Myocarditis - A silent killer in athletes: Comparative analysis on the evidence before and after COVID-19 pandemic.

Myocarditis is a rare cardiomyocyte inflammatory process, typically caused by viruses, with potentially devastating cardiac sequalae in both competitive athletes and in the general population. Investigation into myocarditis prevalence in the Coronavirus disease 2019 (COVID-19) era suggests that infection with Severe acute respiratory syndrome coronavirus (SARS-CoV-2) is an independent risk factor for myocarditis, which is confirmed mainly through cardiovascular magnetic resonance imaging. Recent studies indicated that athletes have a decreased risk of myocarditis after recent COVID-19 infection compared to the general population. However, given the unique nature of competitive athletics with their frequent participation in high-intensity exercise, athletes possess distinct factors of susceptibility for the development of myocarditis and its subsequent severe cardiac complications (e.g., sudden cardiac death, fulminant heart failure, etc.). Under this context, this review focuses on comparing myocarditis in athletes versus non-athletes, owing special attention to the distinct clinical presentations and outcomes of myocarditis caused by different viral pathogens such as cytomegalovirus, Epstein-Barr virus, human herpesvirus-6, human immunodeficiency virus, and Parvovirus B19, both before and after the COVID-19 pandemic, as compared with SARS-CoV-2. By illustrating distinct clinical presentations and outcomes of myocarditis in athletes versus non-athletes, we also highlight the critical importance of early detection, vigilant monitoring, and effective management of viral and non-viral myocarditis in athletes and the necessity for further optimization of the return-to-play guidelines for athletes in the COVID-19 era, in order to minimize the risks for the rare but devastating cardiac fatality.

Therapeutic agents for steroid-refractory immune checkpoint inhibitor-related myocarditis: a narrative review.

Background and Objective: Immune checkpoint inhibitors (ICIs) have become one of the cornerstones of current oncology treatment, and immune checkpoint inhibitor-related myocarditis (IRM) is the most fatal of all immune checkpoint inhibitor-related adverse events (irAEs). Methylprednisolone pulse therapy (500-1,000 mg/day) is the initial treatment for IRM recommended by almost all relevant guidelines. However, subsequent treatment regimens remain unclear for patients who do not respond to methylprednisolone pulse therapy (who are defined as steroid-refractory patients). We propose a potential treatment approach for steroid-refractory IRM. Methods: The PubMed and the Cochrane Library databases were searched using keywords related to IRM. Relevant English-language articles published from January 2000 to February 2024 were included in this narrative review. Key Content and Findings: Abatacept is the preferred choice for the treatment of isolated steroid-refractory IRM. For rapidly progressive or interleukin-6 abnormally elevated steroid-refractory IRM, alemtuzumab or tocilizumab/tofacitinib are the preferred therapeutic agents, respectively. For steroid-refractory IRM comorbid with myositis or comorbid with myasthenia gravis, abatacept + ruxolitinib/mycophenolate mofetil (MMF)/intravenous immunoglobulin (IVIG), or MMF + pyridostigmine/IVIG are the preferred therapeutic agents, respectively. Conclusions: The pathogenesis of steroid-refractory IRM and the treatment regimen remain unclear. A large number of studies need to be conducted to validate or update our proposed treatment approach.

Parkin plays a crucial role in acute viral myocarditis by regulating mitophagy activity.

