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Background The Long-ter M O U tcomes after the Multisystem Inflammatory S yndrome I n C hildren (MUSIC) study aims to characterize the frequency and time course of acute and long-term cardiac and non-cardiac sequelae in multisystem inflammatory syndrome in children associated with COVID-19 (MIS-C), which are currently poorly understood. Methods This multicenter observational cohort study will enroll at least 600 patients Conclusion The MUSIC study, with the largest cohort of MIS-C patients and the longest follow-up period to date, will make an important contribution to our understanding of the acute cardiac and non-cardiac manifestations of MIS-C and the long-term effects of this public health emergency.

BACKGROUND: American Heart Association (AHA) guidelines for management of Kawasaki disease (KD) rely on coronary artery (CA) z-scores from echocardiograms. Compared with echocardiography, cardiac CT (CCT) offers better visualization of distal segments and evaluation for thrombosis and stenosis. Despite increasing use of CCT in KD, CA z-scores for CCT are not available and measurement concordance between imaging modalities is a critical knowledge gap. METHODS: We retrospectively reviewed KD patients with CA aneurysms who had concurrent echocardiography and CCT between 2016-2020. Patients were included if they had history of CA z-scores of ≥ 3 on echocardiography during their clinical course. Agreement between CCT and echocardiography was assessed using Bland-Altman analysis. RESULTS: Paired CCT and echocardiography studies were available in 18 patients (21 studies). The largest CA aneurysms were large/giant (z-score ≥10) in 14 studies, medium (z-score ≥5

Kawasaki disease is an acute vasculitis affecting children, which can lead to coronary artery (CA) aneurysms. Optical coherence tomography (OCT) has identified CA wall damage in KD patients, but it is unclear if these findings correlate with any distensibility changes in the CA and how these changes evolve over time. This paper seeks to establish the link between OCT findings and vessel distensibility with a novel deep learning coronary artery segmentation system and use the segmentation framework to automatically analyze the temporal evolution of coronary stiffness over many years. 27 KD patients underwent catheterization with coronary angiography of the left coronary artery (LCA), followed by OCT of proximal and distal segments of the LCA. Changes in the CA caliber over the cardiac cycle were measured automatically and compared against OCT findings suggestive of KD-related vascular damage. In addition, 34 KD patients with regressed or persistent CA aneurysms were followed with serial CA angiography over an average of 14.5 years. Distensibility changes were calculated using a deep learning coronary artery segmentation framework and evaluated longitudinally. Distensibility in the coronary arteries after KD negatively correlated with increasing severity of OCT findings of KD-related vessel damage. KD patients have a significant increase in CA wall stiffness at 1 year after diagnosis, which then plateaus subsequently, compared to controls. Also, patients with persistent CA aneurysms have a statistically significant increase in wall stiffness over time in comparison to those with regressed CA aneurysms. Distensibility changes in the CA of KD patients calculated using our automated deep learning approach correlates with the severity of OCT findings of KD-related CA damage. This decreased distensibility peaks at 1 year in KD patients when following longitudinally and is more severe in those with persistent CA aneurysms.

Background: Cardiac manifestations in multisystem inflammatory syndrome in children (MIS-C) occur in ∼80% of patients. Left ventricular (LV) systolic dysfunction is the most frequent cardiac finding. Methods: In this single-centre, retrospective cohort study, we report on detailed assessment of LV function in MIS-C patients using strain and strain rate analysis. We compare those with normal peak systolic strain z-scores (both longitudinal and circumferential strain) to those with abnormal peak systolic strain z-scores (decreased circumferential and/or longitudinal strain). Results: Among 25 patients, 14 (56%) were male, 20 (80%) were Black or Hispanic, 13 (52%) were overweight/obese, and the median age was 11.4 years (interquartile range: 7.5 to 16). Median ejection fraction (EF) was 55.2% (interquartile range: 48.3% to 58%), with the abnormal strain patients having a lower EF (P < 0.01). Demographics were similar between groups. The abnormal strain patients had more organ systems involved and were more likely to require inotropic support. In a comparison of MIS-C patients with normal EF (n = 15) to controls, MIS-C patients had lower peak systolic strain as well as lower early diastolic strain rates. In patients with initially depressed function, EF normalized in 8 of 10 (80%), but 4 of 11 (36%) patients had persistently abnormal systolic strain after discharge. Conclusions: LV systolic dysfunction is common in the acute phase of MIS-C, and detection may be improved with strain imaging. Longitudinal cardiac follow-up is imperative, as some patients may be at risk for persistent LV dysfunction. Résumé: Contexte: Des manifestations cardiaques sont observées chez environ 80 % des patients atteints du syndrome inflammatoire multisystémique de l'enfant (SIM-E). La dysfonction systolique ventriculaire gauche est le problème cardiaque observé le plus fréquemment. Méthodologie: Dans cette étude de cohorte rétrospective et unicentrique, nous rapportons les résultats d'une évaluation détaillée de la fonction ventriculaire gauche chez des patients atteints du SIM-E sous l'angle de l'étude des contraintes et des taux de contrainte. Nous comparons les patients dont les écarts z des pics de contrainte systolique sont normaux (contraintes tant longitudinales que circonférentielles) et ceux dont les écarts z des pics de contrainte systolique sont anormaux (réduction de la contrainte circonférentielle ou longitudinale). Résultats: Sur 25 patients, 14 (56 %) étaient de sexe masculin, 20 (80 %) étaient noirs ou hispaniques, 13 (52 %) étaient en surpoids ou obèses, et l'âge médian était de 11,4 ans (intervalle interquartile : de 7,5 à 16). La fraction d'éjection (FE) médiane était de 55,2 % (intervalle interquartile : de 48,3 % à 58 %), et était moins élevée chez les patients présentant une contrainte anormale (p < 0,01). Les caractéristiques démographiques étaient comparables dans tous les groupes. Les patients chez lesquels la contrainte était anormale présentaient un plus grand nombre d'organes atteints et étaient plus susceptibles de nécessiter un soutien inotrope. Comparativement au groupe témoin, les patients SIM-E ayant une FE normale (n = 15) présentaient un pic de contrainte systolique moins élevé et des taux de contrainte diastolique précoce plus faibles. Chez les patients dont la fonction était déprimée à l'origine, la FE s'est normalisée chez huit patients sur 10 (80 %), mais quatre sur 11 (36 %) présentaient une contrainte systolique persistant après leur sortie de l'hôpital. Conclusions: La dysfonction systolique ventriculaire gauche est fréquente dans la phase aiguë du SIM-E, et son repérage pourrait être amélioré par l'imagerie permettant de visualiser les contraintes. Un suivi cardiaque longitudinal est impératif, car certains patients peuvent être à risque de souffrir d'une dysfonction ventriculaire gauche persistante.

