Cardiotropic Viruses Research Articles

High prevalence of cardiotropic viruses in endomyocardial biopsies from patients with inflammatory cardiomyopathy demonstrated by a novel targeted NGS approach

Abstract Background Viral infection of the heart muscle is a common cause of myocarditis and viral persistence can lead to chronic inflammatory cardiomyopathies (DCMi). A number of viruses including parvovirus B19 (B19V), adenovirus (AdV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes virus 6 (HHV-6) and enteroviruses (EV) are known to infect the myocardium, but their prevalence and role in persisting DCMi are not well understood. Virological etiologies can only be determined via endomyocardial biopsy (EMB), but the low tissue amount limits the number of conventional viral nucleic acid tests (virus-specific PCR) that can be performed in parallel. This study aimed to detect known and novel cardiotropic viruses in EMB of DCMi patients using a targeted next generation sequencing (NGS) approach. Methods A cohort of 33 patients with inflammatory cardiomyopathy (DCMi) (LVEF=29±12%) were retrospectively analyzed and compared to previous results of virus-specific PCR. DNA and RNA extracted from EMB were used for sequencing library preparation, and viral nucleic acids were enriched via a custom myBaits hybridization capture approach. Enriched libraries were sequenced on an Illumina MiSeq-platform in paired-end mode (500.000 reads/sample), and reads were taxonomically classified via Kraken2 and mapped against viral reference genomes using BWA-MEM2 or HiSat2, and subsequently deduplicated. Viral reads detected via both Kraken2 and mapping were classified as valid. Results Targeted NGS confirmed 19 out of 22 (86%) of the previous PCR-based viral detections. However, NGS was able to detect B19V DNA and RNA in an additional 11 and 15 patient samples respectively; CMV DNA/RNA in additional 5 and 4 samples respectively; EBV DNA/RNA in additional 5 and 1 samples respectively; and HHV-6 DNA/RNA in additional 3 and 1 samples respectively. Furthermore, viral reads of adenovirus type 2, adenovirus-associated virus type 2 (AAV-2), herpes viruses 7 and 8, and human parvovirus 4 were also found among the cohort. Thus, targeted NGS was able to identify 82 viral infections in a cohort of 33 DCMi patients, while only 22 were found using routine PCR tests. For routinely tested B19V, the use of the new NGS diagnostic approach improved sensitivity by 42% and specificity by 72%. Conclusions The presented NGS method represents a powerful new tool for the diagnosis of viral and inflammatory heart disease. The sensitivity is significantly higher than with conventional PCR approaches and the taxonomic classification is more specific. This enables the detection of previously false-negative routine viruses as well as potentially new cardiotropic pathogens from limited bioptic patient material – thus significantly increasing the diagnostic yield of EMB. In addition, our study demonstrates a high prevalence of non-enteroviral cardiotropic viruses in DCMi patients, shedding new light on the etiology of this heterogenous diseases and paving the way for more specific future treatments.

Cardiomyocyte regeneration in human myocarditis

Abstract Background Newly generated cardiomyocytes (NGC) concur to recovery of human myocarditis. Purpose describe NGC’s contribute with age and their modality of myocardial homing and integration. Methods We retrospectively assessed NGC in 213 consecutive patients with endomyocardial biopsy diagnostic for myocarditis, normal coronaries and valves. Tissue samples were processed for histology and immune-histochemistry for CD3+ T lymphocytes, alpha-sarcomeric-actin, junctional connexin-43, Ki-67, phosphorylated STAT3 (p-STAT3) and Western Blot (WB) for HMGB1. Frozen samples were analyzed with polymerase chain reaction (PCR) for cardiotropic viruses. Controls included 20 normal surgical biopsies. NGC were defined as small myocytes (diameter < 10 µ) with nuclear positivity to Ki-67 and p-STAT3, positive immunostaining for cytoplasmic alpha-sarcomeric-actin and connexin 43. Their number/mm2, relation with age and pathway of integration were evaluated. Results PCR was positive for viral genomes in 16% of cases. NGC mean diameter was 6.6 ± 3.34 vs 22.5 ± 3.11 µm adult cells; their number, in comparable LVEF, was 86.3 ± 10.3/mm2 in patients between 10 and 40 years; 50.4 ±13.8/mm2 in those between 41 and 60; 15.1 ± 5.7/ mm2 in those between 61 and 80; control NGC were 0.2± 0.2/mm2 ; NGC were no statistically different in viral and non-viral myocarditis. HMGB1 and STAT-3 were remarkably higher than controls. NGC crossed the membrane and grew integrated within the empty necrotic myocytes. Conclusions NGCs are constantly recognizable in acute human myocarditis. Their number declines with age. Their integration within necrotic myocytes consents preservation of cardiac structure and function.

