Cardiac Biomarkers Aid in Differentiation of Kawasaki Disease from Multisystem Inflammatory Syndrome in Children Associated with COVID-19.

Kawasaki disease (KD) and Multisystem Inflammatory Syndrome in Children (MIS-C) associated with COVID-19 show clinical overlap and both lack definitive diagnostic testing, making differentiation challenging. We sought to determine how cardiac biomarkers might differentiate KD from MIS-C. The International Kawasaki Disease Registry enrolled contemporaneous KD and MIS-C pediatric patients from 42 sites from January 2020 through June 2022. The study population included 118 KD patients who met American Heart Association KD criteria and compared them to 946 MIS-C patients who met 2020 Centers for Disease Control and Prevention case definition. All included patients had at least one measurement of amino-terminal prohormone brain natriuretic peptide (NTproBNP) or cardiac troponin I (TnI), and echocardiography. Regression analyses were used to determine associations between cardiac biomarker levels, diagnosis, and cardiac involvement. Higher NTproBNP (≥ 1500 ng/L) and TnI (≥ 20 ng/L) at presentation were associated with MIS-C versus KD with specificity of 77 and 89%, respectively. Higher biomarker levels were associated with shock and intensive care unit admission; higher NTproBNP was associated with longer hospital length of stay. Lower left ventricular ejection fraction, more pronounced for MIS-C, was also associated with higher biomarker levels. Coronary artery involvement was not associated with either biomarker. Higher NTproBNP and TnI levels are suggestive of MIS-C versus KD and may be clinically useful in their differentiation. Consideration might be given to their inclusion in the routine evaluation of both conditions.

Access to Care and Therapy for Kawasaki Disease in the Arab Countries: A Kawasaki Disease Arab Initiative (Kawarabi) Multicenter Survey.

Kawasaki Disease (KD) is still the most common acquired heart disease in children below the age of five years; it has been well described in the developed world; however, data from the Arab world are limited to case reports or single-center case series. In an effort of optimizing KD research in the Arab world, a group of physicians and researchers established the KD Arab Initiative (Kawarabi) in 2021, and published the first survey, which showed disparities in the availability of intravenous immunoglobulin (IVIG); this had prompted Kawarabi to assess the access to care and therapy of KD patients in Arab countries. A 32 structured questions survey was conducted in thirteen Arab countries and addressed KD patients' access to healthcare in urban and rural settings. The survey results showed that access to care was uniform across large, mid-size cities and rural areas in 7/13 (54%) countries, while in 6/13 (46%) countries, it was in favor of large and mid-size cities over rural areas. The quality of medical services received by children with KD in large cities was rated as excellent in 6/13 or good in 7/13 countries compared to fair in 4/13 or poor in 4/13 countries in rural areas. Availability of IVIG was limited (23%) in mid-size cities and almost impossible (23%) in rural areas. The KD patients in mid-size cities and rural areas have limited access to standard healthcare in the Arab world. This survey laid the foundation for future Kawarabi endeavors to improve the care of children with KD.

Etanercept with IVIg for acute Kawasaki disease: a long-term follow-up on the EATAK trial.

BACKGROUND: The Etanercept as Adjunctive Treatment for Acute Kawasaki Disease, a phase-3 clinical trial, showed that etanercept reduced the prevalence of IVIg resistance in acute Kawasaki disease. In patients who presented with coronary artery involvement, it reduced the maximal size and short-term progression of coronary artery dilation. Following up with this patient group, we evaluated the potential long-term benefit of etanercept for coronary disease. METHODS: Patients were followed for at least 1 year after the trial. The size of dilated arteries (z-score ≥ 2.5) was measured at each follow-up visit. The z-score and size change from baseline were evaluated at each visit and compared between patients who received etanercept versus placebo at the initial trial. RESULTS: Forty patients who received etanercept (22) or placebo (18) in the Etanercept as Adjunctive Treatment for Acute Kawasaki Disease trial were included. All patients showed a persistent decrease in coronary artery size measurement: 23.3 versus 5.9% at the 6-month visit, 24 versus 13.1% at the 1-year visit, and 20.8 versus 19.3% at the ≥ 2-year visit for etanercept or placebo, respectively, with similar results for decrease in coronary artery z-scores. In a multivariate analysis, correcting for patients' growth, a greater size reduction for patients on the etanercept arm versus placebo was proved significant for the 6-month (p = 0.005) and the 1-year visits (p = 0.019) with a similar end outcome at the ≥ 2-year visit. DISCUSSION: Primary adjunctive therapy with etanercept for children with acute Kawasaki disease does not change the end outcome of coronary artery disease but may promote earlier resolution of artery dilation.

