Role of endomyocardial biopsy for children presenting with acute systolic heart failure

Acute myocarditis secondary to human metapneumovirus: a case series and mini-review

Among viral myocarditis, human metapneumovirus (hMPV) is a rare causative agent with associated cardiac complications. This report provides insight into the disease progression and sheds light on reported cases from the literature. We present the clinical courses of two patients, aged 68 and 58, who developed myocarditis secondary to hMPV infection. Despite the typical severity associated with viral myocarditis in older populations, both patients experienced significant improvement in their condition and ultimately survived. This report highlights the necessity of recognizing hMPV as a potential cause of myocarditis, particularly in older adults presenting with simultaneous respiratory and cardiac symptoms. The recovery and survival of these patients underscore the critical need for awareness and timely treatment strategies to manage this potentially severe condition.

Myocarditis-A Helpful Algorithm to Overcome Diagnostic Challenges in the Pediatric Population

OBJECTIVES

This study was designed to investigate clinical differences between pediatric patients who presented with chest pain, tachycardia, and/or tachypnea who subsequently were or were not diagnosed with myocarditis. The results were used to develop a decision tree to aid in rapid diagnosis of pediatric myocarditis.

METHODS

A retrospective case-control study was performed using the electronic medical records of children aged 0 to 18 years between the years 2003 and 2020 with a complaint of chest pain, tachycardia, and/or tachypnea. Patients included in the study were those diagnosed with myocarditis and those with suspected myocarditis, which was ultimately ruled out. Demographic and clinical differences between the research groups were analyzed. A decision tree was rendered using the rpart (Recursive Partitioning and Regression Trees) package.

RESULTS

Four thousand one hundred twenty-five patients were screened for eligibility. Seventy-three myocarditis patients and 292 nonmyocarditis patients were included. Compared with the control group, the study group was found to have a higher mean respiratory rate (37 ± 23 vs 23 ± 7 breaths per minute) and mean heart rate (121 ± 44 vs 97 ± 25 beats per minute) and lower mean systolic and diastolic blood pressure (102 ± 27/56 ± 17 mm Hg vs 114 ± 14/67 ± 10 mm Hg). The mean white blood cell count was greater in the case group (13 ± 6 vs 10 ± 5 × 10 3 /μL). A decision tree was rendered using simple demographic and clinical variables. The accuracy of the algorithm was 85.2%, with 100% accuracy in patients aged 0 to 2.5 years and 69% in patients aged 2.5 to 18 years.

CONCLUSION

The clinical and laboratory characteristics described in this study were similar to what is described in the literature. The decision tree may aid in the diagnosis of myocarditis in patients 2.5 years and younger. In the population aged 2.5 to 18 years, the decision tree did not constitute an adequate tool for detecting myocarditis.

Findings and Outcome of Transcatheter Right Ventricular Endomyocardial Biopsy and Hemodynamic Assessment in Children with Suspected Myocarditis or Cardiomyopathy

OBJECTIVE

The study objective is assessing findings and outcome in children with suspected cardiomyopathy (CMP) or myocarditis undergoing cardiac catheterization with transcatheter right ventricular endomyocardial biopsy (RV-EMB).

METHODS

All consecutive children undergoing cardiac catheterization with RV-EMB for suspected CMP/myocarditis between 2002-2021 were analysed regarding clinical presentation, cardiac biomarkers, periprocedural management, hemodynamic, histological/immunohistological findings, and outcome.

RESULTS

Eighty-five RV-EMBs were performed in 81 patients at a median age of 6.8 (IQR 9.9) years and a bodyweight of 20 (32.2) kg. Histological/immunohistological findings of RV-EMB revealed dilated CMP in 10 (12%), chronic myocarditis in 28 (33%), healing myocarditis in 5 (6%), acute myocarditis in 9 (11%), other heart muscle diseases in 23 (27%) (7 restrictive CMP, 5 hypertrophic CMP, 4 toxic/anthracycline-induced CMP, 4 endocardfibroelastosis, 1 arrhythmogenic right ventricular CMP, 1 laminin CMP, 1 haemangioma), no conclusive histology in 7 (8%), and normal histology in 3 (4%) patients. Median LVEDP was 17 mmHg (IQR 9), LAP 15 mmHg (10), and PVR 1.83 (1.87) Wood Units/m². There were 3 major complications (3%), all patients recovered without any sequelae. At follow-up (median 1153, IQR 1799 days) 47 (59%) patients were alive, 11 (13%) dead, 15 (18%) underwent cardiac transplantation, and 8 (9%) were lost to follow-up. Death/cardiac transplantation occurred within 3 years from RV-EMB. All patients with an acute myocarditis survived. NT-pro-BNP, echo parameters, and invasive hemodynamics correlate independently with death/cardiac transplant.

CONCLUSION

Hemodynamic invasive data and morphological findings in RV-EMB complete clinical diagnosis in children with suspected CMP/myocarditis and provide important information for further clinical management.

