each other. This is the first study assessing these values in these two groups of patients.

METHOD

Patients who are diagnosed with multisystem inflammatory syndrome in children and isolated viral myocarditis/myopericarditis at a university hospital from September 2021 to February 2023 are screened by electrocardiography, echocardiography, and 24-hour Holter monitoring. A healthy control group, compatible in age and gender with the patient groups, was selected from healthy subjects that applied to the hospital for palpitation, murmur, and/or chest pain. Heart rate variability parameters and related laboratory markers were analyzed and compared among the three groups.

RESULTS

There were 30 patients with multisystem inflammatory syndrome in children, 43 patients with isolated viral myocarditis/myopericarditis, and 109 participants in the healthy control group. Statistically significant differences were found in most of the heart rate variability parameters: standard deviation of normal to normal intervals (SDNN), the mean of the 5- minute RR interval standard deviations (SDNNİ), the standard deviation of 5-minute R wave to R wave(RR) interval means (SDANN), the root mean square of successive RR interval differences (RMSSD), and the percentage of the beats with a consecutive RR interval difference of more than 50 ms (pNN50%), very low frequency, high frequency, low frequency, triangular index, and low frequency/high-frequency ratio. Multisystem inflammatory syndrome in children patients had impaired and declined heart rate variability values compared to the other two groups. In patients with myocarditis/myopericarditis, we couldn't find a significant difference in these parameters with the control group.

CONCLUSION

Heart rate variability can be used as an important non-invasive autonomic function parameter in determining prognosis and treatment plans, especially in patients diagnosed with multisystem inflammatory syndrome in children. This impairment of autonomic activity could be more prominent in patients with decreased left ventricular systolic functions.

Outpatient Pediatric Cardiology Follow-Up of Patients with Multisystem Inflammatory Syndrome in Children (MIS-C): A Single-Institution, Medium-Term Follow-Up Study

We are continuing to learn about the multisystem inflammatory syndrome in children (MIS-C) associated with SARS-CoV-2 infection. There are many published studies regarding the acute management of MIS-C; however, there is still much to learn regarding the long-term outcomes of patients with MIS-C. In this study, we report the outcomes of patients admitted at our institution with MIS-C and the follow-up practices in Pediatric Cardiology over the last three years. We included patients who were admitted at Lucile Packard Children's Hospital between January 1, 2020 and October 31, 2022, who met the CDC criteria for MIS-C, and were followed in the Pediatric Cardiology Outpatient Clinic at our institution. There were 25 patients who met our inclusion criteria. Eighteen patients (72%) had their initial follow-up visit within 1-2 weeks of discharge and seven patients (28%) had their initial follow-up visit within 4-6 weeks of discharge. Six patients out of the 25 (24%) had decreased left ventricular ejection fraction (LVEF < 50%) during their hospitalization. No patients had left main coronary artery aneurysm (z-score > 2.5), two patients (8%) had proximal right coronary artery aneurysm (z-score > 2.5), and one patient (4%) had left anterior descending coronary artery aneurysm (z-score > 2.5) during hospitalization. Patients who were admitted with the diagnosis of MIS-C showed normalization of left ventricular dysfunction at their initial follow-up visit as early as 2-4 weeks after discharge. In this cohort of MIS-C patients, a 4-6-week window for the first follow-up visit after discharge seems reasonable.

Overview of COVID-19 Infection, Treatment, and Prevention in Children

Coronavirus disease 2019 (COVID-19), caused by the novel respiratory virus-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-was declared a global pandemic by the World Health Organization on 11 March 2020. Since then, substantial gains have been made in our understanding of COVID-19 epidemiology, disease presentation, and management. While children tend to have less severe disease courses compared to adults, children can still develop severe COVID-19 infections, particularly in those with underlying medical conditions such as obesity, chronic lung disease, or prematurity. In addition, children are at risk of severe complications of COVID-19 infection, such as multisystem inflammatory syndrome in children (MIS-C) or long COVID. The case definitions of MIS-C and long COVID have continued to evolve with the increased understanding of these new entities; however, improved methods of diagnosis and determination of the optimal management are still needed. Furthermore, with the continued circulation of SARS-CoV-2 variants, there remains a need for clinicians to remain up-to-date on the latest treatment and prevention options. The purpose of this review is to provide an evidence-based review of what we have learned about COVID-19 in children since the start of the pandemic and how best to counsel children and their families on the best methods of prevention.

Multisystem Inflammatory Syndrome in Children during the COVID-19 Pandemic: A Review of Clinical Manifestations, Cardiac Complications and Medical Management

The SARS-CoV-2 pandemic has led to widespread research on associated clinical syndromes. While pediatric patients were initially deemed as a low-risk population for severe COVID-related disease, an increasing number of case reports have revealed a rare but potentially life-threatening syndrome, multisystem inflammatory syndrome in children (MIS-C). MIS-C is hypothesized to be due to hyperactivation of the immune system via a cytokine storm which leads to end-organ damage via endothelial dysfunction and changes in vascular permeability. Laboratory studies have displayed increased inflammatory markers such as C-reactive protein, erythrocyte sedimentation rate, D-dimer, tumor necrosis factor-alpha, and various interleukins. Studies have reported a wide range of clinical manifestations, including but not limited to fever, hypotension, shock, rash, coagulopathy, and gastrointestinal distress. Cardiac imaging and screening tests have revealed several complications, such as left ventricular failure, arrhythmias, and pericardial effusions. Medical management of MIS-C and cardiac sequelae have included supportive care, intravenous immunoglobulins, and corticosteroids, as well as immunomodulators, monoclonal antibodies, aspirin, and therapeutic anticoagulation, which have prevented serious outcomes in the majority of pediatric patients. Future multicenter and large-scale research is required for precise risk-stratification of MIS-C as well as long-term monitoring of sequelae. In this review, we aim to (1) outline the laboratory findings and clinical manifestations of MIS-C, and (2) describe cardiac complications and medical management of MIS-C.

