Myocardial involvement in children with post-COVID multisystem inflammatory syndrome: a cardiovascular magnetic resonance based multicenter international study-the CARDOVID registry

Myocarditis in children 2024, new themes and continued questions

PURPOSE OF REVIEW

While pediatric myocarditis incidence has increased since the coronavirus disease 2019 (COVID-19) pandemic, there remain questions regarding diagnosis, risk stratification, and optimal therapy. This review highlights recent publications and continued unanswered questions related to myocarditis in children.

RECENT FINDINGS

Emergence from the COVID-19 era has allowed more accurate description of the incidence and prognosis of myocarditis adjacent to COVID-19 infection and vaccine administration as well that of multi-system inflammatory disease in children (MIS-C). As cardiac magnetic resonance technology has shown increased availability and evidence in pediatric myocarditis, it is important to understand conclusions from adult imaging studies and define the use of this imaging biomarker in children. Precision medicine has begun to allow real-time molecular evaluations to help diagnose and risk-stratify cardiovascular diseases, with emerging evidence of these modalities in myocarditis.

SUMMARY

Recent information regarding COVID-19 associated myocarditis, cardiac magnetic resonance, and molecular biomarkers may help clinicians caring for children with myocarditis and identify needs for future investigations.

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.

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.

Design and implementation of multicenter pediatric and congenital studies with cardiovascular magnetic resonance: Big data in smaller bodies

Cardiovascular magnetic resonance (CMR) has become the reference standard for quantitative and qualitative assessment of ventricular function, blood flow, and myocardial tissue characterization. There is a preponderance of large CMR studies and registries in adults; However, similarly powered studies are lacking for the pediatric and congenital heart disease (PCHD) population. To date, most CMR studies in children are limited to small single or multicenter studies, thereby limiting the conclusions that can be drawn. Within the PCHD CMR community, a collaborative effort has been successfully employed to recognize knowledge gaps with the aim to embolden the development and initiation of high-quality, large-scale multicenter research. In this publication, we highlight the underlying challenges and provide a practical guide toward the development of larger, multicenter initiatives focusing on PCHD populations, which can serve as a model for future multicenter efforts.

Echocardiographic screening in pediatric asymptomatic or paucisymptomatic coronavirus disease 2019 outpatients: is it a useful test or an excess of zeal?

INTRODUCTION

Data regarding echocardiographic findings during follow-up of asymptomatic or pauci-symptomatic coronavirus disease 2019 (COVID-19) are scarce in pediatric patients. The aim of the present study is to assess post-COVID-19 sequelae through echocardiography in children who have experienced mild SARS-CoV-2.

METHODS

This single-center, retrospective, observational study enrolled a cohort of 133 pediatric outpatients, born between 2005 and 2022, with a history of asymptomatic or paucisymptomatic SARS-CoV-2 infection, who underwent transthoracic echocardiographic (TTE) evaluation at an outpatient pediatric clinic in Northern Italy.

RESULTS

The percentage of the pediatric activity of the clinic which was focused on post-COVID evaluation was not negligible, representing almost 10% of the ∼1500 pediatric patients examined from 1 January 2021 to 31 August 2022. According to ACEP classification, children enrolled in this study had previously experienced in 72.9% (97) asymptomatic COVID-19 and nearly 27% (36) a mild illness. Clinical and instrumental examinations did not show any relevant abnormality in the functional [left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery systolic pressure (PASP)] or structural [interventricular septum diameter (IVSd), left ventricular internal diameter (LViD, end-diastolic volume (EDV), left atrium volume (LAV)] parameters examined related to SARS-CoV-2 infection in the total of 133 children.

CONCLUSION

According to our results, children who experienced an asymptomatic or mild SARS-CoV-2 infection should not be systematically investigated with second-level techniques, such as TTE, in the absence of clinical suspicion or other risk conditions such as congenital heart diseases, comorbidities or risk factors.

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.

