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Background: COVID-19 is a new infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). Since the outbreak in December 2019, it has caused an unprecedented world pandemic, leading to a global human health crisis. Although SARS CoV-2 mainly affects the lungs, causing interstitial pneumonia and severe acute respiratory distress syndrome, a number of patients often have extensive clinical manifestations, such as gastrointestinal symptoms, cardiovascular damage and renal dysfunction. Purpose: This review article discusses the pathogenic mechanisms of cardiovascular damage in COVID-19 patients and provides some useful suggestions for future clinical diagnosis, treatment and prevention. Methods: An English-language literature search was conducted in PubMed and Web of Science databases up to 12th April, 2024 for the terms "COVID-19", "SARS CoV-2", "cardiovascular damage", "myocardial injury", "myocarditis", "hypertension", "arrhythmia", "heart failure" and "coronary heart disease", especially update articles in 2023 and 2024. Salient medical literatures regarding the cardiovascular damage of COVID-19 were selected, extracted and synthesized. Results: The most common cardiovascular damage was myocarditis and pericarditis, hypertension, arrhythmia, myocardial injury and heart failure, coronary heart disease, stress cardiomyopathy, ischemic stroke, blood coagulation abnormalities, and dyslipidemia. Two important pathogenic mechanisms of the cardiovascular damage may be direct viral cytotoxicity as well as indirect hyperimmune responses of the body to SARS CoV-2 infection. Conclusions: Cardiovascular damage in COVID-19 patients is common and portends a worse prognosis. Although the underlying pathophysiological mechanisms of cardiovascular damage related to COVID-19 are not completely clear, two important pathogenic mechanisms of cardiovascular damage may be the direct damage of the SARSCoV-2 infection and the indirect hyperimmune responses. [ABSTRACT FROM AUTHOR]

Vaccine-related myocarditis associated with the BNT162b2 vaccine is a rare complication, with a higher risk observed in male adolescents. However, the contribution of genetic factors to this condition remains uncertain. In this study, we conducted a comprehensive genetic association analysis in a cohort of 43 Hong Kong Chinese adolescents who were diagnosed with myocarditis shortly after receiving the BNT162b2 mRNA COVID-19 vaccine. A comparison of whole-genome sequencing data was performed between the confirmed myocarditis cases and a control group of 481 healthy individuals. To narrow down potential genomic regions of interest, we employed a novel clustering approach called ClusterAnalyzer, which prioritised 2,182 genomic regions overlapping with 1,499 genes for further investigation. Our pathway analysis revealed significant enrichment of these genes in functions related to cardiac conduction, ion channel activity, plasma membrane adhesion, and axonogenesis. These findings suggest a potential genetic predisposition in these specific functional areas that may contribute to the observed side effect of the vaccine. Nevertheless, further validation through larger-scale studies is imperative to confirm these findings. Given the increasing prominence of mRNA vaccines as a promising strategy for disease prevention and treatment, understanding the genetic factors associated with vaccine-related myocarditis assumes paramount importance. Our study provides valuable insights that significantly advance our understanding in this regard and serve as a valuable foundation for future research endeavours in this field. [ABSTRACT FROM AUTHOR]

Nonischaemic myocardial fibrosis is associated with cardiac dysfunction, malignant arrhythmias and sudden cardiac death. In the absence of a specific aetiology, its finding as late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging is often attributed to preceding viral myocarditis. Athletes presenting with ventricular arrhythmias often have nonischaemic LGE. Previous studies have demonstrated an adverse effect of exercise on the course of acute viral myocarditis. In this study, we have investigated, for the first time, the impact of endurance training on longer-term outcomes such as myocardial fibrosis and arrhythmogenicity in a murine coxsackievirus B3 (CVB)-induced myocarditis model. Male C57BL/6J mice (n = 72) were randomly assigned to 8 weeks of forced treadmill running (EEX) or no exercise (SED). Myocarditis was induced 2 weeks later by a single intraperitoneal injection with CVB, versus vehicle in the controls (PBS). In a separate study, mice (n = 30) were subjected to pretraining for 13 weeks (preEEX), without continuation of exercise during myocarditis. Overall, continuation of exercise resulted in a milder clinical course of viral disease, with less weight loss and better preserved running capacity. CVB-EEX and preEEX-CVB mice tended to have a lower mortality rate. At sacrifice (i.e. 6 weeks after inoculation), the majority of virus was cleared from the heart. Histological assessment demonstrated prominent myocardial inflammatory infiltration and cardiomyocyte loss in both CVB groups. Inflammatory lesions in the CVB-EEX group contained higher numbers of pro-inflammatory cells (iNOS-reactive macrophages and CD8+ T lymphocytes) compared to these in CVB-SED. Treadmill running during myocarditis increased interstitial fibrosis [82.4% (CVB-EEX) vs. 56.3% (CVB-SED); P = 0.049]. Additionally, perivascular and/or interstitial fibrosis with extensive distribution was more likely to occur with exercise [64.7% and 64.7% (CVB-EEX) vs. 50% and 31.3% (CVB-SED); P = 0.048]. There was a numerical, but not significant, increase in the number of scars per cross-section (1.9 vs. 1.2; P = 0.195), with similar scar distribution and histological appearance in CVB-EEX and CVB-SED. In vivo electrophysiology studies did not induce sustained monomorphic ventricular tachycardia, only nonsustained (usually polymorphic) runs. Their cumulative beat count and duration paralleled the increased fibrosis between CVB-EEX and CVB-SED, but the difference was not significant (P = 0.084 for each). Interestingly, in mice that were subjected to pretraining only without continuation of exercise during myocarditis, no differences between pretrained and sedentary mice were observed at sacrifice (i.e. 6 weeks after inoculation and training cessation) with regard to myocardial inflammation, fibrosis, and ventricular arrhythmogenicity. In conclusion, endurance exercise during viral myocarditis modulates the inflammatory process with more pro-inflammatory cells and enhances perivascular and interstitial fibrosis development. The impact on ventricular arrhythmogenesis requires further exploration. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Immune checkpoint inhibitors can rarely lead to occurrence of myositis, myocarditis, and myasthenia gravis (MG). Early recognition and multidisciplinary management are crucial for optimal outcomes. Vigilance for overlapping toxicities is essential in patients receiving combination immunotherapy. The use of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, but it is associated with immune‐related adverse events (IRAEs) affecting various organ systems. The simultaneous occurrence of MG, myocarditis, and myositis highlights the complex nature of IRAEs. Early recognition and comprehensive multidisciplinary management are crucial for optimal patient outcomes. We present a unique case report of a 76‐year‐old male patient with advanced melanoma who developed concurrent myositis, myocarditis, and MG while receiving combination immunotherapy with Nivolumab and Ipilimumab. This case underscores the significance of recognizing and addressing the "Terrible Triad" of IRAEs in patients receiving ICIs. Healthcare providers should maintain a high index of suspicion for overlapping toxicities and promptly initiate appropriate interventions. [ABSTRACT FROM AUTHOR]

Myocardial fibrosis is an important factor in the progression of cardiovascular diseases. However, there is still no universal lifetime method of myocardial fibrosis assessment that has a high prognostic significance. The aim of the study was to determine the significance of ventricular endomyocardial biopsies for the assessment of myocardial fibrosis and to identify the severity of myocardial fibrosis in different cardiovascular diseases. Material and Methods: Endomyocardial biopsies (EMBs) of 20 patients with chronic lymphocytic myocarditis (CM), endomyocardial fragments obtained during septal reduction of 21 patients with hypertrophic cardiomyopathy (HCM), and 36 patients with a long history of hypertensive and ischemic heart disease (HHD + IHD) were included in the study. The control group was formed from EMBs taken on 12–14 days after heart transplantation (n = 28). Also, for one patient without clinical and morphological data for cardiovascular pathology, postmortem myocardial fragments were taken from typical EMB and septal reduction sites. The relative area of fibrosis was calculated as the ratio of the total area of collagen fibers to the area of the whole biopsy. Endocardium and subendocardial fibrosis were not included in the total biopsy area. Results: The relative fibrosis area in the EMBs in the CM patient group was 5.6 [3.3; 12.6]%, 11.1 [6.6; 15.9]% in the HHD + IHD patient group, 13.4 [8.8; 16.7]% in the HCM patient group, and 2.7 [1.5; 4.6]% in the control group. When comparing the fibrosis area of the CM patients in repeat EMBs, it was found that the fibrosis area in the first EMBs was 7.6 [4.8; 12.0]%, and in repeat EMBs, it was 5.3 [3.2; 7.6]%. No statistically significant differences were found between the primary and repeat EMBs (p = 0.15). In ROC analysis, the area of fibrosis in the myocardium of 1.1% (or lower than one) was found to be highly specific for the control group of patients compared to the study patients. Conclusions: EMB in the assessment of myocardial fibrosis has a questionable role because of the heterogeneity of fibrotic changes in the myocardium. [ABSTRACT FROM AUTHOR]