Variation in Pharmacologic Management of Patients with Kawasaki Disease with Coronary Artery Aneurysms.

OBJECTIVE: To evaluate practice variation in pharmacologic management in the International Kawasaki Disease Registry (IKDR). STUDY DESIGN: Practice variation in intravenous immunoglobulin (IVIG) therapy, anti-inflammatory agents, statins, beta-blockers, antiplatelet therapy, and anticoagulation was described. RESULTS: We included 1627 patients from 30 IKDR centers with maximum coronary artery aneurysm (CAA) z scores 2.5-4.99 in 848, 5.0-9.99 in 349, and ≥10.0 (large/giant) in 430 patients. All centers reported IVIG and acetylsalicylic acid (ASA) as primary therapy and use of additional IVIG or steroids as needed. In 23 out of 30 centers, (77%) infliximab was also used; 11 of these 23 centers reported using it in <10% of their patients, and 3 centers used it in >20% of patients. Nonsteroidal anti-inflammatory agents were used in >10% of patients in only nine centers. Beta-blocker (8.8%, all patients) and abciximab (3.6%, all patients) were mainly prescribed in patients with large/giant CAAs. Statins (2.7%, all patients) were mostly used in one center and only in patients with large/giant CAAs. ASA was the primary antiplatelet modality for 99% of patients, used in all centers. Clopidogrel (18%, all patients) was used in 24 centers, 11 of which used it in >50% of their patients with large/giant CAAs. CONCLUSIONS: In the IKDR, IVIG and ASA therapy as primary therapy is universal with common use of a second dose of IVIG for persistent fever. There is practice variation among centers for adjunctive therapies and anticoagulation strategies, likely reflecting ongoing knowledge gaps. Randomized controlled trials nested in a high-quality collaborative registry may be an efficient strategy to reduce practice variation.

Kawasaki Disease Arab Initiative [Kawarabi]: Establishment and Results of a Multicenter Survey.

Studies on Kawasaki disease (KD) in Arab countries are scarce, often providing incomplete data. This along with the benefits of multicenter research collaboratives led to the creation of the KD Arab Initiative [Kawarabi] consortium. An anonymous survey was completed among potential collaborative Arab medical institutions to assess burden of KD in those countries and resources available to physicians. An online 32-item survey was distributed to participating institutions after conducting face validity. One survey per institution was collected. Nineteen physicians from 12 countries completed the survey representing 19 out of 20 institutions (response rate of 95%). Fifteen (79%) institutions referred to the 2017 American Heart Association guidelines when managing a patient with KD. Intravenous immunoglobulin (IVIG) is not readily available at 2 institutions (11%) yet available in the country. In one center (5%), IVIG is imported on-demand. The knowledge and awareness among countries' general population was graded (0 to 10) at median/interquartiles (IQR) 3 (2-5) and at median/IQR 7 (6-8) in the medical community outside their institution. Practice variations in KD management and treatment across Arab countries require solid proactive collaboration. The low awareness and knowledge estimates about KD among the general population contrasted with a high level among the medical community. The Kawarabi collaborative will offer a platform to assess disease burden of KD, among Arab population, decrease practice variation and foster population-based knowledge.

Impact of Z score system on the management of coronary artery lesions in Kawasaki disease.