Kawasaki Disease in the Time of COVID-19 and MIS-C: The International Kawasaki Disease Registry

BACKGROUND

Patients with multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease (KD) have overlapping clinical features. We compared demographics, clinical presentation, management, and outcomes of patients according to evidence of previous SARS-CoV-2 infection.

METHODS

The International Kawasaki Disease Registry (IKDR) enrolled KD and MIS-C patients from sites in North, Central, and South America, Europe, Asia, and the Middle East. Evidence of previous infection was defined as: Positive (household contact or positive polymerase chain reaction [PCR]/serology), Possible (suggestive clinical features of MIS-C and/or KD with negative PCR or serology but not both), Negative (negative PCR and serology and no known exposure), and Unknown (incomplete testing and no known exposure).

RESULTS

Of 2345 enrolled patients SARS-CoV-2 status was Positive for 1541 (66%) patients, Possible for 89 (4%), Negative for 404 (17%) and Unknown for 311 (13%). Clinical outcomes varied significantly among the groups, with more patients in the Positive/Possible groups presenting with shock, having admission to intensive care, receiving inotropic support, and having longer hospital stays. Regarding cardiac abnormalities, patients in the Positive/Possible groups had a higher prevalence of left ventricular dysfunction, and patients in the Negative and Unknown groups had more severe coronary artery abnormalities.

CONCLUSIONS

There appears to be a spectrum of clinical features from MIS-C to KD with a great deal of heterogeneity, and one primary differentiating factor is evidence for previous acute SARS-CoV-2 infection/exposure. SARS-CoV-2 Positive/Possible patients had more severe presentations and required more intensive management, with a greater likelihood of ventricular dysfunction but less severe coronary artery adverse outcomes, in keeping with MIS-C.

Clinical manifestations and outcomes associated with PICU admission in children with multisystem inflammatory syndrome in Taiwan: A retrospective cohort study

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a rare and serious systemic inflammatory disorder that occurs following a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aims to investigate the clinical manifestations, risk factors associated with pediatric intensive care unit (PICU) admission, and outcome among children with MIS-C in Taiwan.

METHODS

A retrospective analysis was conducted among pediatric patients diagnosed with MIS-C between June 2022 and February 2023 at Chang Gung Memorial Hospital, Linkou, Taiwan. Data on demographics, clinical features, laboratory findings, treatment modalities, and outcomes were collected and analyzed.

RESULTS

Twenty-eight MIS-C patients, including 9 boys and 19 girls, with an average age of 5.3 ± 3.8 years old, were enrolled. Most of the cases (78.6%) were diagnosed following the first pandemic wave of COVID-19 in Taiwan. The leading clinical manifestations observed were fever (100%), skin rash (64.3%), tachycardia (46.4%), and vomiting (46.4%). Nine patients (32.1%) were admitted to the PICU due to hypotension or neurological manifestations. Higher levels of band-form white blood cells, procalcitonin, ferritin, d-dimer, prothrombin time, NT-proBNP, and lower platelet levels on arrival were associated with PICU admission (p = 3.9 × 10-2 ,9 × 10-3 , 4 × 10-3 ,1 × 10-3 , 5 × 10-3 , 4.1 × 10-2 , and 3.4 × 10-2 , respectively). Arrhythmia in one case (3.5%) and coronary artery abnormalities, including dilatation in two cases (7.1%) and small aneurysms in one case (3.5%) were identified. Regardless of ICU admission, no patients experienced systolic dysfunction or mortality following treatment.

CONCLUSION

MIS-C cases in Taiwan have a favorable outcome. Although one-third of the patients required PICU admission, none of the MIS-C cases resulted in severe cardiovascular morbidity or mortality. This study provides valuable insights into the clinical manifestations and outcomes associated with PICU admission in children with MIS-C in Taiwan.

Cardiac MRI six months after the onset of multisystem inflammatory syndrome in children and adolescents temporally related to COVID-19: A retrospective follow-up study

BACKGROUND

In 2020, reports revealed cases called multisystem inflammatory syndrome in children and adolescents temporally related to COVID-19 or multisystem inflammatory syndrome in children. A small proportion of patients suffer from persistent left ventricular dysfunction at discharge. The primary aim was to investigate if myocardial impairment persists during follow-up in these patients.

METHODS

Children fulfilling the criteria for multisystem inflammatory syndrome in children with cardiac involvement hospitalized between December 2020 and February 2022 were included in this retrospective single centre study. Cardiac MRI was performed six months after the onset of symptoms to evaluate possible persistent myocardial damage.

RESULTS

Fifteen patients (80% male) with a median age of 8 years (interquartile range 4.5 - 13.5 years) were included. Upon admission, eight patients (53%) presented with reduced left ventricular function, with a median left ventricular ejection fraction of 54% (interquartile range 49.5%-61.5%) on transthoracic echocardiography. Elevated levels of cardiac-specific markers were found in 14 patients (93%). Cardiac MRI was performed in 12 patients at a median of 190.5 days after the onset of symptoms. Nine patients (75%) had normal left ventricular function, with a median left ventricular ejection fraction of 59.45%, while the remaining patients showed mildly to moderately reduced values. None of the patients showed signs of late gadolinium enhancement, indicating the absence of persistent myocardial scarring.

CONCLUSION

During a follow-up of 6.2 months, mild to moderate cardiac impairment was revealed in 25% of patients evaluated by cardiac MRI. Although a majority of patients do not show signs of cardiac impairment, close follow-ups should be performed in a proportion of patients.

