Giant Cell Myocarditis: A Brief Review

At the heart of inflammation: Unravelling cardiac resident macrophage biology

Cardiovascular disease remains one of the leading causes of death globally. Recent advancements in sequencing technologies have led to the identification of a unique population of macrophages within the heart, termed cardiac resident macrophages (CRMs), which exhibit self-renewal capabilities and play crucial roles in regulating cardiac homeostasis, inflammation, as well as injury and repair processes. This literature review aims to elucidate the origin and phenotypic characteristics of CRMs, comprehensively outline their contributions to cardiac homeostasis and further summarize their functional roles and molecular mechanisms implicated in the onset and progression of cardiovascular diseases. These insights are poised to pave the way for novel therapeutic strategies centred on targeted interventions based on the distinctive properties of resident macrophages.

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.

Prostaglandin E2 and myocarditis; friend or foe?

This review article summarizes the role of prostaglandin E2 (PGE2) and its receptors (EP1-EP4) as it relates to the inflammatory cardiomyopathy, myocarditis. During the COVID-19 pandemic, the onset of myocarditis in a subset of patients prompted a debate on the use of nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen, which act to inhibit the actions of prostaglandins. This review aims to further understanding of the role of PGE2 in the pathogenesis or protection of the myocardium in myocarditis. Inflammatory cardiomyopathies encompass a broad spectrum of disorders, all characterized by cardiac inflammation. Therefore, for the purpose of this review, the authors have placed particular emphasis on etiologies of myocarditis where effects of PGE2 have been documented.

Update on Myocarditis: From Etiology and Clinical Picture to Modern Diagnostics and Methods of Treatment

Although the frequency of myocarditis in the general population is very difficult to accurately determine due to the large number of asymptomatic cases, the incidence of this disease is increasing significantly due to better defined criteria for diagnosis and the development of modern diagnostic methods. The multitude of different etiological factors, the diversity of the clinical picture, and the variability of the diagnostic findings make this disease often demanding both for the selection of the diagnostic modality and for the proper therapeutic approach. The previously known most common viral etiology of this disease is today overshadowed by new findings based on immune-mediated processes, associated with diseases that in their natural course can lead to myocardial involvement, as well as the iatrogenic cause of myocarditis, which is due to use of immune checkpoint inhibitors in the treatment of cancer patients. Suspecting that a patient with polymorphic and non-specific clinical signs and symptoms, such as changes in ECG and echocardiography readings, has myocarditis is the starting point in the diagnostic algorithm. Cardio magnetic resonance imaging is non-invasive and is the gold standard for diagnosis and clinical follow-up of these patients. Endomyocardial biopsy as an invasive method is the diagnostic choice in life-threatening cases with suspicion of fulminant myocarditis where the diagnosis has not yet established or there is no adequate response to the applied therapeutic regimen. The treatment of myocarditis is increasingly demanding and includes conservative methods of treating heart failure, immunomodulatory and immunospressive therapy, methods of mechanical circulatory support, and heart transplantation. The goal of developing new diagnostic and therapeutic methods is to reduce mortality from this complex disease, which is still high.

