Acute and Fulminant Myocarditis: a Pragmatic Clinical Approach to Diagnosis and Treatment

Myocarditis and Inflammatory Cardiomyopathy in Dilated Heart Failure

Inflammatory cardiomyopathy is a condition that is characterised by the presence of inflammatory cells in the myocardium, which can lead to a significant deterioration in cardiac function. The etiology of this condition involves multiple factors, both infectious and non-infectious causes. While it is primarily associated with viral infections, other potential causes include bacterial, protozoal, or fungal infections, as well as a wide variety of toxic substances and drugs, and systemic immune-mediated pathological conditions. In spite of comprehensive investigation, the presence of inflammatory cardiomyopathy accompanied by left ventricular dysfunction, heart failure or arrhythmia is indicative of an unfavourable outcome. The reasons for the occurrence of either favourable outcomes, characterised by the absence of residual myocardial injury, or unfavourable outcomes, marked by the development of dilated cardiomyopathy, in patients afflicted by the condition remain to be elucidated. The relative contributions of pathogenic agents, genomic profiles of the host, and environmental factors in disease progression and resolution remain subjects of ongoing discourse. This includes the determination of which viruses function as active inducers and which merely play a bystander role. It remains unknown which changes in the host immune profile are critical in determining the outcome of myocarditis caused by various viruses, including coxsackievirus B3 (CVB3), adenoviruses, parvoviruses B19 and SARS-CoV-2. The objective of this review is unambiguous: to provide a concise summary and comprehensive assessment of the extant evidence on the pathogenesis, diagnosis and treatment of myocarditis and inflammatory cardiomyopathy. Its focus is exclusively on virus-induced and virus-associated myocarditis. In addition, the extant lacunae of knowledge in this field are identified and the extant experimental models are evaluated, with the aim of proposing future directions for the research domain. This includes differential gene expression that regulates iron and lipid and metabolic remodelling. Furthermore, the current state of knowledge regarding the cardiovascular implications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is also discussed, along with the open questions that remain to be addressed.

Lactate Dehydrogenase Indicates Development From Fulminant Myocarditis to Chronic Persistent Myocarditis: A Multicenter Retrospective Cohort Study in China

Background

Fulminant myocarditis (FM) is a critical manifestation of myocarditis. However, the clinical features and risk factors associated with its adverse outcomes are not fully understood. Given the high mortality and potential for long-term complications, it is crucial to identify factors that could predict the progression of FM to chronic persistent myocarditis. We hypothesize some clinical or laboratory markers may be predictive of this progression. This study aims to identify clinical factors that may help predict the progress of FM to chronic persistent myocarditis.

Methods

A total of 82 patients with FM treated based on Chinese protocol were included. Kaplan-Meier curve and regression analysis were used to determine the clinical features and prognostic predictors of chronic persistent myocarditis in patients with 24 months of follow-up.

Results

Chronic persistent myocarditis was observed in 20 patients during the follow-up. ROC curve showed that the critical value for chronic persistent myocarditis caused by lactate dehydrogenase (LDH) was 577.00U/L (sensitivity 75.0%, specificity 74.2%). Time from onset to admission over 6 days and LDH > 577.00U/L were identified as risk factors for chronic persistent myocarditis in patients with FM in both univariate and multivariate cox analysis. The hazard ratio and 95% Confidence intervals were 3.35 (1.32-8.50) (p = 0.011) and 6.11 (2.02-18.48) (p < 0.001), respectively. The per standard deviation of increment in LDH was associated with the 55% (1.55, 1.11-2.18) in HR and 95% CI of the occurrence of chronic persistent myocarditis.

Conclusion

About 24.4% of the patients with FM treated based on the life support measures proposed in the consensus of Chinese Society of Cardiology have been observed chronic persistent myocarditis. Time from onset to admission over 6 days and LDH levels >577.00 U/L at admission may serve as risk factors for the progression from FM to chronic persistent myocarditis.

ANOCA, INOCA, MINOCA: The New Frontier of Coronary Syndromes

The growing prevalence in the diagnosis of INOCA (Ischemia with Non-Obstructive Coronary Arteries), ANOCA (Angina with Non-Obstructive Coronary Arteries), and MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) highlights the need to reassess their clinical relevance. Historically regarded as benign syndromes, emerging evidence suggests that these conditions may cause serious cardiovascular events and considerable long-term disability. Additionally, emerging studies suggest that non-obstructive coronary artery disease (CAD) may have a higher prevalence compared to traditional obstructive forms of CAD. This leads to the need to better clarify the underlying pathogenic mechanisms as well as the risk factors associated with these syndromes. This is precisely the aim of this review, which focuses on the complex and heterogeneous mechanisms underlying these syndromes as well as the associated risk factors. This review also sums up the diagnostic steps necessary to achieve an accurate diagnosis, along with the interventional and pharmacological approaches to be implemented in light of the latest evidence.

Emerging Biomarkers in Cardiac Sarcoidosis and Other Inflammatory Cardiomyopathies

PURPOSE OF REVIEW

Cardiac sarcoidosis and other inflammatory cardiomyopathies are disorders causing cardiac inflammation and leading to heart failure, arrythmias and cardiac arrest. Diagnosis of these entities remains challenging and multimodal. Thus, there is a growing need to develop reliable biomarkers that can aid in the diagnosis. This review aims to summarize and highlight recent findings in the field of biomarkers for cardiac sarcoidosis and inflammatory cardiomyopathy.

RECENT FINDINGS

Multiple categories of biomarkers including novel molecules are being investigated with the latest evidence showing promising results. Some of these biomarkers are proven to be useful as diagnostic and prognostic aids in cardiac sarcoid and inflammatory cardiomyopathy. The identification of cost-effective and accurate biomarkers is useful not only for enhancing diagnostic accuracy but also for informing therapeutic decision-making processes. This advancement would facilitate the timely institution of immunosuppressive therapies, ultimately leading to improved patient outcomes.

Management Status of Myocarditis-Related Sudden Cardiac Death

Myocarditis, a life-threatening disease that can result in cardiac arrest and sudden cardiac death, has garnered significant attention in recent years. This review provides a comprehensive overview of the management of myocarditis-related sudden cardiac death, encompassing its pathology, diagnostic methods, therapeutic strategies, preventive measures, prognostic factors, and risk stratification. Additionally, the review highlights current challenges and future directions in this field. The aim is to enhance understanding of myocarditis-related sudden cardiac death and inform clinical practice, ultimately leading to improved patient outcomes.

Clinically suspected acute right ventricular fulminant dengue myocarditis masquerading with dual lethal arrhythmias: a case report

BACKGROUND

Acute right ventricular myocarditis is rare, comprising only 18% of myocarditis cases. Despite being relatively infrequent at 12.4%, dengue-induced myocarditis has a high mortality risk of 26.4%. This report presents a novel case of acute fulminant right ventricular myocarditis due to severe dengue infection, complicated by dual electrical disturbances: complete heart block and ventricular tachycardia.

CASE REPORT

A 49-year-old Asian male patient was referred to our hospital with a temporary pacemaker due to a complete heart block. He had a history of recurrent syncope over three days and a fever five days before admission. Initial electrocardiography showed a total atrioventricular nodal block progressing to a high-degree atrioventricular block with a left bundle branch block, indicating an infra-Hisian block. Laboratory findings included thrombocytopenia, elevated troponin, high creatinine, increased liver transaminases, and a positive dengue nonstructural protein 1 test, confirming a diagnosis of dengue infection. Echocardiography showed reduced right ventricular systolic function, normal left ventricular systolic function (ejection fraction: 50%), and dyskinetic intraventricular septum. Coronary angiography revealed normal coronary anatomy. An endomyocardial biopsy was deferred due to severe thrombocytopenia. On the third day, the patient's condition worsened, developing cardiogenic shock and left ventricular systolic dysfunction (ejection fraction: 35%). He subsequently experienced a seizure and slow ventricular tachycardia originating from the right coronary cusp, followed by cardiac arrest. The patient's family claimed not to resuscitate the patient. Furthermore, the patient died shortly after.

CONCLUSION

This case underscores the critical need for prompt diagnosis and aggressive management of clinically suspected acute fulminant right ventricular myocarditis because complications can rapidly progress to left ventricular systolic dysfunction, leading to cardiogenic shock and sudden cardiac death.