Cardiovascular Manifestations of Multisystem Inflammatory Syndrome in Children: A Single-Center Bulgarian Study

Background and objectives: Multisystem inflammatory syndrome in children (MIS-C) poses challenges to the healthcare system, especially with frequent heart involvement. The current retrospective observational study aims to summarize the type and degree of cardiovascular involvement in children with MISC and to find possible associations between laboratory, inflammatory, and imaging abnormalities and the predominant clinical phenotype using a cluster analysis. Material and methods: We present a retrospective observational single-center study including 51 children meeting the MIS-C criteria. Results: Fifty-three percent of subjects presented with at least one sign of cardiovascular involvement (i.e., arterial hypotension, heart failure, pericardial effusion, myocardial dysfunction, pericarditis without effusion, myocarditis, coronaritis, palpitations, and ECG abnormalities). Acute pericarditis was found in 30/41 of the children (73%) assessed using imaging: 14/30 (46.7%) with small pericardial effusion and 16/30 (53.3%) without pericardial effusion. The levels of CRP were significantly elevated in the children with pericarditis (21.6 ± 13 mg/dL vs. 13.9 ± 11 mg/dL, p = 0.035), and the serum levels of IL-6 were higher in the children with small pericardial effusion compared to those without (191 ± 53 ng/L vs. 88 ± 27 ng/L, p = 0.041). Pericarditis with detectable pericardial effusion was significantly more frequent in the female vs. male subjects, 72% vs. 30% (p = 0.007). The hierarchical clustering analysis showed two clusters: Cluster 1 includes the children without cardiovascular symptoms, and Cluster 2 generalizes the MIS-C children with mild and severe cardiovascular involvement, combining pericarditis, myocarditis, heart failure, and low blood pressure. Also, subjects from Cluster 2 displayed significantly elevated levels of fibrinogen (5.7 ± 0.3 vs. 4.6 ± 0.3, p = 0.03) and IL-6 (158 ± 36 ng/mL vs. 66 ± 22 ng/mL, p = 0.032), inflammatory markers suggestive of a cytokine storm. Conclusions: Our results confirm that children with oligosymptomatic MIS-C or those suspected of long COVID-19 should be screened for possible cardiological involvement.

COVID-19 and Cardiovascular Diseases: From Cellular Mechanisms to Clinical Manifestations

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), quickly spread worldwide and led to over 581 million confirmed cases and over 6 million deaths as 1 August 2022. The binding of the viral surface spike protein to the human angiotensin-converting enzyme 2 (ACE2) receptor is the primary mechanism of SARS-CoV-2 infection. Not only highly expressed in the lung, ACE2 is also widely distributed in the heart, mainly in cardiomyocytes and pericytes. The strong association between COVID-19 and cardiovascular disease (CVD) has been demonstrated by increased clinical evidence. Preexisting CVD risk factors, including obesity, hypertension, and diabetes etc., increase susceptibility to COVID-19. In turn, COVID-19 exacerbates the progression of CVD, including myocardial damage, arrhythmia, acute myocarditis, heart failure, and thromboembolism. Moreover, cardiovascular risks post recovery and the vaccination-associated cardiovascular problems have become increasingly evident. To demonstrate the association between COVID-19 and CVD, this review detailly illustrated the impact of COVID-19 on different cells (cardiomyocytes, pericytes, endothelial cells, and fibroblasts) in myocardial tissue and provides an overview of the clinical manifestations of cardiovascular involvements in the pandemic. Finally, the issues related to myocardial injury post recovery, as well as vaccination-induced CVD, has also been emphasized.

Cardiovascular Follow-up of Patients Treated for MIS-C

OBJECTIVES

To assess the prevalence of residual cardiovascular pathology by cardiac MRI (CMR), ambulatory rhythm monitoring, and cardiopulmonary exercise testing (CPET) in patients ∼6 months after multisystem inflammatory disease in children (MIS-C).

METHODS

Patients seen for MIS-C follow-up were referred for CMR, ambulatory rhythm monitoring, and CPET ∼6 months after illness. Patients were included if they had ≥1 follow-up study performed by the time of data collection. MIS-C was diagnosed on the basis of the Centers for Disease Control and Prevention criteria. Myocardial injury during acute illness was defined as serum Troponin-I level >0.05 ng/mL or diminished left ventricular systolic function on echocardiogram.

RESULTS

Sixty-nine of 153 patients seen for MIS-C follow-up had ≥1 follow-up cardiac study between October 2020-June 2022. Thirty-seven (54%) had evidence of myocardial injury during acute illness. Of these, 12 of 26 (46%) had ≥1 abnormality on CMR, 4 of 33 (12%) had abnormal ambulatory rhythm monitor results, and 18 of 22 (82%) had reduced functional capacity on CPET. Of the 37 patients without apparent myocardial injury, 11 of 21 (52%) had ≥1 abnormality on CMR, 1 of 24 (4%) had an abnormal ambulatory rhythm monitor result, and 11 of 15 (73%) had reduced functional capacity on CPET. The prevalence of abnormal findings was not statistically significantly different between groups.

CONCLUSIONS

The high prevalence of abnormal findings on follow-up cardiac studies and lack of significant difference between patients with and without apparent myocardial injury during hospitalization suggests that all patients treated for MIS-C warrant cardiology follow-up.

Significant exercise limitations after recovery from MIS-C related myocarditis

BACKGROUND

Myocarditis is one of the presentations of multisystemic inflammatory syndrome in children (MIS-C) following coronavirus disease 2019 (COVID-19). Although the reported short-term prognosis is good, data regarding medium-term functional capacity and limitations are scarce. This study aimed to evaluate exercise capacity as well as possible cardiac and respiratory limitations in children recovered from MIS-C related myocarditis.

METHODS

Fourteen patients who recovered from MIS-C related myocarditis underwent spirometry and cardiopulmonary exercise testing (CPET), and their results were compared with an age-, sex-, weight- and activity level-matched healthy control group (n = 14).