High-risk and low prevalence disease: Cardiac sarcoidosis and some of its mimics

In this narrative review of cardiac sarcoidosis, based on a literature search using the terms "cardiac sarcoidosis", "tuberculous myocarditis", "Whipple's disease and myocarditis", and"idiopathic giant cell myocarditis", I have defined cardiac sarcoidosis as a disorder which can be diagnosed either by documentation of the presence of sarcoid-related granulomas in myocardial tissue or by documentation of the association of the presence of sarcoid-related granulomas in extracardiac tissue and symptoms such as complete heart block, ventricular tachyarrhythmia, sudden death or dilated cardiomyopathy which are typical of cardiac sarcoidosis. The differential diagnosis of cardiac sarcoidosis includes granulomatous myocarditis attributable to underlying causes such as such as tuberculosis, Whipple's disease, and idiopathic giant cell myocarditis. Diagnostic pathways for cardiac sarcoidosis include biopsy of cardiac and extracardiac tissue, nuclear magnetic resonance imaging, positron emission tomography, and a diagnostic trial of empiric therapy. Problem areas include differentiation between noncaseating granulomatosis attributable to sarcoidosis versus noncaseating granulomatosis attributable to tuberculosis and whether or not the workup of suspected cardiac sarcoidosis should always include evaluation of biopsy tissue by molecular methods for M tuberculosis DNA as well as by mycobacterium tuberculosis culture. The diagnostic significance of necrotising granulomatosis is also unclear. Evaluation of patients on long term immunotherapy should also take due account of the risk of tuberculosis attributable to the use of tumor necrosis factor-alpha antagonists.

Advancing Precision Medicine in Myocarditis: Current Status and Future Perspectives in Endomyocardial Biopsy-Based Diagnostics and Therapeutic Approaches

The diagnosis and specific and causal treatment of myocarditis and inflammatory cardiomyopathy remain a major clinical challenge. Despite the rapid development of new imaging techniques, endomyocardial biopsies remain the gold standard for accurate diagnosis of inflammatory myocardial disease. With the introduction and continued development of immunohistochemical inflammation diagnostics in combination with viral nucleic acid testing, myocarditis diagnostics have improved significantly since their introduction. Together with new technologies such as miRNA and gene expression profiling, quantification of specific immune cell markers, and determination of viral activity, diagnostic accuracy and patient prognosis will continue to improve in the future. In this review, we summarize the current knowledge on the pathogenesis and diagnosis of myocarditis and inflammatory cardiomyopathies and highlight future perspectives for more in-depth and specialized biopsy diagnostics and precision, personalized medicine approaches.

Inhibition of NETosis via PAD4 alleviated inflammation in giant cell myocarditis

Giant cell myocarditis (GCM) is a rare, usually rapidly progressive, and potentially fatal disease. Detailed inflammatory responses remain unknown, in particular the formation of multinucleate giant cells. We performed single-cell RNA sequencing analysis on 15,714 Cd45+ cells extracted from the hearts of GCM rats and normal rats. NETosis has been found to contribute to the GCM process. An inhibitor of NETosis, GSK484, alleviated GCM inflammation in vivo. MPO (a marker of neutrophils) and H3cit (a marker of NETosis) were expressed at higher levels in patients with GCM than in patients with DCM and healthy controls. Imaging mass cytometry analysis revealed that immune cell types within multinucleate giant cells included CD4+ T cells, CD8+ T cells, neutrophils, and macrophages but not B cells. We elucidated the role of NETosis in GCM pathogenesis, which may serve as a potential therapeutic target in the clinic.

Immunomodulatory Therapy for Giant Cell Myocarditis: A Narrative Review

Giant cell myocarditis (GCM) is a rare, often rapidly progressive, and potentially fatal disease because of myocardium inflammation due to the infiltration of giant cells triggered by infectious as well as non-infectious etiologies. Several studies have reported that GCM can occur in patients of all ages but is more commonly found in adults. It is relatively more common among African American and Hispanic patients than in the White population. Early diagnosis and treatment are critical. Electrocardiogram (EKG), complete blood count, erythrocyte sedimentation rate, C-reactive protein, and cardiac biomarkers such as troponin and brain natriuretic peptide (BNP), echocardiogram, cardiac magnetic resonance imaging (MRI), myocardial biopsy, and myocardial gene profiling are useful diagnostic tools. Current research has identified several potential biomarkers for GCM, including myocarditis-associated immune cells, cytokines, and other chemicals. The standard of care for GCM includes aggressive immunosuppressive therapy with corticosteroids and immunomodulatory agents like rituximab, cyclosporine, and infliximab, which have shown promising results in GCM by balancing the immune system and preventing the attack on healthy tissues, resulting in the reduction of inflammation, promotion of healing, and decreasing the necessity for cardiac transplantation. Without immunosuppression, the chance of mortality or cardiac surgery was 100%. Multiple studies have revealed that a treatment combination of corticosteroids and immunomodulatory agents is superior to corticosteroids alone. Combination therapy significantly increased transplant-free survival (TFS) and decreased the likelihood of heart transplantation, hence improving overall survival. It is important to balance the benefits of immunosuppression with its potentially adverse effects. In conclusion, immunomodulatory therapy adds significant long-term survival benefits to GCM.