Post-COVID Myocarditis in Patients with Primary Cardiomyopathies: Diagnosis, Clinical Course and Outcomes.

The aim of this study was to evaluate the clinical course and outcomes of post-COVID myocarditis in patients with cardiomyopathies (CMP). This case series includes 10 patients with different CMPs who had COVID-19 (seven men; 48.4 ± 11.4 yr.): left ventricular non-compaction (n = 2), arrhythmogenic right ventricular CMP in combination with a heterozygous form of hemochromatosis (n = 1, HFE), restrictive CMP (n = 1, MyBPC3), laminopathy (n = 1, LMNA), dilated cardiomyopathy (n = 1, MYH7 + MyBPC3), Danon's disease (n = 1, LAMP2) and AL cardiac amyloidosis (n = 3). Myocardial morphological examination with immunohistochemical staining and PCR for SARS-CoV-2 and cardiotropic viruses was performed in six patients, while cardiac MRI and anti-cardiac antibody titres were evaluated in all patients. Post-COVID lymphocytic myocarditis was confirmed morphologically in six patients (with LVNC, RCM, ARCV, Danon's disease, and AL amyloidosis). Spike and nucleocapsid coronavirus proteins were detected in cell infiltrates, endothelium and cardiomyocytes in all biopsies; SARS-CoV-2 RNA was found in five out of six. In four patients, the diagnosis of myocarditis was based on MRI, high titres of anti-cardiac antibodies and clinical data. The mean time from COVID-19 to the diagnosis of myocarditis was 7 (5; 10.5) months. Myocarditis manifested with the onset/increase of arrhythmias and heart failure. Immunosuppressive therapy with corticosteroids was administered to six patients and led to an increase in ejection fraction and improvement of heart failure symptoms in five of them. CMPs are a favourable background for the development of post-COVID myocarditis. The onset or deterioration of heart failure and/or arrhythmias in patients with CMPs after COVID-19 requires the exclusion of myocarditis and, if present, the administration of immunosuppressive therapy.

Cardiomyocyte Regeneration in Human Myocarditis.

Newly generated cardiomyocytes (NGCs) concur with the recovery of human myocarditis occurring spontaneously in around 50% of cases. However, NGCs decline with age, and their modality of myocardial homing and integration are still unclear. We retrospectively assessed NGCs in 213 consecutive patients with endomyocardial biopsy denoting acute myocarditis, with normal coronaries and valves. Tissue samples were processed for histology (H&E), immunohistochemistry for the evaluation of inflammatory infiltrates, immunostaining for alpha-sarcomeric-actin, junctional connexin-43, Ki-67, and phosphorylated STAT3 (p-STAT3), and Western blot (WB) for HMGB1. Frozen samples were analyzed using polymerase chain reaction (PCR) for cardiotropic viruses. Controls included 20 normal surgical biopsies. NGCs were defined as small myocytes (diameter < 10 µm) with nuclear positivity to Ki-67 and p-STAT3 and positive immunostaining for cytoplasmic α-sarcomeric actin and connexin-43. Their number/mm2 in relation to age and pathway of integration was evaluated. NGCs crossed the membrane and grew integrated within the empty necrotic myocytes. NGC mean diameter was 6.6 ± 3.34 vs. 22.5 ± 3.11 µm adult cells; their number, in comparison to LVEF, was 86.3 ± 10.3/mm2 in patients between 18 and 40 years, 50.4 ± 13.8/mm2 in those between 41 and 60, and 15.1 ± 5.7/mm2 in those between 61 and 80. Control NGCs' mean diameter was 0.2 ± 0.2 mm2. PCR was positive for viral genomes in 16% of cases; NGCs were not statistically different in viral and non-viral myocarditis. WB analysis revealed a higher expression of HMGB1 in myocarditis compared to myocardial controls. NGCs are constantly recognizable in acute human myocarditis. Their number declines with age. Their integration within necrotic myocytes allows for the preservation of the cardiac structure and function.

