OBJECTIVES: To describe presentation, hospital course, and predictors of bad outcome in multisystem inflammatory syndrome in children (MIS-C). METHODS: Retrospective data review of a case series of children meeting the published definition for MIS-C who were discharged or died between March 1, 2020, and June 15, 2020, from 33 participating European, Asian, and American hospitals. Data were collected through a Web-based survey and included clinical, laboratory, electrocardiographic, and echocardiographic findings and treatment management. RESULTS: We included 183 patients with MIS-C: male sex, 109 (59.6%); mean age 7.0 ± 4.7 years; Black race, 56 (30.6%); obesity, 48 (26.2%). Overall, 114 of 183 (62.3%) had evidence of severe acute respiratory syndrome coronavirus 2 infection. All presented with fever, 117 of 183 (63.9%) with gastrointestinal symptoms, and 79 of 183 (43.2%) with shock, which was associated with Black race, higher inflammation, and imaging abnormalities. Twenty-seven patients (14.7%) fulfilled criteria for Kawasaki disease. These patients were younger and had no shock and fewer gastrointestinal, cardiorespiratory, and neurologic symptoms. The remaining 77 patients (49.3%) had mainly fever and inflammation. Inotropic support, mechanical ventilation, and extracorporeal membrane oxygenation were indicated in 72 (39.3%), 43 (23.5%), and 4 (2.2%) patients, respectively. A shorter duration of symptoms before admission was found to be associated with poor patient outcome and for extracorporeal membrane oxygenation and/or death, with 72.3% (95% confidence interval: 0.56–0.90; P = .006) increased risk per day reduction and 63.3% (95% confidence interval: 0.47–0.82; P < .0001) increased risk per day reduction respectively. CONCLUSIONS: In this case series, children with MIS-C presented with a wide clinical spectrum, including Kawasaki disease–like, life-threatening shock and milder forms with mainly fever and inflammation. A shorter duration of symptoms before admission was associated with a worse outcome.

Transcatheter closure has become an accepted alternative to surgical repair for ostium secundum atrial septal defects (ASD). However, large ASDs (>38 mm) and defects with deficient rims are usually not offered transcatheter closure but are referred for surgical closure. Transcatheter closure also remains controversial for other complicated ASDs with comorbidities, additional cardiac features and in small children. This article not only provides a comprehensive, up-to-date description of the current indications and contra-indications for ASD device closure, but also further explores the current limits for transcatheter closure in controversial cases. With the devices and technology currently available, several cohort studies have reported successful percutaneous closure in the above-mentioned complex cases. However the feasibility and safety of transcatheter technique needs to be confirmed through larger studies and longer follow-up.

Background: Left ventricular (LV) diastolic dysfunction (DD) carries worse prognosis in childhood. 2-dimensional (2-D) left atrial (LA) strain accurately categorizes DD in adults but its role in children is unknown. Thus, the aim of this study is to investigate whether LA strain and strain rate could diagnose and classify DD in children with dilated (CMD), hypertrophic (HCM) and restrictive (RCM) cardiomyopathies (CM). Methods and Results: The study includes 136 children (aged 8.8 ± 6 years): 44 with DCM, 40 with HCM, 7 with RCM and 45 healthy controls (CTRL). They underwent standard echocardiographic examination and 2-D speckle-tracking analyses (LV longitudinal peak systolic strain (LS), LA peak systolic strain and strain rate). No significant differences in mitral E/A and pulmonary S/D ratios were observed among the four groups. Although E/E’ and indexed left atrial volumes were found to be significantly higher in HCM, DCM and RCM compared to CTRL (p < 0.001), they showed no significant difference among the three CM groups. LV LS values were significantly reduced in CM vs CTRL (p < 0.001) and in DCM vs HCM (p < 0.01), with no other differences between the remaining groups. LA peak systolic strain and strain rate values showed a steady and significant decrease with worsening of DD. Receiver Operating Characteristics (ROC) curves showed area under the curve of 0.976 (p < 0.001) for LA strain and 0.946 (p < 0.001) for LA strain rate, to distinguish CTRL from CMs. Conclusions: LA strain and strain rate could be a promising tool to better understand and classify DD in children with cardiomyopathies, opening the way to its clinical use.

Multisystem inflammatory syndrome in children (MIS‐C) is a rare, but severe complication of coronavirus disease 2019 (COVID‐19). It develops approximately 4 weeks after severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection and involves hyperinflammation with multisystem injury, commonly progressing to shock. The exact pathomechanism of MIS‐C is not known, but immunological dysregulation leading to cytokine storm plays a central role. In response to the emergence of MIS‐C, the European Academy of Allergy and Clinical Immunology (EAACI) established a task force (TF) within the Immunology Section in May 2021. With the use of an online Delphi process, TF formulated clinical statements regarding immunological background of MIS‐C, diagnosis, treatment, follow‐up, and the role of COVID‐19 vaccinations. MIS‐C case definition is broad, and diagnosis is made based on clinical presentation. The immunological mechanism leading to MIS‐C is unclear and depends on activating multiple pathways leading to hyperinflammation. Current management of MIS‐C relies on supportive care in combination with immunosuppressive and/or immunomodulatory agents. The most frequently used agents are systemic steroids and intravenous immunoglobulin. Despite good overall short‐term outcome, MIS‐C patients should be followed‐up at regular intervals after discharge, focusing on cardiac disease, organ damage, and inflammatory activity. COVID‐19 vaccination is a safe and effective measure to prevent MIS‐C. In anticipation of further research, we propose a convenient and clinically practical algorithm for managing MIS‐C developed by the Immunology Section of the EAACI.