Giant cell myocarditis following COVID-19 successfully treated by immunosuppressive therapy

It has been shown that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), by coronavirus disease 2019 (COVID-19), can lead to multi-organ impairment including cardiac involvement and immunological problems. Acute myocarditis is one of serious and fatal complications of COVID-19. In this case report, we present a 46-year-old lady with a history of lichen planus dermatitis who has developed a rapidly progressive heart failure after an episode of COVID-19. The pathologic examination of her endomyocardial biopsy specimens was compatible with GCM, and she was successfully treated with a combined immunosuppressive therapy regimen.

Neurological Manifestations of Myocarditis

PURPOSE OF REVIEW

The present review discusses the neurological complications associated with myocarditis of different etiologies.

RECENT FINDINGS

Myocarditis can be idiopathic or caused by different conditions, including toxins, infections, or inflammatory diseases. Clinical findings are variable and range from mild self-limited shortness of breath or chest pain to hemodynamic instability which may result in cardiogenic shock and death. Several neurologic manifestations can be seen in association with myocarditis. Tissue remodeling, fibrosis, and myocyte dysfunction can result in heart failure and arrhythmias leading to intracardiac thrombus formation and cardioembolism. In addition, peripheral neuropathies, status epilepticus, or myasthenia gravis have been reported in association with specific types of myocarditis. Multiple studies suggest the increasing risk of neurologic complications in patients with myocarditis. Neurologists should maintain a high suspicion of myocarditis in cases presenting with both cardiovascular and neurological dysfunction without a clear etiology.

Pediatric Myocarditis: What Have We Learnt So Far?

Myocarditis is an inflammatory disease of the myocardium that is troublesome to diagnose and manage, especially in children. Since the introduction of endomyocardial biopsy (EMB), new diagnostic tools have provided useful data. Especially when enhanced with immunohistochemistry and polymerase chain reaction (PCR) studies, EMB remains the gold standard for the diagnosis. Notably, cardiac magnetic resonance (MRI) is a non-invasive tool that can confirm the diagnosis and has a particular usefulness during the follow-up. The causes of myocarditis are heterogeneous (mostly viral in children). The course and outcome of the illness in the pediatric population represent a complex interaction between etiologic agents and the immune system, which is still not fully understood. The clinical presentation and course of myocarditis vary widely from paucisymptomatic illness to acute heart failure refractory to therapy, arrhythmias, angina-like presentation and sudden cardiac death. In this setting, cardiac biomarkers (i.e., troponins and BNP), although unspecific, can be used to support the diagnosis. Finally, the efficacy of therapeutic strategies is controversial and not confirmed by clinical trials. In this review, we summarized the milestones in diagnosis and provided an overview of the therapeutic options for myocarditis in children.

Giant Cell Myocarditis in Children: Elusive Giant Cells Might Not Be the Only Clue

Giant cell myocarditis (GCM) is a form of fulminant myocarditis that is rapidly progressive and frequently lethal even in children. Over the course of 20 years, a definitive histopathologic diagnosis of GCM has been made at our institution in only two pediatric patients, and in neither instance was the diagnosis of GCM rendered on initial cardiac biopsy. We present the two patients and highlight the similarities in their clinical presentation and their challenging and inconclusive- albeit histologically similar- initial cardiac biopsy findings.

