The management of myocarditis

Immunomodulating and Immunosuppressive Therapy for Virus-Negative Immune-Mediated Myocarditis

Myocarditis is an inflammatory disease of the myocardium caused by infectious and noninfectious agents. Clinical manifestations range from mildly symptomatic forms to acute heart failure, cardiogenic shock, life-threatening arrhythmias and sudden death. Myocarditis is still a challenging diagnosis because of its wide variability in clinical presentation and unpredictable course. Moreover, a standardized, specific treatment in not yet available. Immunosuppressive treatment for virus-negative lymphocytic myocarditis is still controversial. Conversely, immunosuppression is well established in sarcoidosis, eosinophilic, giant-cell, drug hypersensitivity, and trauma-related myocarditis as well as lymphocytic myocarditis associated with connective tissue diseases or with the rejection of a transplanted heart. Recently, immunosuppressive therapy has been also recognized as an effective treatment in virus-negative inflammatory cardiomyopathy. The aim of this review is to underline the role of immunomodulating and immunosuppressive therapies in patients with immune-mediated myocarditis and illustrate the different treatment strategies depending on the etiology. An endomyocardial biopsy remains the gold standard for the diagnosis of myocarditis as well as for a tailored treatment.

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.

Epstein-Barr Virus (EBV)-Associated Myopericarditis Provoking Severe Heart Failure in an Immunocompetent Young Male

Myopericarditis, a rare inflammatory condition affecting the heart and its surrounding layers, can lead to serious consequences if not promptly diagnosed and treated. A recent case involved a 28-year-old man with no significant medical history who developed severe chest pain and was diagnosed with myopericarditis induced by the Epstein-Barr virus (EBV). The patient's symptoms, imaging, and lab test results suggest myopericarditis. Initially, he was treated with non-steroidal anti-inflammatory drugs (NSAIDs) and colchicine, and upon discharge, he continued with NSAIDs, as well as guideline-directed medical therapy, including an angiotensin-converting enzyme inhibitor, beta blocker, and SGLT2 inhibitor. Close follow-up with the cardiology and heart failure programs was planned. This case highlights the rare occurrence of this condition in individuals with a healthy immune system.

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.

The Epidemiology of COVID-19 Vaccine-Induced Myocarditis

Background

In December 2019, the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) led to the COVID-19 pandemic, with millions of deaths worldwide. Vaccine breakthroughs in late 2020 resulted in the authorization of COVID-19 vaccines. While these vaccines have demonstrated efficacy, evidence from vaccine safety monitoring systems around the globe supported a causal association between COVID-19 vaccines, in particular those using mRNA technology, i.e., Moderna's mRNA-1273 and Pfizer-BioNTech's BNT162b2, and myocarditis.

Objective

This paper aims to investigate the epidemiology of mRNA COVID-19 vaccine-induced myocarditis, including age, ethnicity, and gender associations with these vaccines. It also discusses the immunopathophysiological mechanisms of mRNA COVID-19 vaccine-associated myocarditis and outlines principles of diagnosis, clinical presentation, and management.

Methods

A literature review was conducted using PubMed, Embase, and Queen Mary University of London Library Services databases. Search terms included "myocarditis," "coronavirus disease 2019," "SARS-CoV-2," "mRNA Covid-19 vaccines," "Covid vaccine-associated myocarditis," "epidemiology," "potential mechanisms," "myocarditis diagnosis," and "myocarditis management."

Results

While the definite mechanism of mRNA COVID-19 vaccine-associated myocarditis remains ambiguous, potential mechanisms include molecular mimicry of spike proteins and activation of the adaptive immune response with dysregulated cytokine expression. Male predominance in COVID-19 vaccine-induced myocarditis may be attributed to sex hormones, variations in inflammatory reactions, coagulation states based on gender, and female-specific protective factors. Moreover, an analysis of diagnostic and management strategies reveals a lack of consensus on acute patient presentation management.

Conclusion

In contrast to viral infections that stand as the predominant etiological factor for myocarditis with more severe consequences, the mRNA COVID-19 vaccination elicits a mild and self-limiting manifestation of the condition. There is currently insufficient evidence to confirm the definite underlying mechanism of COVID-19 vaccine-associated myocarditis. Further research is needed to develop preventive and therapeutic solutions in this context.

An Update on Myocarditis in Forensic Pathology

In forensic medicine, myocarditis is a complicated topic in the context of sudden death and medical malpractice. A good knowledge of the etiopathology, histopathology, and available literature are both indispensable and essential for the correct management and evaluation of the causal link. Some agents, which are rarely lethal for humans, are not necessarily related to death from myocarditis, even if an infection in other organs such as the gastrointestinal tract is documented. The diagnosis of the causes of death is often difficult and confusing. In some cases, the hypothetical diagnosis of myocarditis as the cause of death is formulated by deduction, causing error and misleading the correct temporal evaluation of pathological events. We reviewed the literature realizing that histomorphological data are scarce and often poorly documented. Only after COVID-19 have the histomorphological aspects of myocarditis been better documented. This is due to poor autopsy practice and poor accuracy in identifying the specific histotype of myocarditis with identification of the responsible agent. We believe that four points are essential for a better understanding and complete diagnosis of the disease: (1) clinical classification of myocarditis; (2) etiological classification of myocarditis; (3) pathophysiology of viral and bacterial infections with host response; and (4) histopathological diagnosis with precise identification of the histotype and pathogen. In the review we provide histological images from authoritative scientific references with the aim of providing useful information and food for thought to readers.

A rare case report of type 1 congenital disorders of glycosylation with acute decompensated heart failure and the incidental discovery of congenital disorders of glycosylation associated dilated cardiomyopathy and acute myocarditis

Background

Congenital disorders of glycosylation (CDG) are rare genetically inherited defects leading to enzyme deficiency or malfunction in the glycosylation pathway. Normal glycosylation is essential to the development of normal cardiac anatomy and function. Congenital disorders of glycosylation-related cardiomyopathy are often the first manifestation detected in early life and may lead to sudden cardiac death. Approximately one-fifth of CDG types are related to cardiac diseases that include cardiomyopathy, rhythm disturbances, pericardial effusions, and structural heart disease.

Case summary

We report a rare case of a 26-year-old lady with CDG-1 who presented with acute-onset dyspnoea. She had respiratory tract symptoms for the past 2 weeks. With the relevant clinical and biochemical findings, including supportive findings on echocardiogram and cardiac magnetic resonance imaging, we have managed to arrive at a diagnosis of severe pneumonia leading to acute decompensated heart failure, as well as the discovery of an underlying CDG-associated dilated cardiomyopathy (DCM) and acute myocarditis. Anti-failure medications and i.v. methylprednisolone were commenced, and she showed gradual clinical improvement with an increase of her left ventricular function. She was discharged home well with anti-failure therapy, prednisolone, and a follow-up echocardiogram with further review in the heart failure clinic.