Creatine phosphate improves myocardial function and myocardial enzyme profile in children with myocarditis

Myocarditis in children is more common in clinical practice, which can cause different degrees of cardiac function damage. We investigated the effects of creatine phosphate in the treatment of myocarditis in children. Children in the control group were treated with sodium fructose diphosphate, and children in the observation group were treated with creatine phosphate on the basis of the control group. After treatment, the myocardial enzyme profile and cardiac function of children in the observation group were better than the control group. The total effective rate of treatment for children in the observation group was higher than that in the control group. In conclusion, creatine phosphate could significantly improve myocardial function, improve myocardial enzyme profile and reduce myocardial damage in children with pediatric myocarditis and had a high safety of use, which was worthy of clinical promotion.

Extracorporeal cardiopulmonary resuscitation successfully used in a two-hour cardiac arrest caused by fulminant myocarditis: a case report

Fulminant myocarditis (FM) is characteristically associated with rapid progressive decline in cardiac function and high mortality, with rapid onset of hemodynamic dysfunction and severe arrhythmias. In this report, we describe a case concerning a patient clinically diagnosed with FM, marked by rapid progression leading to intractable ventricular fibrillation and subsequent cardiac arrest. Conventional cardiopulmonary resuscitation (CCPR) was performed 120 min before extracorporeal membrane oxygenation (ECMO) was initiated. This critical situation was effectively addressed through the utilization of extracorporeal cardiopulmonary resuscitation (ECPR). By providing sustained cardiopulmonary support, effective hemodynamics were obtained. Eventually, the patient made a full recovery, and discharged without neurologic complications on hospital day 13.

Prognostic role of systemic immune-inflammation index versus other cardiac markers in acute myocarditis in young adults

Aim: Myocarditis, an inflammatory disease of the myocardium, can range from asymptomatic cases to severe forms such as fulminant myocarditis. The systemic immune-inflammation index (SII) has emerged as a potential biomarker for various inflammatory diseases. This study aimed to determine the effect of SII on the prognosis of young adults with acute myocarditis and compare it with other cardiac markers.Methods: We retrospectively analyzed patients aged 18-40 years who were admitted to the emergency department with a diagnosis of acute myocarditis between January 2014 and January 2024. Patients were divided into non-fulminant and fulminant myocarditis groups based on diagnostic criteria.Results: SII, troponin I and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were significantly higher in the fulminant myocarditis group (p < 0.001 for all). Logistic regression analysis identified SII and NT-proBNP as independent predictors of fulminant myocarditis but not for troponin I (p = 0.064). The optimal cutoff value for SII in diagnosing fulminant myocarditis was 1020, with a sensitivity of 91% and specificity of 83%, outperforming troponin I. Patients with SII ≥1020 had a significantly higher risk of adverse outcomes.Conclusion: The SII enables early detection of adverse outcomes and is an independent predictor of prognosis in young adults with myocarditis.

Novel Immunohistochemical and Morphological Approaches in a Retrospective Study of Post-Mortem Myocarditis

Background and Objectives: This study presents a retrospective analysis of 26 autopsy cases from a single centre, primarily focusing on forensic cases, with a majority of male individuals. Materials and Methods: We systematically analysed autopsy reports and cardiac tissue slides using haematoxylin-eosin stain and immunohistochemistry for CD3, CD163, and IL-6. The histological assessment evaluated key variables such as inflammation severity, necrosis, and background changes using a standardised grading system. Quantitative analysis of immunohistochemical markers was performed, calculating the percentage of positively stained cells within the inflammatory infiltrate. Results: The average age was 51.6 years, slightly skewed towards older males. The fatalities varied widely, with sudden death and drug abuse being the most common conditions linked to myocarditis findings on histological examination. A strong correlation was found between the severity of inflammation (measured by size within a myocardium section) and the scoring system based on the number of inflammatory foci per section (p ≤ 0.001). Most cases showed mild to minimal fibrosis, with some exhibiting moderate to severe fibrosis, arteriosclerosis, and myocyte hypertrophy. The presence of protein CD3 in the inflammatory infiltrate revealed a moderate inverse correlation between the CD3 values and the severity of inflammation and necrosis, and a strong inverse correlation with neutrophil levels. CD3 levels were higher in sudden death cases and lower in cases with numerous inflammatory foci, highlighting the discreet nature of lymphocytic myocarditis. Macrophage presence, assessed using CD163, showed a moderate inverse correlation with neutrophil levels and significant differences between sudden death and non-sudden death cases. Macrophage-rich inflammation was observed in cases with pneumonia/bronchopneumonia-associated lesions. IL-6 expression showed a moderate direct correlation with inflammation severity (p = 0.028), severity of necrosis (p = 0.005), and the number of inflammatory foci per section (p = 0.047). A moderate inverse correlation was found between CD3 and IL-6 expression (p = 0.005). Conclusions: These findings highlight the need for a unique immunohistochemical approach in forensic cases of myocarditis, differing from guidelines for endomyocardial biopsies due to diverse inflammatory cells. The study suggests exploring inflammatory chemokines within myocarditis foci for their significance in clinical scenarios. Specifically, IL-6, a crucial pro-inflammatory interleukin, correlated significantly with the severity of inflammation and necrosis (p < 0.05). This study provides novel and valuable insights into the histopathological and immunological markers of myocarditis in autopsy cases.

Yohimbine Treatment Alleviates Cardiac Inflammation/Injury and Improves Cardiac Hemodynamics by Modulating Pro-Inflammatory and Oxidative Stress Indicators

Acute myocarditis, also known as myocardial inflammation, is a self-limited condition caused by systemic infection with cardiotropic pathogens, primarily viruses, bacteria, or fungi. Despite significant research, inflammatory cardiomyopathy exacerbated by heart failure, arrhythmia, or left ventricular dysfunction and it has a dismal prognosis. In this study, we aimed to evaluate the therapeutic effect of yohimbine against lipopolysaccharide (LPS) induced myocarditis in rat model. The anti-inflammatory activity of yohimbine was assessed in in-vitro using RAW 264.7 and H9C2 cells. Myocarditis was induced in rats by injecting LPS (10 mg/kg), following the rats were treated with dexamethasone (2 mg/kg) or yohimbine (2.5, 5, and 10 mg/kg) for 12 h and their therapeutic activity was examined using various techniques. Yohimbine treatment significantly attenuated the LPS-mediated inflammatory markers expression in the in-vitro model. In-vivo studies proved that yohimbine treatment significantly reduced the LPS-induced increase of cardiac-specific markers, inflammatory cell counts, and pro-inflammatory markers expression compared to LPS-control samples. LPS administration considerably affected the ECG, RR, PR, QRS, QT, ST intervals, and hemodynamic parameters, and caused abnormal pathological parameters, in contrast, yohimbine treatment substantially improved the cardiac parameters, mitigated the apoptosis in myocardial cells and ameliorated the histopathological abnormalities that resulted in an improved survival rate. LPS-induced elevation of cardiac troponin-I, myeloperoxidase, CD-68, and neutrophil elastase levels were significantly attenuated upon yohimbine treatment. Further investigation showed that yohimbine exerts an anti-inflammatory effect partly by modulating the MAPK pathway. This study emphasizes yohimbine's therapeutic benefit against LPS-induced myocarditis and associated inflammatory markers response by regulating the MAPK pathway.

Myocardical Infarction with Non-Obstructive Coronary Arteries (MINOCA): pathogenesis, diagnosis and treatment

The term MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) refers to myocardial infarction cases where coronary arteries exhibit less than 50 % stenosis. MINOCA encompasses a diverse range of pathologies with varying etiologies. Diagnosis involves meeting acute myocardial infarction criteria and excluding other causes (myocarditis, takotsubo syndrome). Clinical features often resemble those of traditional myocardial infarction, but MINOCA patients tend to be younger and more frequently female. Etiological investigations include coronary angiography, intracoronary imaging, and vasomotor function tests. Causes include plaque rupture, coronary dissection, vasospasm, microvascular dysfunction, thromboembolism. Prognosis varies, with some subsets at higher risk. Management involves a tailored approach addressing underlying causes, with emphasis on cardioprotective therapy, risk factor modification, and lifestyle interventions. Further research is needed to refine diagnostic strategies and optimize therapeutic approaches in MINOCA patients.