"Heart in DRESS": Cardiac Manifestations, Treatment and Outcome of Patients with Drug Reaction with Eosinophilia and Systemic Symptoms Syndrome: A Systematic Review

Cardiac involvement in drug reaction with eosinophilia and systemic symptoms (DS) is rare but associated with high mortality. The aim of this research was to systematically review case reports by PRISMA guidelines in order to synthetize the knowledge of cardiac manifestations of DS. We identified 42 cases from 36 case reports. Women were two times more affected than men. Two-thirds of patients had cardiac manifestation in the initial phase of the disease, while in one-third of cases cardiac manifestations developed later (mean time of 70 ± 63 days). The most common inciting medications were minocycline (19%) and allopurinol (12%). In 17% of patients, the heart was the only internal organ affected, while the majority (83%) had at least one additional organ involved, most commonly the liver and the kidneys. Dyspnea (55%), cardiogenic shock (43%), chest pain (38%), and tachycardia (33%) were the most common cardiac signs and symptoms reported. Patients frequently had an abnormal ECG (71.4%), and a decrease in left ventricular ejection fraction was the most common echocardiographic finding (45%). Endomyocardial biopsy or histological examination at autopsy was performed in 52.4%, with the predominant finding being fulminant eosinophilic myocarditis with acute necrosis in 70% of those biopsied. All patients received immunosuppressive therapy with intravenous steroids, while non-responders were more likely to have received IVIG, cyclosporine, mycophenolate, and other steroid-sparing agents (60%). Gender and degree of left ventricular systolic dysfunction were not associated with outcomes, but short latency between drug exposure and the first DRESS symptom onset (<15 days) and older age (above 65 years) was associated with death. This underscores the potential importance of heightened awareness and early treatment.

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

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

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

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

Immune Checkpoint Inhibitors Mediated Lymphocytic and Giant Cell Myocarditis: Uncovering Etiological Mechanisms

The advent of immune checkpoint inhibitors (ICIs) has revolutionized the field of oncology, but these are associated with immune related adverse events. One such adverse event, is myocarditis, which has limited the continued immunosuppressive treatment options in patients afflicted by the disease. Pre-clinical and clinical data have found that specific ICI targets and precipitate distinct myocardial infiltrates, consistent with lymphocytic or giant cell myocarditis. Specifically, it has been reported that CTLA-4 inhibition preferentially results in giant cell myocarditis with a predominately CD4+ T cell infiltrate and PD-1 inhibition leads to lymphocytic myocarditis, with a predominately CD8+ T cell infiltrate. Our manuscript discusses the latest literature surrounding ICI pathways and targets, while detailing proposed mechanisms behind ICI mediated myocarditis.

Diagnosis, treatment and predictors of prognosis of myocarditis. A narrative review

Although it has been recognized for almost two centuries, myocarditis is still a challenging diagnosis due to the wide heterogeneity of its clinical manifestations and evolution. Moreover, the diagnostic gold standard, endomyocardial biopsy (EMB), is infrequently used, making hard to determine the exact incidence of myocarditis. Clinical presentation includes a wide range of symptoms, ranging from asymptomatic or subclinical disease with mild dyspnea and chest pain to sudden death, due to cardiogenic shock or malignant ventricular arrhythmias. Equally, the evolution of myocarditis largely varies: albeit short-term prognosis is usually good, with complete or partial recovery, dilated cardiomyopathy with chronic heart failure is the major long-term consequence of myocarditis, developing often several years after the acute onset. This narrative review aims to summarize the current knowledge about myocarditis, with a particular attention to predictors of short- and long-term prognosis, in order to provide a rational and practical approach to the diagnosis, evaluation and treatment of suspected myocarditis.

Clinical Identification and Characteristic Analysis of Giant Cell Myocarditis in 12 Cases

Aims: Giant cell myocarditis (GCM) is a rare, rapidly progressing cardiomyopathy with high mortality, if not diagnosed and treated in time. We analyzed the progression and clinical manifestations of patients with definitive diagnosis of GCM.