OBJECTIVES Little is known about cardiac hemodynamics in the fetus with transposition of the great arteries and intact ventricular septum (TGA-IVS). Better understanding of the fetal physiology in TGA-IVS would help to provide insights into specific clinical complications observed after birth, in particular neonatal hypoxia and pulmonary hypertension. The aim of this study was to assess cardiac hemodynamics in fetuses with TGA-IVS by performing systematic longitudinal echocardiographic follow-up from diagnosis to delivery. METHODS This was a longitudinal retrospective study of fetuses referred between 2010 and 2018 to the Sainte-Justine University Hospital Centre. Complete assessment of cardiac hemodynamics was performed in fetuses with TGA-IVS at 18-22, 28-32 and 35-38 weeks' gestation, which were compared with normal fetuses matched for gestational age. The maximum diameter of the foramen ovale was measured using two-dimensional echocardiography under the guidance of color Doppler echocardiography. Fetal cardiac hemodynamics were analyzed according to postnatal preductal transcutaneous oxygen saturation (TcSO2 )

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with substantial cardiovascular implications. Although infection with SARS-CoV-2 is usually mild in children, some children later develop a severe inflammatory disease that can have manifestations similar to toxic shock syndrome or Kawasaki disease. This syndrome has been defined by the US Centers for Disease Control and Prevention as multisystem inflammatory syndrome in children. Although the prevalence is unknown, >600 cases have been reported in the literature. Multisystem inflammatory syndrome in children appears to be more common in Black and Hispanic children in the United States. Multisystem inflammatory syndrome in children typically occurs a few weeks after acute infection and the putative etiology is a dysregulated inflammatory response to SARS-CoV-2 infection. Persistent fever and gastrointestinal symptoms are the most common symptoms. Cardiac manifestations are common, including ventricular dysfunction, coronary artery dilation and aneurysms, arrhythmia, and conduction abnormalities. Severe cases can present as vasodilatory or cardiogenic shock requiring fluid resuscitation, inotropic support, and in the most severe cases, mechanical ventilation and extracorporeal membrane oxygenation. Empirical treatments have aimed at reversing the inflammatory response using immunomodulatory medications. Intravenous immunoglobulin, steroids, and other immunomodulatory agents have been used frequently. Most patients recover within days to a couple of weeks and mortality is rare, although the medium- and long-term sequelae, particularly cardiovascular complications, are not yet known. This review describes the published data on multisystem inflammatory syndrome in children, focusing on cardiac complications, and provides clinical considerations for cardiac evaluation and follow-up.

Aim This study aimed to describe the current management practices for Kawasaki disease (KD) in Australia and New Zealand. Methods We performed a secondary analysis on the Australian and New Zealand responses to a large international survey of clinicians' perspectives on KD diagnosis and management. Results There was general consensus among Australian and New Zealand clinicians regarding the indications for intravenous immunoglobulin and aspirin in the management of acute KD. There was less consensus on the dose of these agents, the definition and management of treatment-resistant KD and the approach to long-term thromboprophylaxis. Conclusion Most clinicians use intravenous immunoglobulin for primary treatment of KD. There is variation regarding other aspects of KD diagnosis and important management issues. Future studies should confirm whether this reported variation occurs in real-world practice and assess potential impacts on patient outcome.

Background Since April 2020, there have been numerous reports of children presenting with systemic inflammation, often in critical condition, and with evidence of recent infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This condition, since defined as the multisystem inflammatory syndrome in children (MIS-C), is assumed to be a delayed immune response to COVID-19, and there are frequently cardiac manifestations of ventricular dysfunction and/or coronary artery dilation. Methods We surveyed the inpatient MIS-C management approaches of the members of the International Kawasaki Disease Registry across 38 institutions and 11 countries. Results Among the respondents, 56% reported using immunomodulatory treatment for all MIS-C patients, regardless of presentation. Every respondent reported use of intravenous immunoglobulin (IVIG), including 53% administering IVIG in all patients. Steroids were most often used for patients with severe clinical presentation or lack of response to IVIG, and only a minority used steroids in all patients (14%). ASA was frequently used among respondents (91%), including anti-inflammatory and/or anti-platelet dosing. Respondents reported use of prophylactic anticoagulation, especially in patients at higher risk for venous thromboembolism, and therapeutic anticoagulation, particularly for patients with giant coronary artery aneurysms. Conclusions There is variation in management of MIS-C patients with suboptimal evidence to assess superiority of the various treatments; evidence-based gaps in knowledge should be addressed through worldwide collaboration to optimize treatment strategies., There is a delayed and often critical presentation of a multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. Cardiac manifestations can include ventricular dysfunction and/or coronary artery dilation. We surveyed the management approaches of the membership of the International Kawasaki Disease Registry. Management often includes immunomodulatory therapies and thromboprophylaxis with variation in indications across institutions.

ObjectivePatients with Kawasaki disease (KD) with coronary artery enlargement at diagnosis are at the highest risk for persistent coronary artery aneurysms (CAAs) and may benefit from primary adjunctive anti-inflammatory therapy beyond intravenous immunoglobulin (IVIG). We evaluate the effect of primary adjunctive corticosteroid therapy on outcomes in patients with CAA at diagnosis.DesignSingle-centre, retrospective review.PatientsPatients with KD diagnosed within 10 days of fever onset and with baseline CA z-score ≥2.5.InterventionsPrimary treatment with IVIG (n=162) versus IVIG plus corticosteroids (n=48).Main outcome measuresTreatment resistance (persistent fever >36 hours after initial treatment), CAA regression rate.ResultsOf the 92 patients with KD who received corticosteroids at our institution from 2012 to 2019, 48 met the inclusion criteria for primary adjunctive therapy. The corticosteroid group was younger and had larger baseline CAAs compared with historical controls. Demographics and laboratory values were otherwise similar between groups. The corticosteroid group had a less treatment resistance (4% vs 30%, p=0.003) and a greater improvement in C reactive protein. After adjusting for baseline CA z-score, age and baseline bilateral versus unilateral CAA, the corticosteroid group had a higher odds of (OR 2.77 (1.04, 7.42), p=0.042) and a shorter time to CAA regression (HR 1.94 (1.27, 2.96), p=0.002).ConclusionPrimary adjunctive corticosteroid therapy is associated with decreased initial treatment resistance, greater improvement in inflammatory markers and higher likelihood of CAA regression in patients who have CAA at diagnosis. Multi-centre, randomised controlled trials are needed to confirm the benefits of corticosteroids in patients with CAA at diagnosis and to compare corticosteroids with other adjunctive therapies.