Simple Summary: Feline infectious peritonitis (FIP) is a very common coronavirus (FCoV) infectious disease in the feline population. FIP infection is a cause of death in cats and is widespread in domestic cats. FIP can have an acute or chronic clinical form, also known as effusive or non-effusive FIP, respectively. The typical lesion found in the acute form is an effusion in the thoracic and/or abdominal cavities, while collection in the pericardial sac is rare. The chronic form is characterized by pyogranulomatous necrotizing lesions in organs such as the kidney, liver, intestine, lung, eyes, skin, and central nervous system. FIP does not represent a zoonotic risk. The reported case is an uncommon pyogranuloma found in the myocardium in a cat with clinical heart dysfunction. The most important histopathological finding was the myocarditis/myocardial necrosis associated with the presence of S gene-mutated FCoV (M1058L biotype). This is the first described case of myocarditis in an FCoV/FIP M1058L biotype-positive cat. An 8-month-old intact male domestic shorthair cat was referred to the Emergency Service of the Veterinary Teaching Hospital (VTH) of the Department of Veterinary Science of the University of Parma (Italy) from the Parma municipal multi-cat shelter, during the winter season (January 2023), for lethargy, anorexia, hypothermia, and hypoglycemia. At the VTH, upon cardiologic examination, an increase in heart rate, under normal blood pressure conditions, was detected. Signalment, clinical history, basal metabolic panel (BMP), ultrasound investigations, and cytological findings were all consistent with a diagnosis of feline infectious peritonitis (FIP). FIP was confirmed in the effusive abdominal fluid by a molecular genetic test (real-time PCR for feline coronavirus RNA). The molecular genetic investigation also detected an FCoV S gene single-nucleotide mutation: biotype M1058L. At necropsy, an effusive collection was recorded in the abdomen, thoracic cavity, and pericardium sac. White parenchymal nodules, of about 1 mm diameter, were found on the surface and deep in the lungs, liver, kidneys, and heart. Histopathology revealed the typical FIP pyogranulomatous vasculitis and IHC confirmed the presence of the FIP virus (FIPV) antigen. The most relevant histopathological finding was the myocarditis/myocardial necrosis associated with the presence of the S gene-mutated FCoV (M1058L biotype). This is the first case of myocarditis in a cat positive for the FCoV/FIP M1058L biotype. Further studies are necessary to support the mutated FCoV M1058L biotype, as an uncommon, but possible, causative pathogen of myocarditis in FCoV/FIP-positive cats. Studies including several FCoV/FIP M1058L-positive cases could allow us to make a correlation with heart gross pathology, histopathology, and immunolocalization of the FCoV/FIP M1058L biotype in the myocardium. The investigation will potentially allow us to determine the effective tropism of the FCoV/FIP M1058L biotype for myocardiocytes or whether myocardiocyte lesions are evident in the presence of concomitant causes related to the patient, its poor condition, or external environmental distress such as cold season, and whether the aforementioned concomitant events are correlated. [ABSTRACT FROM AUTHOR]

The Epstein-Barr virus (EBV) is frequently found in endomyocardial biopsies (EMBs) from patients with heart failure, but the detection of EBV-specific DNA has not been associated with progressive hemodynamic deterioration. In this paper, we investigate the use of targeted next-generation sequencing (NGS) to detect EBV transcripts and their correlation with myocardial inflammation in EBV-positive patients with heart failure with reduced ejection fraction (HFrEF). Forty-four HFrEF patients with positive EBV DNA detection and varying degrees of myocardial inflammation were selected. EBV-specific transcripts from EMBs were enriched using a custom hybridization capture-based workflow and, subsequently, sequenced by NGS. The short-read sequencing revealed the presence of EBV-specific transcripts in 17 patients, of which 11 had only latent EBV genes and 6 presented with lytic transcription. The immunohistochemical staining for CD3+ T lymphocytes showed a significant increase in the degree of myocardial inflammation in the presence of EBV lytic transcripts, suggesting a possible influence on the clinical course. These results imply the important role of EBV lytic transcripts in the pathogenesis of inflammatory heart disease and emphasize the applicability of targeted NGS in EMB diagnostics as a basis for specific treatment. [ABSTRACT FROM AUTHOR]

Myocarditis is characterized by an influx of inflammatory cells, predominantly of myeloid lineage. The progression of myocarditis to a dilated cardiomyopathy is markedly influenced by TGF-β signalling. Here, we investigate the role of TGF-β signalling in inflammatory cardiac macrophages in the development of myocarditis and post-inflammatory fibrosis. Experimental autoimmune myocarditis (EAM) was induced in the LysM-Cre × R26-stop-EYFP × Tgfbr2-fl/fl transgenic mice showing impaired TGF-β signalling in the myeloid lineage and the LysM-Cre × R26-stop-EYFP control mice. In EAM, immunization led to acute myocarditis on day 21, followed by cardiac fibrosis on day 40. Both strains showed a similar severity of myocarditis and the extent of cardiac fibrosis. On day 21 of EAM, an increase in cardiac inflammatory macrophages was observed in both strains. These cells were sorted and analysed for differential gene expression using whole-genome transcriptomics. The analysis revealed activation and regulation of the inflammatory response, particularly the production of both pro-inflammatory and anti-inflammatory cytokines and cytokine receptors as TGF-β-dependent processes. The analysis of selected cytokines produced by bone marrow-derived macrophages confirmed their suppressed secretion. In conclusion, our findings highlight the regulatory role of TGF-β signalling in cytokine production within inflammatory cardiac macrophages during myocarditis. [ABSTRACT FROM AUTHOR]

Cardiomyopathy is a severe cardiac condition characterized by complex immune regulatory mechanisms. While the role of immune genes is recognized, the specifics of their regulation in cardiomyopathy are not fully understood. Recent studies highlight the significance of transposable elements (TEs) in various diseases, particularly their potential to modulate immune responses. This paper utilizes publicly available databases to explore the role of TEs in myocarditis: RNA Seq data and single-cell sequencing data were analyzed, with a focus on the mouse model of experimental autoimmune myocarditis (EAM). The RNA-Seq analysis revealed substantial upregulation of a range of immune genes in cardiac tissue. Further investigation using single-cell sequencing of cardiac immune cells identified specific expression of certain transposable elements (TEs) across different types of immune cells in the heart. Additionally, there was an overall increase in the expression of the ERVB7-1. LTR-MM transposon across various cells in the EAM model, suggesting a widespread impact of this transposon on the immune response in this disease context. The findings of this study highlight the intricate interplay between transposable elements and the immune system in cardiomyopathy, providing new insights into the molecular mechanisms underlying this condition. The discovery of specific TEs expression in cardiac immune cells and the overall increase in ERVB7-1. LTR-MM expression across the EAM model underscore the potential of these elements in modulating immune responses and contribute to our understanding of cardiomyopathy's pathogenesis. These observations open avenues for further research into the role of TEs in cardiac disases and may lead to novel therapeutic strategies. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to unravel the clinical effect analysis of different doses of creatine phosphate sodium (CPS) combined with immunoglobulin in the treatment of pediatric viral myocarditis (VMC). One hundred and twenty children with VMC were recruited and randomized into three groups (40 patients each). Group I received 1.0 g of CPS dissolved in 100 mL of 5% glucose injection intravenously 1 time/day; group II received 1.25 g of CPS dissolved in 125 mL of 5% glucose injection intravenously 1 time/day; group III received 1.5 g of CPS dissolved in 150 mL of 5% glucose injection intravenously 1 time/day; then all three groups were treated with combined use of immunoglobulin (300–400 mg/day) intravenously once a day; and all three groups were treated for 14 days. The clinical efficacy, cardiac function, serum inflammatory factor levels, immune function, and the occurrence of drug toxicity and adverse effects of the children in the three groups were compared after 14 days of treatment. All three groups achieved better therapeutic effects after treatment, in which the effective rate of the Group II and Group III was notably higher versus the Group I. Lower levels of cTnI, CK-MB, LDH, AST, IL-18, IL-6, IFN-γ, and LVEDD and higher CD3+, CD4+, and CD4+/CD8+, FS, and LVEF values were noted in the Group II and Group III versus the Group I, and the results were more pronounced in the high-dose group. The liver and kidney functions of the children in the three groups before and after treatment did not show any significant changes and the incidence of adverse reactions during the treatment period was low in all three groups. Children with VMC can be treated with high-dose CPS in combination with immunoglobulin, which can improve their cardiac function and immune function and reduce the inflammatory response with good overall therapeutic efficacy and fewer adverse effects. [ABSTRACT FROM AUTHOR]

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) is a complex and potentially fatal hypersensitivity condition. We present a unique case report and literature review focusing on DRESS syndrome-associated myocarditis resulting from reactivated viral infections in a 21-year-old female. 3 weeks after 5-day oral co-trimoxazole consumption due to acne, she developed symptoms consistent with DRESS syndrome, including a generalized maculopapular rash. Despite prednisolone treatment, the patient developed fatal fulminant myocarditis linked to HHV-6 and CMV reactivation. The patient's death highlights the importance of early recognition and careful management of DRESS syndrome, especially considering the potential viral reactivation that can lead to severe complications. Postmortem investigations revealed that viral reactivation caused myocarditis. Careful consideration must be given to corticosteroid usage in DRESS treatment, as inappropriate prescribing may promote viral reactivation and subsequent complications. While high-dose corticosteroids initiated within the first week effectively suppress HHV-6 reactivation. Conversely, low-dose or late-start high-dose corticosteroids prove ineffective in preventing HHV-6 viremia. Late- onset or low- dose corticosteroids may lead to fatal complications following the primary viral reactivation. [ABSTRACT FROM AUTHOR]