A multidisciplinary approach of a patient with pheochromocytoma presenting as recurrent acute fulminant myocarditis: A rare case report and comprehensive review of literature

Fulminant myocarditis (FM) is a rare illness characterized by abrupt and severe widespread cardiac inflammation, which frequently results in mortality due to cardiogenic shock, ventricular arrhythmias, or multiorgan system failure. Pheochromocytoma is an uncommon and difficult-to-diagnose cause of FM, and it is associated with a significant risk of recurrent acute myocarditis. There is, however, little information on reoccurring acute FM. Herein, we report a rare case of recurrent acute FM due to pheochromocytoma. We present the case of a 22-year-old woman who was admitted to our hospital three days previously with acute dyspnea. Five months prior, the patient was diagnosed with post-acute myocarditis, and a massive tumor on the right adrenal gland was discovered, which lead to pheochromocytoma diagnosis. In this present admission, following the exclusion of infection, autoimmune, and metabolic derangements, pheochromocytoma was presumed to be the reason for the recurrence and more severe acute FM during the current hospitalization. The patient responded favorably to high-dose steroids combined with heart failure therapy regimens. To detect recurrent acute myocarditis related to pheochromocytoma, a multidisciplinary approach was used, including several laboratory biomarkers and imaging findings. Following pheochromocytoma removal and biopsy, the patient recovered satisfactorily. Our findings may provide beneficial contributions to the literature as pheochromocytoma is an uncommon but important cause of recurrent acute myocarditis. A multidisciplinary approach is essential in identifying acute FM and determining the underlying causes of this malady.

Acute myocarditis: an overview of pathogenesis, diagnosis and management

Acute myocarditis encompasses a diverse presentation of inflammatory cardiomyopathies with infectious and non-infectious triggers. The clinical presentation is heterogeneous, from subtle symptoms like mild chest pain to life-threatening fulminant heart failure requiring urgent advanced hemodynamic support. This review provides a comprehensive overview of the current state of knowledge regarding the pathogenesis, diagnostic approach, management strategies, and directions for future research in acute myocarditis. The pathogenesis of myocarditis involves interplay between the inciting factors and the subsequent host immune response. Infectious causes, especially cardiotropic viruses, are the most frequently identified precipitants. However, autoimmune processes independent of microbial triggers, as well as toxic myocardial injury from drugs, chemicals or metabolic derangements also contribute to the development of myocarditis through diverse mechanisms. Furthermore, medications like immune checkpoint inhibitor therapies are increasingly recognized as causes of myocarditis. Elucidating the nuances of viral, autoimmune, hypersensitivity, and toxic subtypes of myocarditis is key to guiding appropriate therapy. The heterogeneous clinical presentation coupled with non-specific symptoms creates diagnostic challenges. A multifaceted approach is required, incorporating clinical evaluation, electrocardiography, biomarkers, imaging studies, and endomyocardial biopsy. Cardiovascular magnetic resonance imaging has become pivotal for non-invasive assessment of myocardial inflammation and fibrosis. However, biopsy remains the gold standard for histological classification and definitively establishing the underlying etiology. Management relies on supportive care, while disease-specific therapies are limited. Although some patients recover well with conservative measures, severe or fulminant myocarditis necessitates aggressive interventions such as mechanical circulatory support devices and transplantation. While immunosuppression is beneficial in certain histological subtypes, clear evidence supporting antiviral or immunomodulatory therapies for the majority of acute viral myocarditis cases remains insufficient. Substantial knowledge gaps persist regarding validated diagnostic biomarkers, optimal imaging surveillance strategies, evidence-based medical therapies, and risk stratification schema. A deeper understanding of the immunopathological mechanisms, rigorous clinical trials of targeted therapies, and longitudinal outcome studies are imperative to advance management and improve the prognosis across the myocarditis spectrum.

Chinese Society of Cardiology guidelines on the diagnosis and treatment of adult fulminant myocarditis

Fulminant myocarditis is an acute diffuse inflammatory disease of myocardium. It is characterized by acute onset, rapid progress and high risk of death. Its pathogenesis involves excessive immune activation of the innate immune system and formation of inflammatory storm. According to China's practical experience, the adoption of the "life support-based comprehensive treatment regimen" (with mechanical circulation support and immunomodulation therapy as the core) can significantly improve the survival rate and long-term prognosis. Special emphasis is placed on very early identification,very early diagnosis,very early prediction and very early treatment.

Peri-Myocarditis as a Dire Consequence of Coronavirus Disease: A Clinical Challenge

Myocarditis is an inflammation of the heart muscle, most commonly caused by viral infections, with other contributing factors including medications or systemic inflammatory conditions. Coronavirus disease 2019 (COVID-19) is a disease caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2 virus). In this report, we present a case of fulminant myocarditis in a patient with COVID-19 infection. Fulminant myocarditis is an aggressively progressive and severe variant that can result in substantial cardiac impairment. We present a case of fulminant myocarditis with a unique time course, progression, and potential challenges faced in diagnosis and management. Healthcare providers need to remain vigilant and anticipate the potential rapid progression of this disease.

CD73/adenosine axis exerts cardioprotection against hypobaric hypoxia-induced metabolic shift and myocarditis in a sex-dependent manner

BACKGROUND

Clinical and experimental studies have shown that the myocardial inflammatory response during pathological events varies between males and females. However, the cellular and molecular mechanisms of these sex differences remain elusive. CD73/adenosine axis has been linked to anti-inflammatory responses, but its sex-specific cardioprotective role is unclear. The present study aimed to investigate whether the CD73/adenosine axis elicits sex-dependent cardioprotection during metabolic changes and myocarditis induced by hypobaric hypoxia.

METHODS

For 7 days, male and female mice received daily injections of the CD73 inhibitor adenosine 5'- (α, β-methylene) diphosphate (APCP) 10 mg/kg/day while they were kept under normobaric normoxic and hypobaric hypoxic conditions. We evaluated the effects of hypobaric hypoxia on the CD73/adenosine axis, myocardial hypertrophy, and cardiac electrical activity and function. In addition, metabolic homeostasis and immunoregulation were investigated to clarify the sex-dependent cardioprotection of the CD73/adenosine axis.

RESULTS

Hypobaric hypoxia-induced cardiac dysfunction and adverse remodeling were more pronounced in male mice. Also, male mice had hyperactivity of the CD73/adenosine axis, which aggravated myocarditis and metabolic shift compared to female mice. In addition, CD73 inhibition triggered prostatic acid phosphatase ectonucleotidase enzymatic activity to sustain adenosine overproduction in male mice but not in female mice. Moreover, dual inhibition prostatic acid phosphatase and CD73 enzymatic activities in male mice moderated adenosine content, alleviating glycolytic shift and proinflammatory response.

CONCLUSION

The CD73/adenosine axis confers a sex-dependent cardioprotection. In addition, extracellular adenosine production in the hearts of male mice is influenced by prostatic acid phosphatase and tissue nonspecific alkaline phosphatase.

Fulminant Myocarditis Temporally Associated with COVID-19 Vaccination

PURPOSE OF REVIEW

Coronavirus disease-2019 (COVID-19) vaccines have been related to rare cases of acute myocarditis, occurring between 1 in 10,000 and 1 in 100,000 individuals, approximately. Incidence of COVID-19 vaccine-associated myocarditis varies with age, sex, and type of vaccine. Although most patients with acute myocarditis temporally associated with COVID-19 vaccines have an uneventful course, a small subpopulation presents with cardiogenic shock (termed fulminant myocarditis [FM]). This review explored the prevalence, clinical presentation, management, and prognosis of COVID-19 vaccine-associated acute myocarditis, specifically focusing on FM and comparing patients with fulminant versus non-fulminant myocarditis.

RECENT FINDINGS

Cases of FM represent about 2-4% (0 to 7.5%) of COVID-19 vaccine-associated acute myocarditis cases, and mortality is around 1%, ranging between 0 and 4.4%. First, we identified 40 cases of FM up to February 2023 with sufficient granular data from case reports and case series of COVID-19 vaccine-associated acute myocarditis that occurred within 30 days from the last vaccine injection. This population was compared with 294 cases of non-fulminant acute myocarditis identified in the literature during a similar time. Patients with FM were older (48 vs. 27 years), had a larger proportion of women (58% vs. 9%), and mainly occurred after the first shot compared with non-fulminant cases (58% vs. 16%). The reported mortality was 27% (11 out of 40), in line with non-vaccine-associated fulminant myocarditis. These data were in agreement with 36 cases of FM from a large Korean registry. Herein, we reviewed the clinical features, imaging results, and histological findings of COVID-19 vaccine-associated fulminant myocarditis. In conclusion, COVID-19 vaccine-associated FM differs from non-fulminant forms, suggesting potential specific mechanisms in these rare and severe forms. Mortality in vaccine-associated FM remains high, in line with other forms of FM.

