Myocarditis

The double-edged role of IL-22 in organ fibrosis

Fibrosis is unregulated tissue repair in damaged or diseased organs, and the accumulation of excess extracellular matrix (ECM) impacts the structure and functions of organs, leading to death. Fibrosis is usually triggered by inflammation and tissue damage, and inflammatory mediators stimulate the proliferation of myofibroblasts and the excessive production of ECM. The IL-10 family cytokines play important roles in the development of fibrosis, and its member IL-22 has recently attracted specific attention. IL-22 plays great roles in preventing pathogens invasion and tissue damage, as well as making a contribution to pathogenic processes. Increasing evidence suggested that IL-22 is a key molecule in tissue repair, proliferation and mucosal barrier defense, and it has also been suggested to play both pro-fibrotic and anti-fibrotic roles in tissues. In this review, we summarized the pro-fibrotic and anti-fibrotic functions of IL-22 in various organs which may be of great significance for the development of potential therapeutic strategies for fibrosis-related diseases.

Cardiac Involvement in a Patient With Coronavirus Disease 2019 (COVID-19)

Importance

Virus infection has been widely described as one of the most common causes of myocarditis. However, less is known about the cardiac involvement as a complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Objective

To describe the presentation of acute myocardial inflammation in a patient with coronavirus disease 2019 (COVID-19) who recovered from the influenzalike syndrome and developed fatigue and signs and symptoms of heart failure a week after upper respiratory tract symptoms.

Design, Setting, and Participant

This case report describes an otherwise healthy 53-year-old woman who tested positive for COVID-19 and was admitted to the cardiac care unit in March 2020 for acute myopericarditis with systolic dysfunction, confirmed on cardiac magnetic resonance imaging, the week after onset of fever and dry cough due to COVID-19. The patient did not show any respiratory involvement during the clinical course.

Exposure

Cardiac involvement with COVID-19.

Main Outcomes and Measures

Detection of cardiac involvement with an increase in levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity troponin T, echocardiography changes, and diffuse biventricular myocardial edema and late gadolinium enhancement on cardiac magnetic resonance imaging.

Results

An otherwise healthy 53-year-old white woman presented to the emergency department with severe fatigue. She described fever and dry cough the week before. She was afebrile but hypotensive; electrocardiography showed diffuse ST elevation, and elevated high-sensitivity troponin T and NT-proBNP levels were detected. Findings on chest radiography were normal. There was no evidence of obstructive coronary disease on coronary angiography. Based on the COVID-19 outbreak, a nasopharyngeal swab was performed, with a positive result for SARS-CoV-2 on real-time reverse transcriptase-polymerase chain reaction assay. Cardiac magnetic resonance imaging showed increased wall thickness with diffuse biventricular hypokinesis, especially in the apical segments, and severe left ventricular dysfunction (left ventricular ejection fraction of 35%). Short tau inversion recovery and T2-mapping sequences showed marked biventricular myocardial interstitial edema, and there was also diffuse late gadolinium enhancement involving the entire biventricular wall. There was a circumferential pericardial effusion that was most notable around the right cardiac chambers. These findings were all consistent with acute myopericarditis. She was treated with dobutamine, antiviral drugs (lopinavir/ritonavir), steroids, chloroquine, and medical treatment for heart failure, with progressive clinical and instrumental stabilization.

Conclusions and Relevance

This case highlights cardiac involvement as a complication associated with COVID-19, even without symptoms and signs of interstitial pneumonia.

The Dynamic Interplay Between Cardiac Inflammation and Fibrosis

Heart failure is a leading cause of death worldwide. While there are multiple etiologies contributing to the development of heart failure, all cause result in impairments in cardiac function that is characterized by changes in cardiac remodeling and compliance. Fibrosis is associated with nearly all forms of heart failure and is an important contributor to disease pathogenesis. Inflammation also plays a critical role in the heart and there is a large degree of interconnectedness between the inflammatory and fibrotic response. This review discusses the cellular and molecular mechanisms contributing to inflammation and fibrosis and the interplay between the two.

Cardiomyocyte-specific deletion of Senp2 contributes to CVB3 viral replication and inflammation

Viral myocarditis (VMC) is characterized by cardiac inflammation and excessive inflammatory responses after viral infection. SENP2, a deSUMO-specific protease, has been reported to regulate antiviral innate immunity. This study aimed to investigate whether SENP2 affects CVB3-induced VMC. We generated a CVB3-induced VMC mouse model in 6-week-old cardiomyocyte-specific Senp2 knockout mice. The mice were sacrificed at days 0, 2, 4 and 6 after CVB3 infection. The survival rate, body weight, myocardial histopathological changes, viral load, cytokine levels and antiviral gene expression in cardiac tissues of both groups were investigated. Our study indicated that the expression of Senp2 in primary cardiomyocytes was upregulated by CVB3 infection. Moreover, deletion of Senp2 in the heart exacerbated CVB3 infection-induced myocarditis, facilitated CVB3 viral replication and downregulated the expression of antiviral proteins. In conclusion, our findings suggest a protective role for SENP2 in CVB3-induced VMC.

[Novel coronavirus infection COVID-19: extrapulmonary manifestations]

The novel coronavirus infection COVID-19 in most cases manifests with respiratory symptoms and fever, however, some patients may have cardiovascular and gastroenterological manifestations. A feature of the clinical syndrome of COVID-19 is the development of pronounced immunopathological reactions and disorders of hemostasis, leading to the development of a wide range of cardiovascular complications. The course of COVID-19 may be complicated by the development of acute myocardial infarction, venous and arterial thrombosis and thromboembolism in various vascular pools, the development of acute myocardial damage and myocarditis. Among the gastroenterological manifestations, diarrhea, nausea or vomiting, as well as abdominal pain, are most often detected. These symptoms may precede the appearance of respiratory signs of the disease, and in some cases come to the fore in the clinical picture of the disease. In addition, in some patients there are laboratory signs of liver injury (increased serum transaminases). The exact pathogenesis of the above disorders continues to be studied.