BACKGROUND: Coronary artery aneurysms are well-described in Kawasaki disease and the Multisystem Inflammatory Syndrome in Children and are graded using Z scores. Three Z score systems (Boston, Montreal, and DC) are widely used in North America. The recent Pediatric Heart Network Z score system is derived from the largest diverse sample to-date. The impact of Z score system on the rate of coronary dilation and management was assessed in a large real-world dataset. METHODS: Using a combined dataset of patients with acute Kawasaki disease from the Children's Hospital at Montefiore and the National Heart, Lung, and Blood Institute Kawasaki Disease Study, coronary Z scores and the rate of coronary lesions (Z ≥ 2.0) and aneurysms (Z ≥ 2.5) were determined using four Z score systems. Agreement among Z scores and the effect on Kawasaki management were assessed. RESULTS: Of 333 patients analysed, 136 were from Montefiore and 197 from the Kawasaki Disease Study. Age, sex, body surface area, and rate of coronary lesions did not differ between the samples. Among the four Z score systems, the rate of acute coronary lesions varied from 24 to 55%. The mean left anterior descending Z scores from Pediatric Heart Network and Boston had a large uniform discrepancy of 1.3. Differences in Z scores among the four systems may change anticoagulation management in up to 22% of a Kawasaki population. CONCLUSIONS: Choice of Z score system alone may impact Kawasaki disease diagnosis and management. Further research is necessary to determine the ideal coronary Z score system.

Multisystem Inflammatory Syndrome in Children: Survey of Protocols for Early Hospital Evaluation and Management.

OBJECTIVE: To describe the similarities and differences in the evaluation and treatment of multisystem inflammatory syndrome in children (MIS-C) at hospitals in the US. STUDY DESIGN: We conducted a cross-sectional survey from June 16 to July 16, 2020, of US children's hospitals regarding protocols for management of patients with MIS-C. Elements included characteristics of the hospital, clinical definition of MIS-C, evaluation, treatment, and follow-up. We summarized key findings and compared results from centers in which >5 patients had been treated vs those in which ≤5 patients had been treated. RESULTS: In all, 40 centers of varying size and experience with MIS-C participated in this protocol survey. Overall, 21 of 40 centers required only 1 day of fever for MIS-C to be considered. In the evaluation of patients, there was often a tiered approach. Intravenous immunoglobulin was the most widely recommended medication to treat MIS-C (98% of centers). Corticosteroids were listed in 93% of protocols primarily for moderate or severe cases. Aspirin was commonly recommended for mild cases, whereas heparin or low molecular weight heparin were to be used primarily in severe cases. In severe cases, anakinra and vasopressors frequently were recommended; 39 of 40 centers recommended follow-up with cardiology. There were similar findings between centers in which >5 patients vs ≤5 patients had been managed. Supplemental materials containing hospital protocols are provided. CONCLUSIONS: There are many similarities yet key differences between hospital protocols for MIS-C. These findings can help healthcare providers learn from others regarding options for managing MIS-C.

Association of Anemia and Blood Pressure With Novel Markers of Diastolic Function in Pediatric Sickle Cell Disease.

Diastolic dysfunction is a known cause of mortality in adults with sickle cell disease (SCD). Left atrial function (LAf) and strain (LAS) are novel echocardiographic parameters to assess early diastolic dysfunction, which have not been assessed in pediatric SCD. Through a retrospective single-center study, we describe echocardiographic parameters of diastology in children with SCD and evaluate their relationship with clinical variables including anemia and blood pressure. Baseline clinical data, 24-hour ambulatory blood pressure monitoring data and echocardiography results were collected. LAf and LAS were measured using volumetric data and speckle-tracking echocardiography, respectively. Sixty-seven children with SCD (13.5±7 y, 47% male, 7% hypertensive) with a mean hemoglobin of 8.8±1.3 g/dL, LAf of 61±8% (n=53) and LAS of 46.3±7.4% (n=28) were included. LAS was significantly associated with hemoglobin (ρ=0.43, P=0.022) but not with maximal left atrial (LA) volume (ρ=-0.05, P=0.79) or any blood pressure parameters. On multivariate analysis, LAS decreased by 3.2% (1.3, 5.1) and LA volume increased by 1.6 mL/m2 (3.1, 0.08) for every 1 g/dL decrease in hemoglobin. Thus, severity of baseline anemia in pediatric SCD correlates with diastolic function as measured by LAS, independent of LA dilation.