Rationale: Parkin (an E3 ubiquitin protein ligase) is an important regulator of mitophagy. However, the role of Parkin in viral myocarditis (VMC) remains unclear. Methods: Coxsackievirus B3 (CVB3) infection was induced in mice to create VMC. Cardiac function and inflammatory response were evaluated by echocardiography, histological assessment, and molecular analyses. AAV9 (adeno-associated virus 9), transmission electron microscopy (TEM) and western blotting were used to investigate the mechanisms by which Parkin regulates mitophagy and cardiac inflammation. Results: Our data indicated that Parkin- and BNIP3 (BCL2 interacting protein 3 like)-mediated mitophagy was activated in VMC mice and neonatal rat cardiac myocytes (NRCMs) infected with CVB3, which blocked autophagic flux by inhibiting autophagosome-lysosome fusion. Parkin silencing aggravated mortality and accelerated the development of cardiac dysfunction in CVB3-treated mice. While silencing of Parkin did not significantly increase inflammatory response through activating NF-κB pathway and production of inflammatory cytokines post-VMC, the mitophagy activity were reduced, which stimulated the accumulation of damaged mitochondria. Moreover, Parkin silencing exacerbated VMC-induced apoptosis. We consistently found that Parkin knockdown disrupted mitophagy activity and inflammatory response in NRCMs. Conclusion: This study elucidated the important role of Parkin in maintaining cardiac function and inflammatory response by regulating mitophagy activity and the NF-κB pathway during acute VMC. Although the functional impact of mitophagy remains unclear, our findings suggest that Parkin silencing may accelerate VMC development.

Myocardial calcification: case reports and a systematic review.

Aims: Myocardial calcification is an unusual condition in which excess calcium is deposited in the myocardium. Herein, we report two cases of myocardial calcification from our clinical experience. Furthermore, we conduct a systematic review to examine the clinical course and associated pathologies of myocardial calcification. Methods and results: This systematic review was registered in PROSPERO (CRD42023463285). PubMed and Scopus were searched according to the following inclusion criteria: (i) case reports or case series describing patients with myocardial calcification; (ii) diagnosis of myocardial calcification by computed tomography (CT); (iii) adequate description of patients, including their chief complaint, medical history, evaluations, and treatments; and (iv) publication in English. Among the 75 patients, 24 had sepsis, 14 had myocarditis, and 37 had other pathologies. The mortality rate was 33% for patients with sepsis, 14% for patients with myocarditis, and 11% for patients with other pathologies. Follow-up CT findings beyond 2 years were reported in six patients, showing that the CT findings of myocardial calcification persisted but subsided over time. Autopsy was performed in seven patients, and extensive interstitial fibrosis and collection of inflammatory cells were observed in patients with myocarditis, sepsis, and ischaemic heart disease. Conclusion: While various medical conditions can cause myocardial calcification, accompanying conditions commonly reported with myocardial calcification were sepsis and myocarditis. The CT findings of myocardial calcification tend to regress over time if the underlying disease can be treated.

Effectiveness of Additional Immunosuppressive Drugs for Corticosteroid-refractory Immune Checkpoint Inhibitor-induced Myocarditis: Two Case Reports.

Immune checkpoint inhibitors (ICIs) improve the outcomes of several types of cancer. However, they are also associated with various immune-related adverse events including myocarditis. ICI-induced myocarditis is a rare, potentially life-threatening adverse event. We herein report two cases of corticosteroid-refractory ICI-induced myocarditis. In both cases, additional immunosuppressive therapies, such as intravenous immunoglobulin and tacrolimus, successfully resolved myocarditis. Given the corticosteroid-refractory nature of these cases, we suggest that prompt addition of other immunosuppressive drugs to corticosteroid therapy should be considered in the treatment of ICI-induced myocarditis.

Acute Viral Myocarditis in a Young Adult: A Case Report.

Viral myocarditis is a serious complication of viral infections that is known to impact young adults and can result in significant cardiac issues like earlier onset of heart failure, arrhythmia, or structural heart disease if not detected and treated promptly. This is a case report focusing on a 25-year-old woman diagnosed with viral myocarditis highlighting the diagnostic difficulties it can present with due to its diverse symptoms. Following a thorough diagnostic workup and appropriate treatment, including diuretics, antibiotics, and guideline-directed medical therapy, her condition significantly improved. Early suspicion and prompt treatment are important because myocarditis can lead to long-term heart failure. This case shows the nature of the symptoms and the challenges posed by current diagnostic methods. By conducting clinical assessments and using advanced imaging techniques, the diagnosis was confirmed, leading to appropriate treatment for this patient.

