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

A systematic review of cardiovascular toxicities induced by cancer immune therapies: Underlying mechanisms, clinical manifestations and therapeutic approaches

Immunotherapy has revolutionized the management of various types of cancers, even those previously deemed untreatable. Nonetheless, these medications have been associated with inflammation and damage across various organs. These challenges are exemplified by the adverse cardiovascular impacts of cancer immunotherapy, which need comprehensive understanding, clarification, and management integrated into the overall care of cancer patients. Numerous anticancer immunotherapies have been linked to the prevalence and severity of cardiovascular toxicity. These challenges emphasize the importance of conducting fundamental and applied research to elucidate disease causes, discover prognostic indicators, enhance diagnostic methods, and create successful therapies. Despite the acknowledged importance of T cells, there remains a knowledge gap regarding the inciting antigens, the reasons for their recognition, and the mechanisms of how they contribute to cardiac cell injury. In this review, we summarize the molecular mechanism, epidemiology, diagnosis, pathophysiology and corresponding treatment of cardiovascular toxicity induced by immunotherapy, including immune checkpoint inhibitors (ICIs), adoptive cell therapies (ACT), and bi-specific T-cell engagers (BiTEs) among others. By elucidating these aspects, we aim to provide a better understanding of immunotherapies in cancer treatment and offer guidance for their clinical application.

Immunoglobin attenuates fulminant myocarditis by inhibiting overactivated innate immune response

BACKGROUND AND PURPOSE

Fulminant myocarditis (FM) is a myocardial inflammatory disease that can result from either viral diseases or autoimmune diseases. In this study, we have determined the treatment effects of immunomodulatory drugs on FM.

EXPERIMENTAL APPROACH

FM was induced in A/JGpt mice by intraperitoneal administration of coxsackievirus B3, after which immunoglobins were administered daily by intraperitoneal injection. On the seventh day, the cardiac structure and function were determined using echocardiography and cardiac catheterisation. Single-cell RNA sequencing (scRNA-seq) was performed to evaluate CD45+ cells in the heart.

KEY RESULTS

Immunoglobin, a typical immunomodulatory drug, dramatically reduced mortality and significantly improved cardiac function in mice with FM. ScRNA-seq revealed that immunoglobin treatment effectively modulated cardiac immune homeostasis, particularly by attenuating overactivated innate immune responses. At the cellular level, immunoglobin predominantly targeted Plac8+ monocytes and S100a8+ neutrophils, suppressing their proinflammatory activities, and enhancing antigen processing and presentation capabilities, thereby amplifying the efficiency and potency of the immune response against the virus. Immunoglobin benefits are mediated by the modulation of multiple signalling pathways, including relevant receptors on immune cells, direction of inflammatory cell chemotaxis, antigen presentation and anti-viral effects. Subsequently, Bst2-ILT7 ligand-receptor-mediated cellular interactions manipulated by immunoglobin were further confirmed in vivo.

CONCLUSIONS AND IMPLICATIONS

Immunoglobin treatment significantly attenuated FM-induced cardiac inflammation and improved cardiac function by inhibiting overactivated innate immune responses.

Return-to-Play Post-Myocarditis for Athletes: To Play or Not to Play?

Myocarditis is a condition marked by inflammation of the heart muscle, which can lead to serious outcomes such as sudden cardiac death (SCD) and life-threatening arrhythmias. While myocarditis can affect any population, athletes, especially those engaged in high-intensity training, are at increased risk due to factors such as reduced immunity and increased exposure to pathogens. This review examines the clinical presentation, current guidelines, diagnostic challenges, and the significance of cardiac magnetic resonance imaging (CMR) in detecting myocardial inflammation and scarring. Current guidelines recommend a period of exercise restriction followed by thorough reassessment before athletes can return-to-play (RTP). However, there are several knowledge gaps, including the implications of persistent late gadolinium enhancement (LGE) on CMR and the optimal duration of exercise restriction. Additionally, the psychological impact of myocarditis on athletes highlights the importance of incorporating mental health support in the recovery process. A shared decision-making approach should be encouraged in RTP, considering the athlete's overall health, personal preferences, and the potential risks of resuming competitive sports. We have proposed an algorithm for RTP in athletes following myocarditis, incorporating CMR. Future research is warranted to refine RTP protocols and improve risk stratification, particularly through longitudinal studies that examine recovery and outcomes in athletes.

Myocardial injury in dogs: a retrospective analysis on etiological, echocardiographic, electrocardiographic, therapeutic, and outcome findings in 102 cases

INTRODUCTION

In dogs, myocardial injury (MI) is a poorly characterized clinical entity; therefore, this study aimed to provide a detailed description of dogs affected by this condition.

ANIMALS, MATERIALS, AND METHODS

Dogs diagnosed with MI according to the concentration of cardiac troponin I (cTnI) were retrospectively searched. Signalment, diagnostic, therapeutic, and outcome data were retrieved. Dogs were divided into six echocardiographic (dilated cardiomyopathy phenotype; hypertrophic cardiomyopathy phenotype; hypertrophic cardiomyopathy phenotype with systolic dysfunction; abnormal echogenicity only; endocarditis; and no echocardiographic abnormalities suggestive of MI), four electrocardiographic (abnormalities of impulse formation; abnormalities of impulse conduction; abnormalities of ventricular repolarization; and no electrocardiographic abnormalities suggestive of MI), and nine etiological (infective; inflammatory; neoplastic; metabolic; toxic; nutritional; immune-mediated; traumatic/mechanical; and unknown) categories. Statistical analysis was performed to compare cTnI values among different categories and analyze survival.

RESULTS

One hundred two dogs were included. The median cTnI value was 3.71 ng/mL (0.2-180 ng/mL). Echocardiographic and electrocardiographic abnormalities were documented in 86 of 102 and 89 of 102 dogs, respectively. Among echocardiographic and electrocardiographic categories, the dilated cardiomyopathy phenotype (n = 52) and abnormalities of impulse formation (n = 67) were overrepresented, respectively. Among dogs in which a suspected etiological trigger was identified (68/102), the infective category was overrepresented (n = 20). Among dogs belonging to different echocardiographic, electrocardiographic, and etiological categories, cTnI did not differ significantly. The median survival time was 603 days; only eight of 102 dogs died due to MI.

CONCLUSIONS

Dogs with MI often have an identifiable suspected trigger, show various echocardiographic and electrocardiographic abnormalities, and frequently survive to MI-related complications.