Cardiac manifestations of MIS-C: cardiac magnetic resonance and speckle-tracking data

Background

Cardiac involvement is central in MIS-C and represents the main cause of morbidity. In this study, we aimed to assess myocardial damage in patients with MIS-C using cardiac magnetic resonance (CMR) during the acute phase, as well as left ventricular and atrial longitudinal strain on admission, at discharge, and after 3 months.

Methods

We performed a single-center prospective cohort study and case-control study. Between September 2020 and February 2022, we enrolled 39 patients hospitalized for MIS-C at our center. We performed left ventricular and atrial longitudinal 2D strain analysis on admission and during follow-up; echocardiographic data were compared to a matched control population. Patients above 4 years old with increased troponin underwent CMR.

Results

Of 24 patients (mean age: 8.2 ± 4.9 years) who underwent CMR, 14 (58%) presented myocardial edema and 6 (25%) late gadolinium enhancement (LGE). LGE was associated with older age (p < 0.01), increased BMI (p = 0.03), increased ferritin levels (p < 0.001), lower left ventricular (LV) ejection fraction (p < 0.001), LV longitudinal strain (p = 0.004), left atrial (LA) strain (p = 0.05), and prolonged hospital stay (p = 0.02). On admission, LV ejection fraction, LV longitudinal strain, and LA strain were impaired, but each improved gradually over time; LVEF was the fastest to recover, while global LV longitudinal strain was still impaired as compared to controls after 3 months (p = 0.01).

Conclusion

Our study demonstrates that myocardial injury is present in a quarter of MIS-C patients, and impaired LA and LV myocardial deformation persist for at least several weeks after the acute phase. CMR and LV/LA strain could help us to individualize follow-up of MIS-C patients.

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.

Exercise testing in patients with multisystem inflammatory syndrome in children-related myocarditis versus idiopathic or viral myocarditis

BACKGROUND

While most children with multisystem inflammatory syndrome in children have rapid recovery of cardiac dysfunction, little is known about the long-term outcomes regarding exercise capacity. We aimed to compare the exercise capacity among patients with multisystem inflammatory syndrome in children versus viral/idiopathic myocarditis at 3-6 months after initial diagnosis.

METHODS

We performed a retrospective cohort study among patients with multisystem inflammatory syndrome in children in June 2020 to May 2021 and patients with viral/idiopathic myocarditis in August 2014 to January 2020. Data from cardiopulmonary exercise test as well as echocardiographic and laboratory data were obtained. Inclusion criteria included diagnosis of multisystem inflammatory syndrome in children or viral/idiopathic myocarditis, exercise test performed within 3-6 months of hospital discharge, and maximal effort on cardiopulmonary exercise test as determined by respiratory exchange ratio >1.10.

RESULTS

Thirty-one patients with multisystem inflammatory syndrome in children and 25 with viral/idiopathic myocarditis were included. The mean percent predicted peak VO2 was 90.84% for multisystem inflammatory syndrome in children patients and 91.08% for those with viral/idiopathic myocarditis (p-value 0.955). There were no statistically significant differences between the groups with regard to percent predicted maximal heart rate, metabolic equivalents, percent predicted peak VO2, percent predicted anerobic threshold, or percent predicted O2 pulse. There was a statistically significant correlation between lowest ejection fraction during hospitalisation and peak VO2 among viral/idiopathic myocarditis patients (r: 0.62, p-value 0.01) but not multisystem inflammatory syndrome in children patients (r: 0.1, p-value 0.6).

CONCLUSIONS

Patients with multisystem inflammatory syndrome in children and viral myocarditis appear to, on average, have normal exercise capacity around 3-6 months following hospital discharge. For patients with viral/idiopathic myocarditis, those with worse ejection fraction during hospitalisation had lower peak VO2 on cardiopulmonary exercise test.

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.

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.