Methods and Result: We enrolled 12 patients diagnosed with GCM in the explanted heart during heart transplantation (HTx) or by endomyocardial biopsy (EMB) and collected information on demographic data, cardiac structure and function, arrhythmias, preliminary diagnosis, and delay of the diagnosis. Seven cases were diagnosed from biopsy samples during HTx, and five cases were diagnosed through EMB. Before the diagnosis of GCM based on pathological analysis, these patients had been incorrectly diagnosed with arrhythmogenic right ventricular cardiomyopathy (n = 5), dilated cardiomyopathy (n = 2), ventricular tachycardia (n = 2), viral myocarditis (n = 1), cardiac amyloidosis (n = 1), and ischemic cardiomyopathy (n = 1) based on clues such as symptoms, arrhythmia, and cardiac imaging. Patients diagnosed with GCM through EMB had a shorter symptom-onset-to-diagnosis time (6.6 ± 2.7 months) and milder heart damage (left ventricular ejection fraction, 47.2 ± 8.8%) than those diagnosed during HTx (11.0 ± 3.3 months, P = 0.034; 31.4 ± 10.9%, P = 0.024).

Conclusion: GCM is easily misdiagnosed as other types of myocarditis and cardiomyopathy. Pathological examination of the myocardium is the most reliable diagnostic method for GCM. Endocardial biopsy can identify patients with GCM at an earlier stage.

Giant Cell, Giant Problems: A Case of Giant Cell Myocarditis Complicated by Cardiogenic Shock and Refractory Ventricular Tachycardia Managed With a Mechanical Circulatory Support Device

This report reviews the management of a case of Giant Cell Myocarditis (GCM) that presented with cardiogenic shock. This case highlights the importance of a multi-disciplinary approach to the care of these patients including the use of a mechanical circulatory support (MCS) device.

Giant cell myocarditis

Giant cell myocarditis (GCM) usually affects previously healthy adults and is a rapidly progressive and frequently fatal disease. It has a median survival of 3 months to death or transplant without appropriate therapy. Hence, early diagnosis is critical, with evidence showing rapidly instituted cyclosporine-based immunosuppression can improve transplant-free survival. Although transplant is an effective strategy, GCM can recur in 25% of transplanted hearts. We present a case of GCM in a patient who presented with conduction abnormalities and fulminant heart failure.

Giant cell myositis and myocarditis revisited

Giant cell myositis (GCMm) and giant cell myocarditis (GCMc) are two rare autoimmune conditions. Among these, GCMc is a life-threatening disease with a 1-year mortality rate of 70%. Lethal ventricular arrhythmias, rapid evolution to heart failure and sudden death risk makes GCMc an emergency condition. It is thought to be mediated by T-cells and characterized by the presence of myofiber necrosis and giant cells in biopsies. Most commonly co-manifesting conditions with GCMm and/or GCMc are thymoma, myasthenia gravis and orbital myositis, all of which are treatable. As suspicion is the key approach in diagnosis, the physician following patients with thymoma with or without myasthenia gravis and with orbital myositis should always be alert. The fatal nature of GCMc associated with these relatively benign diseases deserves a special emergency attention with prompt institution of combined immunosuppressive treatment and very early inclusion of heart failure teams.

Fulminant myocarditis: a comprehensive review from etiology to treatments and outcomes

Fulminant myocarditis (FM) is characterized by a rapid progressive decline in cardiac function and a high mortality rate. Since the first report of FM patients in the 1980s, several clinical trials and research studies have been published increasing our knowledge regarding FM. Currently, the diagnosis of FM depends on various techniques including electrocardiography, echocardiography, endomyocardial biopsy, and cardiac magnetic resonance. The development of mechanical circulation support (MCS) devices and progress in our understanding of the pathophysiological mechanisms underlying FM, treatment regimens have evolved from simple symptomatic treatment to a life support-based comprehensive treatment approach. The core mechanism underlying the development of FM is the occurrence of an inflammatory cytokine storm. This review provides a comprehensive account of the current understanding of FM pathophysiology and knowledge regarding its etiology, pathophysiology, treatments, and outcomes.