Advancement of Mechanisms of Coxsackie Virus B3-Induced Myocarditis Pathogenesis and the Potential Therapeutic Targets

Viral myocarditis is a cardiac disease caused by Group B Coxsackie virus of Enterovirus genus in the Picorna viridae family. It causes heart failure in children, young and adults. Ten Percent (10%) of acute heart failure and 12% of sudden deaths in young and adults who are less than 40 years is due to this viral myocarditis. If treatment action is not taken earlier, the viral disease can develop into chronic myocarditis and Dilated Cardiomyopathy which lead to congestive heart failure. And these eventually result in a reduced cardiac function which finally brings the victim to death. The only treatment option of the disease is heart transplantation once the acute stage of disease develops to chronic and Dilated Cardiomyopathy. Currently, there is a limitation in daily clinical treatments and even some available treatment options are ineffective. Therefore, focusing on search for treatment options through investigation is imperative. Recent studies have reported that biological molecules show a promising role. But their mechanism of pathogenesis is still unclear. A detailed study on identifying the role of biological molecules involved in Coxsackie B3 virus induced myocarditis and their mechanisms of pathogenesis; compiling and disseminating the findings of the investigation to the scientific communities contribute one step forward to the solution. Therefore, this review is aimed at compiling information from findings of current studies on the potential therapeutic role of micro RNA, cytokines and chemokines on the mechanism of pathogenesis of Coxsackie virus B3- induced myocarditis to give brief information for scholars to conduct a detailed study in the area.

The Cardiac Microenvironment Instructs Divergent Monocyte Fates and Functions in Myocarditis

Two types of monocytes, Ly6C^hi and Ly6C^lo, infiltrate the heart in murine experimental autoimmune myocarditis (EAM). We discovered a role for cardiac fibroblasts in facilitating monocyte-to-macrophage differentiation of both Ly6C^hi and Ly6C^lo cells, allowing these macrophages to perform divergent functions in myocarditis progression. During the acute phase of EAM, IL-17A is highly abundant. It signals through cardiac fibroblasts to attenuate efferocytosis of Ly6C^hi monocyte-derived macrophages (MDMs) and simultaneously prevents Ly6C^lo monocyte-to-macrophage differentiation. We demonstrated an inverse clinical correlation between heart IL-17A levels and efferocytic receptor expressions in humans with heart failure (HF). In the absence of IL-17A signaling, Ly6C^hi MDMs act as robust phagocytes and are less proinflammatory, whereas Ly6C^lo monocytes resume their differentiation into MHCII⁺ macrophages. We propose that MHCII⁺Ly6C^lo MDMs are associated with the reduction of cardiac fibrosis and prevention of the myocarditis sequalae.

Hou et al. show that cardiac fibroblasts facilitate infiltrating Ly6C^hi and Ly6C^lo monocytes to become macrophages. IL-17A trans-signaling through cardiac fibroblasts increases MerTK shedding and promotes a pro-inflammatory and pro-tissue remodeling gene expression profile in Ly6C^hi monocyte-derived macrophages. Paradoxically, IL-17A signaling through cardiac fibroblasts can substantially inhibit Ly6C^lo monocyte-to-macrophage differentiation.

SARS-CoV-2 Infection with Associated Rhabdomyolysis and Probable Myocarditis

We describe a patient with SARS-CoV-2 and severe pneumonia who required mechanical ventilation and developed associated rhabdomyolysis with probable myocardial involvement as evidenced by cardiac enzyme abnormalities and echocardiographic findings. Repeat testing should be done in cases highly suspicious for SARS-CoV-2 as initial molecular tests may be negative, as in our case.

LEARNING POINTS

SARS-CoV-2 infection may be associated with rhabdomyolysis and myocarditis.Negative results for SARS-CoV-2 despite a clinical presentation suggestive of COVID-19 disease should be treated with caution.Drugs known to cause rhabdomyolysis and myocarditis should be carefully reviewed when treating SARS-CoV-2 patients.

Histopathological observations in COVID-19: a systematic review

BACKGROUND

Coronavirus disease-2019 (COVID-19) has caused a great global threat to public health. The World Health Organization (WHO) has declared COVID-19 disease as a pandemic, affecting the human respiratory and other body systems, which urgently demands for better understanding of COVID-19 histopathogenesis.

OBJECTIVE

Data on pathological changes in different organs are still scarce, thus we aim to review and summarise the latest histopathological changes in different organs observed after autopsy of COVID-19 cases.

MATERIALS AND METHODS

Over the period of 3 months, authors performed vast review of the articles. The search engines included were PubMed, Medline (EBSCO & Ovid), Google Scholar, Science Direct, Scopus and Bio-Medical. Search terms used were 'Histopathology in COVID-19', 'COVID-19', 'Pathological changes in different organs in COVID-19' or 'SARS-CoV-2'. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines were used for review writing.

RESULT

We identified various articles related to the histopathology of various organs in COVID-19 positive patients. Overall, 45 articles were identified as full articles to be included in our study. Histopathological findings observed are summarised according to the systems involved.

CONCLUSION

Although COVID-19 mainly affects respiratory and immune systems, but other systems like cardiovascular, urinary, gastrointestinal tract, reproductive system, nervous system and integumentary system are not spared, especially in elderly cases and those with comorbidity. This review would help clinicians and researchers to understand the tissue pathology, which can help in better planning of the management and avoiding future risks.

The role of sphingosine 1-phosphate and its receptors in cardiovascular diseases

There are many different types of cardiovascular diseases, which impose a huge economic burden due to their extremely high mortality rates, so it is necessary to explore the underlying mechanisms to achieve better supportive and curative care outcomes. Sphingosine 1‐phosphate (S1P) is a bioactive lipid mediator with paracrine and autocrine activities that acts through its cell surface S1P receptors (S1PRs) and intracellular signals. In the circulatory system, S1P is indispensable for both normal and disease conditions; however, there are very different views on its diverse roles, and its specific relevance to cardiovascular pathogenesis remains elusive. Here, we review the synthesis, release and functions of S1P, specifically detail the roles of S1P and S1PRs in some common cardiovascular diseases, and then address several controversial points, finally, we focus on the development of S1P‐based therapeutic approaches in cardiovascular diseases, such as the selective S1PR1 modulator amiselimod (MT‐1303) and the non‐selective S1PR1 and S1PR3 agonist fingolimod, which may provide valuable insights into potential therapeutic strategies for cardiovascular diseases.