Emerging Insights Into the Pathophysiology of Multisystem Inflammatory Syndrome Associated With COVID-19 in Children

Multisystem inflammatory syndrome in children (MIS-C) has emerged as a rare delayed hyperinflammatory response to SARS-CoV-2 infection and causes severe morbidity in the pediatric age group. Although MIS-C shares many clinical similarities to Kawasaki disease (KD), important differences in epidemiologic, clinical, immunologic, and potentially genetic factors exist and suggest potential differences in pathophysiology and points to be explored and explained. Epidemiologic features include male predominance, peak age of 6 to12 years, and specific racial or ethnicity predilections. MIS-C is characterized by fever, prominent gastrointestinal symptoms, mucocutaneous manifestations, respiratory symptoms, and neurologic complaints, and patients often present with shock. Cardiac complications are frequent and include ventricular dysfunction, valvular regurgitation, pericardial effusion, coronary artery dilation and aneurysms, conduction abnormalities, and arrhythmias. Emerging evidence regarding potential immunologic mechanisms suggest that an exaggerated T-cell response to a superantigen on the SARS-CoV-2 spike glycoprotein-as well as the formation of autoantibodies against cardiovascular, gastrointestinal, and endothelial antigens-are major contributors to the inflammatory milieu of MIS-C. Further studies are needed to determine both shared and distinct immunologic pathway(s) that underlie the pathogenesis of MIS-C vs both acute SARS-CoV-2 infection and KD. There is evidence to suggest that the rare risk of more benign mRNA vaccine-associated myopericarditis is outweighed by a reduced risk of more severe MIS-C. In the current review, we synthesize the published literature to describe associated factors and potential mechanisms regarding an increased risk of MIS-C and cardiac complications, provide insights into the underlying immunologic pathophysiology, and define similarities and differences with KD.

Multisystem inflammatory syndrome in children during the COVID-19 waves: data from the Juvenile Inflammatory Rheumatism cohort

Introduction

Multisystem inflammatory syndrome in children (MIS-C) is a new condition that first appeared in children and adolescents during the COVID-19 pandemic. We aimed to describe the diagnostic course, clinical and biological manifestations, and treatment of MIS-C during the first three COVID-19 waves.

Methods

We extracted patient data from the Juvenile Inflammatory Rheumatism (JIR) cohort. We analyzed data for patients meeting the World Health Organization diagnostic criteria for MIS-C from the start of the COVID-19 pandemic from March 2020 to June 30, 2021. We then compared data for patients in wave one to those in waves two and three.

Results

We identified 136 patients with MIS-C. The median age decreased but not significantly during the waves, from 9.9 years to 7.3 years (p = 0.105). Boys represented 52.2% (n = 71) of patients, and 46% (n = 41) of patients originated from sub-Saharan Africa (p < 0.001). Patients presented less diarrhea (p = 0.004), respiratory distress (p < 0.001), and myocarditis (p < 0.001) with progressive waves. Biological inflammation also decreased, namely, C-reactive protein level (p < 0.001), neutrophil count (p = 0.004), and albumin level (p < 0.001). Patients received more corticosteroids (p < 0.001) and required less ventilation support (p < 0.01) and less inotrope treatment (p < 0.001) in the later waves. The duration of hospitalization gradually decreased (p < 0.001), as did critical care unit admissions (p = 0.002).

Conclusion

Over the three COVID-19 waves, with a change in the management of MIS-C, children in the JIR cohort in France showed a less severe disease course, in particular, a greater use of corticosteroids. This observation may reflect the impact of both improved management and different SARS-CoV-2 variant.