Discussion

In conclusion, this case report highlights the need for accurate diagnosis and prompt management of CDG-associated DCM, leading to a successful recovery and discharge from hospital care. With this, we hope to add to the increasing number of reported cases of CDG-related cardiac disease in the medical literature to emphasize the importance of screening and follow-up for any underlying cardiac diseases in patients with CDG.

Role of immune cells in the pathogenesis of myocarditis

Myocarditis is an inflammatory heart disease that mostly affects young people. Myocarditis involves a complex immune network; however, its detailed pathogenesis is currently unclear. The diversity and plasticity of immune cells, either in the peripheral blood or in the heart, have been partially revealed in a number of previous studies involving patients and several kinds of animal models with myocarditis. It is the complexity of immune cells, rather than one cell type that is the culprit. Thus, recognizing the individual intricacies within immune cells in the context of myocarditis pathogenesis and finding the key intersection of the immune network may help in the diagnosis and treatment of this condition. With the vast amount of cell data gained on myocarditis and the recent application of single-cell sequencing, we summarize the multiple functions of currently recognized key immune cells in the pathogenesis of myocarditis to provide an immune background for subsequent investigations.

Myocardial Oedema as a Consequence of Viral Infection and Persistence-A Narrative Review with Focus on COVID-19 and Post COVID Sequelae

Microvascular integrity is a critical factor in myocardial fluid homeostasis. The subtle equilibrium between capillary filtration and lymphatic fluid removal is disturbed during pathological processes leading to inflammation, but also in hypoxia or due to alterations in vascular perfusion and coagulability. The degradation of the glycocalyx as the main component of the endothelial filtration barrier as well as pericyte disintegration results in the accumulation of interstitial and intracellular water. Moreover, lymphatic dysfunction evokes an increase in metabolic waste products, cytokines and inflammatory cells in the interstitial space contributing to myocardial oedema formation. This leads to myocardial stiffness and impaired contractility, eventually resulting in cardiomyocyte apoptosis, myocardial remodelling and fibrosis. The following article reviews pathophysiological inflammatory processes leading to myocardial oedema including myocarditis, ischaemia-reperfusion injury and viral infections with a special focus on the pathomechanisms evoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In addition, clinical implications including potential long-term effects due to viral persistence (long COVID), as well as treatment options, are discussed.

Cardiovascular implications of inflammatory bowel disease: An updated review

Emerging data highlights the heightened risk of atherosclerotic cardiovascular diseases (ASCVD) in patients with chronic inflammatory disorders, particularly those afflicted with inflammatory bowel disease (IBD). This review delves into the epidemiological connections between IBD and ASCVD, elucidating potential underlying mechanisms. Furthermore, it discusses the impact of current IBD treatments on cardiovascular risk. Additionally, the cardiovascular adverse effects of novel small molecule drugs used in moderate-to-severe IBD are investigated, drawing parallels with observations in patients with rheumatoid arthritis. This article aims to comprehensively evaluate the existing evidence supporting these associations. To achieve this, we conducted a meticulous search of PubMed, spanning from inception to August 2023, using a carefully selected set of keywords. The search encompassed topics related to IBD, such as Crohn's disease and ulcerative colitis, as well as ASCVD, including coronary artery disease, cardiovascular disease, atrial fibrillation, heart failure, conduction abnormalities, heart blocks, and premature coronary artery disease. This review encompasses various types of literature, including retrospective and prospective cohort studies, clinical trials, meta-analyses, and relevant guidelines, with the objective of providing a comprehensive overview of this critical intersection of inflammatory bowel disease and cardiovascular health.

Spectre of COVID-19 infection confounding myocarditis related to cytomegalovirus mononucleosis syndrome and hyperinflammatory syndrome

Viral infections have multiple mechanisms of affecting internal and external organs by direct invasion or by molecular mimicry. They have also been described as triggers for inflammatory processes like hyperinflammatory syndrome (HIS), Adult-onset Stills Disease (AOSD), and myocarditis [1]. Here we report an interesting case of a young adult with recent infection with SARS-CoV-2 (COVID-19) who presented with myocarditis requiring circulatory support in the cardiac care unit. During the admission, he was found to have concurrent cytomegalovirus (CMV) mononucleosis syndrome and presentation consistent with HIS resembling AOSD. This patient had multiple etiologies that could have caused myocarditis: CMV infection, COVID-19 infection, and HIS. As noted, viral infections have been proposed as potential triggers for the onset of HIS and AOSD with unknown mechanisms. We aim to add to the literature regarding CMV infection in an immunocompetent host causing myocarditis and HIS with features of AOSD with recent history of COVID-19 infection.

Long-term impact of myocardial inflammation on quantitative myocardial perfusion-a descriptive PET/MR myocarditis study

PURPOSE

Whether myocardial inflammation causes long-term sequelae potentially affecting myocardial blood flow (MBF) is unknown. We aimed to assess the effect of myocardial inflammation on quantitative MBF parameters, as assessed by 13N-ammonia positron emission tomography myocardial perfusion imaging (PET-MPI) late after myocarditis.

METHODS

Fifty patients with a history of myocarditis underwent cardiac magnetic resonance (CMR) imaging at diagnosis and PET/MR imaging at follow-up at least 6 months later. Segmental MBF, myocardial flow reserve (MFR), and 13N-ammonia washout were obtained from PET, and segments with reduced 13N-ammonia retention, resembling scar, were recorded. Based on CMR, segments were classified as remote (n = 469), healed (inflammation at baseline but no late gadolinium enhancement [LGE] at follow-up, n = 118), and scarred (LGE at follow-up, n = 72). Additionally, apparently healed segments but with scar at PET were classified as PET discordant (n = 18).

RESULTS

Compared to remote segments, healed segments showed higher stress MBF (2.71 mL*min-1*g-1 [IQR 2.18-3.08] vs. 2.20 mL*min-1*g-1 [1.75-2.68], p < 0.0001), MFR (3.78 [2.83-4.79] vs. 3.36 [2.60-4.03], p < 0.0001), and washout (rest 0.24/min [0.18-0.31] and stress 0.53/min [0.40-0.67] vs. 0.22/min [0.16-0.27] and 0.46/min [0.32-0.63], p = 0.010 and p = 0.021, respectively). While PET discordant segments did not differ from healed segments regarding MBF and MFR, washout was higher by ~ 30% (p < 0.014). Finally, 10 (20%) patients were diagnosed by PET-MPI as presenting with a myocardial scar but without a corresponding LGE.

CONCLUSION

In patients with a history of myocarditis, quantitative measurements of myocardial perfusion as obtained from PET-MPI remain altered in areas initially affected by inflammation. CMR = cardiac magnetic resonance; PET = positron emission tomography; LGE = late gadolinium enhancement.

