Cardiac manifestations and outcomes of COVID-19 vaccine-associated myocarditis in the young in the USA: longitudinal results from the Myocarditis After COVID Vaccination (MACiV) multicenter study.

Background: We aimed to study the clinical characteristics, myocardial injury, and longitudinal outcomes of COVID-19 vaccine-associated myocarditis (C-VAM). Methods: In this longitudinal retrospective observational cohort multicenter study across 38 hospitals in the United States, 333 patients with C-VAM were compared with 100 patients with multisystem inflammatory syndrome in children (MIS-C). We included patients ≤30 years of age with a clinical diagnosis of acute myocarditis after COVID-19 vaccination based on clinical presentation, abnormal biomarkers and/or cardiovascular imaging findings. Demographics, past medical history, hospital course, biochemistry results, cardiovascular imaging, and follow-up information from April 2021 to November 2022 were collected. The primary outcome was presence of myocardial injury as evidenced by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging. Findings: Patients with C-VAM were predominantly white (67%) adolescent males (91%, 15.7 ± 2.8 years). Their initial clinical course was more likely to be mild (80% vs. 23%, p < 0.001) and cardiac dysfunction was less common (17% vs. 68%, p < 0.0001), compared to MIS-C. In contrast, LGE on CMR was more prevalent in C-VAM (82% vs. 16%, p < 0.001). The probability of LGE was higher in males (OR 3.28 [95% CI: 0.99, 10.6, p = 0.052]), in older patients (>15 years, OR 2.74 [95% CI: 1.28, 5.83, p = 0.009]) and when C-VAM occurred after the first or second dose as compared to the third dose of mRNA vaccine. Mid-term clinical outcomes of C-VAM at a median follow-up of 178 days (IQR 114-285 days) were reassuring. No cardiac deaths or heart transplantations were reported until the time of submission of this report. LGE persisted in 60% of the patients at follow up. Interpretation: Myocardial injury at initial presentation and its persistence at follow up, despite a mild initial course and favorable mid-term clinical outcome, warrants continued clinical surveillance and long-term studies in affected patients with C-VAM. Funding: The U.S. Food and Drug Administration.

Clinical outcomes after a biopsy diagnosis of antibody-mediated rejection in pediatric heart transplant recipients.

BACKGROUND: Extending survival after heart transplant (HT) is of paramount importance for childhood recipients of HT. Acute rejection is a significant event, and biopsy remains the most specific means for distinguishing between cellular (ACR) and antibody-mediated rejection (AMR). METHODS: All children in the Pediatric Heart Transplant Society Registry who underwent HT between January 2015 and June 2022 and had ≥1 rejection episode were included. Survival was compared between AMR and ACR-only. Secondary outcomes of infection, malignancy, and cardiac allograft vasculopathy (CAV) were assessed. Risk factors for graft loss after AMR were identified using Cox proportional hazard modeling. RESULTS: Among 906 children with rejection, 697 (77%) with complete biopsy information were included. AMR was present on biopsy in 261 (37%) patients; ACR-only was present in 436 (63%). Time to rejection was earlier for AMR, median time from HT to rejection 0.11 versus 0.29 years, p = 0.0006. Survival after AMR in the 1st year was lower than survival after ACR-only. Predictors of graft loss after AMR were younger age at HT, congenital heart disease, and rejection with hemodynamic compromise. There was no difference in time to CAV, infection, or malignancy after rejection between groups. CONCLUSIONS: The largest analysis of pediatric HT rejection with biopsy data to identify AMR underscores the continued importance of AMR on survival. AMR is associated with higher graft loss versus ACR when occurring in the first-year post-HT. Predictors of graft loss after AMR identify patients who may benefit from increased surveillance or augmented maintenance immunosuppression.

A Review of Pediatric Cardiomyopathy.

Though pediatric cardiomyopathy is rare in children, there is significant associated morbidity and mortality. Etiology varies from inborn errors of metabolism to familial genetic mutations and myocyte injury. Major classes include dilated, hypertrophic, restrictive, and non-compaction. Diagnosis generally involves a combination of clinical history and echocardiography. The use of cross-sectional imaging is gaining popularity. Management varies between subtype and may involve a combination of medical and surgical interventions depending on clinical status.

Enhanced congenital cardiac surgery knowledge with multidisciplinary collaborative education series for paediatric cardiology fellows and nurse practitioners.