Multimodality Cardiac Imaging in COVID

Infection with SARS-CoV-2, the virus that causes COVID, is associated with numerous potential secondary complications. Global efforts have been dedicated to understanding the myriad potential cardiovascular sequelae which may occur during acute infection, convalescence, or recovery. Because patients often present with nonspecific symptoms and laboratory findings, cardiac imaging has emerged as an important tool for the discrimination of pulmonary and cardiovascular complications of this disease. The clinician investigating a potential COVID-related complication must account not only for the relative utility of various cardiac imaging modalities but also for the risk of infectious exposure to staff and other patients. Extraordinary clinical and scholarly efforts have brought the international medical community closer to a consensus on the appropriate indications for diagnostic cardiac imaging during this protracted pandemic. In this review, we summarize the existing literature and reference major societal guidelines to provide an overview of the indications and utility of echocardiography, nuclear imaging, cardiac computed tomography, and cardiac magnetic resonance imaging for the diagnosis of cardiovascular complications of COVID.

Cardiovascular magnetic resonance for evaluation of cardiac involvement in COVID-19: recommendations by the Society for Cardiovascular Magnetic Resonance

Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic that has affected nearly 600 million people to date across the world. While COVID-19 is primarily a respiratory illness, cardiac injury is also known to occur. Cardiovascular magnetic resonance (CMR) imaging is uniquely capable of characterizing myocardial tissue properties in-vivo, enabling insights into the pattern and degree of cardiac injury. The reported prevalence of myocardial involvement identified by CMR in the context of COVID-19 infection among previously hospitalized patients ranges from 26 to 60%. Variations in the reported prevalence of myocardial involvement may result from differing patient populations (e.g. differences in severity of illness) and the varying intervals between acute infection and CMR evaluation. Standardized methodologies in image acquisition, analysis, interpretation, and reporting of CMR abnormalities across would likely improve concordance between studies. This consensus document by the Society for Cardiovascular Magnetic Resonance (SCMR) provides recommendations on CMR imaging and reporting metrics towards the goal of improved standardization and uniform data acquisition and analytic approaches when performing CMR in patients with COVID-19 infection.

Natural Course of COVID-19 and Independent Predictors of Mortality

BACKGROUND

During the SARS-CoV-2 pandemic, several biomarkers were shown to be helpful in determining the prognosis of COVID-19 patients. The aim of our study was to evaluate the prognostic value of N-terminal pro-Brain Natriuretic Peptide (NT-pro-BNP) in a cohort of patients with COVID-19.

METHODS

One-hundred and seven patients admitted to the Covid Hospital of Messina University between June 2022 and January 2023 were enrolled in our study. The demographic, clinical, biochemical, instrumental, and therapeutic parameters were recorded. The primary outcome was in-hospital mortality. A comparison between patients who recovered and were discharged and those who died during the hospitalization was performed. The independent parameters associated with in-hospital death were assessed by multivariable analysis and a stepwise regression logistic model.

RESULTS

A total of 27 events with an in-hospital mortality rate of 25.2% occurred during our study. Those who died during hospitalization were older, with lower GCS and PaO2/FiO2 ratio, elevated D-dimer values, INR, creatinine values and shorter PT (prothrombin time). They had an increased frequency of diagnosis of heart failure (p < 0.0001) and higher NT-pro-BNP values. A multivariate logistic regression analysis showed that higher NT-pro-BNP values and lower PT and PaO2/FiO2 at admission were independent predictors of mortality during hospitalization.

CONCLUSIONS

This study shows that NT-pro-BNP levels, PT, and PaO2/FiO2 ratio are independently associated with in-hospital mortality in subjects with COVID-19 pneumonia. Further longitudinal studies are warranted to confirm the results of this study.

Ventricular function and tissue characterization by cardiac magnetic resonance imaging following hospitalization for multisystem inflammatory syndrome in children: a prospective study

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a severe life-threatening manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that often presents with acute cardiac dysfunction and cardiogenic shock. While recovery from acute illness is excellent, the long-term myocardial impact is unknown.

OBJECTIVE

To compare cardiac MRI findings in children 6-9 months after their hospitalization with MIS-C against MRI findings in healthy controls to assess for residual myocardial disease.