Abstract We119: Treatment of Viral Myocarditis by Targeting the TRIM29-PERK Axis-Mediated ER Stress Immune Response

Viral myocarditis, an inflammatory disease of the myocardium, is a significant cause of sudden death in children and young adults. The current coronavirus disease 19 pandemic emphasizes the need to understand the pathogenesis mechanisms and potential treatment strategies for viral myocarditis. Here, we found that TRIM29 was highly induced by cardiotropic viruses and promoted protein kinase RNA-like endoplasmic reticulum kinase (PERK)-mediated endoplasmic reticulum (ER) stress, apoptosis, and reactive oxygen species (ROS) responses that promote viral replication in cardiomyocytes in vitro . TRIM29 deficiency protected mice from viral myocarditis by promoting cardiac antiviral functions and reducing PERK-mediated inflammation and immunosuppressive monocytic myeloid-derived suppressor cells (mMDSC) in vivo . Mechanistically, TRIM29 interacted with PERK to promote SUMOylation of PERK to maintain its stability, thereby promoting PERK-mediated signaling pathways. Finally, we demonstrated that the PERK inhibitor GSK2656157 mitigated viral myocarditis by disrupting the TRIM29-PERK connection, thereby bolstering cardiac function, enhancing cardiac antiviral responses, and curbing inflammation and immunosuppressive mMDSC in vivo . Our findings offer insight into how cardiotropic viruses exploit TRIM29-regulated PERK signaling pathways to instigate viral myocarditis, suggesting that targeting the TRIM29-PERK axis could mitigate disease severity.

Increased expression of human endogenous retrovirus K in endomyocardial biopsies from patients with cardiomyopathy – a transcriptomics meta-analysis

Most studied, investigating transcriptional changes in myocardial biopsies focus on human genes. However, the presence and potential consequence of persistent expression of viral genes within the myocardium is unclear. The aim of the study was to analyze viral gene expression in RNAseq data from endomyocardial biopsies. The NCBI Bioproject library was screened for published projects that included bulk RNA sequencing data from endomyocardial biopsies from both healthy and diseased patients with a sample size greater than 20. Diseased patients with hypertrophic, dilated, and ischemic cardiomyopathies were included. A total of 507 patients with 507 samples from 6 bioprojects were included and mapped to the human genome (hg38). Unmappable sequences were extracted and mapped to an artificial ‘super-virus’ genome comprising 12,182 curated viral reference genomes. Subsequently, the sequences were reiteratively permutated and mapped again to account for randomness. In total, sequences from 68 distinct viruses were found, all of which were potentially human pathogenic. No increase in cardiotropic viruses was found in patients with dilated cardiomyopathy. However, the expression levels of the particle forming human endogenous retrovirus K were significantly increased (q < 0.0003, ANOVA). Higher expression levels were associated with increased expression in mitochondrial pathways such as oxidative phosphorylation (p < 0.0001). In Conclusion, expression of human endogenous retrovirus K is significantly increased in patients with dilated cardiomyopathy, which in turn was associated with transcriptional alterations in major cellular pathways.

Viral myocarditis in combination with genetic cardiomyopathy as a cause of sudden death. An autopsy series

Sudden cardiac death (SCD) is a major public health issue worldwide. In the young (< 40 years of age), genetic cardiomyopathies and viral myocarditis, sometimes in combination, are the most frequent, but underestimated, causes of SCD. Molecular autopsy is essential for prevention. Several studies have shown an association between genetic cardiomyopathies and viral myocarditis, which is probably underestimated due to insufficient post-mortem investigations. We report on four autopsy cases illustrating the pathogenesis of these combined pathologies. In two cases, a genetic hypertrophic cardiomyopathy was diagnosed in combination with Herpes Virus Type 6 (HHV6) and/or Parvovirus-B19 (PVB19) in the heart. In the third case, autopsy revealed a dilated cardiomyopathy and virological analyses revealed acute myocarditis caused by three viruses: PVB19, HHV6 and Epstein-Barr virus. Genetic analyses revealed a mutation in the gene coding for desmin. The fourth case illustrated a channelopathy and a PVB19/HHV6 coinfection. Our four cases illustrate the highly probable deleterious role of cardiotropic viruses in the occurrence of SCD in subjects with genetic cardiomyopathies. We discuss the pathogenetic link between viral myocarditis and genetic cardiomyopathy. Molecular autopsy is essential in prevention of these SCD, and a close collaboration between cardiologists, pathologists, microbiologists and geneticians is mandatory.