Autoimmune disorders and paraneoplastic syndromes in thymoma

Thymomas are counted among the rare tumour entities which are associated with autoimmune disorders (AIDs) and paraneoplastic syndromes (PNS) far more often than other malignancies. Through its complex immunological function in the context of the selection and maturation of T cells, the thymus is at the same time highly susceptible to disruptive factors caused by the development and growth of thymic tumours. These T cells, which are thought to develop to competent immune cells in the thymus, can instead adopt autoreactive behaviour due to the uncontrolled interplay of thymomas and become the trigger for AID or PNS affecting numerous organs and tissues within the human body. While myasthenia gravis is the most prevalent PNS in thymoma, numerous others have been described, be they related to neurological, cardiovascular, gastrointestinal, haematological, dermatological, endocrine or systemic disorders. This review article sheds light on the pathophysiology, epidemiology, specific clinical features and therapeutic options of the various forms as well as courses and outcomes of AID/PNS in association with thymomas. Whenever suitable and backed by the limited available evidence, the perspectives from both the thymoma and the affected organ/tissue will be highlighted. Specific issues addressed are the prognostic significance of thymectomy on myasthenia gravis and other thymoma-associated AID/PND and further the impact and safety of immunotherapies on AID and PND relating to thymomas.

Giant cell myocarditis causing sudden death in a patient with sarcoidosis

Giant cell myocarditis (GCM) is a rare and rapidly fatal cardiovascular condition most often seen in young adults. It is characterized microscopically by myocardial necrosis with multinucleated giant cells in the absence of well-defined granulomas. This disorder has typically been attributed to manifest as heart failure, but in some individuals, GCM may present as sudden cardiac death. Herein, we present a fatal case of GCM in a 36-year-old male with a history of autoimmune disorders. The decedent presented to the emergency room due to vomiting and was treated for nausea due to suspected dehydration. He was discharged that night and found dead on his bathroom floor the following day. Postmortem examination revealed psoriasis and granulomatous lesions in the lungs consistent with sarcoidosis, further supporting circumstantial evidence existing between GCM and autoimmune disorders. Additionally, this case provides an opportunity to distinguish GCM from the distinct clinical entity of cardiac sarcoidosis (CS), especially in the setting of systemic sarcoidosis. We hope to raise awareness of this rare disease process and its potential to cause sudden cardiac death so that it may be considered in a differential diagnosis as immunosuppression and early cardiac transplantation largely determine the prognosis.

Unerkannte letale idiopathische Riesenzellmyokarditis – ein Fallbericht

Myokarditiden stellen nach der hypertrophen Kardiomyopathie und der stenosierenden Koronararteriensklerose die dritthäufigste Ursache des plötzlichen Herztodes dar. Die Klinik der Myokarditis ist wie ihr Verlauf äußerst variabel, und ihr Therapieerfolg hängt stark von der Ätiologie und somit einer umfassenden diagnostischen Abklärung ab. Zum Goldstandard gehört nach wie vor die Endomyokardbiopsie, deren Ergebnisse bedeutenden Einfluss auf die Therapieplanung haben können. Vorgestellt wird der Fall einer 35 Jahre alt gewordenen Frau, bei der zu Lebzeiten eine chronisch aktive lymphozytäre Myokarditis mit Nachweis des humanen Herpesvirus 6 (HHV 6) diagnostiziert wurde. Acht Monate nach der Diagnose verstarb sie unerwartet. Die Obduktion mit nachfolgender histopathologischer Aufarbeitung der Myokardproben erbrachte den Nachweis einer Riesenzellmyokarditis, die als Differenzialdiagnose zu Lebzeiten nicht gestellt worden war. Der Fall verdeutlicht die Problematik der Diagnosestellung zu Lebzeiten, wenn Myokardproben nicht repräsentativ sind zum Nachweis der Grunderkrankung und illustriert die autoptischen Befunde dieser seltenen Form der Myokarditis.