MATERIALS AND METHODS

We prospectively performed cardiac MRI on 13 children 6-9 months following their hospitalization with MIS-C: eight of these children had a history of left ventricle ejection fraction (LVEF) < 50%, persistent symptoms, or electrocardiogram (ECG) abnormalities and underwent clinical MRI; five of these children without cardiac abnormalities during their hospitalization underwent research MRIs. We compared their native T1 and T2 mapping values with those of 20 normal controls.

RESULTS

Cardiac MRI was performed at 13.6 years of age (interquartile range [IQR] 11.9-16.4 years) and 8.2 months (IQR 6.8-9.6 months) following hospitalization. Twelve children displayed normal ejection fraction: left ventricle (LV) 57.2%, IQR 56.1-58.4; right ventricle (RV) 53.1%, IQR 52.0-55.7. One had low-normal LVEF (52%). They had normal extracellular volume (ECV) and normal T2 and native T1 times compared to controls. There was no qualitative evidence of edema. One child had late gadolinium enhancement (LGE) with normal ejection fraction, no edema, and normal T1 and T2 times. When stratifying children who had MIS-C according to history of LVEF <55% on echocardiography, there was no difference in MRI values.

CONCLUSION

Although many children with MIS-C present acutely with cardiac dysfunction, residual myocardial damage 6-9 months afterward appears minimal. Long-term implications warrant further study.

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.

2021-2022 state of our JCMR

In 2021, there were 136 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR), including 122 original research papers, six reviews, four technical notes, one Society for Cardiovascular Magnetic Resonance (SCMR) guideline, one SCMR position paper, one study protocol, and one obituary (Nathaniel Reichek). The volume was up 53% from 2020 (n = 89) with a corresponding 21% decrease in manuscript submissions from 435 to 345. This led to an increase in the acceptance rate from 24 to 32%. The quality of the submissions continues to be high. The 2021 JCMR Impact Factor (which is released in June 2022) markedly increased from 5.41 to 6.90 placing us in the top quartile of Society and cardiac imaging journals. Our 5 year impact factor similarly increased from 6.52 to 7.25. Fifteen years ago, the JCMR was at the forefront of medical and medical society journal migration to the Open-Access format. The Open-Access system has dramatically increased the availability and JCMR citation. Full-text article requests in 2021 approached 1.5 M!. As I have mentioned, it takes a village to run a journal. JCMR is very fortunate to have a group of very dedicated Associate Editors, Guest Editors, Journal Club Editors, and Reviewers. I thank each of them for their efforts to ensure that the review process occurs in a timely and responsible manner. These efforts have allowed the JCMR to continue as the premier journal of our field. My role, and the entire editorial process would not be possible without the ongoing high dedication and efforts of our managing editor, Jennifer Rodriguez. Her premier organizational skills have allowed for streamlining of the review process and marked improvement in our time-to-decision (see later). As I conclude my 6th and final year as your editor-in-chief, I thank you for entrusting me with the JCMR editorship and appreciate the time I have had at the helm. I am very confident that our Journal will reach new heights under the stewardship of Dr. Tim Leiner, currently at the Mayo Clinic with a seamless transition occurring as I write this in late November. I hope that you will continue to send your very best, high quality CMR manuscripts to JCMR, and that our readers will continue to look to JCMR for the very best/state-of-the-art CMR publications.

Most Common Long COVID Physical Symptoms in Working Age Adults Who Experienced Mild COVID-19 Infection: A Scoping Review

BACKGROUND

One-third of patients who recover from COVID-19 present with long COVID. Their symptoms are broad, affecting their physical functioning and, ultimately, their quality of life. Many of those individuals who develop long COVID, possibly from a mild COVID-19 infection, are in the 18-65 age group. This prolongation of malaise directly influences national workforce economies.

OBJECTIVES

To summarise the commonly reported physical symptoms of long COVID in order to inform potential adjustments in healthcare for the employable population.