Global, Regional, and National Burden of Myocarditis in 204 Countries and Territories From 1990 to 2019: Updated Systematic Analysis

BACKGROUND

Myocarditis is characterized by high disability and mortality, and imposes a severe burden on population health globally. However, the latest global magnitude and secular trend of myocarditis burden have not been reported.

OBJECTIVE

This study aimed to delineate the epidemiological characteristics of myocarditis burden globally for optimizing targeted prevention and research.

METHODS

Based on the Global Burden of Disease Study 2019, the myocarditis burden from 1990 to 2019 was modeled using the Cause of Death Ensemble tool, DisMod-MR, and spatiotemporal Gaussian regression. We depicted the epidemiology and trends of myocarditis by sex, age, year, region, and sociodemographic index (SDI). R program version 4.2.1 (R Project for Statistical Computing) was applied for all statistical analyses, and a 2-sided P-value of <.05 was considered statistically significant.

RESULTS

The number of incident cases (1,268,000) and deaths (32,450) associated with myocarditis in 2019 increased by over 1.6 times compared with the values in 1990 globally. On the other hand, the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) decreased slightly from 1990 to 2019. The disability-adjusted life years (DALYs) decreased slightly in the past 3 decades, while the age-standardized DALY rate (ASDR) decreased greatly from 18.29 per 100,000 person-years in 1990 to 12.81 per 100,000 person-years in 2019. High SDI regions always showed a more significant ASIR. The ASIR slightly decreased in all SDI regions between 1990 and 2019. Middle SDI regions had the highest ASMR and ASDR in 2019. Low SDI regions had the lowest ASMR and ASDR in 2019. The age-standardized rates (ASRs) of myocarditis were higher among males than among females from 1990 to 2019 globally. All ASRs among both sexes had a downward trend, except for the ASMR among males, which showed a stable trend, and females had a more significant decrease in the ASDR than males. Senior citizens had high incident cases and deaths among both sexes in 2019. The peak numbers of DALYs for both sexes were noted in the under 1 age group in 2019. At the national level, the estimated annual percentage changes in the ASRs had significant negative correlations with the baseline ASRs in 1990.

CONCLUSIONS

Globally, the number of incident cases and deaths associated with myocarditis have increased significantly. On the other hand, the ASRs of myocarditis showed decreasing trends from 1990 to 2019. Males consistently showed higher ASRs of myocarditis than females from 1990 to 2019 globally. Senior citizens gradually predominated in terms of myocarditis burden. Policymakers should establish targeted control strategies based on gender, region, age, and SDI; strengthen aging-related health research; and take notice of the changes in the epidemic characteristics of myocarditis.

Transcriptional and functional analysis of plasma exosomal microRNAs in acute viral myocarditis

AIM

To assess the differential expression profiles of exosome-derived microRNA (miRNA) and reveal their potential functions in patients with acute viral myocarditis (AVMC).

MATERIALS & METHODS

Peripheral blood samples were collected from 9 patients diagnosed with AVMC and 9 healthy controls (HC) in the Affiliated Hospital of Qingdao University from July 2021 to September 2022. The exosomal miRNA expression were tested using RNA high-throughput sequencing. We conducted the GO and KEGG functional analysis to predict the potential molecular, biological functions and related signaling pathways of miRNAs in exosomes. Target genes of exosomal miRNAs were predicted and miRNA-target gene network was mapped using gene databases. Differentially expressed exosomal miRNAs were selected and their expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) to verify the sequencing results.

RESULTS

P < 0.05 and Fold Change>2 were considered as cut-off value to screen miRNAs that were differently expressed. This study identified 14 upregulated and 14 downregulated exosome-derived miRNAs. GO and KEGG analysis showed that differentially expressed miRNAs may be related to β-catenin binding, DNA transcription activities, ubiquitin ligase, PI3K-Akt, FoxO, P53, MAPK, and etc.. The target genes of differentially expressed miRNAs were predicted using gene databases. Real-time PCR confirmed the upregulation of hsa-miR-548a-3p and downregulation of hsa-miR-500b-5p in AVMC.

CONCLUSIONS

Hsa-miR-548a-3p and hsa-miR-500b-5p could serve as a promising biomarker of AVMC. Exosomal miRNAs may have substantial roles in the mechanisms of AVMC.

Biomarkers in Acute Myocarditis and Chronic Inflammatory Cardiomyopathy: An Updated Review of the Literature

Myocarditis is a disease caused by cardiac inflammation that can progress to dilated cardiomyopathy, heart failure, and eventually death. Several etiologies, including autoimmune, drug-induced, and infectious, lead to inflammation, which causes damage to the myocardium, followed by remodeling and fibrosis. Although there has been an increasing understanding of pathophysiology, early and accurate diagnosis, and effective treatment remain challenging due to the high heterogeneity. As a result, many patients have poor prognosis, with those surviving at risk of long-term sequelae. Current diagnostic methods, including imaging and endomyocardial biopsy, are, at times, expensive, invasive, and not always performed early enough to affect disease progression. Therefore, the identification of accurate, cost-effective, and prognostically informative biomarkers is critical for screening and treatment. The review then focuses on the biomarkers currently associated with these conditions, which have been extensively studied via blood tests and imaging techniques. The information within this review was retrieved through extensive literature research conducted on major publicly accessible databases and has been collated and revised by an international panel of experts. The biomarkers discussed in the article have shown great promise in clinical research studies and provide clinicians with essential tools for early diagnosis and improved outcomes.

Development and Validation of a Prediction Model on Adult Emergency Department Patients for Early Identification of Fulminant Myocarditis

OBJECTIVE

It is difficult to predict fulminant myocarditis at an early stage in the emergency department. The objective of this study was to construct and validate a simple prediction model for the early identification of fulminant myocarditis.

METHODS

A total of 61 patients with fulminant myocarditis and 160 patients with acute myocarditis were enrolled in the training and internal validation cohorts. LASSO regression and multivariate logistic regression were selected to develop the prediction model. The selection of the model was based on overall performance and simplicity. A nomogram based on the optimal model was built, and its clinical usefulness was evaluated by decision curve analysis. The predictive model was further validated in an external validation group.

RESULTS

The resulting prediction model was based on 4 factors: systolic blood pressure, troponin I, left ventricular ejection fraction, and ventricular wall motion abnormality. The Brier scores of the final model were 0.078 in the training data set and 0.061 in the internal testing data set, respectively. The C-indexes of the training data set and the testing data set were 0.952 and 0.968, respectively. Decision curve analysis showed that the nomogram model developed based on the 4 predictors above had a positive net benefit for predicting probability thresholds. In the external validation cohort, the model also showed good performance (Brier score=0.007, and C-index=0.989).

CONCLUSION

We developed and validated an early prediction model consisting of 4 clinical factors (systolic blood pressure, troponin I, left ventricular ejection fraction, and ventricular wall motion abnormality) to identify potential fulminant myocarditis patients in the emergency department.

Flagellin-Induced Immune Response in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Pathogen-associated molecular patterns (PAMPs) are involved in the pathogenesis of septic cardiomyopathy through a toll-like receptor (TLR)-mediated immune response. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) can reflect the innate immune abilities of cardiomyocytes. Therefore, hiPSC-CMs may provide an attractive tool with which to study PAMP-induced alterations in cardiomyocytes. HiPSC-CMs from two different healthy donors were exposed to the PAMP flagellin (FLA) at different doses and exposure times. Alterations in the expression levels of distinct inflammation-associated cytokines, intracellular inflammation pathways including TLR5 downstream signaling, reactive oxygen species levels and surface antigen composition were assessed using PCR, ELISA and FACS techniques. Higher doses of flagellin increased the expression levels of inflammation-associated cytokines like TNFα (p < 0.01) and downstream signaling molecules like caspase-8 (p < 0.05). TLR5 expression (p < 0.01) and TLR5 fluorescence proportion (p < 0.05) increased in hiPSC-CMs after prolonged FLA exposure. FLA-induced innate immune response processes in cardiomyocytes might be detectable with an hiPSC-CMs-based in vitro model.