Diagnostic Yield of Electroanatomic Voltage Mapping in Guiding Endomyocardial Biopsies

BACKGROUND

Electroanatomic voltage mapping (EVM) is a promising modality for guiding endomyocardial biopsies (EMBs). However, few data support its feasibility and safety. We now report the largest cohort of patients undergoing EVM-guided EMBs to show its diagnostic yield and to compare it with a cardiac magnetic resonance (CMR)-guided approach.

METHODS

We included 162 consecutive patients undergoing EMB at our institution from 2010 to 2019. EMB was performed in pathological areas identified at EVM and CMR. CMR and EVM sensitivity and specificity regarding the identification of pathological substrates of myocardium were evaluated according to EMB results.

RESULTS

Preoperative CMR showed late gadolinium enhancement in 70% of the patients, whereas EVM identified areas of low voltage in 61%. Right (73%), left (19%), or both ventricles (8%) underwent sampling. EVM proved to have sensitivity similar to CMR (74% versus 77%), with specificity being 70% and 47%, respectively. In 12 patients with EMB-proven cardiomyopathy, EVM identified pathological areas that had been undetected at CMR evaluation. Sensitivity of pooled EVM and CMR was as high as 95%. EMB analysis allowed us to reach a new diagnosis, different from the suspected clinical diagnosis, in 39% of patients. The complications rate was low, mostly related to vascular access, with no patients requiring urgent management.

CONCLUSIONS

EVM proved to be a promising tool for targeted EMB because of its sensitivity and specificity for identification of myocardial pathological substrates. EVM was demonstrated to have accuracy similar to CMR. EVM and CMR together conferred a positive predictive value of 89% on EMB.

COVID-19 cardiovascular epidemiology, cellular pathogenesis, clinical manifestations and management

Coronavirus Disease 2019 (COVID-19) is a rapidly progressing global pandemic that may present with a variety of cardiac manifestations including, but not limited to, myocardial injury, myocardial infarction, arrhythmias, heart failure, cardiomyopathy, shock, thromboembolism, and cardiac arrest. These cardiovascular effects are worse in patients who have pre-existing cardiac conditions such as coronary artery disease, hypertension, diabetes mellitus, and coagulation abnormalities. Other predisposing risk factors include advanced age, immunocompromised state, and underlying systemic inflammatory conditions. Here we review the cellular pathophysiology, clinical manifestations and treatment modalities of the cardiac manifestations seen in patients with COVID-19.

BML-111 treatment prevents cardiac apoptosis and oxidative stress in a mouse model of autoimmune myocarditis

Myocarditis is an inflammation of the myocardium that can progress to a more severe phenotype of dilated cardiomyopathy (DCM). Three main harmful factors determine this progression: inflammation, cell death, and oxidative stress. Lipoxins and their derivatives are endogenous proresolving mediators that induce the resolution of the inflammatory process. This study aims to determine whether these mediators play a protective role in a murine model of experimental autoimmune myocarditis (EAM) by treating with the lipoxin A₄ analog BML-111. We observed that EAM mice presented extensive infiltration areas that correlated with higher levels of inflammatory and cardiac damage markers. Both parameters were significantly reduced in BML-treated EAM mice. Consistently, cardiac dysfunction, hypertrophy, and emerging fibrosis detected in EAM mice was prevented by BML-111 treatment. At the molecular level, we demonstrated that treatment with BML-111 hampered apoptosis and oxidative stress induction by EAM. Moreover, both in vivo and in vitro studies revealed that these beneficial effects were mediated by activation of Nrf2 pathway through CaMKK2-AMPKα kinase pathway. Altogether, our data indicate that treatment with the lipoxin derivative BML-111 effectively alleviates EAM outcome and prevents cardiac dysfunction, thus, underscoring the therapeutic potential of lipoxins and their derivatives to treat myocarditis and other inflammatory cardiovascular diseases.

COVID-19-associated cardiovascular morbidity in older adults: a position paper from the Italian Society of Cardiovascular Researches

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects host cells following binding with the cell surface ACE2 receptors, thereby leading to coronavirus disease 2019 (COVID-19). SARS-CoV-2 causes viral pneumonia with additional extrapulmonary manifestations and major complications, including acute myocardial injury, arrhythmia, and shock mainly in elderly patients. Furthermore, patients with existing cardiovascular comorbidities, such as hypertension and coronary heart disease, have a worse clinical outcome following contraction of the viral illness. A striking feature of COVID-19 pandemics is the high incidence of fatalities in advanced aged patients: this might be due to the prevalence of frailty and cardiovascular disease increase with age due to endothelial dysfunction and loss of endogenous cardioprotective mechanisms. Although experimental evidence on this topic is still at its infancy, the aim of this position paper is to hypothesize and discuss more suggestive cellular and molecular mechanisms whereby SARS-CoV-2 may lead to detrimental consequences to the cardiovascular system. We will focus on aging, cytokine storm, NLRP3/inflammasome, hypoxemia, and air pollution, which is an emerging cardiovascular risk factor associated with rapid urbanization and globalization. We will finally discuss the impact of clinically available CV drugs on the clinical course of COVID-19 patients. Understanding the role played by SARS-CoV2 on the CV system is indeed mandatory to get further insights into COVID-19 pathogenesis and to design a therapeutic strategy of cardio-protection for frail patients.

An unusual cause of ventricular fibrillatory arrest

Myocarditis is an important cause of arrhythmogenic sudden cardiac arrest in the young. A strong index of suspicion is required as not only can arrhythmias be the only clinical manifestation but also because these patients can have normal cardiac biomarkers, electrocardiographic and echocardiographic findings, and inflammatory markers. Patients with ventricular arrhythmias in the setting of viral myocarditis, especially the ones in whom cardiac MRI findings normalise upon follow-up, tend to do well in the long run and an implantable cardioverter-defibrillator should be avoided in these patients; instead, a wearable defibrillator should be temporarily used as we did in this 7-year-old.