Identification of key immune-related genes and potential therapeutic targets in immune checkpoint inhibitor-associated myocarditis.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are widely used in cancer treatment; however, the emergence of ICI-associated myocarditis (ICI-MC) presents a severe and potentially fatal complication with poorly understood pathophysiological mechanisms. This study aimed to identify crucial immune-related genes in ICI-MC and uncover potential therapeutic targets using bioinformatics. METHODS: Using the GSE180045 dataset, which includes three groups-Group A: ICI patients without immune adverse events, Group B: ICI patients with non-myocarditis immune adverse events, and Group C: ICI patients with myocarditis-we analyzed differentially expressed genes (DEGs) between ICI-MC samples (Group C) and non-myocarditis controls (Groups A and B). These DEGs were then cross-referenced with 1796 immune-related genes from the immPort database to identify immune-related DEGs. We conducted functional enrichment analyses (Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, gene set enrichment analysis), constructed a protein-protein interaction network, and identified hub genes. Validation using the GSE4172 dataset led to the identification of optimal feature genes from the overlap between hub genes and DEGs. Predictions of target MicroRNAs (miRNAs) were made, and a competing endogenous RNA (ceRNA) network was constructed. Target drugs for hub genes were predicted using the Connectivity Map database. RESULTS: We identified 58 DEGs between ICI-MC and controls, which led to the identification of 32 immune-related DEGs after intersection with 1796 immune-related genes. Functional analyses revealed enrichment in cell lysis, CD8+ T-cell receptor, natural killer cell-mediated cytotoxicity, and RAGE signaling. Notably upregulated hub genes included IL7R, PRF1, GNLY, CD3G, NKG7, GZMH, GZMB, KLRB1, KLRK1, and CD247. In the validation dataset, 407 DEGs were uncovered, resulting in the identification of 3 optimal feature genes (KLRB1, NKG7, GZMH). The predicted target miRNAs, lincRNAs, and circRNAs constituted a comprehensive ceRNA network. Among the top 10 drugs with elevated connectivity scores was acetohydroxamic acid, indicating a need for caution in ICI treatment. CONCLUSION: KG7, GZMH, and KLRB1 were identified as pivotal immune-related genes in ICI-MC. Biological enrichments included pathways involved in cell lysis, the CD8+ T-cell receptor pathway, natural killer cell-mediated cytotoxicity, RAGE signaling, and proinflammatory responses. The ceRNA network illuminated the role of critical molecules and underscored the importance of avoiding drugs such as acetohydroxamic acid in ICI treatment. Key message What is already known on this topic  Myocarditis is recognized as a serious ICI-associated toxicity, seemingly infrequent yet often fulminant and lethal. The underlying mechanisms of ICI-associated myocarditis remain not fully understood. Although the significance of T cells and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) is evident, the inciting antigens, the reasons for their recognition, and the mechanisms causing cardiac cell injury are not well characterized. An improved understanding of ICI-associated myocarditis will provide insights into the equilibrium between the immune and cardiovascular systems. What this study adds  Our study further validates the significance of T cells and CTLA-4 in ICI-associated myocarditis. More importantly, we identified three genes-NKG7, GZMH, and KLRB1-essential for the development of ICI-MC and proposed ceRNA networks involving these three key genes. How this study might affect research, practice or policy  The newly discovered key genes and their intricate molecular interactions offer a comprehensive perspective on the mechanisms underlying ICI-MC. Furthermore, our findings advise caution regarding the use of drugs like acetohydroxamic acid during ICI treatment. As our understanding of these regulatory networks deepens, our study provides valuable insights that could inform future therapeutic strategies for ICI-MC.

Sex Differences in Expression of Pro-Inflammatory Markers and miRNAs in a Mouse Model of CVB3 Myocarditis.