Giant cell myocarditis in an older patient - reassessing the threshold for endomyocardial biopsy

Giant cell myocarditis is a rare form of autoimmune myocarditis with high morbidity and mortality that affects mainly middle-aged adults. We report a case study of a 70-year-old man on chronic immunosuppression who presented with sustained ventricular tachycardia and symptoms of acute systolic heart failure, both with poor response to standard measures. A decision to pursue endomyocardial biopsy established the diagnosis of GCM and lead to initiation of immunosuppressive therapy and a favourable outcome. Our case illustrates that a low threshold for endomyocardial biopsy in new onset heart failure can lead to actionable information even in patients of advanced age.

Extracorporeal Cardiopulmonary Resuscitation in Acute Fulminant Myocarditis: A Case Report and Review of the Literature

Fulminant myocarditis is a life-threatening fast progressive condition. We present a 7-year-old female patient admitted with a diagnosis of acute myocarditis with a rapidly progressive cardiac dysfunction despite conventional vasoactive and inotropic treatment. The patient presented with ventricular fibrillation and subsequent cardiac arrest. Cardiopulmonary resuscitation (CPR) was performed during 105 minutes before extracorporeal membrane oxygenation (ECMO) cannulation was performed. Effective hemodynamic function was obtained, and ECMO was weaned after 7 days, without neurological complications. There are not established extracorporeal cardiopulmonary resuscitation (eCPR) treatment criteria, and some international guidelines consider up to 100 minutes of "low flow" phase as a time limit to start the support. Some mortality risk factors for ECMO treatment mortality are female gender, renal failure, and arrhythmias. Pre-ECMO good prognostic factors are high levels of pH and blood lactate.

Management of a patient presenting with giant cell myocarditis - A case report

Giant cell myocarditis is a rare and frequently fatal disease that requires extensive cardiac care. Given the rarity of this condition no specific management recommendations exist. We describe a patient who presented with congestive heart failure that required a left ventricular assist device and a temporary right ventricular assist device along with immunosuppressive therapy. This case also brings to attention how undocumented immigration status can limit transplantation opportunities in the USA. <Learning objective: Giant cell myocarditis is a rare and frequently fatal cardiac disease that, until the 1980s, was only diagnosed during autopsy. It is commonly seen in young and middle-aged, otherwise healthy, individuals with median transplant-free survival of 5.5 months from diagnosis. Current treatments with immunosuppressant medications do not seem to be significantly effective. Most patients require transplant or ventricular assist device for survival.>.

Giant Cell Myocarditis: A Time Sensitive Distant Diagnosis

Giant cell myocarditis is a rare type of rapidly progressive myocarditis. We present a dramatic case of giant cell myocarditis in a young female with an initial presentation of acute heart failure. Her clinical course was complicated with recurrent cardiac arrhythmias, specifically non-sustained ventricular tachycardia, for which a dual chamber automated implantable cardioverter defibrillator (AICD) was implanted. Eventually, she presented with cardiac arrest despite being on antiarrhythmic medication and an implantable defibrillator. In the right clinical context, such as an acute presentation of unexplained new-onset heart failure and arrhythmias in a young patient, it is very important to maintain high suspicion of such a rare disease.

Genetic Basis of Myocarditis: Myth or Reality?

The genetic basis of myocarditis remains an intriguing concept, at least as long as the definition of myocarditis constitutes the definitive presence of myocardial inflammation sufficient to cause the observed ventricular dysfunction in the setting of cardiotropic infections. Autoimmune or immune-mediated myocardial inflammation constitutes a complex area of clinical interest, wherein numerous and not yet fully understood role of hereditary auto-inflammatory diseases can result in inflammation of the pericardium and myocardium. Finally, myocardial involvement in hereditary immunodeficiency diseases, cellular and humoral, is a possible trigger for infections which may complicate the diseases themselves. Whether the role of constitutional genetics can make the patient susceptible to myocardial inflammation remains yet to be explored.