RESULTS

All participants completed the CPET with peak oxygen uptake (peak [Formula: see text]), and the results were within the normal range (MIS-C 89.3% ± 8.9% and Control 87.9% ± 13.7% predicted [Formula: see text]). Five post-MIS-C patients (35%) had exercise-related cardio-respiratory abnormalities, including oxygen desaturation and oxygen-pulse flattening, compared to none in the control group. The MIS-C group also had lower peak exercise saturation (95.6 ± 3.5 vs. 97.6 ± 1.1) and lower breathing reserve (17.4% ± 7.5% vs. 27.4% ± 14.0% of MVV).

CONCLUSIONS

Patients who recovered from MIS-C related myocarditis may present exercise limitations. Functional assessment (e.g., CPET) should be included in routine examinations before allowing a return to physical activity in post-MIS-C myocarditis. Larger, longer term studies assessing functional capacity and focusing on physiological mechanisms are needed.

Single-Cell Meta-Analysis of Neutrophil Activation in Kawasaki Disease and Multisystem Inflammatory Syndrome in Children Reveals Potential Shared Immunological Drivers

BACKGROUND

Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) share similar clinical manifestations, including cardiovascular complications, suggesting similar underlying immunopathogenic processes. Aberrant neutrophil activation may play a crucial role in the shared pathologies of KD and MIS-C; however, the associated pathogenic mechanisms and molecular drivers remain unknown.

METHODS

We performed a single-cell meta-analysis of neutrophil activation with 103 pediatric single-cell transcriptomic peripheral blood mononuclear cell data across 9 cohorts, including healthy controls, KD, MIS-C, compared with dengue virus infection, juvenile idiopathic arthritis, and pediatric celiac disease. We used a series of computational analyses to investigate the shared neutrophil transcriptional programs of KD and MIS-C that are linked to systemic damage and cardiac pathologies, and suggested Food and Drug Administration-approved drugs to consider as KD and MIS-C treatment.

RESULTS

We meta-analyzed 521 950 high-quality cells. We found that blood signatures associated with risks of cardiovascular events are enriched in neutrophils of KD and MIS-C. We revealed the expansion of CD177+ neutrophils harboring hyperactivated effector functions in both KD and MIS-C, but not in healthy controls or in other viral-, inflammatory-, or immune-related pediatric diseases. KD and MIS-C CD177+ neutrophils had highly similar transcriptomes, marked by conserved signatures and pathways related to molecular damage. We found the induction of a shared neutrophil expression program, potentially regulated by SPI1 (Spi-1 proto-oncogene), which confers enhanced effector functions, especially neutrophil degranulation. CD177 and shared neutrophil expression program expressions were associated with acute stages and attenuated during KD intravenous immunoglobulin treatment and MIS-C recovery. Network analysis identified hub genes that correlated with the high activation of CD177+ neutrophils. Disease-gene association analysis revealed that the KD and MIS-C CD177+ neutrophils' shared expression program was associated with the development of coronary and myocardial disorders. Last, we identified and validated TSPO (translocator protein) and S100A12 (S100 calcium-binding protein A12) as main molecular targets, for which the Food and Drug Administration-approved drugs methotrexate, zaleplon, metronidazole, lorazepam, clonazepam, temazepam, and zolpidem, among others, are primary candidates for drug repurposing.

CONCLUSIONS

Our findings indicate that CD177+ neutrophils may exert systemic pathological damage contributing to the shared morbidities in KD and MIS-C. We uncovered potential regulatory drivers of CD177+ neutrophil hyperactivation and pathogenicity that may be targeted as a single therapeutic strategy for either KD or MIS-C.

Extracorporeal Membrane Oxygenation in an Adolescent with Multisystem Inflammatory Syndrome in Children

Multisystem inflammatory syndrome in children is a rare and potentially life-threatening disease that is associated with SARS-CoV-2 infection, characterized by hyperinflammation and multiorgan involvement. Cardiovascular involvement is common, including myocardial dysfunction often leading to cardiogenic shock. We present the case of a 17-year-old boy with fever, odynophagia, maculopapular rash and abdominal pain who developed a cardiogenic shock. Due to progressive deterioration of cardiac function despite optimized vasoactive support, veno-arterial extracorporeal membrane oxygenation support was initiated 12 hours after admission, with successful decannulation after seven days and discharge after 23 days, with normal cardiac function. The patient received corticosteroids and intravenous immunoglobulin. Early recognition and intensive care support are crucial for ensuring a successful outcome in severe cases of multisystem inflammatory syndrome. In cases of severe cardiogenic shock, extracorporeal membrane oxygenation support can be critical for survival and rapid recovery.

Describing our experience with the effects of multisystem inflammatory syndrome in children with COVID-19 on the cardiovascular system

Cardiac involvement with multisystem inflammatory syndrome in children can include coronary artery abnormalities, ventricular dysfunction, conduction abnormalities, arrhythmias, pericarditis, and myocarditis. We report the cardiac findings in 34 patients with multisystem inflammatory syndrome in children admitted to a single institution. We looked at patient age, sex, brain natriuretic peptide levels, troponin levels, ejection fraction, presence of pericardial effusion, valvular changes, need for inotropic agents, and electrocardiogram findings. Our data showed that elevated brain natriuretic peptide did not predict troponin elevation and vice versa. Additionally, troponin rise was not a reliable marker for decreased left ventricular ejection fraction. All changes tracked were proven to be transient and resolved after initiating steroids, Intravenous immune globulin (IVIG), and occasionally anakinra.

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.

Cardiovascular effects of COVID-19 in children

Introduction

Although severe acute respiratory failure is the primary cause of morbidity and mortality in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, this viral infection leads to cardiovascular disease in some individuals. Cardiac effects of the virus include myocarditis, pericarditis, arrhythmias, coronary aneurysms and cardiomyopathy, and can result in cardiogenic shock and multisystem organ failure.

Method

This review summarises cardiac manifesta-tions of SARS-CoV-2 in the paediatric population. We performed a scoping review of cardiovascular disease associated with acute coronavirus disease 2019 (COVID-19) infection, multisystem inflammatory syndrome in children (MIS-C), and mRNA COVID-19 vaccines. Also examined are special considerations for paediatric athletes and return to play following COVID-19 infection.