Appendectomy Mitigates Coxsackievirus B3-Induced Viral Myocarditis

Appendix has a distinct abundance of lymphatic cells and serves as a reservoir of microbiota which helps to replenish the large intestine with healthy flora. And it is the primary site of IgA induction, which shapes the composition of the intestinal microbiota. Recent population-based cohort studies report that appendectomy is associated with an increased risk of acute myocardial infarction and ischemic heart disease. Here, whether appendectomy has an effect on the occurrence and development of coxsackievirus B3 (CVB3)-induced viral myocarditis is studied. 103 TCID50 CVB3 was inoculated i.p. into appendectomized and sham-operated mice. RNA levels of viral load and pro-inflammatory cytokines in the hearts and the intestine were detected by RT-PCR. Compared to sham-operated mice, appendectomized mice exhibited attenuated cardiac inflammation and improved cardiac function, which is associated with a systemic reduced viral load. Appendectomized mice also displayed a reduction in cardiac neutrophil and macrophage infiltration and pro-inflammatory cytokine production. Mechanistically, we found that CVB3 induced an early and potent IL-10 production in the cecal patch at 2 days post infection. Appendectomy significantly decreased intestinal IL-10 and IL-10+ CD4+ Treg frequency which led to a marked increase in intestinal (primary entry site for CVB3) anti-viral IFN-γ+ CD4+ T and IFN-γ+ CD8+ T response and viral restriction, eventually resulting in improved myocarditis. Our results suggest that appendix modulates cardiac infection and inflammation through regulating intestinal IL-10+ Treg response.

Myocarditis: Etiology, Pathogenesis, and Their Implications in Clinical Practice

Myocarditis is an inflammatory disease of the myocardium caused by infectious or non-infectious agents. It can lead to serious short-term and long-term sequalae, such as sudden cardiac death or dilated cardiomyopathy. Due to its heterogenous clinical presentation and disease course, challenging diagnosis and limited evidence for prognostic stratification, myocarditis poses a great challenge to clinicians. As it stands, the pathogenesis and etiology of myocarditis is only partially understood. Moreover, the impact of certain clinical features on risk assessment, patient outcomes and treatment options is not entirely clear. Such data, however, are essential in order to personalize patient care and implement novel therapeutic strategies. In this review, we discuss the possible etiologies of myocarditis, outline the key processes governing its pathogenesis and summarize best available evidence regarding patient outcomes and state-of-the-art therapeutic approaches.

Viral Heart Disease: Diagnosis, Management, and Mechanisms

"Viral heart disease" is a term encompassing numerous virus-triggered heart conditions, wherein cardiac myocytes are injured, causing contractile dysfunction, cell death, or both. Cardiotropic viruses may also damage interstitial cells and vascular cells. Clinical presentation of the disorder varies widely. In most cases, patients are asymptomatic. Presentation includes-but is not limited to-flu-like symptoms, chest pain, cardiac arrhythmias, heart failure, cardiogenic shock, and sudden cardiac death. Laboratory studies, including blood-based heart injury indicators and cardiac imaging, may be needed. Management of viral heart disease requires a graded approach. Watchful observation at home may be the first step. Closer observation, with additional testing such as echocardiography in the clinic or hospital is less common yet may inform the use of cardiac magnetic resonance imaging. Intensive care may be indicated in severe acute illness. Viral heart disease mechanisms are complex. Initially, damage is predominantly virus mediated, whereas, in the second week, immune responses bring unintended obverse consequences for the myocardium. Innate immunity is largely beneficial in initial attempts to quell viral replication, whereas adaptive immunity brings helpful and antigen-specific mechanisms to fight the pathogen but also introduces the capability of autoimmunity. Each cardiotropic virus family has its own pathogenesis signature, including attack on myocytes, vascular cells, and other constitutive cells of myocardial interstitium. The stage of disease and preponderant viral pathways lend opportunities for potential intervention but also the likelihood of uncertainty about management. Overall, this review provides a novel glimpse into the depth of and need for solutions in viral heart disease.

Variant Angina and Cannabis-Induced Myocarditis: A Rare Presentation of Myocardial Inflammation

Myocarditis is a rare but serious inflammatory disease of the myocardium, often caused by viral infections. We present a unique case of myocarditis in a previously healthy 29-year-old male who developed symptoms and electrocardiography changes of variant angina following cannabis use. This case report discusses the patient's atypical presentation, diagnostic evaluation, management, and outcome.

Optimising the ECMO treatment regimen increases the survival rate for adult patients with acute fulminant myocarditis: A single-centre retrospective cohort study

Background

Applying Extracorporeal membrane oxygenation (ECMO) to patients with acute fulminant myocarditis (AFM) reduces their mortality. The survival rate is 55.6-71.9% for adult AFM patients, which is lower than that for paediatric patients (63-81%). In our centre, the survival rate of ECMO for adult patients with AFM was 66.7% from January 2003 to 2012. In January 2013, the therapeutic regimen was optimised, and then the survival rate increased to 89.1% by January 2022. This article analyses the reasons for the improved survival rate following the optimisation of treatment protocols.

Methods

The data for adult patients with AFM who underwent ECMO for a poor response conventional treatment from January 2003 to January 2022 were reviewed. According to different treatment regimens, the AFM patients were divided into an old and a new regimen group. Univariate and multivariate logistic regression analyses were performed on the data before and after ECMO.

Results

Fifty-five patients were enrolled in the age (31.2 ± 11.3), including 24 males. Forty-nine patients were weaned successfully from ECMO [duration: (4.1 ± 1.8) d], all of whom were discharged from the hospital, with a survival rate of 89.1%. Compared with the old regimen group, the new regimen group had a shorter duration of shock to ECMO, a lower proportion of patients receiving extracorporeal cardiopulmonary resuscitation (ECPR), a lower Vasoactive Inotropic Score (VIS), and lower levels of lactic acid, and high-sensitivity troponin T before ECMO (p &lt; 0.05). Compared with the old regimen group, after ECMO, the new regimen group had lower ECMO flow, lower proportion of left ventricular dilation and lower limb ischemia injury, the duration of ECMO was shorter, and significantly improved the survival rate, the difference was statistically significant (P &lt; 0.05). The duration of shock to ECMO and VIS before ECMO were independent risk factors for the survival rate (p &lt; 0.05).

Conclusion

Early ECMO initiation in adult AFM patients with a poor response to conventional therapy and low-flow ECMO to meet metabolic needs can reduce serious complications affecting the prognosis, may be associated with better outcomes.

Pathophysiological Mechanisms of Cardiac Dysfunction in Transgenic Mice with Viral Myocarditis

Viral myocarditis is pathologically associated with RNA viruses such as coxsackievirus B3 (CVB3), or more recently, with SARS-CoV-2, but despite intensive research, clinically proven treatment is limited. Here, by use of a transgenic mouse strain (TG) containing a CVB3ΔVP0 genome we unravel virus-mediated cardiac pathophysiological processes in vivo and in vitro. Cardiac function, pathologic ECG alterations, calcium homeostasis, intracellular organization and gene expression were significantly altered in transgenic mice. A marked alteration of mitochondrial structure and gene expression indicates mitochondrial impairment potentially contributing to cardiac contractile dysfunction. An extended picture on viral myocarditis emerges that may help to develop new treatment strategies and to counter cardiac failure.