FULMINANT EOSINOPHILIC MYOCARDITIS TREATED WITH STEROIDS AND INTRA–AORTIC BALLOON PUMP

Abstract Background Hypereosinophilic syndrome (HES) is a hematological disorders characterized by a chronic, unexplained hypereosinophilia (HE) with tissue damage. Cardiac involvement occurs in ∼20% of patients with HES and it carries a poor prognosis.Early detection and treatment of myocardial involvement improves prognosis. Immunosuppressive therapy represents the core treatment in the majority of patients with Eosinophilic Myocarditis. Case Summary 50–year–old man with history of intrinsic asthma and HE was admitted for cardiogenic shock B stage according SCAI classification (heart rate was 130 bpm, systolic blood pressure was 90 mmHg and lactate &amp;lt;2). EKG showed sinus tachycardia and diffuse ST segment depression. Echocardiography revealed severe left ventricular systolic dysfunction and mild pericardial effusion. Blood test showed leukocytosis (33x10^9/L) with HE (47%), mild hepato–renal damage, high TroponinT 3874 pg/mL and NT–proBNP 11060 ng/L. Coronary angiography was unremarkable. Pulmonary artery catheter was placed: IC 1,78 l/min/mq, CPO 0,63, WP 21, SVO2 60%, SVR 17 WU, RAP/WP 0.74. We reclassified patients as SCAI C with “mixed shock” due to inflammatory component and latent right ventricular dysfunction. Intra–aortic balloon pump (IABP) was placed and we performed endomyocardial biopsy (EMB). High dose of intra venous corticosteroids was started obtaining progressive improvement of hemodynamic parameters and reduction of inflammation parameters (Fig.1). EMB confirmed the diagnosis of myocarditis with initial transition into ‘’Loffler’s cardiomyopathy’’. Polymerase chain reaction (PCR) analysis did not detect cardiotropic viruses. After improvement of clinical status we performed cardiac MRI that revealed diffuse biventricular myocardial edema and the presence of subepicardial and mid–wall enhancement with non ischemic pattern,endocardial fibrosis and multiple left ventricular thrombi (Fig. 2). β–blockers and angiotensin–converting enzyme inhibitors were started and the patient was discharged at home with a complete myocardial recovery and immunosuppressive therapy based on corticosteroids and azathioprine. Discussion This case demonstrates the usefulness of myocardial biopsy in fulminant myocarditis. Treatment with corticosteroids resulted in rapid improvement. Early invasive monitoring allowed more precise hemodynamic characterization and mechanical circulatory support with IABP proved feasible and might have helped by unloading the left ventricle.

Loss of TRIM29 mitigates viral myocarditis by attenuating PERK-driven ER stress response in male mice

Viral myocarditis, an inflammatory disease of the myocardium, is a significant cause of sudden death in children and young adults. The current coronavirus disease 19 pandemic emphasizes the need to understand the pathogenesis mechanisms and potential treatment strategies for viral myocarditis. Here, we found that TRIM29 was highly induced by cardiotropic viruses and promoted protein kinase RNA-like endoplasmic reticulum kinase (PERK)-mediated endoplasmic reticulum (ER) stress, apoptosis, and reactive oxygen species (ROS) responses that promote viral replication in cardiomyocytes in vitro. TRIM29 deficiency protected mice from viral myocarditis by promoting cardiac antiviral functions and reducing PERK-mediated inflammation and immunosuppressive monocytic myeloid-derived suppressor cells (mMDSC) in vivo. Mechanistically, TRIM29 interacted with PERK to promote SUMOylation of PERK to maintain its stability, thereby promoting PERK-mediated signaling pathways. Finally, we demonstrated that the PERK inhibitor GSK2656157 mitigated viral myocarditis by disrupting the TRIM29-PERK connection, thereby bolstering cardiac function, enhancing cardiac antiviral responses, and curbing inflammation and immunosuppressive mMDSC in vivo. Our findings offer insight into how cardiotropic viruses exploit TRIM29-regulated PERK signaling pathways to instigate viral myocarditis, suggesting that targeting the TRIM29-PERK axis could mitigate disease severity.

Acute myocarditis: an overview of pathogenesis, diagnosis and management.

Acute myocarditis encompasses a diverse presentation of inflammatory cardiomyopathies with infectious and non-infectious triggers. The clinical presentation is heterogeneous, from subtle symptoms like mild chest pain to life-threatening fulminant heart failure requiring urgent advanced hemodynamic support. This review provides a comprehensive overview of the current state of knowledge regarding the pathogenesis, diagnostic approach, management strategies, and directions for future research in acute myocarditis. The pathogenesis of myocarditis involves interplay between the inciting factors and the subsequent host immune response. Infectious causes, especially cardiotropic viruses, are the most frequently identified precipitants. However, autoimmune processes independent of microbial triggers, as well as toxic myocardial injury from drugs, chemicals or metabolic derangements also contribute to the development of myocarditis through diverse mechanisms. Furthermore, medications like immune checkpoint inhibitor therapies are increasingly recognized as causes of myocarditis. Elucidating the nuances of viral, autoimmune, hypersensitivity, and toxic subtypes of myocarditis is key to guiding appropriate therapy. The heterogeneous clinical presentation coupled with non-specific symptoms creates diagnostic challenges. A multifaceted approach is required, incorporating clinical evaluation, electrocardiography, biomarkers, imaging studies, and endomyocardial biopsy. Cardiovascular magnetic resonance imaging has become pivotal for non-invasive assessment of myocardial inflammation and fibrosis. However, biopsy remains the gold standard for histological classification and definitively establishing the underlying etiology. Management relies on supportive care, while disease-specific therapies are limited. Although some patients recover well with conservative measures, severe or fulminant myocarditis necessitates aggressive interventions such as mechanical circulatory support devices and transplantation. While immunosuppression is beneficial in certain histological subtypes, clear evidence supporting antiviral or immunomodulatory therapies for the majority of acute viral myocarditis cases remains insufficient. Substantial knowledge gaps persist regarding validated diagnostic biomarkers, optimal imaging surveillance strategies, evidence-based medical therapies, and risk stratification schema. A deeper understanding of the immunopathological mechanisms, rigorous clinical trials of targeted therapies, and longitudinal outcome studies are imperative to advance management and improve the prognosis across the myocarditis spectrum.