OBJECTIVE To determine the impact of provocative electrophysiology testing in postoperative congenital heart disease (CHD) patients on the management of supraventricular tachycardia (SVT) and clinical outcomes. METHODS This is a retrospective study including patients

The N-terminal proBNP (NT-proBNP), produced by cardiomyocytes, has several reported utilities and associations in acute Kawasaki disease (KD). The objective of this study is to examine the relationship between serum values of NT-proBNP at time of KD diagnosis with cardiac systolic, diastolic function and electrocardiographic changes, at onset of the disease and during the first year of follow-up. KD was diagnosed in 127 children between March 2007 and July 2014, mean diagnostic age 3.5 ± 2.9 years. Coronary artery maximum z score was 2.6 ± 2.8 (range − 0.6 to + 18.9), with giant aneurysm in 5/122 (4.1%). Age-adjusted NT-proBNP was 2.6 ± 1.6 z score, 78/122 (63.9%) > 2.0. There was a crescendo correlation between onset NT-proBNP z score and C-Reactive protein (CRP) serum levels (slope + 0.49, p

OBJECTIVE: To characterize viscoelastic testing profiles of children with multisystem inflammatory syndrome in children (MIS-C). METHODS: This single-center retrospective review included 30 patients diagnosed with MIS-C from March 1 to September 1, 2020. Thromboelastography (TEG) with platelet mapping was performed in 19 (63%) patients and compared to age- and sex-matched controls prior to cardiac surgery. Relationships between TEG parameters and inflammatory markers were assessed using correlation. RESULTS: Patients with MIS-C had abnormal TEG results compared to controls, including decreased kinetic (K) time (1.1 vs. 1.7 minutes, p

Background Coronary artery (CA) aneurysms in children are a rare but potentially life-threatening finding and are highly associated with Kawasaki disease (KD). Case presentation We describe a four-year-old female with a vasculitis and CA aneurysms. She had a prolonged course with recurrent fever and systemic inflammation several times upon discontinuation of steroid treatment. Due in part to the CA aneurysms, she initially was diagnosed with KD but due to the unusual clinical course, further evaluation was performed. Abdominal and chest MRI/A revealed diffuse aortitis suggestive of a large vessel vasculitis, specifically Takayasu arteritis. With treatment targeted for Takayasu arteritis, there was resolution of fever and inflammation and the CA aneurysms improved. Conclusions This case demonstrates the utility in broadening the differential diagnosis in cases of presumed KD with CA involvement in which the clinical course is atypical for KD.

Importance The BNT162b2 (Pfizer-BioNTech) messenger RNA COVID-19 vaccine was authorized on May 10, 2021, for emergency use in children aged 12 years and older. Initial reports showed that the vaccine was well tolerated without serious adverse events; however, cases of myocarditis have been reported since approval. Objective To review results of comprehensive cardiac imaging in children with myocarditis after COVID-19 vaccine. Design, setting, and participants This study was a case series of children younger than 19 years hospitalized with myocarditis within 30 days of BNT162b2 messenger RNA COVID-19 vaccine. The setting was a single-center pediatric referral facility, and admissions occurred between May 1 and July 15, 2021. Main outcomes and measures All patients underwent cardiac evaluation including an electrocardiogram, echocardiogram, and cardiac magnetic resonance imaging. Results Fifteen patients (14 male patients [93%]; median age, 15 years [range, 12-18 years]) were hospitalized for management of myocarditis after receiving the BNT162b2 (Pfizer) vaccine. Symptoms started 1 to 6 days after receipt of the vaccine and included chest pain in 15 patients (100%), fever in 10 patients (67%), myalgia in 8 patients (53%), and headache in 6 patients (40%). Troponin levels were elevated in all patients at admission (median, 0.25 ng/mL [range, 0.08-3.15 ng/mL]) and peaked 0.1 to 2.3 days after admission. By echocardiographic examination, decreased left ventricular (LV) ejection fraction (EF) was present in 3 patients (20%), and abnormal global longitudinal or circumferential strain was present in 5 patients (33%). No patient had a pericardial effusion. Cardiac magnetic resonance imaging findings were consistent with myocarditis in 13 patients (87%) including late gadolinium enhancement in 12 patients (80%), regional hyperintensity on T2-weighted imaging in 2 patients (13%), elevated extracellular volume fraction in 3 patients (20%), and elevated LV global native T1 in 2 patients (20%). No patient required intensive care unit admission, and median hospital length of stay was 2 days (range 1-5). At follow-up 1 to 13 days after hospital discharge, 11 patients (73%) had resolution of symptoms. One patient (7%) had persistent borderline low LV systolic function on echocardiogram (EF 54%). Troponin levels remained mildly elevated in 3 patients (20%). One patient (7%) had nonsustained ventricular tachycardia on ambulatory monitor. Conclusions and relevance In this small case series study, myocarditis was diagnosed in children after COVID-19 vaccination, most commonly in boys after the second dose. In this case series, in short-term follow-up, patients were mildly affected. The long-term risks associated with postvaccination myocarditis remain unknown. Larger studies with longer follow-up are needed to inform recommendations for COVID-19 vaccination in this population.

Objective Features of multisystem inflammatory syndrome in children (MIS-C) overlap with other febrile illnesses, hindering prompt and accurate diagnosis. The objectives of this study were to identify clinical and laboratory findings that distinguished MIS-C from febrile illnesses in which MIS-C was considered but ultimately excluded, and to examine the diseases that most often mimicked MIS-C in a tertiary medical centre. Study design We identified all children hospitalised with fever who were evaluated for MIS-C at our centre and compared clinical signs and symptoms, SARS-CoV-2 status and laboratory studies between those with and without MIS-C. Multivariable logistic LASSO (least absolute shrinkage and selection operator) regression was used to identify the most discriminative presenting features of MIS-C. Results We identified 50 confirmed MIS-C cases (MIS-C+) and 68 children evaluated for, but ultimately not diagnosed with, MIS-C (MIS-C-). In univariable analysis, conjunctivitis, abdominal pain, fatigue, hypoxaemia, tachypnoea and hypotension at presentation were significantly more common among MIS-C+ patients. MIS-C+ and MIS-C- patients had similar elevations in C-reactive protein (CRP), but were differentiated by thrombocytopenia, lymphopenia, and elevated ferritin, neutrophil/lymphocyte ratio, BNP and troponin. In multivariable analysis, predictors of MIS-C included age, neutrophil/lymphocyte ratio, platelets, conjunctivitis, oral mucosa changes, abdominal pain and hypotension. Conclusions Among hospitalised children undergoing evaluation for MIS-C, children with MIS-C were older, more likely to present with conjunctivitis, oral mucosa changes, abdominal pain and hypotension, and had higher neutrophil/lymphocyte ratios and lower platelet counts. These data may be helpful for discrimination of MIS-C from other febrile illnesses, including bacterial lymphadenitis and acute viral infection, with overlapping features., This single centre cohort study identifies clinical and laboratory findings that distinguish multisystem inflammatory syndrome in children (MIS-C) from other febrile illnesses in which MIS-C was considered but ultimately excluded. The most discriminative features of MIS-C included older age, conjunctivitis, oral mucosa changes, abdominal pain and hypotension, higher neutrophil/lymphocyte ratios and lower platelet counts.