The Role of MicroRNAs in Myocarditis-What Can We Learn from Clinical Trials?

Myocarditis is an inflammatory disease of the heart with a viral infection as the most common cause. It affects most commonly young adults. Although endomyocardial biopsy and cardiac magnetic resonance are used in the diagnosis, neither of them demonstrates all the required qualities. There is a clear need for a non-invasive, generally available diagnostic tool that will still remain highly specific and sensitive. These requirements could be possibly met by microribonucleic acids (miRNAs), which are small, non-coding RNA molecules that regulate many fundamental cell functions. They can be isolated from cells, tissues, or body fluids. Recently, several clinical studies have shown the deregulation of different miRNAs in myocarditis. The phase of the disease has also been evidenced to influence miRNA levels. These changes have been observed both in adult and pediatric patients. Some studies have revealed a correlation between the change in particular miRNA concentration and the degree of cardiac damage and inflammation. All of this indicates miRNAs as potential novel biomarkers in the diagnosis of myocarditis, as well as a prognostic tool for this condition. This review aims to summarize the current knowledge about the role of miRNAs in myocarditis based on the results of clinical studies.

The AIM2 inflammasome: A novel biomarker and target in cardiovascular disease

Absent in melanoma 2 (AIM2) is a cytoplasmic sensor that recognises the double-strand DNA. AIM2 inflammasome is a protein platform in the cell that initiates innate immune responses by cleaving pro-caspase-1 and converting IL-1β and IL-18 to their mature forms. Additionally, AIM2 inflammasome promotes pyroptosis by converting Gasdermin-D (GSDMD) to GSDMD-N fragments. An increasing number of studies have indicated the important and decisive roles of the AIM2 inflammasome, IL-1β, and pyroptosis in cardiovascular diseases, such as coronary atherosclerosis, myocardial infarction, ischaemia/reperfusion injury, heart failure, aortic aneurysm and ischaemic stroke. Here, we review the molecular mechanism of the activation and effect of the AIM2 inflammasome in cardiovascular disease, revealing new insights into pathogenic factors that may be targeted to treat cardiovascular disease and related dysfunctions.

Case report: Acute toxic myocardial damage caused by 5-fluorouracil—from enigma to success

Considering the pandemic of both cardiovascular diseases and oncological diseases, there is an increasing need for the use of chemotherapy, which through various pathophysiological mechanisms leads to damage to heart function. Cardio toxicity of chemotherapy drugs can manifest itself in a variety of clinical manifestations, which is why establishing a valid diagnosis is a real mystery for clinicians. Acute systolic heart failure (AHF) due to the use of 5-fluorouracil (5-FU) is a rare occurrence if it is not associated with myocardial infarction, myocarditis or Takotsubo cardiomyopathy. Therefore, we decided to present a case of an 52-year-old male who was diagnosed with stage IV RAS wild-type adenocarcinoma of the rectum and in whom the direct toxic effect 5-FU is the main reason for the appearance of toxic cardiomyopathy.

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.

Role of the CCL2-CCR2 axis in cardiovascular disease: Pathogenesis and clinical implications

The CCL2-CCR2 axis is one of the major chemokine signaling pathways that has received special attention because of its function in the development and progression of cardiovascular disease. Numerous investigations have been performed over the past decades to explore the function of the CCL2-CCR2 signaling axis in cardiovascular disease. Laboratory data on the CCL2-CCR2 axis for cardiovascular disease have shown satisfactory outcomes, yet its clinical translation remains challenging. In this article, we describe the mechanisms of action of the CCL2-CCR2 axis in the development and evolution of cardiovascular diseases including heart failure, atherosclerosis and coronary atherosclerotic heart disease, hypertension and myocardial disease. Laboratory and clinical data on the use of the CCL2-CCR2 pathway as a targeted therapy for cardiovascular diseases are summarized. The potential of the CCL2-CCR2 axis in the treatment of cardiovascular diseases is explored.

Systemic leak capillary syndrome with myocardial involvement and cardiogenic shock: a case report

Background

Systemic capillary leak syndrome (SCLS) is a potentially fatal disorder characterized by relapses of hypovolemic shock episodes.

Case Summary

We present a case of a 58-year-old man who presented to the Emergency Department with a history of recurrent episodes of syncope in the last hours. A few days before medical contact the patient complained of sore throat, fever, and flu-like symptoms. He was initially admitted with a diagnosis of suspected myopericarditis. Forty-eight hours later, the haemodynamic status suddenly deteriorated to a mixed cardiogenic and shock; an endomyocardial biopsy showed localized inflammatory infiltrates and areas of necrosis of cardiomyocytes with positive viral search for parvovirus B19 (PVB19), therefore the patient was treated with methylprednisolone pulses. Based on the concurrent presence of the typical triad of hypotension, hypoalbuminaemia, and haemoconcentration we suspected systemic leak capillary syndrome potentially triggered by the PVB19 infection with acute myocarditis. The clinical conditions further deteriorated with rhabdomyolysis and acute kidney injury: we started continuous veno-venous haemofiltration adding a cytokines adsorber. In the following hours, we observed a significant clinical improvement. The patient was discharged 1 month later and 5 months after discharge he experienced a new attack of SCLS, this time without myocardial involvement and with prompt symptoms resolution.

Conclusion

Systemic capillary leak syndrome is a potentially fatal disorder: early recognition of this entity and prompt initiation of supportive therapy are warranted, therefore, it is paramount that an emergency physician thinks of SCLS in patients with signs of cardiogenic shock and the classical triad of hypotension, hypoalbuminia, and haemoconcentration.

Are clinical features and cardiac biomarkers at admission related to severity in pediatric acute myocarditis?: Clinical features and cardiac biomarkers in pediatric acute myocarditis

OBJECTIVES

To evaluate the factors associated with intensive care requirement and mortality in pediatric myocarditis.

METHODS

Children aged 28 days to 18 years who were diagnosed with acute myocarditis in a pediatric emergency department between January 2010 and September 2020 were enrolled in the study retrospectively. Demographic and clinical features, cardiac biomarkers, and imaging findings were evaluated. Length of hospital stay, need for hospitalization in the pediatric intensive care unit (PICU), treatments, and survival outcomes were recorded. To define the severity of disease, three groups were created and the data were compared in terms of clinical, laboratory, and imaging findings. The patients treated in the pediatric ward were compared with those hospitalized in the PICU. Ventricular dysfunction was defined in patients with a left ventricular ejection fraction (LVEF) of <50% and these patients were compared with those who had an LVEF of >50%. Also, survivor and non-survivor patients were compared.