Interleukin 17A-correlated myocarditis in patients with psoriasis: cardiac recovery following secukinumab administration

Abstract Background Psoriasis (PS) is a common immune-mediated disease of the skin with possible extension to joints, aorta and eye. Myocardial inflammation has been rarely suggested. Purpose Report of PS-related myocarditis. Methods One hundred consecutive patients with PS were screened for cardiac involvement. Among them, five male patients (aged 56 ± 9.5 years) with moderate-severe form showed a dilated cardiomyopathy (LVEF &amp;lt;35%) with normal coronary arteries and valves. They underwent a left ventricular endomyocardial biopsy for evaluation of myocardial substrate. Endomyocardial samples were processed for histology and immunohistochemistry, including myocardial expression of Toll-Like Receptor 4 (TLR4) and interleukin-17A (IL-17A), which plays a major role in psoriasis pathogenesis; real-time PCR for cardiotropic viruses and Western blot analysis for myocardial expression of IL-17A. Patients’ sera were tested for anti-heart autoantibodies. Results An active lymphocytic myocarditis was revealed in all 5 patients, characterized by absence of viral genomes at PCR, positive anti-heart autoantibodies, overexpression of TLR-4 and enhancement of IL-17-A at western blot analysis showing a 2,48-fold increase in psoriatic myocarditis compared with no psoriatic myocarditis and a 6-fold increase compared to myocardial controls. Treatment included combination of prednisone (1 mg/Kg daily for 4 weeks, tapered to 0.33 mg/Kg) + azathioprine (2 mg/Kg, daily) in 3 pts or secukinumab (SK, 100 mg/monthly) in 2 pts for 6 months. LVEDD and LVEF improved in the first 3 pts (-14% and + 118%, respectively) while completely recovered (LVEF&amp;gt; 50%) in the last 2 pts on SK. Conclusion IL-17A-related myocarditis can occur in up-to 5% of patients with psoriasis. It manifests as a progressive dilated cardiomyopathy. It may completely recover following SK administration. Figure Legend Endomyocardial biopsy findings from pt 5 with PS-related myocarditis including histology (panel A). Immune-histochemistry for IL 17-A (panel B) and anti-heart abs (panels C, D). It shows an active lymphocytic myocarditis with overexpression of IL 17-A and positive anti-heart abs (panel C), cross-reacting with skeletal muscle (panel D).

Two Swords in the Storm: Parvovirus B19 and COVID-19 Clash in a Myocardial Mayhem of Arrhythmias

Myocarditis can be caused by a variety of infectious and non-infectious illnesses [1]. Although viral infection remains the most commonly identified cause of myocarditis, the role of parvovirus B19 (B19V) from the Erythrovirus genus in the pathogenesis of myocarditis has been identified as a potentially important contributor to myocarditis because of the high prevalence of Parvovirus B 19 (B19V) DNA in hearts of patients with myocarditis [2]. Co-infections of cardiotropic viruses are rarely reported and the mechanisms of viral interactions remain unknown [3]. In this report, we present a case of acute myocarditis in a young male, precipitated by a co-infection of Parvovirus B19 and COVID-19, characterized by fulminant progression and the development of multiple arrhythmias.