Objective: To characterize viscoelastic testing profiles of children with multisystem inflammatory syndrome in children (MIS-C). Methods: This single-center retrospective review included 30 patients diagnosed with MIS-C from January 1 to September 1, 2020. Thromboelastography (TEG) with platelet mapping was performed in 19 (63%) patients and compared to age- and gender- matched controls via Student’s t-test and Wilcoxon rank sum test. Pearson’s and Spearman correlation were used to assess relationships between TEG parameters and inflammatory markers. Results: Patients with MIS-C had abnormal TEG results compared to controls, including decreased K time (1.1 vs. 1.7 min, P

Objective To evaluate the association of neighborhood socioeconomic status (SES) with time to intravenous immunoglobulin treatment, length of stay (LOS), and coronary artery aneurysms (CAAs) in patients with Kawasaki disease. Study design We examined the relationship of SES in 915 patients treated at a large academic center between 2000 and 2017. Neighborhood SES was measured using a US census-based score derived from 6 measures related to income, education, and occupation. Linear and logistic regression were used to examine the association of SES with number of days of fever at time of treatment, LOS, and CAA. Results Patients in the lowest SES quartile were treated later than patients with greater SES (7 [IQR 5, 9] vs 6 [IQR 5, 8] days, P = .01). Patients in the lowest SES quartile were more likely to be treated after 10 days of illness, with an OR 1.9 (95% CI 1.3-2.8). In multivariable analysis, SES remained an independent predictor of the number of days of fever at time of treatment (P = .01). Patients in the lowest SES quartile had longer LOS than patients with greater SES (3 [IQR 2, 5] vs 3 [IQR 2, 4], P = .007). In subgroup analysis of white children, those in the lowest SES quartile vs quartiles 2-4 were more likely to develop large/giant CAA 17 (12%) vs 30 (6%), P = .03. Conclusions Lower SES is associated with delayed treatment, prolonged LOS, and increased risk of large/giant CAA. Novel approaches to diagnosis and education are needed for children living in low-SES neighborhoods.

We review the acute management of patients with Kawasaki disease (KD), including adjunctive primary therapies and the treatment of patients with resistance to intravenous immunoglobulin (IVIG). IVIG administered within 10 days of fever in patients with (KD decreases the risk of coronary artery complication from ~ 25% to

OBJECTIVES: To characterize the socioeconomic and racial and/or ethnic disparities impacting the diagnosis and outcomes of multisystem inflammatory syndrome in children (MIS-C). METHODS: This multicenter retrospective case-control study was conducted at 3 academic centers from January 1 to September 1, 2020. Children with MIS-C were compared with 5 control groups: children with coronavirus disease 2019, children evaluated for MIS-C who did not meet case patient criteria, children hospitalized with febrile illness, children with Kawasaki disease, and children in Massachusetts based on US census data. Neighborhood socioeconomic status (SES) and social vulnerability index (SVI) were measured via a census-based scoring system. Multivariable logistic regression was used to examine associations between SES, SVI, race and ethnicity, and MIS-C diagnosis and clinical severity as outcomes. RESULTS: Among 43 patients with MIS-C, 19 (44%) were Hispanic, 11 (26%) were Black, and 12 (28%) were white; 22 (51%) were in the lowest quartile SES, and 23 (53%) were in the highest quartile SVI. SES and SVI were similar between patients with MIS-C and coronavirus disease 2019. In multivariable analysis, lowest SES quartile (odds ratio 2.2 [95% confidence interval 1.1–4.4]), highest SVI quartile (odds ratio 2.8 [95% confidence interval 1.5–5.1]), and racial and/or ethnic minority background were associated with MIS-C diagnosis. Neither SES, SVI, race, nor ethnicity were associated with disease severity. CONCLUSIONS: Lower SES or higher SVI, Hispanic ethnicity, and Black race independently increased risk for MIS-C. Additional studies are required to target interventions to improve health equity for children.

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.We completed a systematic review of KDSS and performed a meta-analysis comparison between reported KDSS cases and KD controls.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; P0.001) 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; P0.001), lower albumin (2.7 ± 0.5 g/dL vs 3.3 ± 0.5 g/dL; P0.01), and lower platelets (255 ± 149 109/L vs 394 ± 132 109/L; P0.001) 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%; (P0.001) and the hospital length of stay (10.9 ± 5.8 vs 5.0 ± 3.0 days; P0.001) were higher in KDSS, as were the odds of coronary-artery abnormalities (33.9% vs 8.6%; P0.001).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.

Background Aortic stiffness has been shown to be abnormal in patients with bicuspid aortic valve (BAV), and is considered a component of the aortopathy associated with this condition. Progressive aortic stiffening associated with aging has been previously described in normal adults. However, it is not known if aging related aortic stiffening occurs at the same rate in BAV patients. We determined the longitudinal rate of decline in segmental distensibility in BAV patients using serial cardiovascular magnetic resonance (CMR) studies, and compared to previously published results from a group of patients with connective tissue disorders (CTD). Methods A retrospective review of CMR and clinical data on children and adults with BAV (n = 49, 73% male; 23 ± 11 years) with at least two CMRs (total 98 examinations) over a median follow-up of 4.1 years (range 1–9 years) was performed to measure aortic distensibility at the ascending (AAo) and descending aorta (DAo). Longitudinal changes in aortic stiffness were assessed using linear mixed-effects modeling. The comparison group of CTD patients had a similar age and gender profile (n = 50, 64% male; 20.6 ± 12 years). Results Compared to CTD patients, BAV patients had a more distensible AAo early in life but showed a steeper decline in distensibility on serial examinations [mean 10-year decline in AAo distensibility (× 10−3 mmHg−1) 2.4 in BAV vs 1.3 in CTD, p = 0.005]. In contrast, the DAo was more distensible in BAV patients throughout the age spectrum, and DAo distensibility declined with aging at a rate similar to CTD patients [mean 10 year decline in DAo distensibility (× 10−3 mmHg−1) 0.3 in BAV vs 0.4 in CTD, p = 0.58]. Conclusions On serial CMR measurements, AAo distensibility declined at significantly steeper rate in BAV patients compared to a comparison group with CTDs, while DAo distensibility declined at similar rates in both groups. These findings offer new mechanistic insights into the differing pathogenesis of the aortopathy seen in BAV and CTD patients.