A case of fulminant myocarditis with full recovery after a 38-h sustained asystole

Key Clinical Message

Even if cardiac rhythm deteriorated to asystole in the clinical course of fulminant myocarditis, cardiac function may recover, and the patient may be discharged without brain damage, if circulation could be maintained by appropriate mechanical cardiac supports.

Abstract

A 69-year-old man was diagnosed with fulminant myocarditis with circulatory collapse. His cardiac rhythm deteriorated to asystole on the second day; however, circulatory status was maintained through extracorporeal membrane oxygenation and intra-aortic balloon pumping. After 38 h-lasting asystole, his heart resumed beating. He was discharged without neurological deficits on Day 25.

Features of Myocarditis: Morphological Differential Diagnosis in Post-COVID-19 Children

Myocarditis is characterized by dysfunction and destruction of cardiomyocytes, infiltrative inflammation, and development of fibrosis. Late diagnosis of myocarditis has been a serious global health problem, especially due to the spread of a new coronavirus infection. The aim of this review is to identify differences between myocarditis of viral etiology, including SARS-CoV-2 lesions, based on instrumental and pathomorphological findings.

MATERIAL AND METHODS

We analyzed publications covering the period from December 2019 to May 2023, published in publicly accessible international databases ("Medline", "PubMed", "Scopus"), with queries for the keywords "myocarditis", "children", "cardiovascular inflammation", "COVID-19", "SARS-CoV-2", "severe acute respiratory syndrome coronavirus 2", "differential diagnosis".

RESULTS

It was found that no unambiguous morphological criteria for the diagnosis of myocarditis coupled to SARS-CoV-2 lesions were identified. However, the detected histopathological changes such as virus-associated degeneration, apoptosis, cardiomyocyte necrosis, moderate interstitial hyperemia, myocardial tissue oedema, and capillary endothelial cell dysfunction were the major markers of SARS-CoV-2 infection.

CONCLUSION

It is necessary further reconsider morphological criteria to diagnose SARS-CoV-2-caused myocarditis, rather than solely relying on detecting viral RNA by PCR as the sole evidence-based criterion. Similar issues accompany diagnostics of myocardial lesions associated with other viral infections. Evidence for an etiological diagnosis of myocarditis can be provided by a comprehensive analysis of the diagnostic criteria obtained, confirming virus exposure, followed by development of distinct clinical symptoms, MRI and CT changes, and morphological criteria.

10-year survival outcome after clinically suspected acute myocarditis in adults: A nationwide study in the pre-COVID-19 era

BACKGROUND

Clinical courses of acute myocarditis are heterogeneous in populations and geographic regions. There is a dearth of long-term outcomes data for acute myocarditis prior to the coronavirus disease pandemic, particularly in the older and female population. This study aimed to provide the nationwide epidemiologic approximates of clinically suspected acute myocarditis across adults of all ages over the long term.

METHODS

From the nationwide governmental health insurance database, a retrospective cohort comprised all patients aged 20-79 who were hospitalized for clinically suspected acute myocarditis without underlying cardiac diseases from 2006 to 2018. The complicated phenotype was defined as requiring hemodynamic or major organ support. Over 10 years, all-cause mortality and index event-driven excess mortality were evaluated according to young-adult (20-39 years), mid-life (40-59 years), and older-adult (60-79 years) age groups.

RESULTS

Among 2,988 patients (51.0±16.9 years, 46.2% women), 362 (12.1%) were of complicated phenotype. Of these, 163 (45.0%) had died within 1 month. All-cause death at 30 days occurred in 40 (4.7%), 52 (4.8%), and 105 (10.0%) patients in the young-adult, mid-life, and older-adult groups, respectively. For 10 years of follow-up, all-cause death occurred in 762 (25.5%). Even in young adult patients with non-complicated phenotypes, excess mortality remained higher compared to the general population.

CONCLUSION

In hospitalized patients with clinically suspected acute myocarditis, short-term mortality is high both in young and older adults, particularly those with comorbidities and severe clinical presentation. Furthermore, excess mortality remains high for at least 10 years after index hospitalization in young adults.

Fulminant lymphocytic myocarditis secondary to Coxsackie A virus with full myocardial recovery following venoarterial extracorporeal membrane oxygenation

We present a case of a 30-year-old female with no pertinent medical history who presented with 4 days of chest pressure, dyspnea and fever. She had hemodynamic compromise and had elevated cardiac and inflammatory markers consistent with cardiogenic shock. ECG demonstrated anterior ST-segment elevations with reciprocal changes. Coronary angiography revealed normal coronaries and echocardiogram showed severe biventricular dysfunction. Endomyocardial biopsy showed signs of lymphocytic myocarditis and viral testing was positive for Coxsackie A. She was initially supported with an intra-aortic balloon pump and later escalated to venoarterial extracorporeal membrane oxygenation due to electromechanical compromise. With supportive care, she was weaned off venoarterial extracorporeal membrane oxygenation and made a full myocardial recovery on follow up echocardiogram and cardiac MRI.

Global Circumferential and Radial Strain Among Patients With Immune Checkpoint Inhibitor Myocarditis

BACKGROUND

Global circumferential strain (GCS) and global radial strain (GRS) are reduced with cytotoxic chemotherapy. There are limited data on the effect of immune checkpoint inhibitor (ICI) myocarditis on GCS and GRS.

OBJECTIVES

This study aimed to detail the role of GCS and GRS in ICI myocarditis.

METHODS

In this retrospective study, GCS and GRS from 75 cases of patients with ICI myocarditis and 50 ICI-treated patients without myocarditis (controls) were compared. Pre-ICI GCS and GRS were available for 12 cases and 50 controls. Measurements were performed in a core laboratory blinded to group and time. Major adverse cardiovascular events (MACEs) were defined as a composite of cardiogenic shock, cardiac arrest, complete heart block, and cardiac death.

RESULTS

Cases and controls were similar in age (66 ± 15 years vs 63 ± 12 years; P = 0.20), sex (male: 73% vs 61%; P = 0.20) and cancer type (P = 0.08). Pre-ICI GCS and GRS were also similar (GCS: 22.6% ± 3.4% vs 23.5% ± 3.8%; P = 0.14; GRS: 45.5% ± 6.2% vs 43.6% ± 8.8%; P = 0.24). Overall, 56% (n = 42) of patients with myocarditis presented with preserved left ventricular ejection fraction (LVEF). GCS and GRS were lower in myocarditis compared with on-ICI controls (GCS: 17.5% ± 4.2% vs 23.6% ± 3.0%; P < 0.001; GRS: 28.6% ± 6.7% vs 47.0% ± 7.4%; P < 0.001). Over a median follow-up of 30 days, 28 cardiovascular events occurred. A GCS (HR: 4.9 [95% CI: 1.6-15.0]; P = 0.005) and GRS (HR: 3.9 [95% CI: 1.4-10.8]; P = 0.008) below the median was associated with an increased event rate. In receiver-operating characteristic (ROC) curves, GCS (AUC: 0.80 [95% CI: 0.70-0.91]) and GRS (AUC: 0.76 [95% CI: 0.64-0.88]) showed better performance than cardiac troponin T (cTnT) (AUC: 0.70 [95% CI: 0.58-0.82]), LVEF (AUC: 0.69 [95% CI: 0.56-0.81]), and age (AUC: 0.54 [95% CI: 0.40-0.68]). Net reclassification index and integrated discrimination improvement demonstrated incremental prognostic utility of GRS over LVEF (P = 0.04) and GCS over cTnT (P = 0.002).

CONCLUSIONS

GCS and GRS are lower in ICI myocarditis, and the magnitude of reduction has prognostic significance.

Multimodality imaging in acute myocarditis

The diagnosis of acute myocarditis often involves several noninvasive techniques that can provide information regarding volumes, ejection fraction, and tissue characterization. In particular, echocardiography is extremely helpful for the evaluation of biventricular volumes, strain and ejection fraction. Cardiac magnetic resonance, beyond biventricular volumes, strain, and ejection fraction allows to characterize myocardial tissue providing information regarding edema, hyperemia, and fibrosis. Contemporary cardiac computed tomography angiography (CCTA) can not only be extremely important for the assessment of coronary arteries, pulmonary arteries and aorta but also tissue characterization using CCTA can be an additional tool that can explain chest pain with a diagnosis of 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.