RESULTS

A total number of 62 patients with a median age of 8 years were included. Chest pain and tachycardia were the most common findings on physical examination. The mean LVEF was 59.3 ± 13.0% at admission. Of the patients, 17 were hospitalized in the PICU (27.4%). Chest pain was more common in patients hospitalized in the pediatric ward (p<0.001), and hypotension, vomiting, arrhythmia, were more common and LVEF was lower in patients in the PICU (p = 0.017, p = 0.008, p = 0.006, and p = 0.025, respectively). The children treated in the PICU were younger than those in the pediatric ward (p = 0.009). Troponin I levels were significantly higher in the pediatric ward (p = 0.035), and brain natriuretic peptide (BNP) levels were higher in patients in the PICU (p = 0.012). Death occurred in four patients. Hypotension and vomiting were significantly more common in non-survivors (p = 0.020 and 0.004, respectively). Inotropes and intravenous immunoglobulin (IVIG) were more commonly used in non-survivors (p = 0.001 and p = 0.015, respectively). BNP levels were higher in non-survivors (p = 0.008), and troponin I levels were not different between survivors and non-survivors (p = 0.260).

CONCLUSION

In pediatric acute myocarditis, lower LVEF, increased BNP, as well as the presence of hypotension and arrhythmia were found to be related to intensive care requirement. Hypotension and vomiting were found to be more common in non-survivors. Due to the possibility of rapidly worsening disease, physicians should be alert to the presence of these findings.

Non-Cardiac Cause of Death in Selected Group Children with Cardiac Pathology: A Retrospective Single Institute Study

Background: Pediatricians and pediatric surgeons often face children with cardiomegaly and dilatative or hypertrophic cardiomyopathies presenting with or without symptoms. Some of these patients have already been diagnosed and received medication, and some present with completely unrelated pathologies. Methods: We performed a 4-year retrospective study on the causes and mechanisms of death of children with cardiac pathology who died outside the cardiology clinic of our hospital by studying the hospital charts and necropsy reports. All children who were in this situation in our hospital were included. Results: Most children in our study group were infants (81.82%), most were boys (81.82%), and in most cases, the cause or mechanism of death was unrelated to their heart condition, whether it had already been diagnosed or not (one case probably died as a result of a malignant ventricular arrhythmia). Additionally, 27.27% of children died as a consequence of bronchopneumonia, the same percentage died as a consequence of an acquired non-pulmonary disease or after surgery, and 18.18% died as a consequence of congenital malformations. Conclusions: Cardiac disease needs to be thoroughly investigated using multiple tools for all children presenting with heart failure symptoms, those with heart murmurs, and children scheduled for surgery of any type. The intensive care specialist and surgeon need to be aware of any heart pathology before non-cardiac surgical interventions.

Case report of Campylobacter jejuni-associated myopericarditis: rare case of cardiac involvement by a common gastroenteritis pathogen

Background

Myocarditis is caused by inflammation affecting the heart muscle. The usual aetiological factor is viral, especially in immunocompetent hosts and developed countries. Campylobacter jejuni is a common cause of bacterial gastroenteritis but has rarely been associated with myocarditis.

Case summary

We report a case of a 22-year-old male admitted with pleuritic chest pain and a diarrhoeal illness. Thorough evaluation of the patient history did not reveal any sources for contracting the diarrhoea. Stool cultures confirmed that the patient had C. jejuni infection as well as myopericarditis confirmed on cardiac magnetic resonance imaging (cardiac MRI). Treatment with colchicine 0.5 mg BD, ibuprofen 600 mg TDS, and ciprofloxacin 500 mg BD orally for 5 days was started, together with an intravenous infusion of 0.9% normal saline 1 L TDS. The patient showed signs of improvement over a span of three days and the ST changes on electrocardiogram resolved.

Discussion

Although C. jejuni-associated myopericarditis is uncommon, it can be potentially life-threatening if not considered in the differential. Its diagnosis involves good history taking, examination, and investigation with electrocardiography, troponins and inflammatory markers, echocardiography, and cardiac MRI. Several mechanisms of infection have been suggested, including direct insult by toxin or bacterium as well as an immune-mediated response. Both supportive and causative treatments are important to ensure recovery while reducing the risk of complications. It is therefore crucial to ensure that the patient receives adequate follow-up to ascertain patient progress and to mitigate any complications that may arise as well as tackle patient concerns. The patient had a rapid recovery.

Personalized Management of Myocarditis and Inflammatory Cardiomyopathy in Clinical Practice

Myocarditis is an inflammatory heart disease induced by infectious and non-infectious causes frequently triggering immune-mediated pathologic mechanisms leading to myocardial damage and dysfunction. In approximately half of the patients, acute myocarditis resolves spontaneously while in the remaining cases, it may evolve into serious complications including inflammatory cardiomyopathy, arrhythmias, death, or heart transplantation. Due to the large variability in clinical presentation, unpredictable course of the disease, and lack of established causative treatment, myocarditis represents a challenging diagnosis in modern cardiology. Moreover, an increase in the incidence of myocarditis and inflammatory cardiomyopathy has been observed in recent years. However, there is a growing potential of available non-invasive diagnostic methods (biomarkers, serum anti-heart autoantibodies (AHA), microRNAs, speckle tracking echocardiography, cardiac magnetic resonance T1 and T2 tissue mapping, positron emission tomography), which may refine the diagnostic workup and/or noninvasive follow-up. Personalized management should include the use of endomyocardial biopsy and AHA, which may allow the etiopathogenetic subsets of myocarditis (infectious, non-infectious, and/or immune-mediated) to be distinguished and implementation of disease-specific therapies. In this review, we summarize current knowledge on myocarditis and inflammatory cardiomyopathy, and outline some practical diagnostic, therapeutic, and follow-up algorithms to facilitate comprehensive individualized management of these patients.

Myocarditis in systemic immune-mediated diseases: Prevalence, characteristics and prognosis. A systematic review

Many systemic immune-mediated diseases (SIDs) may involve the heart and present as myocarditis with different histopathological pictures, i.e. lymphocytic, eosinophilic, granulomatous, and clinical features, ranging from a completely asymptomatic patient to life-threatening cardiogenic shock or arrhythmias. Myocarditis can be part of some SIDs, such as sarcoidosis, systemic lupus erythematosus, systemic sclerosis, antiphospholipid syndrome, dermato-polymyositis, eosinophilic granulomatosis with polyangiitis and other vasculitis syndromes, but also of some organ-based immune-mediated diseases with systemic expression, such as chronic inflammatory bowel diseases. The aim of this review is to describe the prevalence, main clinical characteristics and prognosis of myocarditis associated with SIDs.