METHODS

The Embase, CINAHL, Medline, SCOPUS, and WHO COVID-19 databases were searched. The study selection process was based on the PRISMA guidelines. The extracted data were synthesised and presented narratively.

RESULTS

7403 studies were accessed, comprising 60 cohort studies and 10 case series/studies, representing 289,213 patients who met our criteria. The most frequently reported physical symptoms were fatigue (92%), shortness of breath (SOB) (81.8%), muscle pain (43.6%), and joint pain (34.5%).

CONCLUSIONS

The range of reported physical symptoms was broad and varied; the main ones being fatigue, breathlessness/SOB, and pain. Similarities observed between long COVID and other post-acute infection syndromes may help formulate protocols to manage and promote recovery for long COVID patients. Inconsistencies were evident, particularly with a lack of adherence to the standardised definitions of long COVID.

Role of SARS-CoV-2-induced Cytokine Storm in Multi-Organ Failure: Molecular Pathways and Potential Therapeutic Options

Coronavirus disease 2019 (COVID-19) outbreak has become a global public health emergency and has led to devastating results. Mounting evidence proposes that the disease causes severe pulmonary involvement and influences different organs, leading to a critical situation named multi-organ failure. It is yet to be fully clarified how the disease becomes so deadly in some patients. However, it is proven that a condition called “cytokine storm” is involved in the deterioration of COVID-19. Although beneficial, sustained production of cytokines and overabundance of inflammatory mediators causing cytokine storm can lead to collateral vital organ damages. Furthermore, cytokine storm can cause post-COVID-19 syndrome (PCS), an important cause of morbidity after the acute phase of COVID-19. Herein, we aim to explain the possible pathophysiology mechanisms involved in COVID-19-related cytokine storm and its association with multi-organ failure and PCS. We also discuss the latest advances in finding the potential therapeutic targets to control cytokine storm wishing to answer unmet clinical demands for treatment of COVID-19.

Age-adjusted NT-proBNP could help in the early identification and follow-up of children at risk for severe multisystem inflammatory syndrome associated with COVID-19 (MIS-C)

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) has emerged as a new disease associated with COVID-19 that presents in acute critically ill children with acute cardiovascular dysfunction.

AIM

To determine whether the age-adjusted N-terminal pro-brain natriuretic peptide (NT-proBNP) value (Z-log-NT-proBNP) is associated with severe MIS-C and myocardial dysfunction.

METHODS

A retrospective study was conducted which included children with MIS-C managed at our institution between April 1, 2020, and February 28, 2022. We divided the population into groups depending on severity based on pediatric intensive care unit (PICU) admission. We compared Z-log-NT-proBNP values across these groups and analyzed Z-log-NT-proBNP dynamics during the one-month follow-up.

RESULTS

We included 17 participants [median age 3 (2-9) years] and seven (41%) required PICU admission. All (100%) of these cases presented very high (Z-log > 4) levels of NT-proBNP at the time of admission compared to only 5 (50%) patients with non-severe MIS-C (P = 0.025). NT-proBNP was significantly correlated with high-sensitive Troponin I levels (P = 0.045), Ross modified score (P = 0.003) and left ventricle ejection fraction (P = 0.021).

CONCLUSION

Raised NT-proBNP, specifically very high values (Z-log-NT-proBNP > 4) could help in the early identification of MIS-C patients with myocardial dysfunction requiring inotropic support and PICU admission.

Parametric Mapping Cardiac Magnetic Resonance Imaging for the Diagnosis of Myocarditis in Children in the Era of COVID-19 and MIS-C