Clozapine is effective in up to 50 % of patients resistant to other antipsychotics. Its use is restricted to third-line due to adverse effects which include myocarditis. Australia reports the highest incidence of clozapine-associated myocarditis (CAM) in the context of pharmacovigilance and relatively rapid titration. An audit of patients commenced on clozapine within the Central Adelaide Local Health Network (CALHN) between 2012 and 2015 found an incidence of 8.6 %. We present here a case series from a follow up audit considering titration relevant risk factors for CAM. We reviewed anecdotal cases and data from all hospital-based commencements of clozapine across CALHN for the period July 2021 to June 2022 using pharmacy and medical record databases. We identified 5 cases of CAM and all had risk factors impacting on clozapine metabolism, including rapid titration, elevated baseline CRP, Asian ethnicity and concomitant treatment with inhibitors of clozapine metabolism. While personalisation of clozapine treatment needs further investigation in prospective trials, slower titration to lower targets for risk groups may not impact on hospital length of stay and has the potential to significantly reduce the burden of adverse events. Australian manufacturer approved titration rates exceed those recommended for personalised dosing and may not be safe for patients with risk factors. Early clozapine levels at week two could identify slow metabolisers for dose adjustment. Closer ties between psychiatrists and cardiologists are critical for the development of protocols for safely maintaining clozapine treatment during low level cardiac inflammation and to support safe rechallenge. [ABSTRACT FROM AUTHOR]

Higher frequencies of inflammatory adverse effects of clozapine have been reported in Japan. As the international titration protocol for Asians has set slower dose titration than the Japanese package insert, we hypothesized that a dose titration speed slower than the recommendation of the guideline would be associated with fewer inflammatory-related adverse events. The medical records of all 272 patients who were first started on clozapine at seven hospitals between 2009 and 2023 were studied retrospectively. Of those, 241 were included in the analysis. The patients were divided into two groups regarding whether the titration speed was faster or slower than the guideline for Asians. The incidence of inflammatory adverse events with clozapine was compared between the groups. The frequency of inflammatory adverse events was 34 % (37/110) in the faster titration group and 13 % (17/131) in the slower titration group, and a significant difference was observed by Fisher exact test (odds ratio 3.38; 95 % confidence interval 1.71–6.91; p < 0.001). Serious adverse effects, fever for more than five days, and clozapine discontinuation were significantly more frequent in the faster titration group. Logistic regression analysis indicated significantly more inflammatory adverse events in the faster titration group (adjusted odds ratio 4.01; 95 % confidence interval 2.02–7.87; p < 0.001) considering age, sex, body mass index, concomitant valproic acid, and smoking as confounding factors. Clozapine-induced inflammatory adverse events were less frequent in Japanese individuals when a titration rate was more gradual than the protocol recommended in the Japanese package insert. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Immune checkpoint inhibitors (ICI) are increasingly used in the first‐line treatment of malignant tumors. There is increasing recognition of their cardiotoxicity and, in particular, their potential to lead to myocarditis. Cardiovascular magnetic resonance (CMR) can quantify pathological changes, such as myocardial edema and fibrosis. The purpose of this systematic review and meta‐analysis was to examine the evidence for the roles of CMR in predicting prognosis in ICI‐associated myocarditis. Methods: PubMed, Cochrane Library, and Web of Science databases were searched until October 2023 for published works investigating the relationship between CMR parameters and adverse events in patients with ICI‐associated myocarditis. The analysis included studies reporting the incidence of late gadolinium enhancement (LGE), T1 values, T2 values, and CMR‐derived left ventricular ejection fraction (LVEF). Odds ratios (OR) and weighted mean differences (WMD) were combined for binary and continuous data, respectively. Newcastle‐Ottawa Scale was used to assess the methodological quality of the included studies. Results: Five cohort studies were included (average age 65–68 years; 25.4% female). Of these, four studies were included in the meta‐analysis of LGE‐related findings. Patients with major adverse cardiovascular events (MACE) had a higher incidence of LGE compared with patients without MACE (OR = 4.18, 95% CI: 1.72–10.19, p = 0.002). A meta‐analysis, incorporating data from two studies, showed that patients who developed MACE exhibited significantly higher T1 value (WMD = 36.16 ms, 95% CI: 21.43–50.89, p < 0.001) and lower LVEF (WMD = − 8.00%, 95% CI: −13.60 to −2.40, p = 0.005). Notably, T2 value (WMD = −0.23 ms, 95% CI: −1.86 to −1.39, p = 0.779) was not associated with MACE in patients with ICI‐related myocarditis. Conclusions: LGE, T1 value, and LVEF measured by CMR imaging have potential prognostic value for long‐term adverse events in patients with ICI‐related myocarditis. [ABSTRACT FROM AUTHOR]

Myocarditis has emerged as a rare but lethal immune checkpoint inhibitor (ICI)‐associated toxicity. However, the exact mechanism and the specific therapeutic targets remain underexplored. In this study, we aim to characterise the transcriptomic profiles based on single‐cell RNA sequencing from ICI‐related myocarditis. Peripheral blood mononuclear cell (PBMC) samples were collected from four groups for single‐cell RNA sequencing: (1) patients with newly diagnosed lung squamous cell carcinoma before treatment (Control Group); (2) patients with lung squamous cell carcinoma with PD‐1 inhibitor therapy who did not develop myocarditis (PD‐1 Group); (3) patients during fulminant ICI‐related myocarditis onset (Myocarditis Group); and (4) Patients with fulminant ICI‐related myocarditis during disease remission (Recovery Group). Subcluster determination, functional analysis, single‐cell trajectory and cell–cell interaction analysis were performed after scRNA‐seq. Bulk‐RNA sequencing was performed for further validation. Our results revealed the diversity of cellular populations in ICI‐related myocarditis, marked by their distinct transcriptional profiles and biological functions. Monocytes, NKs as well as B cells contribute to the regulation of innate immunity and inflammation in ICI‐related myocarditis. With integrated analysis of scRNA‐seq and bulk sequencing, we identified S100A protein family as a potential serum marker for ICI‐related myocarditis. Our study has created a cell atlas of PBMC during ICI‐related myocarditis, which would shed light on the pathophysiological mechanism and potential therapeutic targets of ICI‐related myocarditis in continuous exploration. [ABSTRACT FROM AUTHOR]

Vaccines are vital for public health, but concerns about adverse effects, particularly myocarditis and pericarditis linked to COVID-19 vaccines-, persist. This study investigates the application of Brighton Collaboration case definition to national vaccine safety data related to post-COVID-19 vaccine myo/pericarditis, utilizing claims under the Korea National Vaccine Injury Compensation Program (NIVCP). This study analyzed 190 medical records of individuals who claimed to have developed myo/pericarditis after receiving the COVID-19 vaccine, as reported to the NVICP between specified dates, categorizing cases based on the Brighton criteria for myocarditis or pericarditis. Between 2021–2022, NVICP received 190 cases meeting the Brighton criteria for myocarditis or pericarditis at levels 1, 2, or 3. Most cases fell into Level 2 (70%), followed by Level 1 (29%), and one at Level 3 (1%), with Level 1 cases showing a higher hospitalization rate (87.3%) and a notable proportion requiring admission to the Intensive Care Unit (25.5%). Chest pain and Troponin-I/T elevation were common findings in Level 1 cases, while Level 2 cases exhibited similar patterns but at a slightly lower frequency. Electrocardiogram and echocardiography findings differed between the two levels. The Brighton Collaboration case definition proved valuable for classifying and assessing AEFI data, enhancing our understanding of the potential relationship between myocarditis and the COVID-19 vaccine. [ABSTRACT FROM AUTHOR]

Background: There is little literature on the use of temporary pacemakers in children with fulminant myocarditis. Therefore, we summarized the use of temporary cardiac pacemakers in children with fulminant myocarditis in our hospital. Methods: The clinical data of children with fulminant myocarditis treated with temporary pacemakers in Wuhan Children's Hospital from January 2017 to May 2022 were retrospectively analyzed. Results: A total of 6 children were enrolled in the study, including 4 boys and 2 girls, with a median age of 50 months and a median weight of 15 kg. The average time from admission to pacemaker placement was 2.75 ± 0.4 h. The electrocardiogram showed that all 6 children had third-degree atrioventricular block (III°AVB). The initial pacing voltage, the sensory sensitivity of the ventricle and the pacing frequency were set to 5–10 mV, 5 V and 100–120 bpm respectively. The sinus rhythm was recovered in 5 patients within 61 h (17–134) h, and the median time of using temporary pacemaker was 132 h (63–445) h. One of the children had persistent III°AVB after the temporary pacemaker. With parental consent, the child was fitted with a permanent pacemaker on the 12th day of his illness. Conclusions: When fulminant myocarditis leads to severe bradycardia or atrioventricular block in children, temporary pacemakers have the characteristics of high safety to improve the heart function. [ABSTRACT FROM AUTHOR]

We report a series of three patients who developed checkpoint inhibitor-related myocarditis with orbital myositis and/or myasthenia gravis overlap syndrome, with varying degrees of severity. In all cases, checkpoint inhibitor therapy was immediately discontinued upon diagnosis and corticosteroids were initiated. While two patients achieved substantial recovery, one patient passed away on hospital day three. These cases underscore the critical need for prompt recognition of adverse events associated with immune checkpoint inhibitors. [ABSTRACT FROM AUTHOR]