Pediatric Acute Myocarditis With Short-Term Outcomes and Factors for Extracorporeal Membrane Oxygenation: A Single-Center Retrospective Cohort Study in Vietnam

Objective: Data on the management and outcomes of acute myocarditis treated with extracorporeal membrane oxygenation (ECMO) among low- and middle-income countries are limited. This study aimed to determine the short-term outcomes and also identify factors associated with ECMO use among children with acute myocarditis at a tertiary children's hospital in Vietnam. Methods: A single-center, retrospective observational study was conducted between January 2016 and February 2021. Pediatric patients with acute myocarditis, aged 1 month to 16 years, were included. Results: In total, 54 patients (male, 46%; median age, 7 years) with acute myocarditis were included; 37 of them received ECMO support. Thirty percent (16/54) of the patients died, and 12 of them received ECMO. Laboratory variables that differed between survivors and non-survivors included median left ventricular ejection fraction (LVEF) at 48 h (42 vs. 25%; p = 0.001), platelet count (304 g/L [interquartile range (IQR): 243-271] vs. 219 g/L [IQR: 167-297]; p = 0.014), and protein (60 g/dl [IQR: 54-69] vs. 55 [IQR: 50-58]; p = 0.025). Among patients who received ECMO, compared with the survivors, non-survivors had a low LVEF at 48 h (odds ratio (OR), 0.8; 95% confidence interval (CI): 0.6-0.9; p = 0.006) and high vasoactive-inotropic score (OR, 1.0; 95% CI: 1.0-1.0; p = 0.038) and lactate (OR, 2.8; 95% CI, 1.2-6.1; p = 0.013) at 24 h post-ECMO. Conclusions: The case fatality rate among children with acute myocarditis was 30 and 32% among patients requiring ECMO support. Arrhythmia was an indicator for ECMO in patients with cardiogenic shock.

Viral Myocarditis-From Pathophysiology to Treatment

The diagnosis of acute and chronic myocarditis remains a challenge for clinicians. Characterization of this disease has been hampered by its diverse etiologies and heterogeneous clinical presentations. Most cases of myocarditis are caused by infectious agents. Despite successful research in the last few years, the pathophysiology of viral myocarditis and its sequelae leading to severe heart failure with a poor prognosis is not fully understood and represents a significant public health issue globally. Most likely, at a certain point, besides viral persistence, several etiological types merge into a common pathogenic autoimmune process leading to chronic inflammation and tissue remodeling, ultimately resulting in the clinical phenotype of dilated cardiomyopathy. Understanding the underlying molecular mechanisms is necessary to assess the prognosis of patients and is fundamental to appropriate specific and personalized therapeutic strategies. To reach this clinical prerequisite, there is the need for advanced diagnostic tools, including an endomyocardial biopsy and guidelines to optimize the management of this disease. The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has currently led to the worst pandemic in a century and has awakened a special sensitivity throughout the world to viral infections. This work aims to summarize the pathophysiology of viral myocarditis, advanced diagnostic methods and the current state of treatment options.

Cardiovascular consequences of viral infections: from COVID to other viral diseases

Infection of the heart muscle with cardiotropic viruses is one of the major aetiologies of myocarditis and acute and chronic inflammatory cardiomyopathy (DCMi). However, viral myocarditis and subsequent dilated cardiomyopathy is still a challenging disease to diagnose and to treat and is therefore a significant public health issue globally. Advances in clinical examination and thorough molecular genetic analysis of intramyocardial viruses and their activation status have incrementally improved our understanding of molecular pathogenesis and pathophysiology of viral infections of the heart muscle. To date, several cardiotropic viruses have been implicated as causes of myocarditis and DCMi. These include, among others, classical cardiotropic enteroviruses (Coxsackieviruses B), the most commonly detected parvovirus B19, and human herpes virus 6. A newcomer is the respiratory virus that has triggered the worst pandemic in a century, SARS-CoV-2, whose involvement and impact in viral cardiovascular disease is under scrutiny. Despite extensive research into the pathomechanisms of viral infections of the cardiovascular system, our knowledge regarding their treatment and management is still incomplete. Accordingly, in this review, we aim to explore and summarize the current knowledge and available evidence on viral infections of the heart. We focus on diagnostics, clinical relevance and cardiovascular consequences, pathophysiology, and current and novel treatment strategies.

Acute myocarditis: aetiology, diagnosis and management

Acute myocarditis is a serious, likely underdiagnosed condition affecting people of all ages and for which the number of UK hospital admissions is rising. A primary diagnosis of myocarditis accounted for 0.04% (36.5 per 100,000) of all hospital admissions in England between 1998 and 2017, although this is likely to be an underestimate of the true burden of myocarditis. The aetiology is broad, including infective and inflammatory conditions as well as exposure to toxic agents. Clinical features are varied and overlap with other acute cardiac conditions making diagnosis a challenge. Cardiovascular magnetic resonance imaging currently serves as the gold standard non-invasive diagnostic modality. If an underlying aetiological process is identified, then therapy may be directed at the cause; however, for most, treatment is supportive and aimed at managing any complications such as heart failure or arrhythmias. There is emerging evidence for immunosuppressive therapy in certain cases. Prognosis is generally good with recovery in most; however, up to 30% with biopsy-proven myocarditis progress to develop a dilated cardiomyopathy and its potential associated complications. All-cause mortality in the UK for patients presenting to hospital with acute myocarditis is approximately 4%.

SARS-CoV-2 Myocarditis: Insights Into Incidence, Prognosis, and Therapeutic Implications

Purpose of Review

In coronavirus disease 2019 (COVID-19), myocardial injury occurs frequently in severe or critically ill hospitalized patients, yet myocarditis is much less common. In this context, revisiting the definition of myocarditis is appropriate with a specific focus on diagnostic and management considerations in patients infected with SARS-CoV-2.

Recent Findings

Pathologic cardiac specimens from patients with COVID-19 suggest a mixed inflammatory response involving lymphocytes and macrophages, and importantly, cellular injury occurs predominantly at the level of pericytes and endothelial cells, less often involving direct myocyte necrosis. In COVID-19, the diagnosis of myocarditis has understandably been based predominantly on clinical criteria, and the number of patients with clinically suspected myocarditis who would meet diagnostic histological criteria is unclear. Echocardiography and cardiac magnetic resonance are important diagnostic tools, although the prognostic implications of abnormalities are still being defined. Importantly, SARS-CoV2 myocarditis should be diagnosed within an appropriate clinical context and should not be based on isolated imaging findings. Therapies in COVID-19 have focused on the major clinical manifestation of pneumonia, but the promotion of viral clearance early in the disease could prevent the development of myocarditis, and further study of immunosuppressive therapies once myocarditis has developed are indicated.

Summary

A strict and uniform approach is needed to diagnose myocarditis due to SARS-CoV-2 to better understand the natural history of this disease and to facilitate evaluation of potential therapeutic interventions. A methodological approach will also better inform the incidence of COVID-19 associated myocarditis and potential long-term health effects.