Comparison Between Currently Recommended Long-Term Medical Management of Coronary Artery Aneurysms After Kawasaki Disease and Actual Reported Management in the Last Two Decades.

In the 2017 American Heart Association (AHA) Kawasaki disease (KD) guidelines, risk levels (RLs) for long-term management are defined by both maximal and current coronary artery (CA) dimensions normalized as z-scores. We sought to determine the degree to which current recommended practice differs from past actual practice, highlighting areas for knowledge translation efforts. The International KD Registry (IKDR) included 1651 patients with CA aneurysms (z-score > 2.5) from 1999 to 2016. Patients were classified by AHA RL using maximum CA z-score (RL 3 = small, RL 4 = medium, RL 5 = large/giant) and subcategorized based on decreases over time. Medical management provided was compared to recommendations. Low-dose acetylsalicylic acid (ASA) use ranged from 86 (RL 3.1) to 95% (RL 5.1) for RLs where use was "indicated." Dual antiplatelet therapy (ASA + clopidogrel) use ranged from 16% for RL 5.2 to 9% for RL 5.4. Recommended anticoagulation (warfarin or low molecular weight heparin) use was 65% for RL 5.1, while 12% were on triple therapy (anticoagulation + dual antiplatelet). Optional statin use ranged from 2 to 8% depending on RL. Optional beta-blocker use was 2-25% for RL 5, and 0-5% for RLs 3 and 4 where it is not recommended. Generally, past practice was consistent with the latest AHA guidelines, taking into account the flexible wording of recommendations based on the limited evidence, as well as unmeasured patient-specific factors. In addition to strengthening the overall evidence base, knowledge translation efforts may be needed to address variation in thromboprophylaxis management.

Physician variation in ordering of transthoracic echocardiography in outpatient pediatric cardiac clinics.

BACKGROUND: The pediatric Appropriate Use Criteria (AUC) for outpatient transthoracic echocardiography (TTE) aim to reduce practice variation. Little is known on variation in TTE use between physicians. Understanding this variation will help identify areas for improvement in standardization of TTE use. METHODS AND RESULTS: This is a retrospective review of initial outpatient visits at 6 pediatric cardiology centers in the United States prior to AUC release. Variation in TTE use was examined using multilevel generalized mixed effects models. Forward selection identified combinations of variables that explained the most variance in TTE use between physicians. Due to collinearity, physician compensation model and center were analyzed separately. Of 2883 encounters, the most common indication was murmur (36%), followed by chest pain (15.2%). Overall TTE use was 41.9%, and varied widely between centers (22.9%-52.6%), and between physicians within centers. Center alone explained 29% of this physician variance. Adding physician characteristics increased the variance explained to 57%, which only minimally improved by adding patient characteristics. The variance explained was driven by subspecialty. The center-based multivariable model explained more variance over compensation model. CONCLUSIONS: Center was the single largest determinant of physician variance in TTE use, followed by physician subspecialty. Efforts to reduce practice variation, such as the AUC, should be employed across centers and all pediatric cardiac providers. Center appears to have a stronger impact on variance than compensation model, though in this dataset the effect of center and compensation are hard to separate from each other and deserve further evaluation.

Application of Virtual Three-Dimensional Models for Simultaneous Visualization of Intracardiac Anatomic Relationships in Double Outlet Right Ventricle.