Myocarditis comprises many clinical presentations ranging from asymptomatic to sudden cardiac death. The history, physical examination, cardiac biomarkers, inflammatory markers, and electrocardiogram are usually helpful in the initial assessment of suspected acute myocarditis. Echocardiography is the primary tool to detect ventricular wall motion abnormalities, pericardial effusion, valvular regurgitation, and impaired function. The advancement of cardiac magnetic resonance (CMR) imaging has been helpful in clinical practice for diagnosing myocarditis. A recent Scientific Statement by the American Heart Association suggested CMR as a confirmatory test to diagnose acute myocarditis in children. However, standard CMR parametric mapping parameters for diagnosing myocarditis are unavailable in pediatric patients for consistency and reliability in the interpretation. The present review highlights the unmet clinical needs for standard CMR parametric criteria for diagnosing acute and chronic myocarditis in children and differentiating dilated chronic myocarditis phenotype from idiopathic dilated cardiomyopathy. Of particular relevance to today’s practice, we also assess the potential and limitations of CMR to diagnose acute myocarditis in children exposed to severe acute respiratory syndrome coronavirus-2 infections. The latter section will discuss the multi-inflammatory syndrome in children (MIS-C) and mRNA coronavirus disease 19 vaccine-associated myocarditis.

Ventricular Function and Tissue Characterization By Cardiac MRI in Children Following Hospitalization for Multisystem Inflammatory Syndrome in Children (MIS-C): A Prospective Study

Background Multisystem Inflammatory Syndrome in Children (MIS-C) is a severe life-threatening manifestation of SARS-CoV-2 infection. Acute cardiac dysfunction and resultant cardiogenic shock are common in children with MIS-C. While most children recover rapidly from acute illness, the long-term impact on the myocardium and cardiac function is unknown. Methods In this prospective study, cardiac MRI (CMR) was performed on patients <21 years of age with a history of MIS-C, 6-9 months following hospitalization. Per institutional protocol, patients with any history of LVEF<50%, persistent cardiorespiratory symptoms, or ECG abnormalities underwent clinical CMR. Research CMRs were offered to all others >10 years old. Native T1 and T2 mapping values were compared with 20 children with normal CMR examinations. Results We performed CMRs on 13 subjects at a median age of 13.6 years (interquartile range [IQR] 11.9-16.0) and a median time from hospitalization of 8.2 months (IQR 6.8-9.6). Twelve subjects displayed normal ventricular function with a median left ventricle ejection fraction (LVEF) of 57.2% (IQR 56.1-58.4) and median right ventricular (RV) EF of 53.1% (IQR 52.0-55.7). One subject had low normal EF (52%). There was normal T2 and native T1 as compared to normal controls. There was qualitatively no evidence of edema by T2 weighted imaging. One subject had late gadolinium enhancement (LGE) at the inferior insertion point and mid-ventricular inferolateral region, with normal EF, no evidence of edema or perfusion defects, and normal T1 and T2 times. When stratifying by a history of abnormal LVEF (LVEF <55%) on echocardiography, there was no difference in or parametric mapping values, though LVEF and LVEDV approached significance (p=0.06 and 0.05, respectively). Conclusions Although many children with MIS-C present acutely with cardiac dysfunction, myocardial recovery is overall excellent with minimal to no evidence of residual cardiac dysfunction or myocardial involvement. LVEF by CMR at 6-9 months among children with history of echocardiographic LV dysfunction is slightly lower, though does not meet statistical significance and is still within normal range. The long-term functional implications of this finding and the cardiac implications of MIS-C more broadly are unclear and warrant further study.

Outpatient monitoring of patients with multisystem inflammatory syndrome (MIS-C): A mini review

INTRODUCTION

As we learn more about the novel multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 infection, the protocols for long-term follow-up have evolved and only some of these protocols have been published. Here, we review the current literature on follow-up guidelines in MIS-C patients.

METHODS

We conducted a PUBMED search of all articles published on "MIS-C" and the term "follow-up" between 2020 and 2022. Inclusion criteria were that (1) the study was an observational study or case series, and (2) the study population included pediatric population who met the diagnostic criteria for MIS-C.