Bioinformatic analysis of PD-1 checkpoint blockade response in influenza infection

BACKGROUND

The programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1) signaling pathway is significantly upregulated in influenza virus infection, which impairs the antiviral response. Blocking this signaling pathway may reduce the damage, lower the virus titer in lung tissue, and alleviate the symptoms of infection to promote recovery. In addition to the enhanced viral immune response, using of immune checkpoint inhibitors in influenza virus infection is controversial, the aim of this study was to identify the key factors and regulatory mechanisms in the PD-1 checkpoint blockade response microenvironment in influenza infection.

METHODS

A BALB/c mouse model of influenza A/PR8(H1N1) infection was established then constructed, and whole-transcriptome sequencing including mRNAs, miRNAs (microRNAs), lncRNAs (long noncoding RNAs), and circRNAs (circular RNAs) of mice treated with PD-1 checkpoint blockade by antibody treatment and IgG2a isotype control before infection with A/PR8(H1N1) were performed. Subsequently, the differential expression of transcripts between these two groups was analyzed, followed by functional interaction prediction analysis to investigate gene-regulatory circuits.

RESULTS

In total, 84 differentially expressed dif-mRNAs, 36 dif-miRNAs, 90 dif-lncRNAs and 22 dif-circRNAs were found in PD-1 antagonist treated A/PR8(H1N1) influenza-infected lungs compared with the controls (IgG2a isotype control treated before infection). In spleens between the above two groups, 45 dif-mRNAs, 36 dif-miRNAs, 57 dif-lncRNAs, and 24 dif-circRNAs were identified. Direct function enrichment analysis of dif-mRNAs and dif-miRNAs showed that these genes were mainly involved in myocardial damage related to viral infection, mitogen activated protein kinase (MAPK) signaling pathways, RAP1 (Ras-related protein 1) signaling pathway, and Axon guidance. Finally, 595 interaction pairs were obtained for the lungs and 462 interaction pairs for the spleens were obtained in the competing endogenous RNA (ceRNA) complex network, in which the downregulated mmu-miR-7043-3p and Vps39-204 were enriched significantly in PD-1 checkpoint blockade treated A/PR8(H1N1) infection group.

CONCLUSIONS

The present study provided a basis for the identification of potential pathways and hub genes that might be involved in the PD-1 checkpoint blockade response microenvironment in influenza infection.

Successful treatment of fulminant myocarditis with intra-aortic balloon pump counterpulsation combined with immunoglobulin and glucocorticoid in a young male adult

Background

Fulminant myocarditis (FM) is a serious non-specific inflammatory disease of the myocardium. FM tends to occur in adolescents and the course of the disease progresses rapidly. It is prone to cardiogenic shock (CGS) and multiple organ failure (MOF) with high mortality. We report a case of FM with CGS and MOF in a young male who was successfully treated with intra-aortic balloon pump counterpulsation (IABP) combined with intravenous immunoglobulin (IVIG) and glucocorticoid (GC).

Case summary

A 21-year-old previously healthy man presented with fever, headache, and chest tightness. He came to the hospital for emergency treatment. The laboratory data showed that the levels of serum cardiac troponin I (cTnI), N-terminal B-type natriuretic peptide (NT-proBNP), myocardial zymogram, and neutrophils increased. Echocardiography showed pericardial effusion and decreased left ventricular systolic function. ECG showed diffuse ST-segment elevation. He was clinically diagnosed with FM and admitted to the intensive care unit for treatment. Within 48 h of admission, the clinical course of the patient deteriorated rapidly, with CGS accompanied by MOF, high atrioventricular block (AVB), and ventricular tachycardia (VT). After using mechanical circulatory support (MCS) therapy with IABP, IVIG, GC, continuous renal replacement therapy (CRRT), and mechanical ventilation complicated with a temporary cardiac pacemaker, he recovered normal cardiac function. He made a full recovery and was discharged home on day 21.

Discussion

For patients with FM, early diagnosis, close monitoring, timely use of MCS devices, and active comprehensive treatment are very important. MCS devices such as IABP can become lifesaving tools for the treatment of FM.

Fulminant Coxsackievirus Myocarditis in an Immunocompetent Adult: A Case Report and Literature Analysis

Myocarditis is an inflammatory condition that impacts cardiac myocytes and is caused mostly by viruses. It can manifest as chest pain, dyspnea, palpitations, fatigue, syncope, shortness of breath, and in severe cases frank cardiogenic shock. It accounts for around 10 percent of all sudden cardiac deaths in young adults, who are described as being in their early thirties. Inflammatory cardiomyopathy resulting from acute myocarditis may also appear as new-onset heart failure (HF), delaying the diagnosis and treatment of these patients. It is crucial to recognize the sensitivity of symptom onset, especially in young individuals; mildly elevated troponin levels that are inconsistent with the severity of left ventricular ejection fraction (LVEF) impairment and associated left ventricular dilatation strongly suggest inflammatory cardiomyopathy rather than acute myocarditis. The current treatment for myocarditis is primarily supportive, with an emphasis on the management of heart failure and arrhythmias in accordance with clinical practice guidelines. In this case report, we describe a male in his early forties who presented with abrupt onset exertional shortness of breath and chest discomfort. His cardiac catheterization did not show evidence of coronary artery disease; however, an echocardiogram revealed new-onset heart failure with reduced ejection fraction, the diagnosis of coxsackievirus myocarditis was made based on his clinical presentation, and a positive coxsackievirus immunoassay.

Sudden death due to fulminant lymphocytic myocarditis with atypical prodromal symptoms

Diagnosis of myocarditis is complex because it is not always preceded by clear symptoms. We report the case of a woman who died suddenly. Autopsy and histopathological investigations revealed a lymphocytic myocarditis. Clinical history showed the patient went to the hospital some days before for joint pain and low-grade fever.

Luteolin Protects Cardiomyocytes Cells against Lipopolysaccharide-Induced Apoptosis and Inflammatory Damage by Modulating Nlrp3

PURPOSE

In this article, we aimed to investigate the influences of luteolin on inflammatory injury to cardiomyocytes induced by lipopolysaccharide (LPS).

MATERIALS AND METHODS

H9c2 cells were pretreated with different concentrations of luteolin (10, 20, and 50 µM) for 12 h and then stimulated with 10 µg/mL LPS or no LPS for 6 h. Cell viability was detected by CCK-8 assay. Cell apoptosis was determined by flow cytometry. QRT-PCR and Western blotting were utilized to examine mRNA and protein levels. ELISA was used to determine the levels of monocyte chemoattractant protein-1, tumor necrosis factor-alpha, interleukin (IL)-6, IL-1β, and IL-18 in cell supernatants among different groups of H9c2 cells. Immunofluorescence was applied to evaluate reactive oxygen species formation in H9c2 cells. M-mode images of echocardiography, the ejection fraction test, fractional shortening test, end-systolic volume test, and end-diastolic volume test of mouse heart function were obtained by ultrasonic electrocardiogram.

RESULTS

Luteolin could alleviate inflammatory damage and inflammatory factor expression among LPS-induced H9c2 cells. Additionally, we found that luteolin decreased LPS-stimulated inflammatory damage in H9c2 cells by down-regulating NOD-like receptor family pyrin domain containing 3 (Nlrp3). Luteolin also improved myocardial function in mice treated with LPS and reduced myocardial relaxation. Luteolin reversed myocardial histological abnormalities in mice and reduced inflammation and cardiomyocyte apoptosis. Additionally, luteolin inhibited oxidative stress-mediated myocardial and systemic tissue damage in mice. Finally, luteolin reduced LPS-induced inflammatory damage in mouse cardiomyocytes by down-regulating Nlrp3.

CONCLUSION

We found that luteolin could reduce inflammatory damage to cardiomyocytes induced by LPS by down-regulating Nlrp3.