Cell type-specific roles of PAR1 in Coxsackievirus B3 infection

Protease-activated receptor 1 (PAR1) is widely expressed in humans and mice, and is activated by a variety of proteases, including thrombin. Recently, we showed that PAR1 contributes to the innate immune response to viral infection. Mice with a global deficiency of PAR1 expressed lower levels of CXCL10 and had increased Coxsackievirus B3 (CVB3)-induced myocarditis compared with control mice. In this study, we determined the effect of cell type-specific deletion of PAR1 in cardiac myocytes (CMs) and cardiac fibroblasts (CFs) on CVB3-induced myocarditis. Mice lacking PAR1 in either CMs or CFs exhibited increased CVB3 genomes, inflammatory infiltrates, macrophages and inflammatory mediators in the heart and increased CVB3-induced myocarditis compared with wild-type controls. Interestingly, PAR1 enhanced poly I:C induction of CXCL10 in rat CFs but not in rat neonatal CMs. Importantly, activation of PAR1 reduced CVB3 replication in murine embryonic fibroblasts and murine embryonic cardiac myocytes. In addition, we showed that PAR1 reduced autophagy in murine embryonic fibroblasts and rat H9c2 cells, which may explain how PAR1 reduces CVB3 replication. These data suggest that PAR1 on CFs protects against CVB3-induced myocarditis by enhancing the anti-viral response whereas PAR1 on both CMs and fibroblasts inhibits viral replication.

Myocarditis-associated necrotizing coronary vasculitis: incidence, cause, and outcome

AIMS

Necrotizing coronary vasculitis (NCV) is a rare entity usually associated to myocarditis which incidence, cause, and response to therapy is unreported.

METHODS AND RESULTS

Among 1916 patients with biopsy-proven myocarditis, 30 had NCV. Endomyocardial samples were retrospectively investigated with immunohistochemistry for toll-like receptor 4 (TLR4) and real-time polymerase chain reaction (PCR) for viral genomes. Serum samples were processed for anti-heart autoantibodies (Abs), IL-1β, IL-6, IL-8, tumour necrosis factor (TNF)-α. Identification of an immunologic pathway (including virus-negativity, TLR4-, and Ab-positivity) was followed by immunosuppression. Myocarditis-NCV cohort was followed for 6 months with 2D-echo and/or cardiac magnetic resonance and compared with 60 Myocarditis patients and 30 controls. Increase in left ventricular ejection fraction ≥10% was classified as response to therapy. Control endomyocardial biopsy followed the end of treatment. Twenty-six Myocarditis-NCV patients presented with heart failure; four with electrical instability. Cause of Myocarditis-NCV included infectious agents (10%) and immune-mediated causes (chest trauma 3%; drug hypersensitivity 7%; hypereosinophilic syndrome 3%; primary autoimmune diseases 33%, idiopathic 44%). Abs were positive in immune-mediated Myocarditis-NCV and virus-negative Myocarditis; Myocarditis-NCV patients with Ab+ presented autoreactivity in vessel walls. Toll-like receptor 4 was overexpressed in immune-mediated forms and poorly detectable in viral. Interleukin-1β was significantly higher in Myocarditis-NCV than Myocarditis, the former presenting 24% in-hospital mortality compared with 1.5% of Myocarditis cohort. Immunosuppression induced improvement of cardiac function in 88% of Myocarditis-NCV and 86% of virus-negative Myocarditis patients.

CONCLUSION

Necrotizing coronary vasculitis is histologically detectable in 1.5% of Myocarditis. Necrotizing coronary vasculitis includes viral and immune-mediated causes. Intra-hospital mortality is 24%. The immunologic pathway is associated with beneficial response to immunosuppression.

Nucleoside Analogue Reverse Transcriptase Inhibitors Improve Clinical Outcome in Transcriptional Active Human Parvovirus B19-Positive Patients

Human parvovirus B19 (B19V) is the predominant cardiotropic virus associated with dilated inflammatory cardiomyopathy (DCMi). Transcriptionally active cardiotropic B19V infection is clinically relevant and triggers adverse long-term mortality. During the study; we evaluated whether antiviral treatment with the nucleoside analogue telbivudine (LTD) is effective in suppressing transcriptional active B19V in endomyocardial biopsies (EMBs) of B19V positive patients and improving clinical outcomes. Seventeen B19V-positive patients (13 male; mean age 45.7 ± 13.9 years; mean left ventricular ejection fraction (LVEF) 37.7 ± 13.5%) with positive B19V DNA and transcriptional activity (B19V mRNA) in EMBs were treated with 600 mg/d LTD over a period of six months. Patients underwent EMBs before and after termination of the LTD treatment. B19V RNA copy numbers remained unchanged in 3/17 patients (non-responder) and declined or disappeared completely in the remaining 14/17 patients (responder) (p ≤ 0.0001). Notably; LVEF improvement was more significant in patients who reduced or lost B19V RNA (responder; p = 0.02) in contrast to non-responders (p = 0.7). In parallel; responder patients displayed statistically significant improvement in quality of life (QoL) questionnaires (p = 0.03) and dyspnea on exertion (p = 0.0006), reflecting an improvement in New York Heart Association (NYHA) Classification (p = 0.001). Our findings demonstrated for the first time that suppression of B19V transcriptional activity by LTD treatment improved hemodynamic and clinical outcome significantly. Thus; the present study substantiates the clinical relevance of detecting B19V transcriptional activity of the myocardium.

Neurological complications of cardiomyopathies

There is a multifaceted relationship between the cardiomyopathies and a wide spectrum of neurological disorders. Severe acute neurological events, such as a status epilepticus and aneurysmal subarachnoid hemorrhage, may result in an acute cardiomyopathy the likes of Takotsubo cardiomyopathy. Conversely, the cardiomyopathies may result in a wide array of neurological disorders. Diagnosis of a cardiomyopathy may have already been established at the time of the index neurological event, or the neurological event may have prompted subsequent cardiac investigations, which ultimately lead to the diagnosis of a cardiomyopathy. The cardiomyopathies belong to one of the many phenotypes of complex genetic diseases or syndromes, which may also involve the central or peripheral nervous systems. A number of exogenous agents or risk factors such as diphtheria, alcohol, and several viruses may result in secondary cardiomyopathies accompanied by several neurological manifestations. A variety of neuromuscular disorders, such as myotonic dystrophy or amyloidosis, may demonstrate cardiac involvement during their clinical course. Furthermore, a number of genetic cardiomyopathies phenotypically incorporate during their clinical evolution, a gamut of neurological manifestations, usually neuromuscular in nature. Likewise, neurological complications may be the result of diagnostic procedures or medications for the cardiomyopathies and vice versa. Neurological manifestations of the cardiomyopathies are broad and include, among others, transient ischemic attacks, ischemic strokes, intracranial hemorrhages, syncope, muscle weakness and atrophy, myotonia, cramps, ataxia, seizures, intellectual developmental disorder, cognitive impairment, dementia, oculomotor palsies, deafness, retinal involvement, and headaches.