Our goal was to construct three-dimensional (3D) virtual models to allow simultaneous visualization of the ventricles, ventricular septal defect (VSD) and great arteries in patients with complex intracardiac anatomy to aid in surgical planning. We also sought to correlate measurements from the source cardiac magnetic resonance (CMR) image dataset and the 3D model. Complicated ventriculo-arterial relationships in patients with complex conotruncal malformations make preoperative assessment of possible repair pathways difficult. Patients were chosen with double outlet right ventricle for the complexity of intracardiac anatomy and potential for better delineation of anatomic spatial relationships. Virtual 3D models were generated from CMR 3D datasets. Measurements were made on the source CMR as well as the 3D model for the following structures: aortic diameter in orthogonal planes, VSD diameter in orthogonal planes and long axis of right ventricle. A total of six patients were identified for inclusion. The path from the ventricles to each respective outflow tract and the location of the VSD with respect to each great vessel was visualized clearly in all patients. Measurements on the virtual model showed excellent correlation with the source CMR when all measurements were included by Pearson coefficient, r = 0.99 as well as for each individual structure. Construction of virtual 3D models in patients with complex conotruncal defects from 3D CMR datasets allows for simultaneous visualization of anatomic relationships relevant for surgical repair. The availability of these models may allow for a more informed preoperative evaluation in these patients.

Consensus-Based Development of a Pediatric Echocardiography Complexity Score: Design, Rationale, and Results of a Quality Improvement Collaborative.

BACKGROUND: The complexity of congenital heart disease has been primarily stratified on the basis of surgical technical difficulty, specific diagnoses, and associated outcomes. We report on the refinement and validation of a pediatric echocardiography complexity (PEC) score. METHODS AND RESULTS: The American College of Cardiology Quality Network assembled a panel from 12 centers to refine a previously published PEC score developed in a single institution. The panel refined complexity categories and included study modifiers to account for complexity related to performance of the echocardiogram. Each center submitted data using the PEC scoring tool on 15 consecutive inpatient and outpatient echocardiograms. Univariate and multivariate analyses were performed to assess for independent predictors of longer study duration. Among the 174 echocardiograms analyzed, 68.9% had underlying congenital heart disease; 44.8% were outpatient; 34.5% were performed in an intensive care setting; 61.5% were follow-up; 46.6% were initial or preoperative; and 9.8% were sedated. All studies had an assigned PEC score. In univariate analysis, longer study duration was associated with several patient and study variables (age <2 years, PEC 4 or 5, initial study, preoperative study, junior or trainee scanner, and need for additional imaging). In multivariable analysis, a higher PEC score of 4 or 5 was independently associated with longer study duration after controlling for study variables and center variation. CONCLUSIONS: The PEC scoring tool is feasible and applicable in a variety of clinical settings and can be used for correlation with diagnostic errors, allocation of resources, and assessment of physician and sonographer effort in performing, interpreting, and training in pediatric echocardiography.

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.

Mind the Gap! Working Toward Gender Equity in Pediatric and Congenital Heart Disease: Present and Future.

Evidence from medicine and other fields has shown that gender diversity results in better decision making and outcomes. The incoming workforce of congenital heart specialists (especially in pediatric cardiology) appears to be more gender balanced, but past studies have shown many inequities. Gender-associated differences in leadership positions, opportunities presented for academic advancement, and recognition for academic contributions to the field persist. In addition, compensation packages remain disparate if evaluated based on gender with equivalent experience and expertise. This review explores these inequities and has suggested individual and institutional changes that could be made to recruit and retain women, monitor the climate of the institution, and identify and eliminate bias in areas like salary and promotions.

Kawarabi: Administrative Structuring of a Multicenter Research Collaborative to Study Kawasaki Disease in the Arab Countries.