An overview of the immune mechanisms of viral myocarditis

Viral myocarditis has been identified as a major cause of dilated cardiomyopathy (DCM) that can lead to heart failure. Historically, Coxsackieviruses and adenoviruses have been commonly suspected in myocarditis/DCM patients in North America and Europe. However, this notion is changing as other viruses such as Parvovirus B19 and human herpesvirus-6 are increasingly reported as causes of myocarditis in the United States, with the most recent example being the severe acute respiratory syndrome coronavirus 2, causing the Coronavirus Disease-19. The mouse model of Coxsackievirus B3 (CVB3)-induced myocarditis, which may involve mediation of autoimmunity, is routinely used in the study of immune pathogenesis of viral infections as triggers of DCM. In this review, we discuss the immune mechanisms underlying the development of viral myocarditis with an emphasis on autoimmunity in the development of post-infectious myocarditis induced with CVB3.

Major 5'terminally deleted enterovirus populations modulate type I IFN response in acute myocarditis patients and in human cultured cardiomyocytes

Major 5'terminally deleted (5'TD) group-B enterovirus (EV-B) populations were identified in heart biopsies of patients with fulminant myocarditis or dilated cardiomyopathy suggesting that these 5'TD forms are key drivers of host-cell interaction in EV cardiac infections. To date, early emergence of EV-B 5'TD forms and its impact on type 1 IFN response during acute myocarditis remains unknown. Using quantitative RACE-PCR assay, we identified major EV-B 5'TD RNA populations in plasma or heart samples of acute myocarditis cases. Deletions identified within the 5' non-coding region of EV-B populations only affected secondary-structural elements of genomic RNA domain I and were distinguished in two major groups based on the extent of RNA structural deletions. Proportions of these two respective EV-B 5'TD population groups were positively or negatively correlated with IFN-β levels in plasma samples of myocarditis patients. Transfection of synthetic CVB3/28 RNAs harboring various 5'terminal full-length or deleted sequences into human cultured cardiomyocytes demonstrated that viral genomic RNA domain I possessed essential immunomodulatory secondary-structural elements responsible for IFN-β pathway induction. Overall, our results highlight the early emergence of major EVB-TD populations which deletions affecting secondary-structures of RNA domain I can modulate innate immune sensing mechanisms in cardiomyocytes of patients with acute myocarditis.

An Atypical Presentation of Fulminant Myocarditis Secondary to COVID-19 Infection

The potential etiologies of fulminant myocarditis include autoimmune diseases, infections, drug hypersensitivity, and drug/toxin reactions. We present an atypical case of fulminant myocarditis in a patient with a history of diabetic ketoacidosis with recent novel coronavirus (COVID-19) infection, who presented with acute upper gastrointestinal bleeding. The patient improved with a three-day course of methylprednisolone 1 gram daily.

Case report of an isolated myocarditis due to COVID-19 infection in a paediatric patient

Background

Cardiovascular complications of COVID-19 have been reported in the adult population including myocarditis. However, less is known about the myocardial involvement in paediatric patients.

Case summary

A 15-year-old boy was admitted to our intensive cardiac care unit with COVID-19 and an isolated acute myocarditis, confirmed on cardiac magnetic resonance imaging. No pulmonary lesion was observed on the chest CT scan. We report here the initial presentation, medical care, and clinical course of this patient.

Discussion

In the context of the acute COVID-19 outbreak, screening for COVID-19 infection should be performed in children presenting with myocardial injury in an inflammatory context.

The Role of Non-coding RNAs in Viral Myocarditis

Viral myocarditis (VMC) is a disease characterized as myocardial parenchyma or interstitium inflammation caused by virus infection, especially Coxsackievirus B3 (CVB3) infection, which has no accurate non-invasive examination for diagnosis and specific drugs for treatment. The mechanism of CVB3-induced VMC may be related to direct myocardial damage of virus infection and extensive damage of abnormal immune response after infection. Non-coding RNA (ncRNA) refers to RNA that is not translated into protein and plays a vital role in many biological processes. There is expanding evidence to reveal that ncRNAs regulate the occurrence and development of VMC, which may provide new treatment or diagnosis targets. In this review, we mainly demonstrate an overview of the potential role of ncRNAs in the pathogenesis, diagnosis and treatment of CVB3-induced VMC.

Updates of Cardiovascular Manifestations in COVID-19: Korean Experience to Broaden Worldwide Perspectives

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. Not just respiratory complications such as pneumonia and acute respiratory distress syndrome, cardiac manifestations have drawn attention due to the increased risk of mortality and morbidity related to SARS-CoV-2 infections. The mechanisms of the cardiac injury related to SARS-CoV-2 infections have been direct cardiac injury caused by angiotensin converting enzyme 2, hypoxemia, microvascular damage, and a systemic inflammatory response. Stress induced cardiomyopathy in a critically ill condition and acute coronary syndrome due to a vulnerable plaque rupture with coagulopathy can finally lead to acute heart failure with further cardiac manifestations. When dealing with the highly contagious viral disease-related cardiac manifestations, we should carefully apply the diagnostic and therapeutic methods to achieve the best therapeutic results without adding any risk of disease transmission.