INTRODUCTION: Paediatric cardiologists and nurse practitioners lack structured education tools focused on basic cardiac surgery principles. However, non-surgical specialties caring for surgical patients require this knowledge for comprehensive clinical care. We created a cardiac surgical educational curriculum focused on improving knowledge and attitudes towards communication for non-surgical trainees and advanced practice providers. METHODS: Over one academic year, six paediatric cardiology fellows and seven paediatric cardiac surgery nurse practitioners at Seattle Children's Hospital participated in this study. With surgical supervision, six lectures were prepared by each fellow and delivered monthly. Sessions were hybrid and recorded for later viewing. Pre- and post-intervention survey of attitudes regarding surgical topics and pre- and post- test-based knowledge assessments were administered. RESULTS: Participants positively rated the usefulness of the lecture series (4.2/5) and would recommend it to a colleague (4.5/5). Self-reported confidence discussing surgical concepts with patients increased from 2.3 to 3.4 among paediatric cardiology fellows (p < 0.001) and from 2.8 to 3.9 among nurse practitioners (p < 0.001), out of 5. In both groups, knowledge assessment scores improved from 54 to 79% post-intervention (p < 0.001). CONCLUSIONS: After a six-part educational series taught by paediatric cardiology fellows, both paediatric cardiology fellows and paediatric cardiac surgery nurse practitioners demonstrated improved knowledge and reported increased comfort counselling families on basic cardiac surgery topics. Structured, active-learning lessons taught by fellows for non-surgical audiences can improve attitudes and build clinically relevant knowledge. Creating an effective level-appropriate multidisciplinary curriculum accessible to various types of medical providers could enhance comprehensive care of complex congenital cardiac surgery patients.

Applying the Hybrid Concept as a Bridge to Transplantation in Infants Without Hypoplastic Left Heart Syndrome.

Therapies to support small infants in decompensated heart failure that are failing medical management are limited. We have used the hybrid approach, classically reserved for high-risk infants with single ventricle physiology, in patients with biventricular physiology with left ventricular failure. This approach secures systemic circulation, relieves left atrial hypertension, protects the pulmonary vasculature, and allows the right ventricle to support cardiac output. This approach can be used as a bridge to transplantation in select individuals. Infants without single ventricle congenital heart disease who were treated with the hybrid approach between 2008 and 2021 were included in analysis. Eight patients were identified. At the time of hybrid procedure, the median weight was 3.2 kg (range 2.4-3.6 kg) and the median age was 18 days (range 1-153 days). Seventy five percent were mechanically ventilated and 88% were on inotropic support. The median duration from hybrid procedure to transplant was 63 days (range 4-116 days). All patients experienced a good outcome (delisted for improvement or transplanted). The hybrid procedure is an appropriate therapeutic bridge to transplantation in a carefully selected subset of critically ill infants without single ventricle congenital heart disease in whom alternate therapies may confer increased risk for morbidity and mortality.

Treating Pediatric Myocarditis with High Dose Steroids and Immunoglobulin.

There is considerable variability in practice among pediatric centers for treatment of myocarditis. We report outcomes using high dose steroids in conjunction with IVIG. This is a single center retrospective study of children < 21 years of age diagnosed with myocarditis and treated with high dose steroids and IVIG from January 2004-April 2021. Diagnostic criteria for myocarditis included positive endomyocardial biopsy, cardiac magnetic resonance (CMR) imaging meeting Lake Louise criteria, or strictly defined clinical diagnosis. Forty patients met inclusion criteria. Median age at diagnosis was 11.6 years (0.7-14.6). Diagnosis was made clinically in 70% of cases (N = 28), by CMR in 12.5% (N = 5) and by biopsy in 17.5% (N = 7). Median ejection fraction (EF) at diagnosis was 35% (IQR 24-48). Median duration of IV steroids was 7 days (IQR 4-12) followed by an oral taper. Median cumulative dose of IV immunoglobulin (IVIG) was 2 g/kg. There were no serious secondary bacterial infections after steroid initiation. Ten patients (25%) required mechanical circulatory support. Overall transplant free survival was 92.5% with median follow-up of 1 year (IQR 0-6 years). Six patients required re-admission for cardiovascular reasons. By 3 months from diagnosis, 70% of patients regained normal left ventricular function. High dose steroids in conjunction with IVIG to treat acute myocarditis can be safe without significant infections or long-term side effects. Our cohort had excellent recovery of ventricular function and survival without transplant. Prospective comparison of a combination of high dose steroids with IVIG versus other therapies is needed.

Isolated Right Common Carotid Artery Arising from the Right Pulmonary Artery.

Isolated aortic arch vessels arising anomalously from the pulmonary arterial system are rare congenital anomalies. Case reports of isolated arch vessels are often associated with 22q11 deletion, CHARGE syndrome, or right aortic arch. Isolation of the carotid artery may lead to cerebral steal phenomenon and ischemia or to pulmonary overcirculation. The authors report what is, to their knowledge, the first case of isolated right common carotid artery arising from the right pulmonary artery, associated with 22q11 deletion, and describe the challenging multimodality image evaluation. Keywords: Congenital, Anatomy, Carotid Arteries © RSNA, 2022.