Initial reports on COVID-19 described children as largely spared from severe manifestations, with only 2–6% of children requiring intensive care treatment. However, since mid-April 2020, clusters of pediatric cases of severe systemic hyperinflammation and shock epidemiologically linked with COVID-19 have been reported. This condition was named as SARS-Cov-2-associated multisystem inflammatory syndrome in children and showed similarities to Kawasaki disease. Here, we present a narrative review of cases reported in literature and we discuss the clinical acute and follow-up management of these patients. Patients with SARS-Cov-2-associated multisystem inflammatory syndrome frequently presented with persistent fever, gastrointestinal symptoms, polymorphic rash, conjunctivitis, and mucosal changes. Elevated inflammatory markers and evidence of cytokine storm were frequently observed. A subset of these patients also presented with hypotension and shock (20–100%) from either acute myocardial dysfunction or systemic hyperinflammation/vasodilation. Coronary artery dilation or aneurysms have been described in 6–24%, and arrhythmias in 7–60%. Cardiac support, immunomodulation, and anticoagulation are the key aspects for the management of the acute phase. Long-term structured follow-up of these patients is required due to the unclear prognosis and risk of progression of cardiac manifestations.Conclusion: Multisystem inflammatory syndrome is a novel syndrome related to SARS-CoV-2 infection. Evidence is still scarce but rapidly emerging in the literature. Cardiac manifestations are frequent, including myocardial and coronary involvement, and need to be carefully identified and monitored over time. What is Known:• Multisystem inflammatory syndrome in children (MIS-C) has been described associated with SARS-CoV-2.What is New:• Patients with MIS-C often present with fever, gastrointestinal symptoms, and shock.• Cardiac involvement is found in a high proportion of these patients, including ventricular dysfunction, coronary artery dilation or aneurysm, and arrhythmias.• Management is based on expert consensus and includes cardiac support, immunomodulatory agents, and anticoagulation.• Long-term follow-up is required due to the unclear prognosis and risk of progression of cardiac manifestation.

Introduction: The American Heart Association (AHA) guidelines recommend testing for inducible myocardial ischemia in all patients with a history of coronary artery aneurysm (CAA) after Kawasaki disease (KD). Because the prevalence of clinical coronary complications is exceedingly low in patients whose worst-ever CAA dimension was Methods: Retrospective study including patients Results: A total of 588 stress tests were performed in 208 patients at median age of 12.4 [IQR 8.8, 16.8] years, 8.3 [IQR 5.0, 12.9] years after diagnosis (Table). Tests were performed using either exercise stress (545 [93%] tests) or pharmacologic stress with dobutamine (43 [7%] tests). Echocardiography was the most frequently used modality (n=481, 82%), followed by nuclear imaging (n=133, 23%) and cardiac MRI (n=53, 9%). Inducible ischemia was found on 11 (2%) tests in 6 (3%) patients. All patients with inducible ischemia had a history of giant CAA with persistent CAA at time of testing (moderate CAA in 2 (18%) tests, giant CAA in 9 (82%) tests). After finding inducible ischemia on stress test, coronary artery bypass grafting was performed in 3 cases, cardiac catheterization in 4, stress testing using a different imaging modality in 1, and careful clinical monitoring without intervention in 3. Conclusions: Inducible ischemia was found in 2% of test after KD, and only in patients with a history of giant CAA. Recommendations in the 2017 AHA guidelines for KD for testing for myocardial ischemia in patients with non-giant CAA should be reconsidered in light of these findings.

BACKGROUND: Children are at risk for multisystem inflammatory syndrome in children (MIS-C) after infection with severe acute respiratory syndrome coronavirus 2. Cardiovascular complications, including ventricular dysfunction and coronary dilation, are frequent, but there are limited data on arrhythmic complications. METHODS: Retrospective cohort study of children and young adults aged ≤21 years admitted with MIS-C. Demographic characteristics, electrocardiogram (ECG) and echocardiogram findings, and hospital course were described. RESULTS: Among 25 patients admitted with MIS-C (60% male; median age 9.7 [interquartile range 2.7–15.0] years), ECG anomalies were found in 14 (56%). First-degree atrioventricular block (AVB) was seen in 5 (20%) patients a median of 6 (interquartile range 5–8) days after onset of fever and progressed to second- or third-degree AVB in 4 patients. No patient required intervention for AVB. All patients with AVB were admitted to the ICU (before onset of AVB) and had ventricular dysfunction on echocardiograms. All patients with second- or third-degree AVB had elevated brain natriuretic peptide levels, whereas the patient with first-degree AVB had a normal brain natriuretic peptide level. No patient with AVB had an elevated troponin level. QTc prolongation was seen in 7 patients (28%), and nonspecific ST segment changes were seen in 14 patients (56%). Ectopic atrial tachycardia was observed in 1 patient, and none developed ventricular arrhythmias. CONCLUSIONS: Children with MIS-C are at risk for atrioventricular conduction disease, especially those who require ICU admission and have ventricular dysfunction. ECGs should be monitored for evidence of PR prolongation. Continuous telemetry may be required in patients with evidence of first-degree AVB because of risk of progression to high-grade AVB.

Background: Atrioventricular reentrant tachycardia is common in children. Catheter ablation is increasingly used as a first-line therapy with a high acute success rate, but recurrence during follow-up remains a concern. The aim of this study was to identify risk factors for recurrence after accessory pathway (AP) ablation. Methods: Retrospective cohort study including patients who underwent AP ablation between 2013 and 2018. Cox proportional hazards model was used to examine the association between patient and procedural characteristics and recurrence during follow-up. Results: From 558 AP ablation procedure, 542 (97%) were acutely successful. During a median follow-up of 0.4 (interquartile range, 0.1–1.4) years, there were 42 (8%) patients with documented recurrence. On univariate analysis, early recurrence was associated with younger age, congenital heart disease, multiple AP, AP location (right sided and posteroseptal versus left sided), cryoablation (versus radiofrequency), empirical ablation, the lack of full power radiofrequency lesions ( Conclusions: In our institutional experience, radiofrequency consolidation time

BACKGROUND: Pediatric SARS–CoV-2 infection can be complicated by a dangerous hyperinflammatory condition termed multisystem inflammatory syndrome in children (MIS-C). The clinical and immunologic spectrum of MIS-C and its relationship to other inflammatory conditions of childhood have not been studied in detail. METHODS: We retrospectively studied confirmed cases of MIS-C at our institution from March to June 2020. The clinical characteristics, laboratory studies, and treatment response were collected. Data were compared with historic cohorts of Kawasaki disease (KD) and macrophage activation syndrome (MAS). RESULTS: Twenty-eight patients fulfilled the case definition of MIS-C. Median age at presentation was 9 years (range: 1 month to 17 years); 50% of patients had preexisting conditions. All patients had laboratory confirmation of SARS–CoV-2 infection. Seventeen patients (61%) required intensive care, including 7 patients (25%) who required inotrope support. Seven patients (25%) met criteria for complete or incomplete KD, and coronary abnormalities were found in 6 cases. Lymphopenia, thrombocytopenia, and elevation in inflammatory markers, D-dimer, B-type natriuretic peptide, IL-6, and IL-10 levels were common but not ubiquitous. Cytopenias distinguished MIS-C from KD and the degree of hyperferritinemia and pattern of cytokine production differed between MIS-C and MAS. Immunomodulatory therapy given to patients with MIS-C included intravenous immune globulin (IVIG) (71%), corticosteroids (61%), and anakinra (18%). Clinical and laboratory improvement were observed in all cases, including 6 cases that did not require immunomodulatory therapy. No mortality was recorded in this cohort. CONCLUSION: MIS-C encompasses a broad phenotypic spectrum with clinical and laboratory features distinct from KD and MAS. FUNDING: This work was supported by the National Institutes of Health, National Institute of Arthritis and Musculoskeletal and Skin Diseases; the National Institute of Allergy and Infectious Diseases; Rheumatology Research Foundation Investigator Awards and Medical Education Award; Boston Children’s Hospital Faculty Career Development Awards; the McCance Family Foundation; and the Samara Jan Turkel Center.