Viral myocarditis involves the generation of autoreactive T cells with multiple antigen specificities that localize in lymphoid and non-lymphoid organs in the mouse model of CVB3 infection

Autoreactive T cells may contribute to post-viral myocarditis induced with Coxsackievirus B3 (CVB3), but the underlying mechanisms of their generation are unclear. Here, we have comprehensively analyzed the generation of antigen-specific, autoreactive T cells in the mouse model of CVB3 infection for antigens implicated in patients with myocarditis/dilated cardiomyopathy. First, comparative analysis of CVB3 proteome with five autoantigens led us to identify three mimicry epitopes, one each from adenine nucleotide translocator 1 (ANT), sarcoplasmic/endoplasmic reticulum Ca²⁺ ATPase 2a (SERCA2a) and cardiac troponin I. None of these induced cross-reactive T cell responses. Next, we generated major histocompatibility complex (MHC) class II dextramers to enumerate the frequencies of antigen-specific T cells to determine whether T cells with multiple antigen specificities are generated by CVB3 infection. These analyses revealed appearance of CD4 T cells positive for SERCA2a 971-990, and cardiac myosin heavy chain-α (Myhc) 334-352 dextramers, both in the periphery and also in the hearts of CVB3-infected animals. While ANT 21-40 dextramer⁺ T cells were inconsistently detected, the β1-adrenergic receptor 181-200/211-230 or branched chain α-ketoacid dehydrogenase kinase 111-130 dextramer⁺ cells were absent. Interestingly, SERCA2a 971-990, Myhc 334-352 and ANT 21-40 dextramer⁺ cells were also detected in the liver indicating that they may have a pathogenic role. Finally, we demonstrate that the SERCA2a 971-990-reactive T cells generated in CVB3 infection could transfer disease to naïve mice. The data suggest that CVB3 infection can lead to the generation of autoreactive T cells for multiple antigens indicating a possibility that the autoreactive T cells localized in the liver can potentially circulate and contribute to the development of viral myocarditis.

Qidong Yixin Oral Liquid for Viral Myocarditis: A Systematic Review and Meta-Analysis

Objective

This study aimed to evaluate the efficacy and safety of Qidong Yixin (QY) oral liquid in the treatment of viral myocarditis (VMC).

Methods

We searched seven databases for randomized clinical trials on QY for treating VMC. The retrieval period was from database establishment to December 31, 2019. Cochrane risk of bias tool in the Cochrane Handbook was used to assess the methodological quality. Review Manager (RevMan) 5.3 was used to analyze the results.

Results

We included 19 studies comprising 2,608 patients, albeit with low methodological quality. Our meta-analysis revealed that combination therapy with QY and western medicine was more effective than western medicine alone (QY vs other Chinese patent medicines: RR = 1.37, 95% Cl: 1.23∼1.52, P < 0.00001; QY + coenzyme Q10 + routine treatment vs coenzyme Q10 + routine treatment: RR = 1.20, 95% Cl: 1.14∼1.27, P < 0.00001; QY + trimetazidine + acyclovir vs trimetazidine + acyclovir: RR = 1.59, 95% Cl: 1.38∼1.83, P < 0.00001; QY + routine treatment vs routine treatment: RR = 1.09, 95% Cl: 1.03∼1.15, P < 0.003). A study on posttreatment myocardial enzyme levels revealed that QY with western medicine downregulated creatine kinase isoenzyme (CK-MB) (QY + antiviral treatment + routine treatment vs antiviral treatment + routine treatment group: MD = −11.28, 95% CI: −13.33∼−9.22, P < 0.00001; QY + routine treatment vs routine treatment: MD = −4.96, 95% CI: −5.56∼−4.32, P < 0.00001), creatine kinase (CK) (MD = −32.10, 95% CI: −35.63∼−28.57, P < 0.00001), and lactate dehydrogenase (LDH) (QY + antiviral treatment + routine treatment vs antiviral treatment + routine treatment: MD = −48.76 95% CI: −58.18∼−39.33, P < 0.00001; QY + routine treatment vs routine treatment: MD = −23.52, 95% CI: −30.10–16.94, P < 0.00001) rather than western medicine alone, with no evidence of aspartate aminotransferase (AST) downregulation on treatment with QY with western medicine (MD = 2.88, 95% CI: −0.95∼6.71, P < 0.00001) in patients. Two studies reported adverse events, indicating that QY is relatively safe.

Conclusion

Although QY may have potential advantages in treating VMC, they remain unclear owing to the poor methodological quality of most studies. Larger, multicenter, high-quality randomized controlled trials are required to verify the effectiveness of QY.

Evolving Role of Anesthesiology Intensivists in Cardiothoracic Critical Care

The role of cardiothoracic anesthesiology intensivists has expanded over the past few decades. Cardiothoracic anesthesiology intensivists are taking on larger roles in cardiac critical care specializing in cardiogenic shock and extracorporeal membrane oxygenation.

Acute myocarditis associated with COVID-19 infection

We present the case of a 20-year-old male patient without previous history of cardiovascular disease who was admitted to our hospital with a new onset febrile sensation and chest pain. Chest computed tomography revealed a subpleural consolidation with a halo of ground-glass opacification. Blood tests revealed elevated levels of markers of myocyte necrosis (troponin I and creatine kinase–MB). Nasopharyngeal swab was positive for COVID-19. Cardiac MRI showed myocardial edema and late gadolinium enhancement compatible with myocarditis associated with COVID-19 infection. This case showed that acute myocarditis can be the initial presentation of patients with COVID-19 infection.

Adenovirus targets transcriptional and posttranslational mechanisms to limit gap junction function

Adenoviruses are responsible for a spectrum of pathogenesis including viral myocarditis. The gap junction protein connexin43 (Cx43, gene name GJA1) facilitates rapid propagation of action potentials necessary for each heartbeat. Gap junctions also propagate innate and adaptive antiviral immune responses, but how viruses may target these structures is not understood. Given this immunological role of Cx43, we hypothesized that gap junctions would be targeted during adenovirus type 5 (Ad5) infection. We find reduced Cx43 protein levels due to decreased GJA1 mRNA transcripts dependent upon β-catenin transcriptional activity during Ad5 infection, with early viral protein E4orf1 sufficient to induce β-catenin phosphorylation. Loss of gap junction function occurs prior to reduced Cx43 protein levels with Ad5 infection rapidly inducing Cx43 phosphorylation events consistent with altered gap junction conductance. Direct Cx43 interaction with ZO-1 plays a critical role in gap junction regulation. We find loss of Cx43/ZO-1 complexing during Ad5 infection by co-immunoprecipitation and complementary studies in human induced pluripotent stem cell derived-cardiomyocytes reveal Cx43 gap junction remodeling by reduced ZO-1 complexing. These findings reveal specific targeting of gap junction function by Ad5 leading to loss of intercellular communication which would contribute to dangerous pathological states including arrhythmias in infected hearts.