RESULTS

There were 206 publications on MIS-C and follow-up in the last 2 years with 11 studies that fit the inclusion criteria. These papers were representing 11 different centers and encompassed a total of 343 participants. Seven of the 11 studies had participants follow-up with their cardiologist within 1 month of discharge. Between 12% and 62% of patients within each study had depressed left ventricular ejection fraction (LVEF) at admission. At the initial follow-up visit, five studies showed a normal LVEF in all patients while the other seven studies showed 2%-13% patients continuing to have depressed LVEF. In eight of the 11 studies, 9%-52% of patients had coronary artery dilation at admission. At their initial follow-up visit, 3%-28% of patients continued to have coronary artery dilation.

CONCLUSION

There is some institutional variation in the outpatient follow-up protocols in patients diagnosed with MIS-C. A standardized follow-up guidelines might be helpful to monitor long-term prognosis of these patients.

Long-COVID Syndrome and the Cardiovascular System: A Review of Neurocardiologic Effects on Multiple Systems

PURPOSE OF REVIEW

Long-COVID syndrome is a multi-organ disorder that persists beyond 12 weeks post-acute SARS-CoV-2 infection (COVID-19). Here, we provide a definition for this syndrome and discuss neuro-cardiology involvement due to the effects of (1) angiotensin-converting enzyme 2 receptors (the entry points for the virus), (2) inflammation, and (3) oxidative stress (the resultant effects of the virus).

RECENT FINDINGS

These effects may produce a spectrum of cardio-neuro effects (e.g., myocardial injury, primary arrhythmia, and cardiac symptoms due to autonomic dysfunction) which may affect all systems of the body. We discuss the symptoms and suggest therapies that target the underlying autonomic dysfunction to relieve the symptoms rather than merely treating symptoms. In addition to treating the autonomic dysfunction, the therapy also treats chronic inflammation and oxidative stress. Together with a full noninvasive cardiac workup, a full assessment of the autonomic nervous system, specifying parasympathetic and sympathetic (P&S) activity, both at rest and in response to challenges, is recommended. Cardiac symptoms must be treated directly. Cardiac treatment is often facilitated by treating the P&S dysfunction. Cardiac symptoms of dyspnea, chest pain, and palpitations, for example, need to be assessed objectively to differentiate cardiac from neural (autonomic) etiology. Long-term myocardial injury commonly involves P&S dysfunction. P&S assessment usually connects symptoms of Long-COVID to the documented autonomic dysfunction(s).

Cardiovascular Magnetic Resonance in Children with Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19: Institutional Protocol-Based Medium-Term Follow-up Study

Multisystem inflammatory syndrome in children (MIS-C) secondary to COVID-19 infection in previously healthy children often results in subtle but persistent echocardiographic abnormalities despite complete clinical recovery. This study was done to investigate medium-term cardiovascular outcomes of patients with MIS-C using cardiovascular magnetic resonance imaging (CMR). This is a single-center retrospective study of patients aged less than 21 years, diagnosed with MIS-C who received an outpatient CMR, around 6 months after discharge. CMR was done in patients with significant troponin leak or depressed LVEF. CMR performed on a GE Signa HDxt 1.5 Tesla magnet with a myocarditis protocol. Diagnosis of myocarditis was determined by the original Lake Louise Criteria. There were 21 patients with a median age of 11 years, (IQR 8-13 years), who underwent CMR at median follow-up duration of 6 months (IQR 5-7 months). At the peak of illness during admission, there were 95.2% patients with abnormal Troponin I and BNP. By echocardiogram, 76.2% had left ventricular systolic dysfunction and 9.5% had coronary ectasia, which all resolved by 6 months. By CMR, there were five patients (23.8%) with abnormal left atrial volume, one patient (4.8%) with an abnormal indexed left ventricular end-diastolic volume, and three patients (15%) with abnormal LVEF. There was no evidence of myocardial edema in T2-weighted image sequence. There were three patients with persistent late gadolinium enhancement (14.3%). Follow-up CMR is a useful tool in diagnosing subtle myocardial abnormalities and guide necessity for future follow-up.