Results

Children presenting with acute COVID-19 should be screened for cardiac dysfunction and a thorough history should be obtained. Further cardiovascular evaluation should be considered following any signs/symptoms of arrhythmias, low cardiac output, and/or myopericarditis. Patients admitted with severe acute COVID-19 should be monitored with continuous cardiac monitoring. Laboratory testing, as clinically indicated, includes tests for troponin and B-type natriuretic peptide or N-terminal pro-brain natriuretic peptide. Echocardiography with strain evaluation and/or cardiac magnetic resonance imaging should be considered to evaluate diastolic and systolic dysfunction, coronary anatomy, the pericardium and the myocardium. For patients with MIS-C, combination therapy with intravenous immunoglobulin and glucocorticoid therapy is safe and potentially disease altering. Treatment of MIS-C targets the hyperimmune response. Supportive care, including mechanical support, is needed in some cases.

Conclusion

Cardiovascular disease is a striking feature of SARS-CoV-2 infection. Most infants, children and adolescents with COVID-19 cardiac disease fully recover with no lasting cardiac dysfunction. However, long-term studies and further research are needed to assess cardiovascular risk with variants of SARS-CoV-2 and to understand the pathophysiology of cardiac dysfunction with COVID-19.

Return to Play after SARS-CoV-2 Infection: Focus on the Pediatric Population with Potential Heart Involvement

The COVID-19 pandemic has entailed consequences on any type of physical activities, mainly due to the social restriction measures applied to reduce the spreading of SARS-CoV-2. When public health policies progressively reduced limitations and resuming a normal life was possible, the return to previous physical activity and sports was not only requested by people who had deeply suffered from limitations, but was also recommended by experts as a means of reducing the physical and psychological consequences induced by the pandemic. The aim of this narrative review is to summarize the available evidence on the return to play in children after SARS-CoV-2 infection, suggesting an algorithm for clinical practice and highlighting priorities for future studies. Criteria to identify subjects requiring laboratory and radiological tests before returning to physical activity are severity of COVID-19 and existence of underlying disease. Children of any age with asymptomatic infection or mild disease severity, i.e., the great majority of children with previous COVID-19, do not need a cardiologic test before resumption of previous physical activity. Only a visit or a telephonic contact with the primary care pediatricians should be established. On the contrary, children with moderate COVID-19 should not exercise until they are cleared by a physician and evaluated for resting electrocardiogram, exercise testing, and echocardiogram. Finally, in those with severe COVID-19, return to play should be delayed for several months, should be gradual and should be performed only after a cardiologist's clearance. Further studies are needed to assess the risks of returning to sports activity in pediatric age, including careful age-adjusted risk stratification, in order to improve the cost-benefit ratio of specific screenings.

Immune Profiles in Multisystem Inflammatory Syndrome in Children with Cardiovascular Abnormalities

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C), a sequela of severe acute respiratory syndrome coronavirus-2 infection (SARS-CoV2), has been progressively reported worldwide, with cardiac involvement being a frequent presentation. Although the clinical and immunological characteristics of MIS-C with and without cardiac involvement have been described, the immunological differences between cardiac and non-cardiac MIS-C are not well understood.

METHODS

The levels of type 1, type 2, type 17, other proinflammatory cytokines and CC chemokines and CXC chemokines were measured using the Magpix multiplex cytokine assay system in MIS-C children with MIS-C cardiac (MIS-C (C) (n = 88)) and MIS-C non-cardiac (MIS-C (NC) (n = 64)) abnormalities.

RESULTS

MIS-C children with cardiac manifestations presented with significantly increased levels of cytokines such as IFN-γ, IL-2, TNFα, IL-5, IL-1α, IL-1β, IL-6, IL-10 and IL-12p70 and chemokines such as CCL2, CCL3, CCL11 and CXCL10 in comparison to MIS-C children without cardiac manifestations. Clustering analysis revealed that cytokines and chemokines could clearly distinguish MIS-C children with and without cardiac manifestations. In addition, these responses significantly diminished and normalized 9 months after treatment.

CONCLUSIONS

This is one of the first studies characterizing and differentiating systemic inflammation in MIS-C with and without cardiac involvement from a low- and middle-income country (LMIC). Our study contributes to the existing body of evidence and advances our knowledge of the immunopathogenesis of MIS-C in children.

Cardiac involvement in children with paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS): data from a prospective nationwide surveillance study

BACKGROUND

Paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) may occur 4 to 8 weeks after SARS-CoV-2 infection. The acute presentation of PIMS-TS has been well described, but data on longer-term outcomes, particularly cardiac, is scarce.

METHODS

This prospective nationwide surveillance study included children and adolescents less than 18 years of age who were hospitalised with PIMS-TS in Switzerland between March 2020 and March 2022. Data was collected from all 29 paediatric hospitals through the Swiss Paediatric Surveillance Unit (SPSU) during hospitalisation and approximately six weeks after discharge. The data was analysed after categorising the participants into three groups based on their admission status to the intensive care unit (ICU) (non-ICU, ICU-moderate) and the requirement for invasive ventilatory and/or inotropic support (ICU-severe).