Endomyocardial Biopsy in Pediatric Myocarditis and Dilated Cardiomyopathy: A Tool in Search for a Role

Endomyocardial biopsy (EMB) is a well-known diagnostic tool for the investigation and treatment of myocardial diseases and remains the gold standard for the diagnosis of myocarditis. Due to its invasiveness, with a complication rate ranging from 1 to 15%, its role in the diagnostic work-up of pediatric heart failure is not well established. The aim of this review is to define the role of EMB as diagnostic technique in the work up of children presenting with severe left ventricular dysfunction with the support of our center experience.

Myopericarditis after messenger RNA Coronavirus Disease 2019 Vaccination in Adolescents 12 to 18 Years of Age

OBJECTIVES

To characterize the clinical course and outcomes of children 12-18 years of age who developed probable myopericarditis after vaccination with the Pfizer-BioNTech (BNT162b2) coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccine.

STUDY DESIGN

A cross-sectional study of 25 children, aged 12-18 years, diagnosed with probable myopericarditis after COVID-19 mRNA vaccination as per the Centers for Disease Control and Prevention criteria for myopericarditis at 8 US centers between May 10, 2021, and June 20, 2021. We retrospectively collected the following data: demographics, severe acute respiratory syndrome coronavirus 2 virus detection or serologic testing, clinical manifestations, laboratory test results, imaging study results, treatment, and time to resolutions of symptoms.

RESULTS

Most (88%) cases followed the second dose of vaccine, and chest pain (100%) was the most common presenting symptom. Patients came to medical attention a median of 2 days (range, <1-20 days) after receipt of Pfizer mRNA COVID-19 vaccination. All adolescents had an elevated plasma troponin concentration. Echocardiographic abnormalities were infrequent, and 92% showed normal cardiac function at presentation. However, cardiac magnetic resonance imaging, obtained in 16 patients (64%), revealed that 15 (94%) had late gadolinium enhancement consistent with myopericarditis. Most were treated with ibuprofen or an equivalent nonsteroidal anti-inflammatory drug for symptomatic relief. One patient was given a corticosteroid orally after the initial administration of ibuprofen or an nonsteroidal anti-inflammatory drug; 2 patients also received intravenous immune globulin. Symptom resolution was observed within 7 days in all patients.

CONCLUSIONS

Our data suggest that symptoms owing to myopericarditis after the mRNA COVID-19 vaccination tend to be mild and transient. Approximately two-thirds of patients underwent cardiac magnetic resonance imaging, which revealed evidence of myocardial inflammation despite a lack of echocardiographic abnormalities.

Myocarditis and Pericarditis Following mRNA COVID-19 Vaccination: What Do We Know So Far?

This is a cross-sectional study of 29 published cases of acute myopericarditis following COVID-19 mRNA vaccination. The most common presentation was chest pain within 1-5 days after the second dose of mRNA COVID-19 vaccination. All patients had an elevated troponin. Cardiac magnetic resonance imaging revealed late gadolinium enhancement consistent with myocarditis in 69% of cases. All patients recovered clinically rapidly within 1-3 weeks. Most patients were treated with non-steroidal anti-inflammatory drugs for symptomatic relief, and 4 received intravenous immune globulin and corticosteroids. We speculate a possible causal relationship between vaccine administration and myocarditis. The data from our analysis confirms that all myocarditis and pericarditis cases are mild and resolve within a few days to few weeks. The bottom line is that the risk of cardiac complications among children and adults due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection far exceeds the minimal and rare risks of vaccination-related transient myocardial or pericardial inflammation.

Osteoglycin silencing exerts inhibitory effects on myocardial fibrosis and epithelial/endothelial-mesenchymal transformation in a mouse model of myocarditis

Osteoglycin (Ogn), a class III SLRP member with multiple glycosylation sites, has been proposed to be engaged in cardiac dysfunction and adverse remodeling in human heart failure following myocardial infarction. However, the underlying mechanism remains to be elucidated. Thus, we sought to define the role of Ogn in regulation of the Wnt pathway on myocardial fibrosis and epithelial/endothelial-mesenchymal transformation (EMT/EndMT) in mice with myocarditis. The pathological changes are observed, while hematoxylin-eosin staining and picric acid Sirius red staining were conducted in successfully constructed myocarditis mouse models. Immunohistochemistry and enzyme-linked immunosorbent assay were adopted to determine Ogn and β-catenin levels and serum procollagen propeptide concentrations in the mouse myocardial tissues, respectively. Expression of Ogn and Wnt signaling pathway-related factors were measured by reverse transcription quantitative polymerase chain reaction and western blot assay, cell viability by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cell cycle distribution and apoptosis by flow cytometry. We saw indicative pathological changes accompanied by many Ogn and β-catenin positive cells and increased serum procollagen propeptide, in the mouse myocardial tissues. Loss function assays showed reduced levels of Ogn, β-catenin, LRP6, TGF-β1, Twist, FSP-1, α-SMA and higher levels of E-cadherin and VE-cadherin, together with decreased proliferation rate, as well as increased apoptosis rate, indicating that the Wnt signaling pathway, proliferation were inhibited while apoptosis was enhanced with upon gene silencing. Coherently, depletion of Ogn inhibits myocardial fibroblasts proliferation and EMT/EndMT while facilitating myocardial fibroblasts apoptosis in myocarditis through the Wnt signaling pathway, thus serving as an intervention target for the molecular treatment of myocarditis.