A giant mystery in giant cell myocarditis: navigating diagnosis, immunosuppression, and mechanical circulatory support

Giant cell myocarditis is a rare but often devastating diagnosis. Advances in cardiac imaging and mechanical circulatory support have led to earlier and more frequent diagnoses and successful management. This disease state has wide variation in acuity of presentation, and consequently, optimal treatment ranging from intensity and type of immunosuppression to mechanical circulatory support is not well defined. The following case describes the management of a patient with an unusual presentation of giant cell myocarditis over a 10 year course of advanced heart failure therapies and immunomodulatory support. This case highlights emerging concepts in the management of giant cell myocarditis including sub‐acute presentations, challenges in diagnosis, and treatment modalities in the modern era.

Myocarditis: somethings old and something new

"Since the pathological conditions take place at the cellular level, viral myocarditis and postinfectious autoimmunity can be suggested but not diagnosed clinically. All clinical methods including imaging techniques are misleading if infectious agents are involved. Accurate diagnosis demands simultaneous histologic, immunohistochemical, and molecular biological workup of the tissue. If the primary infectious or immune-mediated causes of the disease are carefully defined by clinical and biopsy-based tools, specific antiviral treatment options in addition to basic symptomatic therapy are available under certain conditions. These may allow a tailored cause-specific treatment that improves symptoms and prognosis of patients with acute and chronic disease." Uwe Kühl; Heinz-Peter SchultheissViral myocarditis.Swiss Medical Weekly. 144():w14010, JAN 2014 DOI:10.4414/smw.2014.14010.

Histologic Examination of the Heart in the Forensic Autopsy

Histologic examination of the myocardium, valves, and cardiac blood vessels is often as important as the gross examination. The diagnostic features and categories of heart disease are many and varied, possibly more than any other organ. We present a review of the histologic features of forensically important heart disease.

Left Atrial Giant Cell Myocarditis Presenting as a Tumor: First-in-Man Case Report

Giant cell myocarditis is a rare and highly lethal disorder with resultant cardiac insufficiency. It necessitates aggressive immune suppression therapy, although the results are often fatal. When it affects only the atria, the characteristics of the disease changes completely. In this case report, we present atypical presentation of atrial giant cell myocarditis with mass lesion, which completely resolved after successful surgical resection without immuno suppression therapy.

Giant cell myocarditis causing refractory ventricular tachycardia in a pediatric patient

Giant cell myocarditis should be considered in all pediatric patients with refractory ventricular arrhythmia. Endomyocardial biopsy should be obtained to confirm the diagnosis of giant cell myocarditis.

Comparative immunologic characterization of autoimmune giant cell myocarditis with ipilimumab

Autoimmune myocarditis is a rare but often fatal toxicity of checkpoint inhibitor immunotherapy. To improve the understanding of this complication, we performed immune profiling on post-mortem tissue from a patient with metastatic melanoma who had steroid-responsive hepatitis, steroid-refractory myocarditis, and shrinking lung metastases after ipilimumab treatment. Histological analysis of heart tissue demonstrated findings consistent with giant cell myocarditis (GCM). The immune infiltrate in the heart was largely comprised of CD4+ T cells, whereas the liver had very few T cells, and CD8+ T cells were predominant in the responding lung metastases. TCR sequencing identified high T cell clonality in the lung metastases. The TCR repertoire showed low clonality in the heart and minimal overlap with the liver (1.2%), but some overlap with lung metastases (9.9%). Transcriptional profiling identified several potential mediators of increased inflammation in the heart. These findings provide new insights into the pathogenesis of autoimmune myocarditis with ipilimumab.