Detection of parvovirus mRNAs as markers for viral activity in endomyocardial biopsy-based diagnosis of patients with unexplained heart failure

Erythroparvovirus (B19V) genomes have been detected in various organs of infected individuals including endothelial cells of the heart muscle. However, the role of B19V as a causative pathogen of myocardial damage is still unknown. The majority of reports focus on the presence of viral DNA ignoring proof of viral RNAs as important markers for viral activity. During this study, we established (RT-) qPCR to characterize expression of B19V RNAs (NS1 and VP1/2) in endomyocardial biopsies (EMBs) of 576 patients with unexplained heart failure. 403/576 (70%) EMBs were positive for B19V DNA. B19V mRNAs NS1 and/or VP1/2, indicating viral activity, could be detected in 38.5% of B19V DNA positive samples using the newly established B19V RT-PCRs. 22.1% of samples were characterized by only NS1 mRNA detection while 6.0% revealed only VP1/2 mRNA expression. Detection of both intermediates was successful in 10.4% of samples. Applying the molecular testing, our study revealed that a high proportion (38.5%) of B19V DNA positive EMBs was characterized by viral transcriptional activity. Further prospective studies will evaluate relevance of viral transcription intermediates as a diagnostic marker to differentiate between latent B19V infection and clinically relevant transcriptionally active B19V-infection of the heart muscle.

A Rare Case of Myocarditis Mimicking ST-Elevation Myocardial Infarction

Myocarditis is caused by acute injury and inflammation of cardiac myocytes and is most commonly caused by a viral infection. Myocarditis remains a rare diagnosis and manifests with a wide spectrum of non-specific symptoms that include chest pain, dyspnea, and palpitations associated with electrocardiographic abnormalities that resemble that of ST-elevation myocardial infarction (STEMI). Therefore, clinical diagnosis is often challenging and is often misdiagnosed. We present a case of a 22-year-old male who presented with left-sided non-radiating chest pain associated with shortness of breath, elevated troponin of 3.2 ng/ml (<0.03 ng/ml). Electrocardiogram (ECG) and cardiac echocardiogram revealed ST-segment elevations in the anterolateral leads and an ejection fraction of 35%, respectively. The patient was initially suspected of having a STEMI; however, cardiac catheterization revealed non-obstructed coronary arteries. Due to elevated inflammatory markers, the patient was then started on colchicine for suspected myocarditis and had complete resolution of symptoms one week after. This case highlights that a high index of clinical suspicion and prompt diagnosis is necessary to prevent any delays in appropriate therapy for myocarditis.

MicroRNA profiling as a novel diagnostic tool for identification of patients with inflammatory and/or virally induced cardiomyopathies

AIMS

MicroRNAs (miRNAs) might be used as prospective biomarkers for the identification of unexplained heart failure caused by a viral and/or inflammatory process. The aim of this study was to identify and to evaluate prognostic miRNAs in serum of patients with inflammatory heart diseases diagnosed by endomyocardial biopsies.

METHODS AND RESULTS

After TaqMan® OpenArray® screening of 754 unique circulating miRNAs in serum of biopsy-proven patients [184 patients with inflammatory and/or virally induced myocardial diseases (DCMi), 25 patients with dilated cardiomyopathy (DCM), and 25 healthy donors], we identified seven miRNAs of interest (P < 0.05). These data have been verified by single qRT-PCR assays in other biopsy-proven patients (159 patients with viral and/or inflammatory myocardial diseases, 46 patients with DCM, and 60 healthy donors). The expression of let-7f, miR-197, miR-223, miR-93, and miR-379 allowed us to differentiate between patients with a virus and/or inflammation and healthy donors (P < 0.05) with the specificity over 93%. Based on the expression of miR-21 and miR-30a-5p, we could sort out patients with DCM from all other study groups (P < 0.05) with the specificity over 95%.

CONCLUSIONS

This miRNA profile provides for the first time a new non-invasive diagnostic perspective to identify patients with intramyocardial inflammation and/or viral persistence only from single serum sample, independently of prescribed therapy and time of symptoms onset. It allows the early finding of those patients relevant for myocardial biopsy for exact diagnosis and further proscription of causal aetiology-driven specific treatment.

Myocarditis: imaging up to date

Myocarditis is an inflammatory disease of the heart muscle, diagnosed by histological, immunological, and immunohistochemical criteria. Endomyocardial biopsy represents the diagnostic gold standard for its diagnosis but is infrequently used. Due to its noninvasive ability to detect the presence of myocardial edema, hyperemia and necrosis/fibrosis, Cardiac MR imaging is routinely used in the clinical practice for the diagnosis of acute myocarditis. Recently pixel-wise mapping of T1 and T2 relaxation time have been introduced into the clinical Cardiac MR protocol increasing its accuracy. Our paper will review the role of MR imaging in the diagnosis of acute myocarditis.

Diagnosis, Evaluation, and Treatment of Myocarditis in Children

Myocarditis in the pediatric population can be a challenging diagnosis to make and often requires utilization of multiple diagnostic modalities. The cause is often due to a viral infection with activation of the innate and acquired immune response with either recovery or disease progression. Laboratory testing often includes inflammatory markers, cardiac troponin levels, and natriuretic peptides. Noninvasive testing should include electrocardiogram, echocardiogram, and possibly an MRI. Treatment of myocarditis remains controversial with most providers using immune modulators with intravenous immunoglobulin and corticosteroids.

Liver-Specific siRNA-Mediated Stat3 or C3 Knockdown Improves the Outcome of Experimental Autoimmune Myocarditis

Myocarditis can lead to autoimmune disease, dilated cardiomyopathy, and heart failure, which is modeled in the mouse by cardiac myosin immunization (experimental autoimmune myocarditis [EAM]). Signal transducer and activator of transcription 3 (STAT3) systemic inhibition exerts both preventive and therapeutic effects in EAM, and STAT3 constitutive activation elicits immune-mediated myocarditis dependent on complement C3 and correlating with activation of the STAT3-interleukin 6 (IL-6) axis in the liver. Thus, liver-specific STAT3 inhibition may represent a therapeutic option, allowing to bypass the heart toxicity, predicted by systemic STAT3 inhibition. We therefore decided to explore the effectiveness of silencing liver Stat3 and C3 in preventing EAM onset and/or the recovery of cardiac functions. We first show that complement C3 and C5 genetic depletion significantly prevents the onset of spontaneous myocarditis, supporting the complement cascade as a viable target. In order to interfere with complement production and STAT3 activity specifically in the liver, we took advantage of liver-specific Stat3 or C3 small interfering (si)RNA nanoparticles, demonstrating that both siRNAs can significantly prevent myocarditis onset and improve the recovery of heart functions in EAM. Our data demonstrate that liver-specific Stat3/C3 siRNAs may represent a therapeutic option for autoimmune myocarditis and suggest that complement levels and activation might be predictive of progression to dilated cardiomyopathy.