RESULTS

Overall, 204 children were included of whom 194 (95.1%) had follow-up data recorded. Median age was 9.0 years (interquartile range [IQR] 6.0-11.5) and 142 (69.6%) were male. In total, 105/204 (51.5%) required ICU admission, of whom 55/105 (52.4%) received inotropic support and 14/105 (13.3%) mechanical ventilation (ICU-severe group). Echocardiography was performed in 201/204 (98.5%) children; 132 (64.7%) had a cardiac abnormality including left ventricular systolic dysfunction (73 [36.3%]), a coronary artery abnormality (45 [22.4%]), pericardial effusion (50 [24.9%]) and mitral valve regurgitation (60 [29.9%]). Left ventricular systolic dysfunction was present at admission in 62/201 (30.8%) children and appeared during hospitalisation in 11 (5.5%) children. A coronary artery abnormality was detected at admission in 29/201 (14.2%) children and developed during hospitalisation or at follow-up in 13 (6.5%) and 3 (1.5%) children, respectively. None of the children had left ventricular systolic dysfunction at follow-up, but a coronary abnormality and pericardial effusion were found in 12 (6.6%) and 3 (1.7%) children, respectively. School absenteeism at the time of follow-up was more frequent in children who had been admitted to the ICU (2.5% in the non-ICU group compared to 10.4% and 17.6% in the ICU-moderate and ICU-severe group, respectively) (p = 0.011).

CONCLUSION

Cardiac complications in children presenting with PIMS-TS are common and may worsen during the hospitalisation. Irrespective of initial severity, resolution of left ventricular systolic dysfunction is observed, often occurring rapidly during the hospitalisation. Most of the coronary artery abnormalities regress; however, some are still present at follow-up, emphasising the need for prolonged cardiac evaluation after PIMS-TS.

Imaging Acute and Chronic Cardiac Complications of COVID-19 and after COVID-19 Vaccination

COVID-19 is associated with acute and longer-term cardiovascular manifestations including myocardial injury, myopericarditis, stress-induced cardiomyopathy, myocardial infarction, and thromboembolic disease. Although the morbidity and mortality related to acute COVID-19 have decreased substantially, there is growing concern about the longer-term cardiovascular effects of the disease and postacute sequelae. Myocarditis has also been reported after messenger ribonucleic acid (mRNA)-based COVID-19 vaccination, with the highest risk among adolescent boys and young adult men. Noninvasive imaging including cardiac MRI has a key role in identifying the presence of cardiovascular disease, evaluating for potential mechanisms of injury, stratifying risk of future adverse cardiovascular events, and potentially guiding treatment in patients with suspected cardiovascular injury after COVID-19 and vaccination. Patterns of injury identified at cardiac MRI after COVID-19 include myocarditis and pericarditis, myocardial ischemia, and infarction. Myocardial edema and late gadolinium enhancement have been described months after the initial infection in a minority of patients with persistent cardiac symptoms after COVID-19. In patients with myocarditis after receiving a COVID-19 vaccination, the most common pattern of late gadolinium enhancement is subepicardial at the basal inferolateral wall, and patients tend to have milder imaging abnormalities compared with those from other causes of myocarditis. This article describes the role of multimodality cardiac imaging and imaging findings in patients with acute and longer-term cardiovascular manifestations of COVID-19 and in patients with myocarditis after receiving an mRNA-based COVID-19 vaccination. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Unmasking the enigma: An in-depth analysis of COVID-19 impact on the pediatric population

OBJECTIVES

COVID-19, caused by the novel coronavirus, has had a profound and wide-reaching impact on individuals of all age groups across the globe, including children. This review article aims to provide a comprehensive analysis of COVID-19 in children, covering essential topics such as epidemiology, transmission, pathogenesis, clinical features, risk factors, diagnosis, treatment, vaccination, and others. By delving into the current understanding of the disease and addressing the challenges that lie ahead, this article seeks to shed light on the unique considerations surrounding COVID-19 in children and contribute to a deeper comprehension of this global health crisis affecting our youngest population.

METHODS

A comprehensive literature search was conducted to gather the most recent and relevant information regarding COVID-19 in children. Multiple renowned databases, including MEDLINE, PubMed, Scopus, as well as authoritative sources such as the World Health Organization (WHO), the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and the National Institutes of Health (NIH) websites and others were thoroughly searched. The search included articles, guidelines, reports, clinical trials results and expert opinions published within the past three years, ensuring the inclusion of the latest research findings on COVID-19 in children. Several relevant keywords, including "COVID-19," "SARS-CoV-2," "children," "pediatrics," and related terms were used to maximize the scope of the search and retrieve a comprehensive set of articles.

RESULTS AND CONCLUSION

Three years since the onset of the COVID-19 pandemic, our understanding of its impact on children has evolved, but many questions remain unanswered. While SAR-CoV-2 generally leads to mild illness in children, the occurrence of severe cases and the potential for long-term effects cannot be overlooked. Efforts to comprehensively study COVID-19 in children must continue to improve preventive strategies, identify high-risk populations, and ensure optimal management. By unraveling the enigma surrounding COVID-19 in children, we can strive towards safeguarding their health and well-being in the face of future global health challenges.

Evaluation of late cardiac effects after multisystem inflammatory syndrome in children

Introduction

Multisystem inflammatory syndrome in children (MIS-C) is associated with important cardiovascular morbidity during the acute phase. Follow-up shows a swift recovery of cardiac abnormalities in most patients. However, a small portion of patients has persistent cardiac sequelae at mid-term. The goal of our study was to assess late cardiac outcomes of MIS-C.

Methods

A prospective observational multicenter study was performed in children admitted with MIS-C and cardiac involvement between April 2020 and March 2022. A follow-up by NT-proBNP measurement, echocardiography, 24-h Holter monitoring, and cardiac MRI (CMR) was performed at least 6 months after MIS-C diagnosis.

Results

We included 36 children with a median age of 10 (8.0-11.0) years, and among them, 21 (58%) were girls. At diagnosis, all patients had an elevated NT-proBNP, and 39% had a decreased left ventricular ejection fraction (LVEF) (<55%). ECG abnormalities were present in 13 (36%) patients, but none presented with arrhythmia. Almost two-thirds of patients (58%) had echocardiographic abnormalities such as coronary artery dilation (20%), pericardial effusion (17%), and mitral valve insufficiency (14%). A decreased echocardiographic systolic left ventricular (LV) function was detected in 14 (39%) patients. A follow-up visit was done at a mean time of 12.1 (±5.8) months (range 6-28 months). The ECG normalized in all except one, and no arrhythmias were detected on 24-h Holter monitoring. None had persistent coronary artery dilation or pericardial effusion. The NT-proBNP level and echocardiographic systolic LV function normalized in all patients, except for one, who had a severely reduced EF. The LV global longitudinal strain (GLS), as a marker of subclinical myocardial dysfunction, decreased (z < -2) in 35%. CMR identified one patient with severely reduced EF and extensive myocardial fibrosis requiring heart transplantation. None of the other patients had signs of myocardial scarring on CMR.