Fulminant myocarditis in adults: a narrative review

Fulminant myocarditis (FM) is an uncommon syndrome characterized by sudden and severe hemodynamic compromise secondary to acute myocardial inflammation, often presenting as profound cardiogenic shock, life-threatening ventricular arrhythmias and/or electrical storm. FM may be refractory to conventional therapies and require mechanical circulatory support (MCS). The immune system has been recognized as playing a pivotal role in the pathophysiology of myocarditis, leading to an increased focus on immunosuppressive treatment strategies. Recent data have highlighted not only the fact that FM has significantly worse outcomes than non-FM, but that prognosis and management strategies of FM are heavily dependent on histological subtype, placing greater emphasis on the role of endomyocardial biopsy in diagnosis. The impact of subtype on severity and prognosis will likewise influence how aggressively the myocarditis is managed, including whether MCS is warranted. Many patients with refractory cardiogenic shock secondary to FM end up requiring MCS, with venoarterial extracorporeal membrane oxygenation demonstrating favorable survival rates, particularly when initiated prior to the development of multiorgan failure. Among the challenges facing the field are the need to more precisely identify immunopathophysiological pathways in order to develop targeted therapies, and the need to better optimize the timing and management of MCS to minimize complications and maximize outcomes.

State-of-the-Art of Endomyocardial Biopsy on Acute Myocarditis and Chronic Inflammatory Cardiomyopathy

Purpose of Review

Histologic evidence of myocardial inflammatory infiltrate not secondary to an ischemic injury is required by current diagnostic criteria to reach a definite diagnosis of myocarditis. Endomyocardial biopsy (EMB) is therefore often indicated for the diagnosis of myocarditis, although it may lack sufficient sensitivity considering the limited possibility of myocardial sampling. Improving the diagnostic yield and utility of EMB is of high priority in the fields of heart failure cardiology and myocarditis in particular. The aim of the present review is to highlight indications, strengths, and shortcomings of current EMB techniques, and discuss innovations currently being tested in ongoing clinical studies, especially in the setting of acute myocarditis and chronic inflammatory cardiomyopathy.

Recent Findings

EMB provides unique diagnostic elements and prognostic information which can effectively guide the treatment of myocarditis. Issues affecting the diagnostic performance in the setting of acute myocarditis and chronic inflammatory cardiomyopathies will be discussed in this review in the light of recent expert consensus documents on the management of these conditions and on indication to EMB. Recent innovations using electroanatomic mapping (EAM)-guided EMB and fluoroscopic-guided EMB during temporary mechanical circulatory support have improved the utility of the procedure.

Summary

EMB remains an important diagnostic test whose results need to be interpreted in the context of (1) clinical pre-test probability, (2) timing of sampling, (3) quality of sampling (4) site of sampling, (5) histologic type of myocarditis, and (6) analytic methods that are applied. Herein we will review these caveats as well as perspectives and innovations related to the use of this diagnostic tool.

A Review of the Role of Imaging Modalities in the Evaluation of Viral Myocarditis with a Special Focus on COVID-19-Related Myocarditis

Viral myocarditis is inflammation of the myocardium secondary to viral infection. The clinical presentation of viral myocarditis is very heterogeneous and can range from nonspecific symptoms of malaise and fatigue in subclinical disease to a more florid presentation, such as acute cardiogenic shock and sudden cardiac death in severe cases. The accurate and prompt diagnosis of viral myocarditis is very challenging. Endomyocardial biopsy is considered to be the gold standard test to confirm viral myocarditis; however, it is an invasive procedure, and the sensitivity is low when myocardial involvement is focal. Cardiac imaging hence plays an essential role in the noninvasive evaluation of viral myocarditis. The current coronavirus disease 2019 (COVID-19) pandemic has generated considerable interest in the use of imaging in the early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related myocarditis. This article reviews the role of various cardiac imaging modalities used in the diagnosis and assessment of viral myocarditis, including COVID-19-related myocarditis.

Identification of Cardiac CircRNAs in Mice With CVB3-Induced Myocarditis

Background: Viral myocarditis could initiate various immune response to the myocardium, resulting in myocyte damage and subsequent cardiac dysfunction. The expression profile and functions of circRNAs in this process are unknown.

Methods: Fulminant myocarditis (FM) and non-FM models were induced by coxsackie B3 virus (CVB3) infection in A/J mice and C57BL/6 mice, respectively. CircRNAs expression profile was identified by RNA-seq. Quantitative RT-PCR, Spearman rank correlation, KEGG pathway, GO analysis, Western blot and flow cytometry were performed for functional analysis.

Results: Severer inflammatory cell infiltration and cardiomyocyte necrosis were presented in CVB3-treated A/J mice than those in C57BL/6 mice. The dysregulated circRNAs in both of the mouse strains displayed strong correlation with the immune response, but dysregulated circRNAs in A/J mice were more prone to cardiac dysfunction. KEGG analysis indicated that the target genes of dysregulated circRNAs in A/J mice were mainly involved in viral infection, T cell and B cell receptor signaling pathways, while the target genes of dysregulated circRNAs in C57BL/6 mice were unrelated to immune pathways. Furthermore, knockdown of circArhgap32 that was downregulated in CVB3-treated A/J mice promoted cardiomyocyte apoptosis in vitro.

Conclusion: Our data showed that cardiac circRNAs dysregulation is an important characteristic of viral myocarditis.

Fulminant Giant Cell Myocarditis vs. Lymphocytic Myocarditis: A Comparison of Their Clinical Characteristics, Treatments, and Outcomes

Objectives: Fulminant myocarditis (FM) is a rapidly progressive and frequently fatal form of myocarditis that has been difficult to classify. This study aims to compare the clinical characteristics, treatments and outcomes in patients with fulminant giant cell myocarditis (FGCM) and fulminant lymphocytic myocarditis (FLM).

Methods and Results: In our retrospective study, nine patients with FGCM (mean age 47.9 ± 7.5 years, six female) and 7 FLM (mean age 42.1 ± 12.3 years, four female) patients confirmed by histology in the last 11 years were included. Most patients with FGCM and FLM were NYHA functional class IV (56 vs. 100%, p = 0.132). Patients with FGCM had significantly lower levels of high-sensitivity C-reactive protein [hs-CRP, 4.4 (2.0–10.2) mg/L vs. 13.6 (12.6–14.6) mg/L, P = 0.004, data shown as the median with IQR], creatine kinase-myoglobin [CK-MB, 1.4 (1.0–3.2) ng/ml vs. 14.6 (3.0–64.9) ng/ml, P = 0.025, median with IQR], and alanine aminotransferase [ALT, 38.0 (25.0–61.5) IU/L vs. 997.0 (50.0–3,080.0) IU/L, P = 0.030, median with IQR] and greater right ventricular end-diastolic diameter (RVEDD) [2.9 ± 0.3 cm vs. 2.4 ± 0.6 cm, P = 0.034, mean ± SD] than those with FLM. No differences were observed in the use of intra-aortic balloon pump (44 vs. 43%, p = 1.000) and extracorporeal membrane oxygenation (11 vs. 43%, p = 0.262) between the two groups. The long-term survival rate was significantly lower in FGCM group compared with FLM group (0 vs. 71.4%, p = 0.022). A multivariate cox regression analysis showed the level of hs-CRP (hazard ratio = 0.871, 95% confidence interval: 0.761–0.996, P = 0.043) was an independent prognostic factor for FM patients. Furthermore, the level of hs-CRP had a good ability to discriminate between patients with FGCM and FLM (AUC = 0.94, 95% confidence interval: 0.4213–0.9964).

Conclusions: The inflammatory response and myocardial damage in the patients with FGCM were milder than those with FLM. Patients with FGCM had distinctly poorer prognoses compared with those with FLM. Our results suggest that hs-CRP could be a promising prognostic biomarker and a hs-CRP level of 11.71 mg/L is an appropriate cutoff point for the differentiating diagnosis between patients with FGCM and FLM.

The absolute and relative changes in high-sensitivity cardiac troponin I are associated with the in-hospital mortality of patients with fulminant myocarditis

Background

We sought to describe the tendency and extent of high-sensitivity cardiac troponin I (hs-cTnI) changes in patients with fulminant myocarditis (FM) after admission and to explore the relationship between the in-hospital mortality of FM and the absolute and relative changes in hs-cTnI within 24 h and 48 h after admission.