Background Coronary artery aneurysms (CAAs) may occur after Kawasaki disease (KD) and lead to important morbidity and mortality. As CAA in patients with KD are rare and heterogeneous lesions, prognostication and risk stratification are difficult. We sought to derive the cumulative risk and associated factors for cardiovascular complications in patients with CAAs after KD. Methods and Results A 34‐institution international registry of 1651 patients with KD who had CAAs (maximum CAA Z score ≥2.5) was used. Time‐to‐event analyses were performed using the Kaplan–Meier method and Cox proportional hazard models for risk factor analysis. In patients with CAA Z scores ≥10, the cumulative incidence of luminal narrowing (>50% of lumen diameter), coronary artery thrombosis, and composite major adverse cardiovascular complications at 10 years was 20±3%, 18±2%, and 14±2%, respectively. No complications were observed in patients with a CAA Z score Z score and a greater number of coronary artery branches affected were associated with increased risk of all types of complications. At 10 years, normalization of luminal diameter was noted in 99±4% of patients with small (2.5≤ Z Z Z ≥10). CAAs in the left anterior descending and circumflex coronary artery branches were more likely to normalize. Risk factor analysis of coronary artery branch level outcomes was performed with a total of 893 affected branches with Z score ≥10 in 440 patients. In multivariable regression models, hazards of luminal narrowing and thrombosis were higher for patients with CAAs of the right coronary artery and left anterior descending branches, those with CAAs that had complex architecture (other than isolated aneurysms), and those with CAAs with Z scores ≥20. Conclusions For patients with CAA after KD, medium‐term risk of complications is confined to those with maximum CAA Z scores ≥10. Further risk stratification and close follow‐up, including advanced imaging, in patients with large CAAs is warranted.

Background Troponin levels are frequently obtained in pediatric patients, but the benefit remains unclear. Methods and Results This retrospective study included 1993 patients aged 0 to 21 years without history of cardiac disease in whom troponin levels were obtained during clinical evaluation of cardiac and noncardiac presentations. Troponin was elevated (≥0.1 ng/mL) in 182 patients (9%). A cardiac diagnosis was made in 109 (60%) of those with elevated troponin and in 208 (12%) of those without ( P Conclusions Troponin can be a useful adjunctive test in the evaluation of children when the differential diagnosis includes cardiac etiologies. Serial measurement was not helpful when troponin was elevated at presentation but may merit consideration when the initial level is not elevated and there is ongoing concern about cardiac involvement. Lower reference values may be appropriate when evaluating children in contrast to adults.

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 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.

Intravenous immunoglobulin (IVIG) reduces coronary aneurysms in patients with Kawasaki disease (KD), but additional management options remain challenging, with no generalisable evidence-based recommendations. We performed a survey of 724 physicians from 73 countries to assess variation in practice. IVIG was the preferred initial treatment by 659 (91%) of respondents. Criteria for adjunctive primary treatment varied considerably and definitions of IVIG resistance varied markedly by geographical continent, Human Development Index tiers and medical specialty. A second dose of IVIG was used most often for patients with coronary aneurysm non-responsive to initial treatment (572, 79%), but corticosteroids (379, 52%) and tumour necrosis factor alpha inhibitors (208, 29%) were also frequently used. Our findings highlight the need for international collaborative efforts to optimise management of patients with KD worldwide.

Kawasaki disease (KD) is the most common vasculitis of childhood. Coronary artery aneurysms and myocarditis are common cardiovascular complications of KD. While evidence of myocarditis can be found in all patients with KD on histology specimens, only a minority of patients are clinically symptomatic. Occasionally children can present with KD shock syndrome and hemodynamic instability as a result of decreased systolic function and vasoplegia. Several children with KD have depressed shortening fraction on echocardiography. Increased end-systolic and end-diastolic dimensions, strain abnormalities and diastolic dysfunction are also found in a significant proportion of patients. Echocardiographic signs of myocarditis improve after the acute phase and do so more quickly in patients who have received intravenous immunoglobulins, as opposed to those given only aspirin. Normalization of systolic function is typically observed over long-term follow-up; however, more subtle abnormalities (strain, diastolic function) may persist. It is noteworthy that myocarditis associated with KD can occur in absence of coronary artery abnormalities. KD myocarditis can result in long-term sequelae.

Background Patients with coronary artery aneurysms (CAA) after Kawasaki disease (KD) are at risk of thrombosis, which can lead to myocardial infarction or sudden death. Clinical practice guidelines recommend anticoagulation for high-risk patients. Methods Web-based worldwide survey of physicians completed between 2016 and 2017 investigating anti-thrombotic management after KD. We compared management of patients by geographic location, Human Development Index (HDI) tier, and medical specialty. Results The survey was completed by 603 physicians from 63 countries. In patients with normal coronaries, 95 (25%) of physicians recommended low-dose aspirin during long-term follow-up (>3 months after diagnosis). In patients with non-giant CAA, dual antiplatelet (e.g. aspirin and clopidogrel) was used by 121 (32%) of physicians, and anticoagulation by 72 (19%) of physicians. In patients with giant CAA, dual antiplatelet was used by 39 (10%) of physicians and anticoagulation by 285 (74%). In multivariable analysis, cardiology (OR 6.4 [95% CI 2.7, 16.1]) and rheumatology (OR 4.3 [95% CI 1.6, 12.6]) specialty (versus general pediatrics) were the only independent predictors of anticoagulant use in patients with giant CAA. Conclusion There is significant variation in anti-thrombosis management of patients with CAA after KD, with 26% of physicians not recommending anticoagulation of patients with giant CAA. Further studies are needed to evaluate the drivers of this practice variation to inform educational initiatives and to ascertain impact on long-term outcomes.

Atrial and ventricular arrhythmias are commonly seen with exercise stress testing (EST); these are almost always nonsustained, and the significance of those findings is, at best, modest. For patients with structurally normal hearts and combinations of isolated and repetitive ventricular ectopy, EST offers some mechanistic data and some marginal long-term prognostic data. Patients with increased ectopy during exercise or immediately post exercise deserve enhanced follow-up.