Abstract 13301: TRIM29 Causes Pathogenesis of Viral Myocarditis by Inducing PERK-Mediated Endoplasmic Reticulum Stress and Reactive Oxygen Species Responses

Introduction: Viral myocarditis is an inflammatory disease of the myocardium which contributes to a significant fraction of sudden death in children and young adults. The ongoing coronavirus disease 19 pandemic emphasizes the need for understanding the pathogenesis mechanisms and potential treatment strategies for viral myocarditis. Methods: To understand the role of the novel E3 ligase TRIM29 in controlling viral myocarditis, wild-type and TRIM29 knockout mice were infected with coxsackievirus B3 (CVB3) for inducing viral myocarditis. Mice survival and heart function were monitored by transthoracic echocardiography, and hearts were harvested for histology and immunohistochemistry analysis. Real-time PCR, western blotting, co-immunoprecipitation, enzyme-linked immunoassay, flow cytometry, over-expression and knockdown techniques were used to understand the pathogenic mechanisms of TRIM29 in regulating endoplasmic reticulum stress response after virus infection in this study. Results: We found that TRIM29 was highly induced by cardiotropic viruses, including CVB3 and encephalomyocarditis (EMCV), and promoted protein kinase RNA-like endoplasmic reticulum kinase (PERK) mediated endoplasmic reticulum (ER) stress, apoptosis, and reactive oxygen species (ROS) responses that restrict viral replication in cardiomyocytes in vitro . TRIM29 deficiency protected mice from viral myocarditis by promoting cardiac antiviral functions and reducing PERK-mediated inflammation and immunosuppressive cells in vivo . Mechanistically, TRIM29 interacted with PERK to catalyze SUMOylation of PERK for maintaining its stability, thereby promoting PERK-mediated signaling pathways. Conclusions: Our data provide the first evidence that TRIM29-mediated PERK signaling pathways cause pathogenesis of viral myocarditis and identify the TRIM29-PERK axis as a potential therapeutic target for treating viral induced cardiovascular diseases.

The knowns and unknowns of cardiac autoimmunity in viral myocarditis.

Myocarditis can result from various infectious and non-infectious causes that can lead to dilated cardiomyopathy (DCM) and heart failure. Among the infectious causes, viruses are commonly suspected. But the challenge is our inability to demonstrate infectious viral particles during clinical presentations, partly because by that point, the viruses would have damaged the tissues and be cleared by the immune system. Therefore, viral signatures such as viral nucleic acids and virus-reactive antibodies may be the only readouts pointing to viruses as potential primary triggers of DCM. Thus, it becomes hard to explain persistent inflammatory infiltrates that might occur in individuals affected with chronic myocarditis/DCM manifesting myocardial dysfunctions. In these circumstances, autoimmunity is suspected, and antibodies to various autoantigens have been demonstrated, suggesting that immune therapies to suppress the autoimmune responses may be necessary. From this perspective, we endeavoured to determine whether or not the known viral causes are associated with development of autoimmune responses to cardiac antigens that include both cardiotropic and non-cardiotropic viruses. If so, what their nature and significance are in developing chronic myocarditis resulting from viruses as primary triggers.

Abstract P3083: Trim29 Deficiency Ameliorates Viral Myocarditis By Reducing Perk Mediated Er Stress And Ros Responses

Infections by viruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could cause viral myocarditis. Endoplasmic reticulum (ER) stress is associated with several metabolic diseases such as cardiovascular disease, diabetes and cancer. However, the immune mechanisms of ER stress regulation in controlling the pathogenesis of viral myocarditis are unclear. Here, we found that knockdown or knockout of TRIM29 significantly inhibited PERK (Protein kinase RNA-like endoplasmic reticulum kinase) mediated ER stress and apoptosis induced by cardiotropic viruses CVB3 (coxsackievirus B3) or EMCV (encephalomyocarditis virus) in human and mouse cardiomyocytes. Additionally, TRIM29 deficiency relieved ROS (Reactive oxygen species) mediated STING (Stimulator of interferon genes) inhibition to produce more type I interferon for restricting cardiotropic viruses in cardiomyocytes. Importantly, cardiomyocytes specific TRIM29 deficiency exhibited dramatic protective effects on cardiac damage, cardiac dysfunction, viral replication and promoted survival in CVB3-induced viral myocarditis model in vivo . Mechanistically, TRIM29 was shown to interact with PERK and catalyze SUMOylation for maintaining its stability, thereby promoting PERK mediated ER stress and ROS responses to induce pathogenesis of viral myocarditis. Our results indicate that TRIM29 loss-of-function in cardiomyocytes ameliorates viral myocarditis by reducing PERK mediated ER stress response and unleashing ROS-suppressed interferon response. Our data suggest the TRIM29-PERK axis is a potential therapeutic target for viral myocarditis and other ER stress-associated cardiovascular disease.

Circulating Anti-GB3 Antibody as a Biomarker of Myocardial Inflammation in Patients with Fabry Disease Cardiomyopathy.