Methods

In the retrospective study, the object are patients diagnosed with FM in our single centre. The value of cardiac troponin was recorded after patients admitted to hospital in succession. The absolute and relative changes in hs-cTnI within 24 h and 48 h were described as range distributions. Receiver operating characteristic (ROC) curve and Cox analyses were performed to determine the relationship between in-hospital mortality of FM and hs-cTnI changes.

Results

A total of 83 FM patients admitted to our centre from January 1, 2010 to December 31, 2019 were included; 69 patients survived and 14 patients died. In the survival group, 78% of patients experienced a decline in hs-cTnI within 24 h, while 36% of the mortality group exhibited a declining tendency in hs-cTnI (P = 0.003). Nearly 60% of survival group had a 0–2000 ng/l reduction in troponin from baseline within 24 h of admission. However, troponin levels of 50% of patients in the mortality group were 0–10,000 ng/ L higher than baseline 24 h after admission. Multivariable logistic analysis revealed that the declining tendency of hs-cTnI within 24 h, in addition to time from onset to admittance to hospital, intravenous immunoglobulin treatment and the abnormal level of creatinine, were associated with the in-hospital mortality of FM (for the declining tendency of hs-cTnI within 24 h, OR = 0.10, 95% CI 0.02–0.68, P = 0.018). The ROC curve revealed optimal cut-off values of − 618 ng/l for absolute change within 24 h (AUC = 0.800, P < 0.01), − 4389 ng/l for absolute change within 48 h (area under the curve = 0.711, P < 0.01), − 28.46% for relative change within 24 h (AUC = 0.810, P < 0.01), and − 52.23% for relative change within 48 h (AUC = 0.795, P < 0.01). Absolute changes and relative changes in hs-cTnI within 24 h and 48 h were strong predictors of in-hospital mortality by Cox regression analysis after adjustment for sex, time from onset to admission, and occurrence of ventricular tachycardia or ventricular fibrillation.

Conclusion

Most FM patients who survived experienced a decline in hs-cTnI within 24 h. The absolute and relative changes in hs-cTnI within 24 h and 48 h were strong predictors of in-hospital mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02386-8.

Right ventricular dominant myocarditis requiring cardiac resynchronization therapy-defibrillator: a case report

Fulminant myocarditis is an inflammatory disease of the cardiac muscle that severely deteriorates cardiac function and often causes haemodynamic collapse in a manner similar to acute coronary syndrome. In rare cases, the myocardium of the right ventricle is dominantly damaged. In cases of lymphocytic myocarditis, a common type of fulminant myocarditis, cardiac function is often recovered after peak myocardial inflammation subsides; however, some cases show irreversible myocardial damage. Herein, we report the case of a 43-year-old woman with irreversible, right-side dominant ventricular myocardial damage; she presented with various cardiopulmonary conditions including complete atrioventricular block, ventricular tachycardia, right heart failure, right ventricular thrombosis, and pulmonary embolism. The patient was successfully treated with medications and a cardiac resynchronization therapy-defibrillator device.

Advanced Heart Failure in Special Population: Cardiomyopathies and Myocarditis

Cardiomyopathies are a heterogeneous group of heart muscle diseases and an important cause of heart failure (HF) in young populations. The variety of causes, multiple underlying pathophysiological mechanisms, and different phenotypic expressions influence their presentation and response to treatment. Dilated cardiomyopathy is the most prevalent cause of HF. Advanced HF in hypertrophic, restrictive, and arrhythmogenic cardiomyopathies is rare, but its development portends a poor prognosis. The active phase of fulminant myocarditis may result in acute HF requiring advanced strategies to support the systemic circulation or may determine an irreversible persisting left ventricular failure with end-stage HF.

Update on acute myocarditis

Acute myocarditis (AM), a recent-onset inflammation of the heart, has heterogeneous clinical presentations, varying from minor symptoms to high-risk cardiac conditions with severe heart failure, refractory arrhythmias, and cardiogenic shock. AM is moving from being a definitive diagnosis based on histological evidence of inflammatory infiltrates on cardiac tissue to a working diagnosis supported by high sensitivity troponin increase in association with specific cardiac magnetic resonance imaging (CMRI) findings. Though experts still diverge between those advocating for histological definition versus those supporting a mainly clinical definition of myocarditis, in the real-world practice the diagnosis of AM has undoubtedly shifted from being mainly biopsy-based to solely CMRI-based in most of clinical scenarios. It is thus important to clearly define selected settings where EMB is a must, as information derived from histology is essential for an optimal management. As in other medical conditions, a risk-based approach should be promoted in order to identify the most severe AM cases requiring appropriate bundles of care, including early recognition, transfer to tertiary centers, aggressive circulatory supports with inotropes and mechanical devices, histologic confirmation and eventual immunosuppressive therapy. Despite improvements in recognition and treatment of AM, including a broader use of promising mechanical circulatory supports, severe forms of AM are still burdened by dismal outcomes. This review is focused on recent clinical studies and registries that shed new insights on AM. Attention will be paid to contemporary outcomes and predictors of prognosis, the emerging entity of immune checkpoint inhibitors-associated myocarditis, updated CMRI diagnostic criteria, new data on the use of temporary mechanical circulatory supports in fulminant myocarditis. The role of viruses as etiologic agents will be reviewed and a brief update on pediatric AM is also provided. Finally, we summarize a risk-based approach to AM, based on available evidence and clinical experience.

Anakinra treats fulminant myocarditis from Neisseria meningitidis septicaemia and haemophagocytic lymphohistiocytosis: a case report

Background

Fulminant myocarditis is a life-threatening condition characterized by acute cardiac dysfunction requiring pharmacological or mechanical circulatory support. Haemophagocytic lymphohistiocytosis (HLH) is an uncommon state of immune dysregulation and overactivation. Inflammation mediated by interleukin-1 (IL-1) is thought to play a role in the pathogenesis of myocarditis and HLH, and there is some evidence that the IL-1 receptor antagonist Anakinra may play a role in treating both these conditions.

Case summary

A 26-year-old previously healthy male presented to the Emergency Department with a 3-day history of malaise, headache, vomiting, diarrhoea, and fever. He was profoundly hypotensive on arrival, diagnosed with septic shock, and commenced on broad-spectrum antibiotics and vasopressors. Blood tests showed lymphopenia, thrombocytopenia, low fibrinogen and elevated high sensitivity troponin T, ferritin, and C-reactive protein. Echocardiography demonstrated severely impaired biventricular systolic function and a diagnosis of fulminant myocarditis was made. His condition deteriorated and he required intubation and additional inotropic support. A diagnosis of HLH was made and he was commenced on Anakinra and Methylprednisolone. His condition improved rapidly thereafter. Polymerase chain reaction testing subsequently confirmed infection with Neisseria meningitidis.

Discussion

In this case, fulminant myocarditis and HLH were life-threatening manifestations of meningococcal septicaemia, and the patient's condition improved rapidly following administration of the IL-1 receptor antagonist Anakinra. These complications should be borne in mind in septic patients with marked haemodynamic instability and multiorgan dysfunction, and treatment with Anakinra should be considered in those who fail to respond to conventional therapy.

Diagnosis and Management of Myocarditis: An Evidence-Based Review for the Emergency Medicine Clinician

BACKGROUND

Myocarditis is a potentially fatal condition that can be misdiagnosed in the emergency department (ED) setting.

OBJECTIVE

The purpose of this narrative review article is to provide a summary of the background, pathophysiology, diagnosis, and management of myocarditis, with a focus on emergency clinicians.

DISCUSSION

Myocarditis occurs when inflammation of the heart musculature causes cardiac dysfunction. Symptoms may range from mild to severe and are often preceded by a viral prodrome. Laboratory assessment and an electrocardiogram can be helpful for the diagnosis, but echocardiography is the ideal test in the ED setting. Some patients may also require advanced imaging, though this will often occur during hospitalization or follow-up. Treatment is primarily focused on respiratory and hemodynamic support. Initial hemodynamic management includes vasopressors and inotropes, whereas more severe cases may require an intra-aortic balloon pump, extracorporeal membrane oxygenation, or a ventricular assist device. Nonsteroidal anti-inflammatory drugs should be avoided while intravenous immunoglobulin is controversial.

CONCLUSION

Myocarditis is a serious condition with the potential for significant morbidity and mortality. It is important for clinicians to be aware of the current evidence regarding the diagnosis, management, and disposition of these patients.