Cardiac sarcoidosis is an infiltrative cardiomyopathy that results from granulomatous inflammation of the myocardium and may present with high-grade conduction disease, ventricular arrhythmias, and right or left ventricular dysfunction. Over the past several decades, the prevalence of cardiac sarcoidosis has increased. Definitive histological confirmation is often not possible, so clinicians frequently face uncertainty about the accuracy of diagnosis. Hence, the likelihood of cardiac sarcoidosis should be thought of as a continuum (definite, highly probable, probable, possible, low probability, unlikely) rather than in a binary fashion. Treatment should be initiated in individuals with clinical manifestations and active inflammation in a tiered approach, with corticosteroids as first-line treatment. The lack of randomized clinical trials in cardiac sarcoidosis has led to treatment decisions based on cohort studies and consensus opinions, with substantial variation observed across centers. This scientific statement is intended to guide clinical practice and to facilitate management conformity by providing a framework for the diagnosis and management of cardiac sarcoidosis. [ABSTRACT FROM AUTHOR]

Objective Using Mendelian randomization analysis to explore the immune cells involved in myocarditis (MC). Methods Genome-wide association study (GWAS) was used to mine the data, and the exposure factors were 731 immune cell traits, and the outcome factor was myocarditis. Regression models such as Inverse-Variance Weighted method (IVW), MR-Egger, Simple Mode, weighted median and Weighted Mode were used for Mendelian randomization analysis. At the same time, heterogeneity tests, horizontal multiple validity analyses, and sensitivity analyses were also conducted. Multivariate Mendelian randomization analysis of the relevant immune cell traits was performed by Inverse-Variance Weighted method (IVW) to correct the effect of seven positive immune cell traits on the outcome. Results (1) The results of Mendelian randomization showed that there was a causal relationship between 7 immune cell traits that include CD39 + resting Treg % resting Treg (OR = 1.237, 95% CI: 1.039-1.474), CD4 + CD8dim % leukocyte (OR = 0.737, 95% CI: 0.543-0.100), CD28-CD8dim AC (OR = 0.868, 95% CI: 0.753-0.100), CD28-CD8br AC (OR = 1.398, 95% CI: 1.097-1.780), CD20 on CD20-CD38-(OR = 1.295, 95% CI: 1.012-1.659), CCR2 on monocyte (OR = 1.010, 95% CI: 1.000-1.208), CD11b on basophil (OR = 0.852, 95% CI: 0.727-0.998) and MC. (2) The results of multivariate Mendelian randomization showed that CD39 + resting Treg % resting Treg (OR = 1.228, 95% CI: 1.059-1.423), CD28-CD8dim AC (OR = 0.629, 95% CI: 0.428-0.924), CCR2 on monocyte (OR = 0.661, 95% CI: 0.488-0.895) were correlated with MC. (3) The results of reverse Mendelian randomization did not find a causal relationship between 7 positive immune signatures and MC. ConclusionThis study confirm the close relationship between immune cells and MC through genetics, which will provide a reference for future research. [ABSTRACT FROM AUTHOR]

Background: Over the past decade, immune checkpoint inhibitors (ICIs) have significantly transformed cancer treatment. However, ICIs inevitably may cause a spectrum of immune‐related adverse events, among which cardiovascular toxicity, particularly myocarditis, while infrequent, has garnered increasing attention due to its high fatality rate. Methods: We conducted a multicenter retrospective study to characterize ICI‐associated cardiovascular adverse events. Logistic regression was performed to explore the risk factors for the development of myocarditis and severe myocarditis. Receiver operating characteristic curves were conducted to assess the diagnostic abilities of cardiac biomarkers to distinguish different cardiovascular toxicities, and the performance and calibration were evaluated using Hosmer–Lemeshow test. Results: Forty‐four patients were identified, including thirty‐five myocarditis, five heart failure, three arrhythmias, and one myocardial infarction. Compared with other patients, myocarditis patients had higher cardiac troponin‐I (cTnI) levels (p < 0.001), higher creatine kinase levels (p = 0.003), higher creatine kinase isoenzyme‐MB (CK‐MB) levels (p = 0.013), and shorter time to the incidence of adverse cardiovascular events (p = 0.022) after ICI treatment. Twenty‐one patients (60%) were classified as severe myocarditis, and they presented higher cardiac troponin I (cTnI) levels (p = 0.013), higher N‐terminal pro‐B‐type natriuretic peptide levels (p = 0.031), higher creatine kinase levels (p = 0.018), higher CK‐MB levels (p = 0.026), and higher neutrophil to lymphocyte ratio (NLR) levels (p = 0.016) compared to non‐severe myocarditis patients after ICI treatment. Multivariate logistic regression showed that CK‐MB (adjusted odds ratio [OR]: 1.775, 95% confidence interval [CI]: 1.055–2.984, p = 0.031) was the independent risk factor of the development of ICI‐associated myocarditis, and cTnI (adjusted OR: 1.021, 95% CI: 1.002–1.039, p = 0.03) and NLR (adjusted OR: 1.890, 95% CI: 1.026–3.483, p = 0.041) were the independent risk factors of ICI‐associated severe myocarditis. The receiver operating characteristic curve showed an area under curve of 0.785 (95% CI: 0.642 to 0.928, p = 0.013) for CK‐MB, 0.765 (95% CI: 0.601 to 0.929, p = 0.013) for cTnI, and 0.773 for NLR (95% CI: 0.597 to 0.948, p = 0.016). Conclusions: Elevated CK‐MB after ICI treatment is the independent risk factor for the incidence of ICI‐associated myocarditis, and elevated cTnI and NLR after ICI treatment are the independent risk factors for the development of ICI‐associated severe myocarditis. CK‐MB, cTnI, and NLR demonstrated a promising predictive utility for the identification of ICI‐associated myocarditis and severe myocarditis. [ABSTRACT FROM AUTHOR]

Background: Myocarditis refers to an autoimmune inflammatory response of the myocardium with characterization of self-reactive CD4+ T cell activation, which lacks effective treatment and has a poor prognosis. Acacetin is a natural flavonoid product that has been reported to have anti-inflammatory effects. However, acacetin has not been investigated in myocarditis. Methods: Oral acacetin treatment was administered in an experimental autoimmune myocarditis model established with myosin heavy chain-alpha peptide. Echocardiography, pathological staining, and RT-qPCR were used to detect cardiac function, myocardial injury, and inflammation levels. Flow cytometry was utilized to detect the effect of acacetin on CD4+ T cell function. RNA-seq, molecular docking, and microscale thermophoresis (MST) were employed to investigate potential mechanisms. Seahorse analysis, mitoSOX, JC-1, and mitotracker were utilized to detect the effect of acacetin on mitochondrial function. Results: Acacetin attenuated cardiac injury and fibrosis as well as heart dysfunction, and reduced cardiac inflammatory cytokines and ratio of effector CD4+ T and Th17 cells. Acacetin inhibited CD4+ T cell activation, proliferation, and Th17 cell differentiation. Mechanistically, the effects of acacetin were related to reducing mitochondrial complex II activity thereby inhibiting mitochondrial respiration and mitochondrial reactive oxygen species in CD4+ T cells. Conclusion: Acacetin may be a valuable therapeutic drug in treating CD4+ T cell-mediated myocarditis. [ABSTRACT FROM AUTHOR]

Myocarditis is considered a fatal form of foot-and-mouth disease (FMD) in suckling calves. In the present study, a total of 17 calves under 4 months of age and suspected clinically for FMD were examined for clinical lesions, respiratory rate, heart rate, and heart rhythm. Lesion samples, saliva, nasal swabs, and whole blood were collected from suspected calves and subjected to Sandwich ELISA and reverse transcription multiplex polymerase chain reaction (RT-mPCR) for detection and serotyping of FMD virus (FMDV). The samples were found to be positive for FMDV serotype "O". Myocarditis was suspected in 6 calves based on tachypnoea, tachycardia, and gallop rhythm. Serum aspartate aminotransferase (AST), creatinine kinase myocardial band (CK-MB) and lactate dehydrogenase (LDH), and cardiac troponins (cTnI) were measured. Mean serum AST, cTn-I and LDH were significantly higher (P < 0.001) in < 2 months old FMD-infected calves showing clinical signs suggestive of myocarditis (264.833 ± 4.16; 11.650 ± 0.34 and 1213.33 ± 29.06) than those without myocarditis (< 2 months old: 110.00 ± 0.00, 0.06 ± 0.00, 1050.00 ± 0.00; > 2 months < 4 months: 83.00 ± 3.00, 0.05 ± 0.02, 1159.00 ± 27.63) and healthy control groups (< 2 months old: 67.50 ± 3.10, 0.047 ± 0.01, 1120.00 ± 31.62; > 2 months < 4 months: 72.83 ± 2.09, 0.47 ± 0.00, 1160.00 ± 18.44). However, mean serum CK-MB did not differ significantly amongst the groups. Four calves under 2 months old died and a necropsy revealed the presence of a pathognomic gross lesion of the myocardial form of FMD known as "tigroid heart". Histopathology confirmed myocarditis. This study also reports the relevance of clinical and histopathological findings and biochemical markers in diagnosing FMD-related myocarditis in suckling calves. [ABSTRACT FROM AUTHOR]