Myocarditis is an inflammatory disease that may lead to dilated cardiomyopathy. Viral infection of the myocardium triggers immune responses, which involve, among others, macrophage infiltration, oxidative stress, expression of pro-inflammatory cytokines, and microRNAs (miRNAs). The cardioprotective role of estrogen in myocarditis is well documented; however, sex differences in the miRNA expression in chronic myocarditis are still poorly understood, and studying them further was the aim of the present study. Male and female ABY/SnJ mice were infected with CVB3. Twenty-eight days later, cardiac tissue from both infected and control mice was used for real-time PCR and Western blot analysis. NFκB, IL-6, iNOS, TNF-α, IL-1ß, MCP-1, c-fos, and osteopontin (OPN) were used to examine the inflammatory state in the heart. Furthermore, the expression of several inflammation- and remodeling-related miRNAs was analyzed. NFκB, IL-6, TNF-α, IL-1ß, iNOS, and MCP-1 were significantly upregulated in male mice with CVB3-induced chronic myocarditis, whereas OPN mRNA expression was increased only in females. Further analysis revealed downregulation of some anti-inflammatory miRNA in male hearts (let7a), with upregulation in female hearts (let7b). In addition, dysregulation of remodeling-related miRNAs (miR27b and mir199a) in a sex-dependent manner was observed. Taken together, the results of the present study suggest a sex-specific expression of pro-inflammatory markers as well as inflammation- and remodeling-related miRNAs, with a higher pro-inflammatory response in male CVB3 myocarditis mice.

Early Neonatal Shock: Case Report and Lessons Learned in Management.

We report a case of a neonate, delivered by C-section, that rapidly developed respiratory compromise and hemodynamic instability prompting admission to critical care. Urgent cardiology assessment with echocardiography revealed severe systolic dysfunction from localized myocardial ischemia and pulmonary hypertension. Their management progressively escalated, eventually requiring inotropic support. Despite intensive treatment and meticulous nursing with demonstrable improvement of cardiac function, they deteriorated suddenly and died on Day 2 post-partum. This case emphasizes the challenge in early recognition of neonatal shock due to often nonspecific presentations, with hemodynamic compromise arising later. We recommend close vigilance for deterioration, awareness of indolent etiology including viral myocarditis, titration of appropriate inotropes and synergistic adjunctive vasodilators, and consideration of immune modulators such as corticosteroids that addresses biochemical deficiencies and support cardiac function. Ultimately, aggressive, targeted, and multi-focal treatment, especially in resource-limited environments, maximizes the chances of survival in challenging clinical situations such as progressive neonatal shock.

The Long-Term Cardiovascular Impact of COVID-19: Pathophysiology, Clinical Manifestations, and Management.

The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has resulted in a substantial global health crisis, with effects extending far beyond the acute phase of infection. This review aims to provide a comprehensive overview of the long-term cardiovascular impact of COVID-19, focusing on the pathophysiology, clinical manifestations, diagnostic approaches, management strategies, and future research directions. SARS-CoV-2 induces cardiovascular complications through mechanisms such as inflammation, endothelial dysfunction, and direct myocardial injury, leading to conditions like myocarditis, heart failure, arrhythmias, and thromboembolic events. These long-term effects, collectively called "long COVID" or post-acute sequelae of SARS-CoV-2 infection (PASC), present significant challenges for healthcare systems and patient management. Diagnostic approaches include imaging techniques and laboratory tests to identify and monitor cardiovascular complications. Management strategies emphasize a holistic approach, incorporating pharmacological treatments and lifestyle modifications. Special attention is required for vulnerable populations, including those with pre-existing cardiovascular conditions. Ongoing research is essential to understand the full spectrum of long-term cardiovascular impacts and to develop effective treatments. This review highlights the critical need for continued vigilance, multidisciplinary care, and research to address the cardiovascular sequelae of COVID-19 and improve long-term health outcomes for survivors.

Fulminant Streptococcus suis Infection Causing Myocardial Damage and Toxic Shock-Like Syndrome: A Case Report.

There have been no prior reports of direct myocardial damage caused by Streptococcus suis (S. suis), and understanding the clinical course of myocardial involvement is crucial for early diagnosis and initiation of treatment for this infection. A male pig farmer presented as an outpatient with a fever and sore throat, but within hours, his cardiac function declined, and his general condition deteriorated. Despite receiving comprehensive treatment, he succumbed to complications associated with toxic shock-like syndrome (TSLS). Blood cultures identified S. suis, and myocardial pathology revealed the presence of this bacterium in necrotic areas. This case marks the first reported instance of myocardial damage accompanied by TSLS due to S. suis, highlighting the significance of this infection.