Conclusion

Late cardiac outcomes after MIS-C, if treated according to the current guidelines, are excellent. CMR does not show any myocardial scarring in children with normal systolic LV function. However, a subgroup had a decreased GLS at follow-up, possibly as a reflection of persistent subclinical myocardial dysfunction.

Prognostic role of euthyroid sick syndrome in MIS-C: results from a single-center observational study

Background

Euthyroid sick syndrome (ESS) is characterized by low serum levels of free triiodothyronine (fT3) with normal or low levels of thyroid stimulating hormone (TSH) and free thyroxine (fT4) and is reported in different acute clinical situations, such as sepsis, diabetic ketoacidosis and after cardiac surgery. Our aim was to evaluate the predicting role of ESS for disease severity in patients with Multisystem Inflammatory Syndrome in children (MIS-C).

Methods

A single-centre observational study on consecutive patients with MIS-C. Before treatment clinical, and laboratory data were collected and, in a subset of patients, thyroid function tests were repeated 4 weeks later. Variables distribution was analyzed by Mann-Whitney U-test and correlations between different parameters were calculated by Spearman's Rho coefficient.

Results

Forty-two patients were included and 36 (85.7%) presented ESS. fT3 values were significantly lower in patients requiring intensive care, a strong direct correlation was shown between fT3 and Hb, platelet count and ejection fraction values. A significant inverse correlation was retrieved between fT3 levels and C-reactive protein, brain natriuretic peptide, IL-2 soluble receptor and S-100 protein. Subjects with severe myocardial depression (EF < 45%) had lower fT3 values than subjects with higher EF. The thyroid function tests spontaneously normalized in all subjects who repeated measurement 4 weeks after admission.

Conclusion

ESS is a frequent and transient condition in acute phase of MIS-C. A severe reduction of fT3 must be considered as important prognostic factor for severe disease course, with subsequent relevant clinical impact in the management of these patients.

Thrombosis in Multisystem Inflammatory Syndrome Associated with COVID-19 in Children: Retrospective Cohort Study Analysis and Review of the Literature

Background: The causative agent of the new coronavirus infection SARS-CoV-2 has unique properties causing hyperinflammatory syndrome and cytokine storm, as well as widespread endotheliitis and thrombotic microangiopathy, initially detected in the lungs of adult patients who died from a severe form of the disease. Venous and arterial thrombosis in adults were identified as common causes of severe complications and deaths in new coronavirus infections. There are very few reports of thrombotic events in children with COVID-19 in the literature. Methods: We conducted a retrospective analysis of the histories of 60 patients in the Irkutsk Regional Children's Clinical Hospital from November 2020 to November 2022 with a MIS-C diagnosis established according to WHO criteria, of which 8 (13.3%) were diagnosed with venous and/or arterial thrombosis, confirmed by laboratory and ultrasound and/or X-ray methods. Results: The average age of children with thrombosis (Me) was 7.5 years (min 4 months, max 17 years), with a M:F ratio of 3.0. Venous thrombosis was detected in six of the eight patients, including in the deep veins of the lower extremities in four. Pulmonary embolism occurred in two (one of them was fatal), and cerebral venous sinus thrombosis and thrombosis of the branches of the upper and lower vena cava were found in one patient. Extensive bilateral stroke due to thrombosis of the large cerebral arteries occurred in two patients, including one in combination with distal gangrene. Secondary thrombotic renal microangiopathy took place in three of the eight patients. Among these three, atypical HUS was diagnosed in one case. Multiple thrombosis involving the venous and arterial bed was detected in four of the eight patients. High levels of D-dimer, thrombocytopenia, increased NT-proBNP, cerebral coma, and aseptic meningitis were the events most often associated with thrombosis. All patients received immunomodulatory therapy (immunoglobulin, dexamethasone/methylprednisolone), pathogenetic therapy for multiorgan failure, anticoagulant therapy with heparin/LMWH, and acetylsalicylic acid. Biologics were used in two patients. Conclusions: The main predictors of thrombosis in children with MIS-C were increased D-dimer, thrombocytopenia, hospitalization in the ICU, and noncardiogenic pulmonary edema. Thrombosis of the deep veins of the lower extremities, large cerebral arteries, and secondary thrombotic microangiopathy was common. There was a single death (12.5% of the eight patients), associated with PE.

SARS-CoV-2 RNA positive pediatric organ donors: A case report

BACKGROUND

Preliminary evidence suggests that non-lung organ donation from resolved, asymptomatic or mildly symptomatic SARS-CoV-2 infected adults may be safe. However, several biological aspects of SARS-CoV-2 infection differ in children and the risk for transmission and outcomes of recipients from pediatric donors with SARS-CoV-2 infection are not well described.

METHODS

We report two unvaccinated asymptomatic pediatric non-lung organ deceased donors who tested positive for SARS-CoV-2 RNA by RT-PCR. Donor One unexpectedly had SARS-CoV-2 RNA detected in nasopharyngeal swab and plasma specimens at autopsy despite several negative tests (upper and lower respiratory tract) in the days prior to organ recovery. Donor Two had SARS-CoV- 2 RNA detected in multiple nasopharyngeal swabs but not lower respiratory tract specimens (endotracheal aspirate and bronchoalveolar lavage) during routine surveillance prior to organ recovery and was managed with remdesivir and monoclonal antibodies prior to organ recovery.