Aims: Standardized immunosuppressive therapy (IS) had been previously investigated in biopsy‐proven (BP) lymphocytic myocarditis with heart failure (HF). This study evaluated efficacy and safety of tailored IS in BP immune‐mediated myocarditis, irrespective of histology and clinical presentation. Methods and results: Consecutive BP myocarditis patients treated with long‐term tailored IS on top of optimal medical therapy (OMT), were compared with OMT non‐IS controls using propensity‐score weighting. The primary outcome was a composite of death or heart transplant, the secondary outcome was a composite of biventricular function, New York Heart Association (NYHA) class variation, and relapse. IS was managed by a multidisciplinary Cardioimmunology Team, involved a safety checklist and active patients' education. Ninety‐one IS patients were compared with 267 non‐IS patients. IS patients more frequently had systemic immune‐mediated diseases (35% vs. 9.7%), lower baseline echocardiographic left ventricular ejection fraction (35% vs. 43%), lower right ventricular fractional area change (34% vs. 41%) and higher frequency of active lymphocytic, eosinophilic and giant cell myocarditis (71% vs. 58%, 12% vs. 1.1%, and 6.6% vs. 1.5%, respectively). At 5‐year follow up, no difference was observed in the primary outcome (survival rate 93% in IS vs. 87% in non‐IS), but IS patients had a higher relapse rate. Thus, IS patients, with a lower biventricular function and a higher risk profile at baseline, presented similar biventricular function and NYHA class to non‐IS patients at follow‐up. Minor adverse drug reactions occurred in 13% of patients, all resolved with therapy switch. Conclusions: Prolonged tailored IS is effective and safe in BP immune‐mediated myocarditis irrespective of histology and clinical presentation. [ABSTRACT FROM AUTHOR]

Major 5'-terminally deleted (5'TD) RNA forms of group-B coxsackievirus (CVB-5'TD) has been associated with myocarditis in both mice and humans. Although it is known that interferon-β (IFN-β) signaling is critical for an efficient innate immune response against CVB-induced myocarditis, the link between CVB-5'TD RNA forms and type I IFN signaling in cardiomyocytes remains to be explored. In a mouse model of CVB3/28-induced myocarditis, major early-emerging forms of CVB-5'TD RNA have been characterized as replicative viral populations that impair IFN-β production in the heart. Synthetic CVB3/28 RNA forms mimicking each of these major 5'TD virus populations were transfected in mice and have been shown to modulate innate immune responses in the heart and to induce myocarditis in mice. Remarkably, transfection of synthetic viral RNA with deletions in the secondary structures of the 5'-terminal CVB3 RNA domain I, modifying stem-loops "b", "c" or "d", were found to impair IFN-β production in human cardiomyocytes. In addition, the activation of innate immune response by Poly(I:C), was found to restore IFN-β production and to reduce the burden of CVB-5'TD RNA-forms in cardiac tissues, thereby reducing the mortality rate of infected mice. Overall, our results indicate that major early-emerging CVB3 populations deleted in the domain I of genomic RNA, in the 5' noncoding region, modulate the activation of the type I IFN pathway in cardiomyocytes and induce myocarditis in mice. These findings shed new light on the role of replicative CVB-5'TD RNA forms as key pathophysiological factors in CVB-induced human myocarditis. Author summary: Myocarditis is an inflammatory disease of the heart. Viruses or post-viral immune mediated response are the main causes of myocarditis. Human group B enteroviruses, specifically Coxsackievirus B3 (CVB3), are common infectious causes of acute myocarditis in the young. Early emergence and maintenance of major 5'terminally deleted RNA forms of CVB have been associated with acute and chronic myocarditis in both mice and humans. To achieve viral genome maintenance in the cardiac cells, viruses could modulate innate immunity activation. Here, we report on major early-emerging CVB3 populations deleted in the 5'non-coding region of viral genomic RNA that modulate the activation of the type I interferon pathway in cardiomyocytes and cause myocarditis in mice. Activating the innate immune sensors after CVB3 infection protects mice from CVB3-induced myocarditis and shall promote further studies in immunotherapies in viral acute and chronic myocarditis. [ABSTRACT FROM AUTHOR]

Purpose: Immune checkpoint inhibitors-related myocarditis (ICI-M) is one of the immune-related adverse events (irAEs), which is rare and highly lethal. This study aimed to establish nomograms based on ratio biomarkers to predict the severity and prognosis of ICI-M. Methods: We retrospectively examined patients with advanced cancers who were also diagnosed with ICI-M at the Fourth Hospital of Hebei Medical University. The patients of ICI-M were divided into mild and severe groups and a 40-day following up was carried out. The major adverse cardiovascular events(MACEs) were regarded as the endpoint. Nomogram-based models were established and validated. Results: Seventy-seven patients were involved, including 31 severe cases(40.3%). Lactate dehydrogenase-to-albumin ratio(LAR) combined with the change rate from baseline to onset of LAR(▵ LAR) which performed best to diagnose the severe ICI-M was identified to establish the nomogram-based model. The bootstrap-corrected concordance index [0.752 95% confidence interval (CI): 0.635 - 0.866] and calibration plot with good degree of fitting confirmed this diagnostic model. Neutrophil-to-high-density lipoprotein cholesterol ratio(NHR) and LAR were also screened into the nomogram-based model for 40-day MACEs after ICI-M, which performed well by validating for concordance index(0.779 95% CI: 0.677 - 0.865)and calibration plots after being bootstrap-corrected. Moreover, a ≥ 101% increase in LAR significantly separated patients in MACE-free survival. Conclusion: Ratio indexes at onset and their change rates from baseline showed good diagnostic value for the severity of ICI-M and prognostic value for subsequent MACEs, particularly LAR, NHR and their change rates. The nomogram-based models of ratio indexes could provide a potential choice for early detection and monitor of the severe ICI-M and subsequent MACEs. [ABSTRACT FROM AUTHOR]

Introduction: Cases of myocarditis after COVID-19 messenger RNA (mRNA) vaccines administration have been reported. Although the majority follow a mild course, fulminant presentations may occur. In these cases, cardiopulmonary support with venoarterial extracorporeal membrane oxygenation (V-A ECMO) may be needed. Results: We present two cases supported with V-A ECMO for refractory cardiogenic shock due to myocarditis secondary to a mRNA SARS-CoV2 vaccine. One of the cases was admitted for out-of-hospital cardiac arrest. In both, a peripheral V-A ECMO was implanted in the cath lab using the Seldinger technique. An intra-aortic balloon pump was needed in one case for left ventricle unloading. Support could be successfully withdrawn in a mean of five days. No major bleeding or thrombosis complications occurred. Whereas an endomyocardial biopsy was performed in both, a definite microscopic diagnosis just could be reached in one of them. Treatment was the same, using 1000mg of methylprednisolone/day for three days. A cardiac magnetic resonance was performed ten days after admission, showing a significant improvement of the left ventricular ejection fraction and diffuse oedema and subepicardial contrast intake in different segments. Both cases were discharged fully recovered, with CPC 1. Conclusions: COVID-19 vaccine-associated fulminant myocarditis has a high morbidity and mortality but presents a high potential for recovery. V-A ECMO should be established in cases with refractory cardiogenic shock during the acute phase. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Mycoplasma myocarditis is a rare but potentially serious condition that can cause inflammation of the heart muscle, leading to arrhythmia and heart failure. It is important to consider this condition in the differential diagnosis of young patients presenting with unexplained signs of heart failure and SVT, even in the absence of signs of myocardiocytolysis and extra‐cardiac disease. Mycoplasma pneumoniae infections are often underdiagnosed as a great proportion of patients remain asymptomatic, pauci‐symptomatic, or exhibit varying presentations. M. Pneumoniae manifestations can affect different systems, including the heart, with the potential to lead to high degree of morbidity and debilitating sequelae. Here we present an atypical case of M. Pneumoniae associated myocarditis which presented with sustained refractory SVT, symptoms of heart failure, and with no signs of myocardiocytolysis, pulmonary involvement, or systemic infection. Given the lack of signs of myocardial inflammation, the patient was initially misdiagnosed with tachycardia induced cardiomyopathy (TIC), but later correctly diagnosed after showing signs of pneumonia during the hospitalization. The patient received the appropriate antibiotic treatment in addition to corticosteroids, was discharged on the 15th day of hospitalization, and completely recovered after 1 month with no arrhythmia recurrence and normalization of ventricular function. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Understand the importance of considering alternative diagnosis in patients presenting with atypical features. Understand the importance of considering common presentations of rare cases. Underscoring the critical importance of timely recognition and appropriate management of potentially life‐threatening condition. [ABSTRACT FROM AUTHOR]

Coxsackievirus B3 (CVB3) is a positive single-strand RNA genome virus which belongs to the enterovirus genus in the picornavirus family, like poliovirus. It is one of the most prevalent pathogens that cause myocarditis and pancreatitis in humans. However, a suitable therapeutic medication and vaccination have yet to be discovered. Caboxamycin, a benzoxazole antibiotic isolated from the culture broth of the marine strain Streptomyces sp., SC0774, showed an antiviral effect in CVB3-infected HeLa cells and a CVB3-induced myocarditis mouse model. Caboxamycin substantially decreased CVB3 VP1 production and cleavage of translation factor eIF4G1 from CVB3 infection. Virus-positive and -negative strand RNA was dramatically reduced by caboxamycin treatment. In addition, the cleavage of the pro-apoptotic molecules BAD, BAX, and caspase3 was significantly inhibited by caboxamycin treatment. In animal experiments, the survival rate of mice was improved following caboxamycin treatment. Moreover, caboxamycin treatment significantly decreased myocardial damage and inflammatory cell infiltration. Our study showed that caboxamycin dramatically suppressed cardiac inflammation and mouse death. This result suggests that caboxamycin may be suitable as a potential antiviral drug for CVB3. [ABSTRACT FROM AUTHOR]