Practice Patterns of Cardiovascular Magnetic Resonance Use in the Diagnosis of Pediatric Myocarditis: A Survey-Based Study.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is used to diagnose myocarditis in adults and children based on the original Lake Louise Criteria (LLC) and more recently the revised LLC. The major change included in the revised LLC was the incorporation of parametric mapping, which significantly increases the sensitivity and specificity of diagnosis. Subsequently, scientific statements have recommended the use of parametric mapping in the diagnosis of myocarditis in children. However, there are some challenges to parametric mapping that are unique to the pediatric population. Our goal is to characterize clinical CMR and parametric mapping practice patterns for diagnosis of myocarditis in pediatric centers. METHODS: The Cardiovascular Magnetic Resonance Evaluation in Return to Athletes for Myocarditis in COVID-19 and Immunization Consortium created a REDCap survey to evaluate clinical practice patterns for diagnosis of myocarditis in pediatrics. This survey was distributed to the Society for Cardiovascular Magnetic Resonance community. RESULTS: 59 responses from 51 centers were received, with only one response from each center being utilized. Only 35% of centers (37% of North America, 31% of international) reported using CMR routinely in all patients with a suspicion for myocarditis. Diagnostic uncertainty was noted as the most important reason for CMR, while cost was noted as the least important consideration. The majority of centers reported using the revised LLC (37/51, 72%) compared to original LLC (7/51, 14%) or a hybrid criteria (6/51, 12%). When looking at the use of parametric mapping, only 5/47 (11%) for T1 mapping and 11/49 (22%) for T2 mapping reported having scanner-specific pediatric normative data. CONCLUSION: Routine CMR imaging for diagnosis of myocarditis in pediatrics is infrequently performed at surveyed centers despite the focus on a group of non-invasive cardiac imagers. While the majority reported using parametric mapping, few centers reporting having pediatric scanner-specific normative data. This highlights an important gap in the utilization of CMR that may aid in the diagnosis of myocardial disease.

Occult checkpoint inhibitor myocarditis during adjuvant nivolumab plus ipilimumab: a smoldering but severe toxicity.

Checkpoint inhibitor myocarditis is a rare but life-threatening toxicity of immunotherapy, occasionally manifesting as persistent troponin elevation. Dual checkpoint blockade with ipilimumab and nivolumab has been found to induce immune-related myocarditis in patients with metastatic melanoma. We herein report a case of smoldering immune-related myocarditis in a 54-year-old male after a single infusion of nivolumab plus ipilimumab as adjuvant treatment for completely resected stage IV melanoma. High-dose steroid treatment resulted in decrease in the levels of cardiac enzymes, without any major complications.

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Steroid-Refractory Myocarditis Induced by Immune Checkpoint Inhibitor Responded to Infliximab: Report of Two Cases and Literature Review.

Immune checkpoint inhibitors (ICIs), including anti-programmed cell death protein 1 and its ligand (PD-1/PD-L1) as well as anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4), have been widely used for treating solid tumors. Myocarditis is a potentially lethal immune-related adverse events (irAEs) caused by ICIs therapy. The treatment of steroid-refractory myocarditis is challenging. We reported two non-small-cell lung cancer patients with steroid-refractory myocarditis induced by ICI. The symptoms were not resolved after pulse corticosteroid therapy and subsequent treatment including intravenous immunoglobulin and mycophenolate mofetil. Considering the level of serum interleukin (IL)-6 decreased by > 50% and level of serum tumor necrosis factor-α (TNF-α) increased during the course of the disease, infliximab was used. Myocarditis gradually alleviated after infliximab treatment. The cases revealed that specific cytokine inhibitors have promising roles in the treatment of steroid-refractory myocarditis. Infliximab could be considered for patients with low level of IL-6 and elevated level of TNF-α.

Myopericarditis Following Use of Selective Androgen Receptor Modifier "RAD-140".

We report the case of a 16-year-old boy who had myopericarditis following the first dose of a selective androgen receptor modulator called Testolone ("RAD-140"). These drugs are widely abused by physically active young adults; however, the drugs' side effects, which can be life-threatening, are not well characterized.