Kawasaki disease (KD), the leading cause of acquired heart disease in children in developed countries, merits conducting detailed studies in Arab countries. We introduce Kawarabi, as a multicenter research collaborative effort dedicated to improving diagnosis, care, and outcome of children and adults with KD in the Arab world. During the COVID-19 pandemic, there emerged a new multisystem inflammatory syndrome in children; a disease similar to KD. This highlighted the challenges that Arab physicians face in diagnosing and managing children with KD and KD-like illnesses. Kawarabi brings together experts in North America and Arab nations to study this family of diseases in a not-for-profit, voluntary scientific collaborative setting. Bylaws addressing the vision, objectives, structure, and governance of Kawarabi were established, and vetted by the 45 organizing members in 2021. An initial scientific publication showed evidence of a decreased level of awareness of the disease in the general population, as well as the lack of access to resources available for physicians caring for children with KD in Arab countries. Kawarabi has since held several educational webinars and an inaugural yearly meeting. The groundwork for future initiatives targeted at increasing awareness and understanding of the management and the long-term outcomes of children with KD in the region was established. Data on KD in the Arab world are lacking. Kawarabi is a multicenter research collaborative organization that has the unique resources, diversified ethnic makeup, and energy, to accomplish significant advances in our understanding and management of KD and its variants.

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.

Obesity and Outcomes of Kawasaki Disease and COVID-19-Related Multisystem Inflammatory Syndrome in Children.

Importance: Obesity may affect the clinical course of Kawasaki disease (KD) in children and multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. Objective: To compare the prevalence of obesity and associations with clinical outcomes in patients with KD or MIS-C. Design, Setting, and Participants: In this cohort study, analysis of International Kawasaki Disease Registry (IKDR) data on contemporaneous patients was conducted between January 1, 2020, and July 31, 2022 (42 sites, 8 countries). Patients with MIS-C (defined by Centers for Disease Control and Prevention criteria) and patients with KD (defined by American Heart Association criteria) were included. Patients with KD who had evidence of a recent COVID-19 infection or missing or unknown COVID-19 status were excluded. Main Outcomes and Measures: Patient demographic characteristics, clinical features, disease course, and outcome variables were collected from the IKDR data set. Using body mass index (BMI)/weight z score percentile equivalents, patient weight was categorized as normal weight (BMI <85th percentile), overweight (BMI ≥85th to <95th percentile), and obese (BMI ≥95th percentile). The association between adiposity category and clinical features and outcomes was determined separately for KD and MIS-C patient groups. Results: Of 1767 children, 338 with KD (median age, 2.5 [IQR, 1.2-5.0] years; 60.4% male) and 1429 with MIS-C (median age, 8.7 [IQR, 5.3-12.4] years; 61.4% male) were contemporaneously included in the study. For patients with MIS-C vs KD, the prevalence of overweight (17.1% vs 11.5%) and obesity (23.7% vs 11.5%) was significantly higher (P < .001), with significantly higher adiposity z scores, even after adjustment for age, sex, and race and ethnicity. For patients with KD, apart from intensive care unit admission rate, adiposity category was not associated with laboratory test features or outcomes. For patients with MIS-C, higher adiposity category was associated with worse laboratory test values and outcomes, including a greater likelihood of shock, intensive care unit admission and inotrope requirement, and increased inflammatory markers, creatinine levels, and alanine aminotransferase levels. Adiposity category was not associated with coronary artery abnormalities for either MIS-C or KD. Conclusions and Relevance: In this international cohort study, obesity was more prevalent for patients with MIS-C vs KD, and associated with more severe presentation, laboratory test features, and outcomes. These findings suggest that obesity as a comorbid factor should be considered at the clinical presentation in children with MIS-C.

The Diagnostic Role of Echocardiographic Strain Analysis in Patients Presenting with Chest Pain and Elevated Troponin: A Multicenter Study.