Trypanosoma cruzi infection in dogs can cause heart failure and sudden death with few treatment options available. A litter of 4 dogs living in a T cruzi endemic area were randomized to prophylaxis and nonprophylaxis groups as part of a study evaluating a modified benznidazole dosing regimen administered twice weekly to prevent T cruzi infection during a vector transmission season. The 2 dogs that received prophylaxis remained healthy without T cruzi infection or cardiac disease for >2 years. One dog that did not receive prophylaxis died unexpectedly with acute T cruzi–induced pancarditis, and the second dog tested positive for T cruzi and developed complex arrhythmias with markedly increased cardiac troponin I and improved with a higher benznidazole treatment dose. Although the small sample size precludes definitive conclusions, we describe the potential clinical benefit of prophylactic and early treatment with modified benznidazole dosing regimens for dogs with T cruzi infection. [ABSTRACT FROM AUTHOR]

Myocarditis is defined as an inflammatory infiltration of the myocardium with associated necrosis or degeneration, or both. The disease is also known as inflammatory cardiomyopathy, with various aetiologies contributing to its onset. Among these, viral infections have garnered substantial attention due to their potential to trigger myocardial inflammation and lead to severe cardiac complications. Post-viral myocarditis, a subset of myocarditis, occurs as a consequence of viral infections and represents a critical intersection between infectious diseases and cardiology. Viruses such as enteroviruses, adenoviruses, and more recently, SARS-CoV-2, have been implicated in post-viral myocarditis, underlining the broad spectrum of viral triggers that clinicians must consider. Myocarditis presents in various forms, including Fulminant myocarditis (17%), which can lead to complete resolution or severe cardiac compromise resulting in rapid deterioration and death; Acute myocarditis (65%) typically causes moderate cardiovascular compromise and incomplete recovery with the potential for cardiac dysfunction or subsequent death; Chronic active myocarditis (11%) resembles acute myocarditis but tends to progress to mild or moderate cardiac dysfunction, often with restrictive physiology, and exhibits ongoing fibrosis on histologic examination; and Chronic persistent myocarditis (7%) characterized by non-resolving active or borderline inflammatory infiltrates on histologic examination, typically without cardiovascular compromise. [ABSTRACT FROM AUTHOR]

Introduction: Coenzyme Q10 (CoQ10) is considered to be beneficial for patients with acute viral myocarditis (AVM). In addition, trimetazidine may be also beneficial to patients with AVM by promoting cardiac energy metabolism. This systematic review and meta-analysis examined the efficacy and safety of combining trimetazidine and CoQ10 with respect to CoQ10 alone in patients suffering from AVM. Methodology: PubMed, Embase, the Cochrane Library, Wanfang, and China National Knowledge Infrastructure (CNKI) databases were searched for relevant randomized controlled trials (RCTs). An analysis of random effects was employed to combine the results. Results: Sixteen RCTs that included 1,364 patients with AVM contributed to the meta-analysis. Overall, 687 patients received the combined treatment, while 677 received the CoQ10 alone for a duration of 2-12 weeks (mean: 5.2 weeks). In contrast to monotherapy with CoQ10, combined treatment with trimetazidine and CoQ10 significantly improved overall therapy effectiveness (risk ratio [RR]: 1.19, 95% confidence interval [CI]: 1.13 to 1.24, p < 0.001; I² = 0%). Differences in study parameters such as the incidence of heart failure upon admission, dosage of CoQ10, or length of treatment did not significantly alter the outcomes (p for all subgroup analyses > 0.05). The combined treatment was associated with improved myocardial enzyme levels and recovery of cardiac systolic function as compared to CoQ10 alone (p all < 0.05). In addition, trimetazidine combined with CoQ10 caused no greater increase in adverse events than CoQ10 alone. Conclusions: Trimetazidine combined with CoQ10 is an effective and safe treatment for AVM. [ABSTRACT FROM AUTHOR]

Mast cells are tissue-resident immune cells strategically located in different compartments of the normal human heart (the myocardium, pericardium, aortic valve, and close to nerves) as well as in atherosclerotic plaques. Cardiac mast cells produce a broad spectrum of vasoactive and proinflammatory mediators, which have potential roles in inflammation, angiogenesis, lymphangiogenesis, tissue remodelling, and fibrosis. Mast cells release preformed mediators (e.g. histamine, tryptase, and chymase) and de novo synthesized mediators (e.g. cysteinyl leukotriene C4 and prostaglandin D2), as well as cytokines and chemokines, which can activate different resident immune cells (e.g. macrophages) and structural cells (e.g. fibroblasts and endothelial cells) in the human heart and aorta. The transcriptional profiles of various mast cell populations highlight their potential heterogeneity and distinct gene and proteome expression. Mast cell plasticity and heterogeneity enable these cells the potential for performing different, even opposite, functions in response to changing tissue contexts. Human cardiac mast cells display significant differences compared with mast cells isolated from other organs. These characteristics make cardiac mast cells intriguing, given their dichotomous potential roles of inducing or protecting against cardiovascular diseases. Identification of cardiac mast cell subpopulations represents a prerequisite for understanding their potential multifaceted roles in health and disease. Several new drugs specifically targeting human mast cell activation are under development or in clinical trials. Mast cells and/or their subpopulations can potentially represent novel therapeutic targets for cardiovascular disorders. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the possible extent of bias due to violation of a core assumption (event-dependent exposures) when using self-controlled designs to analyse the association between COVID-19 vaccines and myocarditis. We used data from five European databases (Spain: BIFAP, FISABIO VID, and SIDIAP; Italy: ARS-Tuscany; England: CPRD Aurum) converted to the ConcePTION Common Data Model. Individuals who experienced both myocarditis and were vaccinated against COVID-19 between 1 September 2020 and the end of data availability in each country were included. We compared a self-controlled risk interval study (SCRI) using a pre-vaccination control window, an SCRI using a post-vaccination control window, a standard SCCS and an extension of the SCCS designed to handle violations of the assumption of event-dependent exposures. We included 1,757 cases of myocarditis. For analyses of the first dose of the Pfizer vaccine, to which all databases contributed information, we found results consistent with a null effect in both of the SCRI and extended SCCS, but some indication of a harmful effect in a standard SCCS. For the second dose, we found evidence of a harmful association for all study designs, with relatively similar effect sizes (SCRI pre = 1.99, 1.40 – 2.82; SCRI post 2.13, 95 %CI – 1.43, 3.18; standard SCCS 1.79, 95 %CI 1.31 – 2.44, extended SCCS 1.52, 95 %CI = 1.08 – 2.15). Adjustment for calendar time did not change these conclusions. Findings using all designs were also consistent with a harmful effect following a second dose of the Moderna vaccine. In the context of the known association between COVID-19 vaccines and myocarditis, we have demonstrated that two forms of SCRI and two forms of SCCS led to largely comparable results, possibly because of limited violation of the assumption of event-dependent exposures. [ABSTRACT FROM AUTHOR]

Autoimmune myocarditis is the limited or diffuse inflammation of the myocardium due to dysfunctional cellular and humoral immunity mechanisms. We constructed mouse models of experimental autoimmune myocarditis (EAM) using peptide MyHC-α614-629. On the day after secondary immunization, the mice were intraperitoneally injected with Rho kinase (ROCK) inhibitor Y-27632. On day 21, the cardiac tissues were harvested and weighed. The hearts of EAM mice were significantly enlarged and whitened. Furthermore, body weight (BW) slowly increased during the treatment period, the heart weight (HW) and the ratio of HW/eventual BW were increased, and inflammatory infiltration and fibrosis were aggravated in the myocardial tissue. Y-27632 treatment improved the aforementioned phenotypic and pathological features of EAM mice. Mechanistic analysis revealed a significant increase in Notch1, Hes1, Jag2, Dil1, Toll-like receptor (Tlr) 2, and interleukin (IL)-1β expression in the myocardial tissue of EAM mice. Notably, IL-1β expression was correlated with that of Notch1 and Tlr2. Following Y-27632 treatment, the expression of key target genes of the Notch signaling pathway (Notch1, Hes1, Dil1, and Jag2) and Tlr2 were obviously decreased. Y-27632 treatment also decreased the number of monocytes in the spleen of EAM mice. Thus, ROCK inhibitor Y-27632 exerted a protective effect in EAM mice by downregulating IL-1β expression. This study aimed to provide a reference point for the future treatment of myocarditis in clinical settings. [ABSTRACT FROM AUTHOR]