Endosomal Toll-Like Receptors intermediate negative impacts of viral diseases, autoimmune diseases, and inflammatory immune responses on the cardiovascular system.

INTRODUCTION: Cardiovascular disease (CVD) is the leading cause of morbidity globally, with chronic inflammation as a key modifiable risk factor. Toll-like receptors (TLRs), pivotal components of the innate immune system, including TLR-3, -7, -8, and -9 within endosomes, trigger intracellular cascades, leading to inflammatory cytokine production by various cell types, contributing to systemic inflammation and atherosclerosis. Recent research highlights the role of endosomal TLRs in recognizing self-derived nucleic acids during sterile inflammation, implicated in autoimmune conditions like myocarditis. AREAS COVERED: This review explores the impact of endosomal TLRs on viral infections, autoimmunity, and inflammatory responses, shedding light on their intricate involvement in cardiovascular health and disease by examining literature on TLR-mediated mechanisms and their roles in CVD pathophysiology. EXPERT OPINION: Removal of endosomal TLRs mitigates myocardial damage and immune reactions, applicable in myocardial injury. Targeting TLRs with agonists enhances innate immunity against fatal viruses, lowering viral loads and mortality. Prophylactic TLR agonist administration upregulates TLRs, protecting against fatal viruses and improving survival. TLRs play a complex role in CVDs like atherosclerosis and myocarditis, with therapeutic potential in modulating TLR reactions for cardiovascular health.

Adult with Coxsackie B virus-induced cardiomyopathy presents rare case of complicated acute embolic ischaemic stroke.

Introduction and importance: Stroke, a global health concern, often results from embolic events of cardiac origin. Coxsackie B virus (CBV) myocarditis, a common cause of viral heart infections, can lead to cardiac thrombi formation, subsequently causing devastating complications such as embolic stroke. The authors present a rare case of a 26-year-old male who experienced an embolic stroke following CBV myocarditis and cardiomyopathy. Case presentation: The patient exhibited left-sided weakness, facial droop, and respiratory distress. Laboratory findings indicated leukocytosis, hyponatremia, and elevated troponin I. Imaging revealed an acute right basal ganglia infarct and multifocal pulmonary embolism. The diagnosis involved positive CBV serology, severely reduced left ventricular function, and a large apical thrombus. Discussion: Cardioembolic strokes, often attributable to atrial fibrillation, can also result from intracardiac thrombosis associated with myocarditis. CBV, implicated in up to 40% of acute myocarditis cases, binds to cardiac myocytes, triggering inflammation and potential thrombus formation. Myocarditis-induced hypercoagulability increases the risk of thromboembolic events, complicating the clinical course. Conclusion: CBV myocarditis poses a risk of heart failure, cardiomyopathy, and thromboembolic complications such as embolic stroke. Vigilant monitoring for complications and prompt management is crucial, as primary disease treatment remains primarily supportive. This case highlights the need for increased awareness and further studies to understand the intricate relationship between viral myocarditis and embolic strokes.

Cardiogenic shock secondary to immune checkpoint inhibitor associated myocarditis.

Immune checkpoint inhibitors have transformed the treatment for multiple cancers and are increasingly used in recent years, but they can cause potentially life-threatening cardiac toxicity. We report a case of a 64-year-old gentleman who presented to the Emergency Department with symptoms of fatigue and breathlessness whilst receiving treatment with an immune checkpoint inhibitor, pembrolizumab, for cholangiocarcinoma. He was found to be in cardiogenic shock with an abnormal electrocardiogram and elevated cardiac troponin at presentation. Echocardiogram demonstrated severely impaired right and left ventricular function. Computed tomography pulmonary angiography and invasive coronary angiography excluded pulmonary embolism and acute myocardial infarction, respectively, and he was diagnosed with immune checkpoint inhibitor associated myocarditis. He was treated with high-dose methylprednisolone and a dobutamine infusion. Within days, his troponin and C-reactive protein levels decreased, and his left ventricular function improved. He was established on heart failure therapies and discharged from hospital 12 days later.