Cardiac involvement in COVID-19 patients: Risk factors, predictors, and complications: A review

BACKGROUND

Respiratory complications have been well remarked in the novel coronavirus disease (SARS-CoV-2/COVID-19), yet an emerging body of research indicates that cardiac involvement may be implicated in poor outcomes for these patients.

AIMS

This review seeks to gather and distill the existing body of literature that describes the cardiac implications of COVID-19.

MATERIALS AND METHODS

The English literature was reviewed for papers dealing with the cardiac effects of COVID-19.

RESULTS

Notably, COVID-19 patients with pre-existing cardiovascular disease are counted in greater frequency in intensive care unit settings, and ultimately suffer greater rates of mortality. Other studies have noted cardiac presentations for COVID-19, rather than respiratory, such as acute pericarditis and left ventricular dysfunction. In some patients there has been evidence of acute myocardial injury, with correspondingly increased serum troponin I levels. With regard to surgical interventions, there is a dearth of data describing myocardial protection during cardiac surgery for COVID-19 patients. Although some insights have been garnered in the study of cardiovascular diseases for these patients, these insights remain fragmented and have yet to cement clear guidelines for actionable clinical practice.

CONCLUSION

While some information is available, further studies are imperative for a more cohesive understanding of the cardiac pathophysiology in COVID-19 patients to promote more informed treatment and, ultimately, better clinical outcomes.

Coronavirus Disease 2019 and the Myocardium

Infection with the coronavirus known as COVID-19 has promoted growing interest on the part of cardiologists, emergency care specialists, intensive care specialists, and researchers, due to the study of myocardial involvement based on different clinical forms resulting from immunoinflammatory and neurohumoral demodulation.Myocardial involvement may be minimal and identifiable only by electrocardiographic changes, mainly increased cardiac troponins, or, on the other side of the spectrum, by forms of fulminant myocarditis and takotsubo syndrome.The description of probable acute myocarditis has been widely supported by the observation of increased troponin in association with dysfunction. Classical definition of myocarditis, supported by endomyocardial biopsy of inflammatory infiltrate, is rare; it has been observed in only one case report to date, and the virus has not been identified inside cardiomyocytes.Thus, the phenomenon that has been documented is acute myocardial injury, making it necessary to rule our obstructive coronary disease based on increased markers of myocardial necrosis, whether or not they are associated with ventricular dysfunction, likely associated with cytokine storms and other factors that may synergistically promote myocardial injury, such as sympathetic hyperactivation, hypoxemia, arterial hypotension, and microvascular thrombotic phenomena.Systemic inflammatory and myocardial phenomena following viral infection have been well documented, and they may progress to cardiac remodeling and myocardial dysfunction. Cardiac monitoring of these patients is, therefore, important in order to monitor the development of the phenotype of dilated myocardiopathy.This review presents the main etiological and physiopathological findings, a description of the taxonomy of these types of cardiac involvement, and their correlation with the main clinical forms of the myocardial component present in patients in the acute phase of COVID-19.

Single-Cell RNA Sequencing to Dissect the Immunological Network of Autoimmune Myocarditis

BACKGROUND

Myocarditis can develop into dilated cardiomyopathy, which may require heart transplantation. The immunological network of myocarditis phases remains unknown. This study aimed to investigate the immunological network during the transition from myocarditis to cardiomyopathy and to identify the genes contributing to the inflammatory response to myocarditis.

METHODS

Mice were treated with myosin heavy chain-α peptides to generate an experimental autoimmune myocarditis (EAM) model. We performed single-cell RNA sequencing analysis of Cd45⁺ cells extracted from mouse hearts during different EAM phases, including normal control, acute inflammatory, subacute inflammatory, and myopathy phases. Human heart tissues were collected from the surgically removed hearts of patients who had undergone heart transplantation.

RESULTS

We identified 26 cell subtypes among 34 665 cells. Macrophages constituted the main immune cell population at all disease phases (>60%), and an inflammation-associated macrophage cluster was identified in which the expression of Hif1a-regulated genes was upregulated. The neutrophil population was increased after the induction of EAM, and neutrophils then released Il-1 to participate in the EAM process. T cells were observed at the highest percentage at the subacute inflammatory phase. T-helper 17 cells, in which the expression of Hif1a-regulated genes was upregulated, constituted the main T-cell population detected at the acute inflammatory phase, whereas regulatory T cells were the main T-cell population detected at the subacute inflammatory phase, and γδ T cells releasing Il-17 were the main T-cell population observed at the myopathy phase. Moreover, the Hif1a expression level correlated with the extent of inflammation. In addition, PX-478 could alleviate the inflammatory responses of the different EAM phases. Last, HIF1A was expressed at higher levels in patients with acute autoimmune myocarditis than in patients with dilated cardiomyopathy and healthy control subjects.

CONCLUSIONS

We present here a comprehensive single-cell landscape of the cardiac immune cells in different EAM phases. In addition, we elucidate the contribution of Hif1a to the inflammatory response through the regulation of immune cell activity, particularly of macrophage cluster 2 and T-helper 17 cells. Moreover, an Hif1a inhibitor alleviated inflammatory cell infiltration of the EAM model and may serve as a potential therapeutic target in the clinic.

Immune cell diversity contributes to the pathogenesis of myocarditis

Myocarditis (MCD) is a type of inflammatory disease in which inflammatory cells infiltrate the myocardium, leading to cardiac dysfunction, myocardial necrosis, and fibrosis. Although it has been reported that MCD is mediated by T cells, the immune system is complex and includes many types of immune cells that interact with one another. Through investigations of the inflammatory responses in MCD including myocardial necrosis, fibrosis, and arrhythmia, we have gained further insight into the pathogenesis of MCD. This article aims to discuss the diversity and the roles of immune cells involved in the pathogenesis of MCD. Moreover, immunotherapy for the treatment of MCD remains controversial, and further investigation is required to identify accurate immunotherapies for special cell types.