The aim of this retrospective study was to identify myocardial injury after COVID-19 inflammation and explore whether myocardial damage could be a possible cause of the persistent symptoms following COVID-19 infection in previously healthy individuals. This study included 139 patients who were enrolled between January and June 2021, with a mean age of 46.7 ± 15.2 years, of whom 68 were men and 71 were women without known cardiac or pulmonary diseases. All patients underwent clinical work-up, laboratory analysis, cardiac ultrasound, and CMR on a 1.5 T scanner using a recommended protocol for morphological and functional assessment before and after contrast media application with multi-parametric sequences. In 39% of patients, late gadolinium enhancement (LGE) was found as a sign of myocarditis. Fibrinogen was statistically significantly higher in patients with LGE than in those without LGE (4.3 ± 0.23 vs. 3.2 ± 0.14 g/L, p < 0.05, respectively), as well as D-dimer (1.8 ± 0.3 vs. 0.8 ± 0.1 mg/L FEU). Also, troponin was statistically significantly higher in patients with myocardial LGE (13.1 ± 0.4 ng/L) compared to those with normal myocardium (4.9 ± 0.3 ng/L, p < 0.001). We demonstrated chest pain, fatigue, and elevated troponin to be independent predictors for LGE. Septal LGE was shown to be a predictor for arrhythmias. The use of CMR is a potential risk stratification tool in evaluating outcomes following COVID-19 myocarditis. [ABSTRACT FROM AUTHOR]

COVID-19 vaccination has been associated with myocarditis in adolescents and young adults, and concerns have been raised about possible vaccine-related cardiac fatalities in this age group. In April 2021, cases of myocarditis after COVID-19 vaccination, particularly among young male vaccine recipients, were reported to the Vaccine Adverse Event Reporting System. To assess this possibility, investigators searched death certificates for Oregon residents aged 16-30 years who died during June 2021-December 2022 for cardiac or undetermined causes of death. For identified decedents, records in Oregon's immunization information system were reviewed for documentation of mRNA COVID-19 vaccination received =100 days before death. Among 1,292 identified deaths, COVID-19 was cited as the cause for 30. For 101 others, a cardiac cause of death could not be excluded; among these decedents, immunization information system records were available for 88, three of whom had received an mRNA COVID-19 vaccination within 100 days of death. Of 40 deaths that occurred among persons who had received an mRNA COVID-19 vaccine dose, three occurred =100 days after vaccination. Two of these deaths were attributed to chronic underlying conditions; the cause was undetermined for one. No death certificate attributed death to vaccination. These data do not support an association between receipt of mRNA COVID-19 vaccine and sudden cardiac death among previously healthy young persons. COVID-19 vaccination is recommended for all persons aged =6 months to prevent COVID-19 and complications, including death. [ABSTRACT FROM AUTHOR]

• Rare cases of myocarditis/pericarditis after vaccination with COVID-19 vaccine NVX-CoV2373 have been documented. • This analysis provides a benefit-risk assessment for vaccination with NVX-CoV2373 based on data from clinical studies and recent real-world burden of disease data. • Results indicate that the benefits of vaccination with NVX-Cov2373 outweigh the risks of myocarditis/pericarditis. A benefit–risk assessment of NVX-CoV2373, a vaccine to prevent COVID-19, was conducted to determine if the benefits of vaccination outweigh the risks of myocarditis/pericarditis. This analysis used data on myocarditis/pericarditis cases observed in the NVX-CoV2373 clinical studies, real-world data of mRNA COVID vaccine effectiveness against predominant SARS-CoV-2 strains in early 2023, and recent COVID-19 burden of disease data from the United States. The benefits of NVX-CoV2373 vaccination were estimated as the number of COVID-19 cases, hospitalizations, and deaths prevented. The risks of myocarditis/pericarditis cases and related hospitalizations and deaths occurring within 7 days of vaccination were also estimated. In our analysis, vaccination with NVX-CoV2373, per 100,000 vaccinated, resulted in an estimated 1805 COVID-19 cases prevented compared with an estimated 5.3 excess myocarditis/pericarditis cases. The number of COVID-19 hospitalizations and deaths prevented were also greater than vaccine-associated myocarditis/pericarditis hospitalizations and deaths. Our analysis indicates a positive benefit–risk balance for NVX-CoV2373. [ABSTRACT FROM AUTHOR]

Objective: To analyze the serum levels of exosome miRNA-135-5p in children with viral myocarditis, and to evaluate its clinical value to the myocardial injury degree and prognosis by inhibiting AKT/mTOR signal pathway. Methods: The 50 children with viral myocarditis in our hospital were collected and divided into the two groups according to the degree of viral myocarditis, which were severe group (15 cases) and mild group (35 cases). The 30 healthy examinees were collected to control group. The serum levels of exosome miRNA-135-5p, AKT mRNA and mTOR mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR) and compared among 3 groups. The correlations of exosome miRNA-135-5p to serum AKT mRNA and mTOR mRNA were confirmed by Pearson linear correlation analysis. The risk factors of illness degree of children with viral myocarditis to the clinical indexes were confirmed by multivariate Logistic analysis. Follow-up 12 months, the diagnostic value of exosome miRNA-135-5p to the 12 months follow-up prognosis of the children with viral myocarditis were analyzed by receiver operating characteristic curves (ROC). Results: Compared to control group, the serum levels of exosome miRNA-135-5p in severe group and mild group were higher, and severe group higher than mild group(P<0.05). The serum levels of AKT, mTOR mRNA in severe group and mild group were lower than control group, and severe group lower than mild group (P<0.05). The negative correlations of exosome miRNA-135-5p to serum AKT mRNA and mTOR mRNA were confirmed by Pearson linear correlation analysis (P<0.05). Multivariate Logistic analysis showed that the serum levels of exosome miRNA-135-5p were independent risk factors to the 12 months follow-up prognosis of children with viral myocarditis, but the levels of AKT mRNA and mTOR mRNA were the protective factors (P<0.05). When the cut-off point of exosome miRNA-135-5p was 3.32, the AUC was 0.822 and the sensitivity was 86.3 % and specificity was 80.6 %. Conclusions: The serum levels of exosome miRNA-135-5p is the risk factor to the myocardial injury degree in children with viral myocarditis by inhibiting AKT/mTOR signal pathway, and can perfect assess the 6 months follow-up prognosis. [ABSTRACT FROM AUTHOR]

The article focuses on how adverse effect counting windows impact vaccine safety assessments in both observational studies and clinical trials of COVID‐19 vaccines. It highlights concerns about potential overstatement of vaccine safety due to limited counting windows, particularly regarding the risks of myocarditis associated with mRNA COVID-19 vaccines, which may not be adequately captured within the specified timeframes.

Background and Aims: We found a higher incidence of myocarditis in young males who had received at least two Pfizer‐BioNTech BNT162b2 vaccinations. The human leukocyte antigens (HLA) are known to play an important role in infectious and autoinflammatory diseases. We hypothesized that certain HLA alleles might be associated with vaccination‐induced myocarditis. Methods: HLA typing was performed using next‐generation sequencing technology with the Illumina Iseq100 platform. HLA class I and II loci were genotyped in 29 patients with post‐vaccination myocarditis and compared with HLA data from 300 healthy controls. Results: We demonstrate that the DRB1*14:01, DRB1*15:03 alleles and the motifs in HLA‐A − Leu62 and Gln63, which are part of binding pocket B and HLA‐DR Tyr47, His60, Arg70 and Glu74, which are part of binding pockets P4, P7 and P9, were significantly associated with disease susceptibility. Conclusions: Our findings suggest that immunogenetic fingerprints in HLA peptide‐binding grooves may affect the presentation of peptides derived from the Pfizer‐BioNTech BNT162b2 vaccination to T cells and induce an inflammatory process that results in myocarditis. [ABSTRACT FROM AUTHOR]

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

Multisystem Inflammatory Syndrome in Children (MIS-C) often involves a post-viral myocarditis and associated left ventricular dysfunction. We aimed to assess myocardial function by strain echocardiography after hospital discharge and to identify risk factors for subacute myocardial dysfunction. We conducted a retrospective single-center study of MIS-C patients admitted between 03/2020 and 03/2021. Global longitudinal strain (GLS), 4-chamber longitudinal strain (4C-LS), mid-ventricular circumferential strain (CS), and left atrial strain (LAS) were measured on echocardiograms performed 3–10 weeks after discharge and compared with controls. Among 60 MIS-C patients, hypotension (65%), ICU admission (57%), and vasopressor support (45%) were common, with no mortality. LVEF was abnormal (< 55%) in 29% during hospitalization but only 4% at follow-up. Follow-up strain abnormalities were prevalent (GLS abnormal in 13%, 4C-LS in 18%, CS in 16%, LAS in 5%). Hypotension, ICU admission, ICU and hospital length of stay, and any LVEF < 55% during hospitalization were factors associated with lower strain at follow-up. Higher peak C-reactive protein (CRP) was associated with hypotension, ICU admission, total ICU days, and with lower follow-up GLS (r = − 0.55; p = 0.01) and CS (r = 0.41; p = 0.02). Peak CRP < 18 mg/dL had negative predictive values of 100% and 88% for normal follow-up GLS and CS, respectively. A subset of MIS-C patients demonstrate subclinical systolic and diastolic function abnormalities at subacute follow-up. Peak CRP during hospitalization may be a useful marker for outpatient cardiac risk stratification. MIS-C patients with hypotension, ICU admission, any LVEF < 55% during hospitalization, or a peak CRP > 18 mg/dL may warrant closer monitoring than those without these risk factors. [ABSTRACT FROM AUTHOR]