Fabry disease cardiomyopathy (FDCM) has manifested some resistance to enzyme replacement therapy (ERT), particularly in its advanced phase. Recently, myocardial inflammation of autoimmune origin has been demonstrated in FDCM. The objective of this study was the assessment of circulating anti-globotriaosylceramide (GB3) antibodies as potential biomarkers of myocardial inflammation in FDCM, defined by the additional presence of ≥CD3+ 7 T lymphocytes/low-power field associated with focal necrosis of adjacent myocytes. Its sensitivity was based on the evidence of overlapping myocarditis at left ventricular endomyocardial biopsy. From January 1996 to December 2021, 85 patients received a histological diagnosis of FDCM in our department and 48 (56.5%) of them had an overlapping myocardial inflammation with negative PCR for common cardiotropic viruses, positive antiheart, and antimyosin abs. The presence of anti-GB3 antibodies was evaluated with an in-house ELISA assay (BioGeM scarl Medical Investigational Research, MIR-Ariano Irpino, Italy), along with antiheart and antimyosin abs, in the FDCM patients and compared with control healthy individuals. The correlation between levels of circulating anti-GB3 autoantibody myocardial inflammation and FDCM severity was assessed. Anti-Gb3 antibodies were above the positivity cut-off in 87.5% of FDCM subjects with myocarditis (42 out of 48), while 81.1% of FDCM patients without myocarditis were identified as negative for Gb3 antibodies. Positive anti-Gb3 abs correlated with positive antiheart and antimyosin abs. The present study suggests a potential positive role of anti-GB3 antibodies as a marker of overlapping cardiac inflammation in patients with FDCM.

Interleukin-17A-Correlated Myocarditis in Patients with Psoriasis: Cardiac Recovery following Secukinumab Administration.

(1) Background: Psoriasis (PS) is a common immune-mediated disease of the skin with possible extension to joints, aorta and eye. Myocardial inflammation has rarely been suggested. (2) Aims: Report of PS-related myocarditis. (3) Methods and Results: One hundred consecutive patients with PS were screened for cardiac involvement. Among them, five male patients (aged 56 ± 9.5 years) with a moderate-severe form of PS showed dilated cardiomyopathy (LVEF < 35%) with normal coronary arteries and valves. They underwent a left-ventricular endomyocardial biopsy for evaluation of myocardial substrate. Endomyocardial samples were processed for histology and immunohistochemistry, including myocardial expression of Toll-Like Receptor 4 (TLR4) and interleukin-17A (IL-17A), which play a major role in PS pathogenesis. Real-time PCRs were carried out for cardiotropic viruses, and Western blot analysis was conducted for myocardial expression of IL-17A. Patients' sera were tested for anti-heart autoantibodies. Active lymphocytic myocarditis was revealed in all five patients, characterized by an absence of viral genomes with PCR, positive anti-heart autoantibodies, overexpression of TLR-4 and enhancement of IL-17-A during western blot analysis, showing a 2.48-fold increase in psoriatic myocarditis compared with no psoriatic myocarditis and a six-fold increase compared to myocardial controls. Treatment included combination of prednisone (1 mg/kg daily for 4 weeks, tapered to 0.33 mg/kg) and azathioprine (2 mg/kg, daily) in 3 pts or secukinumab (SK, 150 mg/weekly for 4 weeks followed by 150 mg/monthly) in 2 pts for 6 months. LVEDD and LVEF improved in the first 3 pts (-14% and + 118%, respectively), while they completely recovered (LVEF > 50%) in the last 2 pts on SK. (4) Conclusions: IL-17A-related myocarditis can occur in up to 5% of patients with PS. It manifests as progressive dilated cardiomyopathy. It may completely recover following SK administration.

Viral Heart Disease: Diagnosis, Management, and Mechanisms.