COVID-19 and the Heart

Infection with the severe acute respiratory syndrome novel coronavirus produces a clinical syndrome known as 2019 novel coronavirus disease (COVID-19). When severe, COVID-19 is a systemic illness characterized by hyperinflammation, cytokine storm, and elevations of cardiac injury biomarkers. Here, we review what is known about the pathophysiology of COVID-19, its cardiovascular manifestations, and emerging therapeutic prospects. In this rapidly moving field, this review was comprehensive as of April 3, 2020.

Dysregulated CD4+ T Cells and microRNAs in Myocarditis

Myocarditis is a polymorphic disease complicated with indeterminate etiology and pathogenesis, and represents one of the most challenging clinical problems lacking specific diagnosis and effective therapy. It is caused by a complex interplay of environmental and genetic factors, and causal links between dysregulated microribonucleic acids (miRNAs) and myocarditis have also been supported by recent epigenetic researches. Both dysregulated CD4+ T cells and miRNAs play critical roles in the pathogenesis of myocarditis, and the classic triphasic model of its pathogenesis consists of the acute infectious, subacute immune, and recovery/chronic myopathic phase. CD4+ T cells are key pathogenic factors underlying the development and progression of myocarditis, and the effector and regulatory subsets, respectively, promote and inhibit autoimmune responses. Furthermore, the reciprocal interplay of these subsets influences the pathogenesis as well. Dysregulated miRNAs along with their mRNA and protein targets have been identified in heart biopsies (intracellular miRNAs) and body fluids (circulating miRNAs) during myocarditis. These miRNAs show phase-dependent changes, and correlate with viral infection, immune status, fibrosis, destruction of cardiomyocytes, arrhythmias, cardiac functions, and outcomes. Thus, miRNAs are promising diagnostic markers and therapeutic targets in myocarditis. In this review, we review myocarditis with an emphasis on its pathogenesis, and present a summary of current knowledge of dysregulated CD4+ T cells and miRNAs in myocarditis.

Cleavage and degradation of EDEM1 promotes coxsackievirus B3 replication via ATF6a-mediated unfolded protein response signalling

Our previous study of coxsackievirus B3 (CVB3)-induced unfolded protein responses (UPR) found that overexpression of ATF6a enhances CVB3 VP1 capsid protein production and increases viral particle formation. These findings implicate that ATF6a signalling benefits CVB3 replication. However, the mechanism by which ATF6a signalling is transduced to promote virus replication is unclear. In this study, using a Tet-On inducible ATF6a HeLa cell line, we found that ATF6a signalling downregulated the protein expression of the endoplasmic reticulum (ER) degradation-enhancing α-mannosidase-like protein 1 (EDEM1), resulting in accumulation of CVB3 VP1 protein; in contrast, expression of a dominant negative ATF6a had the opposite effect. Furthermore, we found that EDEM1 was cleaved by both CVB3 protease 3C and virus-activated caspase and subsequently degraded via the ubiquitin-proteasome pathway. However, overexpression of EDEM1 caused VP1 degradation, likely via a glycosylation-independent and ubiquitin-lysosome pathway. Finally, we demonstrated that CRISPR/Cas9-mediated knockout of EDEM1 increased VP1 accumulation and thus CVB3 replication. This is the first study to report the ER protein quality control of non-enveloped RNA virus and reveals a novel mechanism by which CVB3 evades host ER quality control pathways through cleavage and degradation of the UPR target gene EDEM1, to ultimately benefit its own replication.

Tissue Characterization by Mapping and Strain Cardiac MRI to Evaluate Myocardial Inflammation in Fulminant Myocarditis

BACKGROUND

The clinical value of novel mapping techniques and strain measures to assess myocardial inflammation in fulminant myocarditis (FM) has not been fully explored.

PURPOSE

To evaluate the ability of mapping and strain cardiac MRI to assess myocardial inflammation in patients with FM, and to which degree the strain metrics correlate with myocardial edema.

STUDY TYPE

Prospective.

POPULATION

Twenty-nine patients (37 ± 16 years, 48% male) with FM and 29 patients with nonfulminant acute myocarditis (NFAM) (29 ± 14 years, 69% male).

FIELD STRENGTH/SEQUENCE

3.0T; Cine imaging, black blood T₂ -weighted imaging, T₁ mapping, T₂ mapping, and late gadolinium enhancement.

ASSESSMENT

Native T₁ , extracellular volume (ECV), and T₂ were measured. Myocardial strain was evaluated by feature tracking.

STATISTICAL TESTS

Student's t- or Mann-Whitney U-test. Spearman correlation analysis.

RESULTS

The myocardial edema rate (2.6 ± 0.7 vs. 1.6 ± 0.2, P < 0.001) and late gadolinium enhancement (LGE) mass (16.5 [11.7, 41.7] vs. 6.9 [2.2, 15.8] g, P < 0.001) were significantly increased in FM patients when compared to the NFAM group. LGE in the FM group was predominantly located in the septal wall, and 38% of the patients showed a diffuse LGE pattern. Native T₁ , ECV, and T₂ values in the FM group were significantly more elevated than those with NFAM, while global peak radial, circumferential, and longitudinal strain values were significantly reduced (all P < 0.001). Circumferential strain showed the strongest correlations with ECV (r = 0.72, P < 0.001).

DATA CONCLUSION

Patients with FM showed significant differences in LGE patterns, increased edema, and decreased strain measurements compared to those with NFAM. Circumferential strain showed significant associations with quantitative cardiac MRI parameters of myocardial inflammation.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:930-938.

Incidence, clinical features and outcome of Takotsubo syndrome in the intensive care unit

BACKGROUND

Most diseases encountered in the intensive care unit are associated with major stress that can potentially trigger Takotsubo syndrome. Many severe cardiovascular complications are associated with Takotsubo syndrome, yet little is known about Takotsubo syndrome in the intensive care unit.

AIMS

We sought to determine the incidence of Takotsubo syndrome, and to describe its clinical features and outcome in an intensive care unit.