Background: Severe myocarditis is often accompanied by cardiac fibrosis, but the underlying mechanism has not been fully elucidated. CXCL4 is a chemokine that has been reported to have pro‐inflammatory and profibrotic functions. The exact role of CXCL4 in cardiac fibrosis remains unclear. Methods: Viral myocarditis (VMC) models were induced by intraperitoneal injection of Coxsackie B Type 3 (CVB3). In vivo, CVB3 (100 TCID50) and CVB3‐AMG487 (CVB3: 100 TCID50; AMG487: 5 mg/kg) combination were administered in the VMC and VMC+AMG487 groups, respectively. Hematoxylin and eosin staining, severity score, Masson staining, and immunofluorescence staining were performed to measure myocardial morphology in VMC. Enzyme‐linked immunosorbent assay (ELISA) and quantitative reverse transcription polymerase chain reaction (qRT‐PCR) were performed to quantify inflammatory factors (IL‐1β, IL‐6, TNF‐α, and CXCL4). Aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine kinase‐myocardial band (CK‐MB) levels were analyzed by commercial kits. CXCL4, CXCR3B, α‐SMA, TGF‐β1, Collagen I, and Collagen III were determined by Western blot and immunofluorescence staining. Results: In vivo, CVB3‐AMG487 reduced cardiac injury, α‐SMA, Collagen I and Collagen III levels, and collagen deposition in VMC+AMG487 group. Additionally, compared with VMC group, VMC+AMG group decreased the levels of inflammatory factors (IL‐1β, IL‐6, and TNF‐α). In vitro, CXCL4/CXCR3B axis activation TGF‐β1/Smad2/3 pathway promote mice cardiac fibroblasts differentiation. Conclusion: CXCL4 acts as a profibrotic factor in TGF‐β1/Smad2/3 pathway‐induced cardiac fibroblast activation and ECM synthesis, and eventually progresses to cardiac fibrosis. Therefore, our findings revealed the role of CXCL4 in VMC and unveiled its underlying mechanism. CXCL4 appears to be a potential target for the treatment of VMC. [ABSTRACT FROM AUTHOR]

Background and purpose: Outcomes for cancer patients with steroid-resistant immune checkpoint inhibitorassociated myocarditis (srICIAM) are poor. Intensified immunosuppressive therapies, including tofacitinib, a novel Janus kinase (JAK) inhibitor, may have some therapeutic benefits. However, due to the lack of sufficient clinical data, the effectiveness of such treatments and their impact on cardiovascular outcomes remain unclear. This study aimed to investigate the therapeutic effect of tofacitinib on srICIAM. Methods: This retrospective case-control study included 36 malignant tumor patients who received immune checkpoint inhibitor treatment at Zhongshan Hospital affiliated to Fudan University from July 2019 to May 2022 and developed srICIAM. Patients receiving corticosteroids in combination with tofacitinib were assigned to the tofacitinib group (n=19), while those not treated with tofacitinib were allocated to the control group (n=17). The study compared clinical characteristics, laboratory findings, and imaging results between the two groups. Additionally, follow-up was conducted to monitor the incidence of cardiovascular endpoints in these patients. The research plan was approved by the Ethics Committee of Zhongshan Hospital Affiliated to Fudan University (Approval Number: B2021-275R). This study was conducted in accordance with the ethical guidelines of the Helsinki Declaration. Results: Compared to the control group, and with no significant difference in the cumulative dose and duration of corticosteroids (P＜0.05), the tofacitinib group showed a shorter myocarditis recovery time (median recovery time: 86.5 days vs 126.5 days, P=0.021). The myocarditis-related mortality rate was significantly lower in the tofacitinib group than in the control group (5% vs 35%, P=0.025). Conclusion: Tofacitinib may reduce mortality and promote cardiac recovery in srICIAM patients without impeding the anti-tumor effect. It may become one of the potential treatment strategies in the future. [ABSTRACT FROM AUTHOR]

Introduction: Rare myocarditis and pericarditis cases have occurred in coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccine recipients. Troponin levels, a potential marker of myocardial injury, were assessed in healthy participants before and after BNT162b2 vaccination. Methods: Vaccine-experienced 12- to 30-year-olds in phase 3 crossover C4591031 Substudy B (NCT04955626) who had two or three prior BNT162b2 30-μg doses were randomized to receive BNT162b2 30 μg followed by placebo, or placebo followed by BNT162b2 30 µg, 1 month apart. A participant subset, previously unvaccinated against COVID-19, in the phase 3 C4591007 study (NCT04816643) received up to three vaccinations (BNT162b2 10 μg or placebo [5- to 11-year-olds]) or open-label BNT162b2 30 μg (12- to 15-year-olds). Blood samples collected pre-vaccination, 4 days post-vaccination, and 1-month post-vaccination (C4591031 Substudy B only) were analyzed. Frequencies of elevated troponin I levels (male, > 35 ng/l; female, > 17 ng/l) were assessed. Results: Percentages of 12- to 30-year-olds (n = 1485) in C4591031 Substudy B with elevated troponin levels following BNT162b2 or placebo receipt were 0.5% and 0.8% before vaccination, 0.7% and 1.0% at day 4, and 0.7% and 0.5% at 1 month, respectively. In Study C4591007 (n = 1265), elevated troponin I levels were observed in 0.2, 0.4, and 0.2% of 5- to 11-year-old BNT162b2 recipients at baseline and 4 days post-dose 2 and 3, respectively; corresponding values in 12- to 15-year-olds were 0.4, 0.4, and 0.7%. No 5- to 11-year-old placebo recipients had elevated troponin levels. No myocarditis or pericarditis cases or deaths were reported. Conclusions: Among 5- to < 30-year-olds in both studies, troponin levels were rarely elevated (≤ 1.0%) and similar before and post-vaccination; troponin levels were also similar between BNT162b2 and placebo in 12- to 30-year-old and 5- to 11-year-old recipients in the respective studies. No myocarditis or pericarditis cases were reported. These findings did not provide evidence that BNT162b2 causes troponin elevations. No utility of routine measurement of troponin levels in asymptomatic BNT162b2 recipients was identified. [ABSTRACT FROM AUTHOR]

Introduction: Immune checkpoint inhibitors can cause immune-related toxicity in various systems, with myocarditis being the most severe and life-threatening manifestation. This report presents a case in which myocarditis developed following administration of programmed cell death protein-1 (PD-1) inhibitors therapy. We describe the diagnosis and treatment of this patient in detail. Case report: We present the case of a 59-year-old female diagnosed with post-operative esophageal cancer and hepatic metastases. The patient underwent second-line treatment with domestically-made PD-1 inhibitor, camrelizumab, in combination with paclitaxel (albumin-bound) and carboplatin for two cycles. During the course of treatment, an electrocardiogram (ECG) revealed ST segment elevation in leads II, III, aVF, V2, V3, and V4, along with T wave changes in leads I and aVL. Laboratory examinations showed abnormal levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT). Despite the absence of clinical symptoms, the patient was routinely hospitalized three weeks later. Based on the findings from the ECG, cardiac biomarkers, echocardiography, echocardiogram, cardiac magnetic resonance, and angiography, she was diagnosed with immune-checkpoint-inhibitors-related myocarditis. Management and outcome: The patient received immunoglobulin (0.5 g/kg/day) and was initially given methylprednisolone (1000 mg/day). Methylprednisolone was gradually reduced to 40 mg/day in 2 weeks. During this time, the levels of biomarkers indicative of myocardial injury also exhibited a simultaneous decline. Discussion: This case highlights the importance of early detection and prompt intervention, including initiating appropriate steroid therapy and discontinuing of immune checkpoint inhibitors. Such measures can effectively prevent morbidity and mortality, ultimately leading to an improved prognosis. [ABSTRACT FROM AUTHOR]

Background: Immune checkpoint inhibitors (ICIs) are reshaping the prognosis of many cancers, but often cause immune-related adverse events (irAEs). Among neurological irAEs, myositis is the most frequently reported. Our aim is to describe clinical and non-clinical characteristics, treatment and outcome of all irMyositis (skeletal limb-girdle and/or ocular myositis) and irMyocarditis cases in our reference center. Methods: We retrospectively enrolled all irMyositis/irMyocarditis patients seen between 2018 and 2022. We reviewed demographics, clinical characteristics, biological, neurophysiological, imaging workup, treatment and outcome. Results: We included 14 consecutive patients. The most frequent treatments were pembrolizumab (35%) or ipilimumab–nivolumab combination (35%). Limb-girdle, ocular (non-fluctuating palpebral ptosis and/or diplopia with or without ophthalmoparesis) and cardiac phenotypes were equally distributed, overlapping in 40% of cases. Ocular involvement was frequently misdiagnosed; review of brain MRIs disclosed initially missed signs of skeletal myositis in one patient and ocular myositis in 3. Seven patients had other co-existing irAEs. When performed, myography showed a myogenic pattern. CK was elevated in 8/15 patients, troponin-T in 12/12 and troponin-I in 7/9 tested patients. ICI were discontinued in all cases, with further immunosuppressive treatment in nine patients. In most cases, neurological and cardiological outcome was good at last follow-up. Conclusion: Myositis is a potentially severe irAE. Despite its heterogeneous presentation, some highly suggestive clinical symptoms, such as ocular involvement, or radiological signs should raise physicians' attention to avoid misdiagnosis. We thus recommend a multidisciplinary assessment (including complete neuromuscular evaluation) even in case of isolated myocarditis. Our series underlines the importance of an early diagnosis, since suspension of ICI and adequate treatment are usually associated with good functional outcome. [ABSTRACT FROM AUTHOR]