Coronary artery (CA) aneurysms are serious complications of Kawasaki disease (KD) responsible for ischemic events. Percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are reported with limited data on indications and comparative efficacy. Retrospective multicenter comparison of CA intervention following KD is performed in this study. Twenty two cases were available from 5 centers, of whom 11 underwent CABG, 10 PCI and 1 systemic thrombolysis. Age at intervention (8.3 ± 3.9 vs 11.3 ± 4.9 years, p = 0.14) and interval from diagnosis (5.6 ± 4.1 vs 6.5 ± 4.7 years, p = 0.64) were similar between CABG and PCI. Interventions were based on angiography in 15 patients or cardiac event in 7, with no difference between CABG and PCI (p = 0.24). Patients with CABG were more likely to undergo multivessel intervention (73 vs 10 %, p = 0.006). None of the patients needed reintervention after CABG, compared to 6 after PCI and 1 after systemic thrombolysis (p = 0.004). Signs of ischemia on stress testing or MIBI were present in 15 patients before intervention and persisted in 9 patients following last intervention, in a significantly higher proportion after CABG than PCI (80 vs 17 %, p = 0.01). In this series, CABG, which mostly involved multivessel intervention, was superior to PCI. Nevertheless, larger-scale studies may help define patient selection criteria for a beneficial PCI approach.

Coronary artery (CA) aneurysms are a serious complication of Kawasaki disease (KD). Conventional imaging techniques often described segments with regressed aneurysms as normal, whereas studies have shown significant endothelial dysfunction.KD patients with aneurysms scheduled for routine coronary angiography underwent optical coherence tomography (OCT) imaging between 2013 and 2016. Microstructural coronary changes were compared between normal CA segments and those with dilation, regressed aneurysms, and persistent aneurysms.OCT was performed on 33 patients aged 12.0 ± 5.4 years, 8.5 ± 5.4 years after KD diagnosis. Of the 79 segments analyzed, 25 had persistent aneurysms, 22 regressed aneurysms, 11 CA dilation, and 21 no CA involvement. Intimal thickness was 489 ± 173 μm, 304 ± 158 μm, 102 ± 68 μm, and 63 ± 29 μm, respectively (P0.001). There was a linear correlation between the maximum aneurysm size and the intimal thickness, as well as coronary dimension at the time of OCT. Fibrosis (54 segments, 68%) and cellular infiltration (22 segments, 28%) were found more often in segments with CA involvement, but also those without (P = 0.01; P = 0.02). Destruction of the media (34 segments, 43%), calcifications (6 segments, 8%), neovascularization (18 segments, 23%), and white thrombi (8 segments, 10%) were found almost exclusively in segments with a history of aneurysms.Intimal hyperplasia, fibrosis, and cellular infiltration were found in all categories of CA involvement, whereas calcification, destruction of the media, neovascularization, and white thrombi were found essentially only in segments with saccular or fusiform aneurysms. Prospective studies with outcome correlations are needed to see if this is associated with an increased risk of late adverse events.

BACKGROUND Kawasaki disease (KD) is a paediatric systemic vasculitis that can be associated with concomitant viral or bacterial infections. Patients with persistent or recurrent fever 36 hours after the end of intravenous immunoglobulin (IVIG) are considered to be resistant to treatment and are at increased risk for coronary complications. OBJECTIVES However, it is unknown how concomitant infection influences the response to IVIG treatment. The aim of this study was to determine the impact of concurrent infection on the prevalence of IVIG resistance and coronary outcome. DESIGN/METHODS Retrospective study of 154 children (mean age at diagnosis: 3.4 ± 2.8 years) diagnosed with KD, between 2008–2016 in a tertiary paediatric university hospital, of which 59 (38%) had concomitant infection. RESULTS Delay in diagnosis (>10 days of fever) was similar between patients with and without concomitant infection (7% vs 7%, p=0.89). Patients with concomitant infection were more likely to have fever 48 hours after initial treatment (36% vs 20%, p=0.05) and to be treated with a second dose of IVIG (33% vs 18%, p=0.04). Patients with infection had higher C-reactive protein at the time of diagnosis (148 vs 112 mg/L, p=0.04), which persisted after IVIG administration (111 vs 59 mg/L at 48 hours, p=0.003). However, there was no statistically significant difference in the prevalence of coronary artery (CA) complications (coronary artery Z-score > 2.5) between patients with and without concomitant infection (36% vs 39%, p=0.68). CONCLUSION Children with KD and concomitant infection are more likely to have persistent fever and elevated inflammatory markers after treatment requiring a second dose of IVIG. Nevertheless, this is not associated with an increased risk of CA complications. Larger scale studies are needed to help distinguish IVIG resistance from infection in children with persistent fever and guide management of this population. Table/Chart or graphic upload

Introduction Kawasaki disease (KD) can be associated with concomitant viral or bacterial infections. Children with persistent or recurrent fever 36 hours after the end of intravenous immunoglobulin (IVIG) are considered to be resistant to treatment and are at increased risk for coronary complications. Although concomitant infection does not affect coronary outcome, it is unknown how it influences the response to IVIG treatment. Methodology Retrospective cohort study between 2008 and 2016 in a tertiary pediatric university hospital, including 154 children, of which 59 (38%) had concomitant infection. Results Children with concomitant infection were more likely to have fever 48 hours after initial IVIG treatment (36% vs 20%, p = 0.05) and to be treated with a second dose (33% vs 18%, p = 0.04). Children with infection had higher C-reactive protein at the time of diagnosis (148 vs 112 mg/L, p = 0.04), and 48 hours after IVIG administration (111 vs 59 mg/L, p = 0.003). Nevertheless, there was no statistically significant difference in the prevalence of coronary complications (Z-score > 2.5) between children with and without concomitant infection (36% vs 39%, p = 0.68). Conclusion Children with KD and concomitant infection are more likely to have persistent fever and elevated inflammatory markers after treatment. This association increases the likelihood of receiving a second dose of IVIG but not the risk of coronary complication. Accordingly, prospective studies to distinguish true IVIG resistance from infection induced persistent fever is warranted.

Coronary artery aneurysm is a serious complication of Kawasaki disease (KD). A 3-month-old infant presented with severe KD 27 days after onset of fever. The patient presented with shock, inferolateral ischemia on electrocardiogram and high troponin. Echocardiography showed severe myocardial dysfunction with diffuse coronary dilation and right coronary artery aneurysm. Arterial Doppler demonstrated thrombosis of aneurysmal axillary and iliac arteries. Withdrawal of support was implemented due to multi-organ failure. Post-mortem optical coherence tomography correlated with pathology. The pulmonary artery was normal on OCT and histology. Coronary arteries showed aneurysmal dilatation, with intimal hyperplasia and preserved media on OCT. Pathology confirmed these findings, with destruction of the internal elastic lamina, luminal myofibroblastic proliferation, neovascularization, and partial disappearance of the media. This is the first report of pathologic correlation in KD with OCT at the subacute stage, which adequately identified structural wall changes.