Identification of targeting peptides for the diagnosis of myocarditis

Aim: Current diagnostic tests for myocarditis are invasive and have low diagnostic value. Our aim was to identify potential targeting peptides to detect early myocarditis following intravenous delivery. Materials & methods: We used an animal model of experimental autoimmune myocarditis and a phage display library to identify potential targeting peptides. After several steps, we selected two peptides, MyH-PhD-05 and MyH-PhD-120, for in vivo screening using fluorescent imaging. Immunofluorescence and proteonomic analysis was used to identify potential cellular and molecular targets of MyH-PhD-05. Echocardiography was used to assess functional changes. Results: Peptide MyH-PhD-05 was able to detect animals with severe myocarditis even in the absence of functional changes. Immunofluorescence demonstrated that MyH-PhD-05 colocalizes with CD4+ T cells and monocytes (CD11b+) in cardiac infiltrates. Conclusion: We identified potential targeting peptides for the diagnosis of myocarditis. Future studies will focus on better identification of potential targets and translating this technology to clinically relevant imaging modalities.

Acute Myocarditis with Infarct-like Presentation in a Pediatric Population: Role of Cardiovascular Magnetic Resonance

Chest pain is a typical symptom of acute myocarditis in adolescents. It may be indistinguishable from myocardial ischemia so it is called "infarct-like pattern." Cardiovascular magnetic resonance has an important role as a non-invasive diagnostic tool. The aim of our study is to provide a description of an acute myocarditis series with infarct-like pattern and to evaluate the cardiovascular magnetic resonance role in a pediatric population. We included all pediatric patients (0-16 years) admitted to our hospital (May 2007-May 2016) with clinical diagnosis of acute myocarditis and infarct-like presentation (chest pain, EKG alterations, and released cardiac biomarkers). Diagnosis was confirmed with cardiovascular magnetic resonance using Lake Louise criteria. Seven patients (five males, two females) with a median age of 14 years (12.5-15.2) were included. All patients showed ST-segment changes and released cardiac biomarkers. Three patients had left ventricular hypertrophy and two presented mild systolic left ventricular dysfunction. All patients had at least two positive Lake Louise criteria. Late gadolinium enhancement was positive in all of them. With a median follow-up of 23 months (8-47), all of them are alive, with no cardiac symptoms and normal ventricular function. Infarct-like pattern is a typical presentation of acute myocarditis in adolescents. CMR should be performed in this population and may be considered as a first-line diagnostic tool. Its high sensitivity in infarct-like acute myocarditis may allow us to avoid endomyocardial biopsy. Unlike what was described in adults, late gadolinium enhancement does not imply worse outcome in our series.

Human herpesvirus 6-induced inflammatory cardiomyopathy in immunocompetent children

Over the last decade, human herpesvirus 6 (HHV-6) has been implicated in the etiology of pediatric myocarditis and subsequent dilated cardiomyopathy (DCM). This review provides an overview of recent literature investigating the pathophysiological relevance of HHV-6 in inflammatory cardiomyopathy. We examined 11 cases of previously published pediatric myocarditis and/or DCM associated with HHV-6 and also our experience of detection of virus particles in vascular endothelium of HHV-6 positive endomyocardial biopsy tissue by electron microscopy. The exact role of the presence of HHV-6 and its load remains controversial as the virus is also found in the heart of healthy controls. Therefore, the question remains open whether and how cardiac HHV-6 may be of pathogenetic importance. Quantitative polymerase chain reaction or mRNA testing allows differentiation between low-level latent virus found in asymptomatic myocardium and active HHV-6 infection. Although only a small number of pediatric cases have been reported in literature, HHV-6 should be considered as a causative agent of inflammatory cardiomyopathy, especially in children under three who might be experiencing a primary infection. Future studies are needed to establish a threshold for determining active infection in biopsy samples and the role of coinfections other cardiotropic viruses.

New-Onset Myocarditis in an Immunocompetent Adult with Acute Metapneumovirus Infection

Introduction. A number of viruses have been implicated in viral myocarditis; however, there has been no previous report of human metapneumovirus (hMPV) causing this condition. Discovered in 2001, hMPV is typically associated with upper respiratory illness, mainly affecting children. Case Presentation. We report the case of a 25-year-old man with acute systolic heart failure from viral myocarditis secondary to the hMPV. The patient was initially admitted to the general medical ward but developed increasing oxygen requirements resulting in transfer to the cardiac intensive care unit. Cardiac magnetic resonance imaging was used to help confirm the diagnosis. He was treated with intravenous diuretics, and afterload and preload agents, and he was subsequently discharged home after seven days of hospitalization. Discussion. hMPV is typically a respiratory pathogen; however, it was associated with in myocarditis in our patient. Due to the recent ability to detect this virus, we may see more cases of this, particularly during peak months of infection. Conclusion. This is the first case description of myocarditis associated with hMPV infection.