RESULTS

Two hearts, two livers and four kidneys were successfully transplanted into seven recipients. No donor to recipient transmission of SARS-CoV-2 was observed and graft function of all organs has remained excellent for up to 7 months of followup.

CONCLUSIONS

Due to the persistent gap between organ availability and the number of children waiting for transplants, deceased pediatric patients with non-disseminated SARS-CoV-2 infection, isolated to upper and/or lower respiratory tract, should be considered as potential non-lung organ donors.

Investigation of QT Dispersion and T-Peak to T-End/Corrected QT Ratio in Multisystem Inflammatory Syndrome in Children

Introduction Multisystem inflammatory syndrome in children (MIS-C) is characterized by hyperinflammation, heart involvement, and multiorgan failure, which develop following coronavirus disease 2019. Ventricular arrhythmias have been identified during this syndrome. It is known that the risk of ventricular arrhythmia is associated with ventricular repolarization changes. The aim of this study was to investigate the corrected QT interval, QT dispersion, T wave peak-to-end interval, and T-peak to T-end/corrected QT ratio in MIS-C. Methods The study included 35 patients diagnosed with MIS-C and 35 subjects as the control group. The ventricular diameters, ejection fraction, valve insufficiency, and coronary artery were examined in both groups using echocardiography. Corrected QT interval, QT dispersion, T wave peak-to-end interval, and T-peak to T-end/corrected QT ratio were determined by 12-lead electrocardiogram. Results The patient group had increased corrected QT interval (p<0.05), QT dispersion (p = 0.001), T-peak to T-end interval (p=0.001), and T-peak to T-end/corrected QT ratio (p = 0.001) compared to the control group. Moreover, there was a correlation between increased QT dispersion, T-peak to T-end, T-peak to T-end/corrected QT ratio, and decreased ejection fraction (r = -0.51 and p = 0.001, r = -0.71 and p < 0.001, r = -0.69 and p < 0.001, r = -0.56 and p < 0.001, respectively). Conclusions Our study demonstrated increased QTc interval, QT dispersion, T-peak to T-end interval, T-peak to T-end/corrected QT ratio in MIS-C. This result may indicate an increased risk of ventricular arrhythmia for these patients.

Multisystem Inflammatory Syndrome in Children and Kawasaki Disease: A Spectrum of Postinfectious Hyperinflammatory Disease

Kawasaki disease and multisystem inflammatory syndrome in children are hyperinflammatory conditions that share similar emerging pathophysiology hypotheses, clinical features, treatment strategies, and outcomes. Although both conditions have key differences, growing evidence suggests that both conditions might be closely related on a larger spectrum of postinfectious autoimmune responses.

Endothelial Cell Response in Kawasaki Disease and Multisystem Inflammatory Syndrome in Children

Although Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) share some clinical manifestations, their cardiovascular outcomes are different, and this may be reflected at the level of the endothelial cell (EC). We performed RNA-seq on cultured ECs incubated with pre-treatment sera from KD (n = 5), MIS-C (n = 7), and healthy controls (n = 3). We conducted a weighted gene co-expression network analysis (WGCNA) using 935 transcripts differentially expressed between MIS-C and KD using relaxed filtering (unadjusted p < 0.05, >1.1-fold difference). We found seven gene modules in MIS-C, annotated as an increased TNFα/NFκB pathway, decreased EC homeostasis, anti-inflammation and immune response, translation, and glucocorticoid responsive genes and endothelial-mesenchymal transition (EndoMT). To further understand the difference in the EC response between MIS-C and KD, stringent filtering was applied to identify 41 differentially expressed genes (DEGs) between MIS-C and KD (adjusted p < 0.05, >2-fold-difference). Again, in MIS-C, NFκB pathway genes, including nine pro-survival genes, were upregulated. The expression levels were higher in the genes influencing autophagy (UBD, EBI3, and SQSTM1). Other DEGs also supported the finding by WGCNA. Compared to KD, ECs in MIS-C had increased pro-survival transcripts but reduced transcripts related to EndoMT and EC homeostasis. These differences in the EC response may influence the different cardiovascular outcomes in these two diseases.

Predicting Delayed Shock in Multisystem Inflammatory Disease in Children: A Multicenter Analysis From the New York City Tri-State Region

OBJECTIVES

Patients with multisystem inflammatory disease in children (MIS-C) are at risk of developing shock. Our objectives were to determine independent predictors associated with development of delayed shock (≥3 hours from emergency department [ED] arrival) in patients with MIS-C and to derive a model predicting those at low risk for delayed shock.

METHODS

We conducted a retrospective cross-sectional study of 22 pediatric EDs in the New York City tri-state area. We included patients meeting World Health Organization criteria for MIS-C and presented April 1 to June 30, 2020. Our main outcomes were to determine the association between clinical and laboratory factors to the development of delayed shock and to derive a laboratory-based prediction model based on identified independent predictors.

RESULTS

Of 248 children with MIS-C, 87 (35%) had shock and 58 (66%) had delayed shock. A C-reactive protein (CRP) level greater than 20 mg/dL (adjusted odds ratio [aOR], 5.3; 95% confidence interval [CI], 2.4-12.1), lymphocyte percent less than 11% (aOR, 3.8; 95% CI, 1.7-8.6), and platelet count less than 220,000/uL (aOR, 4.2; 95% CI, 1.8-9.8) were independently associated with delayed shock. A prediction model including a CRP level less than 6 mg/dL, lymphocyte percent more than 20%, and platelet count more than 260,000/uL, categorized patients with MIS-C at low risk of developing delayed shock (sensitivity 93% [95% CI, 66-100], specificity 38% [95% CI, 22-55]).

CONCLUSIONS

Serum CRP, lymphocyte percent, and platelet count differentiated children at higher and lower risk for developing delayed shock. Use of these data can stratify the risk of progression to shock in patients with MIS-C, providing situational awareness and helping guide their level of care.