A unique cardiovascular presentation of Marfan syndrome.

We report a neonate with severe Marfan syndrome (MS), prenatally identified to have persistent atrial tachycardia, biventricular dysfunction, and an unusual structure within the atria. Detailed postnatal echocardiographic evaluation and cross-sectional imaging confirmed congenital pseudoaneurysm of the mitral-aortic intervalvular fibrosa. Emergent testing by next-generation sequencing identified a FBN1 pathological variant, key to establishing goals of care. To our knowledge, this is the first reported case of a congenital pseudoaneurysm of the mitral-aortic intervalvular fibrosa in MS.

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.

Persistent Cardiac Magnetic Resonance Imaging Findings in a Cohort of Adolescents with Post-Coronavirus Disease 2019 mRNA Vaccine Myopericarditis.

We describe the evolution of cardiac magnetic resonance imaging findings in 16 patients, aged 12-17 years, with myopericarditis after the second dose of the Pfizer mRNA coronavirus disease 2019 vaccine. Although all patients showed rapid clinical improvement, many had persistent cardiac magnetic resonance imaging findings at 3- to 8-month follow-up.

Clinically Suspected Myocarditis Temporally Related to COVID-19 Vaccination in Adolescents and Young Adults: Suspected Myocarditis After COVID-19 Vaccination.

BACKGROUND: Understanding the clinical course and short-term outcomes of suspected myocarditis after the coronavirus disease 2019 (COVID-19) vaccination has important public health implications in the decision to vaccinate youth. METHODS: We retrospectively collected data on patients <21 years old presenting before July 4, 2021, with suspected myocarditis within 30 days of COVID-19 vaccination. Lake Louise criteria were used for cardiac MRI findings. Myocarditis cases were classified as confirmed or probable on the basis of the Centers for Disease Control and Prevention definitions. RESULTS: We report on 139 adolescents and young adults with 140 episodes of suspected myocarditis (49 confirmed, 91 probable) at 26 centers. Most patients were male (n=126, 90.6%) and White (n=92, 66.2%); 29 (20.9%) were Hispanic; and the median age was 15.8 years (range, 12.1-20.3; interquartile range [IQR], 14.5-17.0). Suspected myocarditis occurred in 136 patients (97.8%) after the mRNA vaccine, with 131 (94.2%) after the Pfizer-BioNTech vaccine; 128 (91.4%) occurred after the second dose. Symptoms started at a median of 2 days (range, 0-22; IQR, 1-3) after vaccination. The most common symptom was chest pain (99.3%). Patients were treated with nonsteroidal anti-inflammatory drugs (81.3%), intravenous immunoglobulin (21.6%), glucocorticoids (21.6%), colchicine (7.9%), or no anti-inflammatory therapies (8.6%). Twenty-six patients (18.7%) were in the intensive care unit, 2 were treated with inotropic/vasoactive support, and none required extracorporeal membrane oxygenation or died. Median hospital stay was 2 days (range, 0-10; IQR, 2-3). All patients had elevated troponin I (n=111, 8.12 ng/mL; IQR, 3.50-15.90) or T (n=28, 0.61 ng/mL; IQR, 0.25-1.30); 69.8% had abnormal ECGs and arrhythmias (7 with nonsustained ventricular tachycardia); and 18.7% had left ventricular ejection fraction <55% on echocardiogram. Of 97 patients who underwent cardiac MRI at a median 5 days (range, 0-88; IQR, 3-17) from symptom onset, 75 (77.3%) had abnormal findings: 74 (76.3%) had late gadolinium enhancement, 54 (55.7%) had myocardial edema, and 49 (50.5%) met Lake Louise criteria. Among 26 patients with left ventricular ejection fraction <55% on echocardiogram, all with follow-up had normalized function (n=25). CONCLUSIONS: Most cases of suspected COVID-19 vaccine myocarditis occurring in persons <21 years have a mild clinical course with rapid resolution of symptoms. Abnormal findings on cardiac MRI were frequent. Future studies should evaluate risk factors, mechanisms, and long-term outcomes.

Myopericarditis After the Pfizer Messenger Ribonucleic Acid Coronavirus Disease Vaccine in Adolescents.

Reports have emerged of myocarditis and pericarditis predominantly after the second dose of the coronavirus disease messenger ribonucleic acid vaccine. We describe 13 patients aged 12-17 years who presented with chest pain within 1 week after their second dose of the Pfizer vaccine and were found to have elevated serum troponin levels and evidence of myopericarditis.