BACKGROUND:Acetylsalicylic acid (ASA) is part of the recommended treatment of Kawasaki disease (KD). Controversies remain regarding the optimal dose of ASA to be used. We aimed to evaluate the noninferiority of ASA at an antiplatelet dose in acute KD in preventing coronary artery (CA) abnormalities.METHODS:This is a multicenter, retrospective, nonrandomized cohort study including children 0 to 10 years of age with acute KD between 2004 and 2015 from 5 institutions, of which 2 routinely use low-dose ASA (3–5 mg/kg per day) and 3 use high-dose ASA (80 mg/kg per day). Outcomes were CA abnormalities defined as a CA diameter with a z score ≥2.5. We assessed the risk difference of CA abnormalities according to ASA dose. All subjects received ASA and intravenous immunoglobulin within 10 days of fever onset.RESULTS:There were 1213 subjects included, 848 in the high-dose and 365 in the low-dose ASA group. There was no difference in the risk of CA abnormalities in the low-dose compared with the high-dose ASA group (22.2% vs 20.5%). The risk difference adjusted for potential confounders was 0.3% (95% confidence interval [CI]: −4.5% to 5.0%). The adjusted risk difference for CA abnormalities persisting at the 6-week follow-up was −1.9% (95% CI: −5.3% to 1.5%). The 95% CI of the risk difference of CA abnormalities adjusted for confounders was within the prespecified 5% margin considered to be noninferior.CONCLUSIONS:In conjunction with intravenous immunoglobulin, low-dose ASA in acute KD is not inferior to high-dose ASA for reducing the risk of CA abnormalities.

QT-interval variations in response to exercise-induced increases in heart rate have been reported in children and adults in the diagnosis of long QT syndrome (LQTS). A quick standing challenge has been proposed as an alternative provocative test in adults, with no pediatric data yet available.A standing test was performed in 100 healthy children (mean age, 9.7 ± 3.1 years) after 10 minutes in a supine position with continuous electrocardiographic recording. QT intervals were measured at baseline, at maximal heart rate, at maximal QT, and at each minute of a 5-minute recovery while standing. Measurements were taken in leads II/VOn standing, the heart rate increased by 29 ± 10 beats per minute (bpm). The QT interval was similar at baseline and on standing (394 ± 34 ms vs 394 ± 34 ms; P = 1.0). However, QTc increased from 426 ± 21 to 509 ± 41 ms (P0.001). The 95th percentile for QTc at baseline and maximal heart rate was 457 ms and 563 ms, respectively. At 1 minute of recovery, the QT interval was shorter (375 ± 31 ms) compared with baseline (394 ± 34 ms; P0.001) and standing (394 ± 34 ms; P0.001). QTc reached baseline values after 1 minute of recovery and remained stable thereafter (423 ± 23 ms at 1 minute; 426 ± 22 ms at 5 minutes; P = 1.0).This first characterization of QTc changes on standing in children shows substantial alterations, which are greater than those seen in adults. Two-thirds of the children would have been misclassified as having LQTS by adult criteria, indicating the need to create child-specific standards.

Objective While thyrotrophin receptor (TSHR) is recognized as the main autoantigen in Graves' disease (GD), the actual antigen specificity of T cells that infiltrate the thyroid and the orbit is unknown. Identifying T cell responses to TSHR peptides has been difficult in the past due to the low frequency of autoreactive T cells and to the diversity of the putative epitopes identified by proliferation assays. Methods We used the interferon-gamma ELISPOT assay to identify T cell reactivity to TSHR peptides in patients with GD. Peripheral blood T cells were exposed in vitro to four pools of 10 overlapping TSHR peptides. Results T cells from 11 of 31 (35%) patients with GD and 1 of 22 (4%) healthy controls reacted to at least one peptide pool (P = 0·009). Mean time since diagnosis was 3·2 years in responder patients and 5·6 years in nonresponders (P = 0·07). In two patients, T cell reactivity was observed shortly after radioiodine treatment and not thereafter. Conclusions Our findings demonstrate that the ELISPOT assay is effective to test T cell reactivity in patients with GD and that patients with GD have significantly more interferon-gamma responses towards TSHR peptides than controls. The data suggest that screening for T cell responses in patients with GD might be more efficient in recent-onset disease or after radioiodine treatment.

IntroductionIn Kawasaki disease, although coronary dilatation is attributed to vasculitis, the effect of myocardial inflammation is underestimated. Coronary dilatations are determined by Z-scores, which do not take into account dominance. The aim of the present study was to describe the impact of coronary dominance on dilatation in Kawasaki disease.MethodsWe performed a retrospective analysis of coronary dilatations according to angiography categorisation of dominance.ResultsOf 28 patients (2.6 [0.2–10.1] years), right dominance was present in 15 patients and left in 13. Early dilatation was present in all patients, of whom 11 were ipsilateral to the dominant segment and 17 contralateral. Ipsilateral dilatations were present at diagnosis (9/11 versus 6/17, p=0.02) compared with contralateral dilatations, which developed 2 weeks after diagnosis (9/11 versus 16/17, p=0.29). Coronary artery Z-scores of patients with contralateral dilatation increased at 2 weeks, before returning to baseline values (2.0±2.2 at diagnosis, 4.1±1.8 at 2 weeks, 1.8±1.2 at 3–6 months, p=0.001), compared with patients with ipsilateral dilatation in whom Z-scores were maximal at diagnosis and remained stable (3.0±0.9, 2.7±1.1 and 2.6±1.5, respectively, p=0.13). Dominant coronary artery Z-scores were higher compared with non-dominant segments at diagnosis (3.0±0.9 versus 1.0±0.8, pConclusionProgression of coronary dilatation after diagnosis may be a sign of dilatation secondary to vasculitis, as opposed to regression of Z-scores in ipsilateral dilatations, probably related to physiological vasodilatation in response to carditis. This needs to be validated in larger studies against vasculitic and myocardial inflammatory markers.

Background Diagnosis of Kawasaki Disease (KD) can be challenging in the absence of a confirmatory test or pathognomonic finding, especially when clinical criteria are incomplete. We recently proposed serum NT-proBNP as an adjunctive diagnostic test. Methods We retrospectively tested a new algorithm to help KD diagnosis based on NT-proBNP, coronary artery dilation (CAD) at onset, and abnormal serum albumin or C-reactive protein (CRP) levels. The goal was to assess the performance of the algorithm and compare its performance to the 2004 American Heart Association (AHA)/ American Academy of Pediatrics (AAP) algorithm. Results The algorithm was tested on 124 KD patients who had NT-proBNP on admission at our institutions between 2007 and 2013. Age at diagnosis was 3.4±3.0 years, with a median of 5 diagnostic criteria, of whom 55/124 (44%) had incomplete KD. CA complications occurred in 64 (52%) patients, with aneurysm in 14 (11%) of patients. Using this algorithm, 120/124 (97%) were to be treated: based on high NT-proBNP alone for 79 (64%), onset CAD for 14 (11%), and high CRP or low albumin levels for 27 (22%). Applying the AHA/AAP algorithm to our patients with incomplete KD, 22/47 (47%) of eligible patients would not have been referred for treatment, compared to 3/55 (5%) with the NT-proBNP algorithm, p