BACKGROUND: Myocarditis presenting as acute chest pain with elevated troponins without significant cardiac compromise is rare in previously healthy children, often referred to as myopericarditis. Diagnosis is challenging, as conventional echocardiographic measures of systolic function can be normal. The aim of this study was to demonstrate the diagnostic utility of strain imaging in this scenario. METHODS: This was a multicenter, retrospective study including patients presenting with chest pain and elevated troponin from 10 institutions who underwent cardiac magnetic resonance imaging and transthoracic echocardiography within 30 days of each other (group 1). Findings were compared with those among 19 control subjects (group 2). Clinical data and conventional echocardiographic and cardiac magnetic resonance imaging data were collected. Echocardiography-derived strain was measured at the core laboratory. Group 1 was divided into subgroups as myocarditis positive (group 1a) or negative (group 1b) on cardiac magnetic resonance imaging on the basis of established criteria. RESULTS: Group 1 included 108 subjects (88 in group 1a, 20 in group 1b). Although all groups had normal mean fractional shortening and mean left ventricular ejection fraction, group 1 had significantly lower ejection fraction (56.8 ± 7.0%) compared with group 2 (62.3 ± 4.9%; P < .005) and fractional shortening (31.2 ± 4.9%) compared with group 2 (34.1 ± 3.5%; P < .05). Additionally, peak global longitudinal strain (GLS) was markedly abnormal in group 1 (-13.9 ± 3.4%) compared with group 2 (-19.8 ± 2.1%; P < .001). In subgroup analysis, GLS was markedly abnormal in group 1a (-13.2 ± 3.0%) compared with group 1b (-17.3 ± 2.6%; P < .001). Fifty-four subjects underwent follow-up echocardiography (46 in group 1a, eight in group 1b), with mean a follow-up time of 10 ± 11 months. At follow-up, whereas ejection fraction and fractional shortening returned to normal in all patients, abnormalities in strain persisted in group 1, with 22% still having abnormal GLS. Moreover, mean GLS was more abnormal in group 1a (-16.1 ± 2.6%) compared with group 1b (-17.4 ± 1.2%; P < .05). CONCLUSIONS: The present study demonstrates that echocardiographic GLS is significantly worse in subjects with myopericarditis presenting with chest pain and elevated troponins compared with control subjects even when conventional measures of systolic function are largely normal and that these abnormalities persisted over time.

Kawasaki Disease Shock Syndrome vs Classical Kawasaki Disease: A Meta-analysis and Comparison With SARS-CoV-2 Multisystem Inflammatory Syndrome.

BACKGROUND: The emergence of increasing reports worldwide of a severe inflammatory process and shock in pediatric patients resembling Kawasaki disease (KD)-and, more specifically, Kawasaki disease shock syndrome (KDSS)-prompted us to explore KDSS in a preamble of a systematic comparison between the 2 conditions. METHODS: We completed a systematic review of KDSS and performed a meta-analysis comparison between reported KDSS cases and KD controls. RESULTS: A total of 10 case-control series were included in the meta-analysis. Patients with KDSS were older (38.4 ± 30.6 vs 21.9 ± 19.5 months; P < 0.001) compared with standard KD with equal sex distribution and completeness of clinical diagnostic criteria. KDSS present higher C-reactive protein (59.4 ± 29.2 mg/dL vs 20.8 ± 14.8 mg/dL; P < 0.001), lower albumin (2.7 ± 0.5 g/dL vs 3.3 ± 0.5 g/dL; P < 0.01), and lower platelets (255 ± 149 109/L vs 394 ± 132 109/L; P < 0.001) but only borderline higher white blood cells (P = 0.06). Differences in alanine transaminase, aspartate aminotransferase, and erythrocyte sedimentation rate were nonsignificant. The odds of intravenous immunoglobulin resistance (44.4% vs 9.6%; (P < 0.001) and the hospital length of stay (10.9 ± 5.8 vs 5.0 ± 3.0 days; P < 0.001) were higher in KDSS, as were the odds of coronary-artery abnormalities (33.9% vs 8.6%; P < 0.001). CONCLUSIONS: This first meta-analysis on KDSS vs KD represents a basis for future works on KDSS and opens the opportunity for future multicentre studies in the search of causal relationships between presenting elements and the eventual complications of KDSS. The similarities between SARS-CoV-2 multisystem inflammatory syndrome in children and KDSS open new horizons to the understanding of the etiology and pathophysiology related to KDSS.