METHODS

This prospective single-centre study included all patients admitted consecutively over a 12-month period who had transthoracic echocardiography, electrocardiography and a troponin I assay performed on admission, at 24 and 48hours after admission, and at discharge and in the case of clinical worsening.

RESULTS

The incidence of Takotsubo syndrome was 4.6% (13/280 patients) and female sex predominated (69.2%). The median age of the subgroup with Takotsubo syndrome was 64 (56-72) years. Pulmonary disease and sepsis were the most frequent triggers (46.2% and 38.5%, respectively). Median left ventricular ejection fraction was 29.0% (20.0-37.0). Patients with Takotsubo syndrome presented with shock and arrhythmias and needed ventilation more frequently than patients without Takotsubo syndrome (69.2% vs. 36.3%, P=0.035; 46.2% vs. 13.5%, P=0.006; and 92.3% vs. 60.7%, P=0.021), but mortality rates were similar. The median delay to cardiac index recovery, when impaired, was 2.0 (1.0-2.75) days, and that of left ventricular ejection fraction was 12.5 (7-14.75) days.

CONCLUSION

Takotsubo syndrome in the intensive care unit is not uncommon and is associated with substantial haemodynamic and respiratory instability. New-onset arrhythmias and respiratory and haemodynamic worsening could arouse suspicion of and prompt screening for Takotsubo syndrome in the intensive care unit.

Animal models of arrhythmia: classic electrophysiology to genetically modified large animals

Arrhythmias are common and contribute substantially to cardiovascular morbidity and mortality. The underlying pathophysiology of arrhythmias is complex and remains incompletely understood, which explains why mostly only symptomatic therapy is available. The evaluation of the complex interplay between various cell types in the heart, including cardiomyocytes from the conduction system and the working myocardium, fibroblasts and cardiac immune cells, remains a major challenge in arrhythmia research because it can be investigated only in vivo. Various animal species have been used, and several disease models have been developed to study arrhythmias. Although every species is useful and might be ideal to study a specific hypothesis, we suggest a practical trio of animal models for future use: mice for genetic investigations, mechanistic evaluations or early studies to identify potential drug targets; rabbits for studies on ion channel function, repolarization or re-entrant arrhythmias; and pigs for preclinical translational studies to validate previous findings. In this Review, we provide a comprehensive overview of different models and currently used species for arrhythmia research, discuss their advantages and disadvantages and provide guidance for researchers who are considering performing in vivo studies.

MicroRNA Modification of Coxsackievirus B3 Decreases Its Toxicity, while Retaining Oncolytic Potency against Lung Cancer

We recently discovered that coxsackievirus B3 (CVB3) is a potent oncolytic virus against KRAS mutant lung adenocarcinoma. Nevertheless, the evident toxicity restricts the use of wild-type (WT)-CVB3 for cancer therapy. The current study aims to engineer the CVB3 to decrease its toxicity and to extend our previous research to determine its safety and efficacy in treating TP53/RB1 mutant small-cell lung cancer (SCLC). A microRNA-modified CVB3 (miR-CVB3) was generated via inserting multiple copies of tumor-suppressive miR-145/miR-143 target sequences into the viral genome. In vitro experiments revealed that miR-CVB3 retained the ability to infect and lyse KRAS mutant lung adenocarcinoma and TP53/RB1-mutant SCLC cells, but with a markedly reduced cytotoxicity toward cardiomyocytes. In vivo study using a TP53/RB1-mutant SCLC xenograft model demonstrated that a single dose of miR-CVB3 via systemic administration resulted in a significant tumor regression. Most strikingly, mice treated with miR-CVB3 exhibited greatly attenuated cardiotoxicities and decreased viral titers compared to WT-CVB3-treated mice. Collectively, we generated a recombinant CVB3 that is powerful in destroying both KRAS mutant lung adenocarcinoma and TP53/RB1-mutant SCLC, with a negligible toxicity toward normal tissues. Future investigation is needed to address the issue of genome instability of miR-CVB3, which was observed in ~40% of mice after a prolonged treatment.

Potential Clinical Implications of miR-1 and miR-21 in Heart Disease and Cardioprotection

The interest in non-coding RNAs, which started more than a decade ago, has still not weakened. A wealth of experimental and clinical studies has suggested the potential of non-coding RNAs, especially the short-sized microRNAs (miRs), to be used as the new generation of therapeutic targets and biomarkers of cardiovascular disease, an ever-growing public health issue in the modern world. Among the hundreds of miRs characterized so far, microRNA-1 (miR-1) and microRNA-21 (miR-21) have received some attention and have been associated with cardiac injury and cardioprotection. In this review article, we summarize the current knowledge of the function of these two miRs in the heart, their association with cardiac injury, and their potential cardioprotective roles and biomarker value. While this field has already been extensively studied, much remains to be done before research findings can be translated into clinical application for patient’s benefit.

Recognition and Initial Management of Fulminant Myocarditis: A Scientific Statement From the American Heart Association

Fulminant myocarditis (FM) is an uncommon syndrome characterized by sudden and severe diffuse cardiac inflammation often leading to death resulting from cardiogenic shock, ventricular arrhythmias, or multiorgan system failure. Historically, FM was almost exclusively diagnosed at autopsy. By definition, all patients with FM will need some form of inotropic or mechanical circulatory support to maintain end-organ perfusion until transplantation or recovery. Specific subtypes of FM may respond to immunomodulatory therapy in addition to guideline-directed medical care. Despite the increasing availability of circulatory support, orthotopic heart transplantation, and disease-specific treatments, patients with FM experience significant morbidity and mortality as a result of a delay in diagnosis and initiation of circulatory support and lack of appropriately trained specialists to manage the condition. This scientific statement outlines the resources necessary to manage the spectrum of FM, including extracorporeal life support, percutaneous and durable ventricular assist devices, transplantation capabilities, and specialists in advanced heart failure, cardiothoracic surgery, cardiac pathology, immunology, and infectious disease. Education of frontline providers who are most likely to encounter FM first is essential to increase timely access to appropriately resourced facilities, to prevent multiorgan system failure, and to tailor disease-specific therapy as early as possible in the disease process.