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

136 A SHOCKING CASE OF MYOCARDITIS?

Abstract Background Cardiac involvement is common in systemic sclerosis (SSc), being a poor prognostic factor and the leading cause of mortality. Cardiac involvement ranges from a serendipitous diagnosis to relevant cardiac manifestations such as arrhythmias, pericardial effusion, myocardial dysfunction, and valvular diseases. Case report A 39-year-old female without remarkable medical history, on estroprogestinic therapy was admitted to our hospital in June 2020 after an out-of-hospital cardiovascular arrest due to ventricular fibrillation (VF). A coronary angiography ruled out coronary artery disease. Magnetic resonance imaging (MRI) showed a picture of acute myopericarditis characterized by late linear and nodular intramyocardial and subepicardial gadolinium enhancement of the septal and inferior segments of the left ventricle, with trivial oedema in the same location in turbo inversion recovery magnitude (TIRM) sequences. A subcutaneous-implantable cardiac defibrillator (S-ICD) was positioned for secondary prevention. At the 5 months ICD interrogation, 3 episodes of VF detected and treated by the device were documented. In December 2020 two more appropriate device interventions on polymorphic VT/VF occurred. A septal myocardial biopsy was then performed showing diffused replacement fibrosis in the absence of signs of acute inflammation or virus on the molecular investigation. In March 2021 the patient was referred to our institution after experiencing several ventricular arrhythmia episodes successfully treated by the ICD. A myocardial positron emission tomography (PET) scan documented the uptake of 18-fluorodeoxyglucose at middle and basal septum. A 'targeted' myocardial biopsy showed a substitutive fibroadiposis with sporadic inflammatory cells, in absence of cardiotropic viruses on the molecular investigation. We then initiated Anakinra, an anti-IL1 agent with an anti-inflammatory effect to prevent further development of "inflammation-driven fibrosis". Given the Raynaud's phenomenon reported by the patient, a capillaroscopy was performed, confirming isolated megacapillaries and apical haemorrhages, compatible with early pattern scleroderma. Immunologic examinations found homogeneous ANA 1:320 and anti-RNA polymerase III, while other autoantibodies, viral serologies and tubercular analysis were negative. In October 2021, the patient was readmitted to our hospital for recurrence of arrhythmic storm. A radiofrequency catheter-based ablation was performed. After a new episode of VT properly treated by the S-ICD in May 2022, the device was explanted, and a cardiac resynchronization therapy defibrillator was implanted. The genetic analysis identified a heterozygous deletion (c1262_1263del) of Lamin A (LMNA) classified as probably pathogenic in left ventricular arrhythmogenic cardiomyopathy or dilated cardiomyopathy. Conclusion A diagnosis of borderline myocarditis in anti-RNA-polymerase III+ systemic sclerosis with heterozygous deletion of LMNA was finally formulated, after having excluded pulmonary (PET, forced vital capacity, and CO lung diffusion in normal range), cutaneous, musculoskeletal and gastro-oesophageal involvement as well as a paraneoplastic nature (by total body PET) given the positivity for antiRNA-polymerase III.

433 A PRO-ARRHYTHMIC DOUBLE HIT

Abstract A 42-year-old man went to the emergency room complaining about dyspnea and palpitations. He reported an episode of atrial fibrillation (AF) with symptoms of dizziness 8 years before. He had a family history of ischemic cardiopathy, his father has suffered from AF since a young age.Acute course: The ECG revealed AF at high ventricular frequency. The echocardiography demonstrated mild reduction of the left ventricular function (EF 45%) with diffuse hypokinesis, and mitral valve prolapse (MVP) with mild mitral regurgitation. The blood tests showed a troponin peak of 750 ng/L (n.v. 0–34 ng/L). The suspect was acute coronary syndrome. Thus, he was treated with dual antiplatet therapy and low doses of beta-blockers, and he underwent coronarography, which demonstrated no significant lesions. So, after a transesophageal echocardiography that excluded thrombosis, and a loading dose of amiodarone, a successful electrical cardioversion was performed. The discharge diagnosis was AF with mild left ventricular disfunction. Three months later: He came back to the emergency room because of suffering some days of progressive epigastric and retrosternal pain radiating to the shoulders. The ECG and the echocardiography were unchanged, the troponin-I values were 79 ng/L-74 ng/L. Therefore, he underwent cardiac magnetic resonance (CMR), which showed normal biventricular dimensions and function (LVEF 64%, LVEDV 80 ml/mq), MVP with mitral annular disjunction (MAD) and curling of the infero-lateral basal wall (Figure A). The native T1, T2 and ECV values were increased, and there was a wide left ventricular subepicardial late gadolinium enhancement (LGE). The conclusion was MVP and active myocarditis. Moreover, he underwent endomyocardial biopsy that revealed focal lymphocytic infiltration, PCRs for common cardiotropic viruses or bacteria were negative. Six months later: The basal ECG was characterized by low QRS voltages in limb leads (Figure B). The CMR revealed a wide left ventricular non-ischemic fibrosis with a ring-like pattern (Figure C). The 24-hours Holter ECG showed premature ventricular beats with a right bundle branch block/superior and inferior axis morphology (Figure D), in keeping with MVP. The next step was the genetic testing that resulted positive for a Filamin-C (FLNC) mutation associated with cardiomyopathy. The final diagnosis was “Hot-phase of Left Ventricular Arrhythmogenic Cardiomyopathy (ACM), MVP and paroxysmal AF”. Discussion: The ACM is a rare hereditary heart muscle disease, and the “hot phase” represents its uncommon clinical presentation. Mutations in FLNC gene could be involved in the pathogenesis of ACM. Moreover, there are few cases in literature about the correlation between FLNC mutations and MVP. FLNC mutation may be a cross-sectional substrate for both these pro-arrhythmic conditions.