The Spontaneous Course of Human Herpesvirus 6 DNA-Associated Myocarditis and the Effect of Immunosuppressive Intervention

Myocarditis incidence and hospital mortality from 2007 to 2022: insights from a nationwide registry

OBJECTIVES

To investigate the burden of disease of myocarditis in Germany and identify similarities and differences in myocarditis with or without COVID-19.

METHODS

All patients hospitalized with myocarditis in Germany were included in this nationwide retrospective analysis. Data were retrieved from the Federal Statistical Office of Germany (DESTATIS) for the years from 2007 to 2022. The primary endpoint was hospital mortality.

RESULTS

A total of 88,159 patients hospitalized with myocarditis were analyzed. Annual cases increased from 5100 in 2007 to 6593 in 2022 (p < 0.001 for trend) with higher incidence during winter months. Incidence per 100,000 inhabitants was 6.2 in 2007 rising to 7.8 in 2022 (p < 0.001 for trend). Hospital mortality remained constant at an average of 2.44% (p = 0.164 for trend). From 2020 to 2022, 1547/16,229 (9.53%) patients were hospitalized with both, myocarditis and COVID-19 (incidence 0.62/100,000 inhabitants and 180/100,000 hospitalizations with COVID-19). These patients differed significantly in most patient characteristics and had a higher rate of hospital mortality compared to myocarditis without COVID-19 (12.54% vs. 2.26%, respectively, p < 0.001).

CONCLUSIONS

Myocarditis hospitalizations were slowly rising over the past 16 years with hospital mortality remaining unchanged. Incidence of hospitalizations with combined myocarditis and COVID-19 was low, but hospital mortality was high.

Current Treatment and Immunomodulation Strategies in Acute Myocarditis

ABSTRACT

Myocarditis is an inflammatory disease of the myocardium characterized by a great heterogeneity of presentation and evolution. Treatment of myocarditis is often supportive, and the evidence for immunosuppression is scarce and debated. Conventional treatment is based on clinical presentation, ranging from conservative to advanced mechanical assist devices. In this setting, immunosuppression and immunomodulation therapies are mostly reserved for patients presenting with major clinical syndromes. In this review, we will summarize the current evidence and strategies for conventional and immunosuppressive treatments for patients presenting with acute myocarditis.

Advances in the mechanism of inflammasomes activation in herpes virus infection

Herpesviruses, prevalent DNA viruses with a double-stranded structure, establish enduring infections and play a part in various diseases. Despite their deployment of multiple tactics to evade the immune system, both localized and systemic inflammatory responses are triggered by the innate immune system's recognition of them. Recent progress has offered more profound understandings of the mechanisms behind the activation of the innate immune system by herpesviruses, specifically through inflammatory signaling. This process encompasses the initiation of an intracellular nucleoprotein complex, the inflammasome associated with inflammation.Following activation, proinflammatory cytokines such as IL-1β and IL-18 are released by the inflammasome, concurrently instigating a programmed pathway for cell death. Despite the structural resemblances between herpesviruses, the distinctive methods of inflammatory activation and the ensuing outcomes in diseases linked to the virus exhibit variations.The objective of this review is to emphasize both the similarities and differences in the mechanisms of inflammatory activation among herpesviruses, elucidating their significance in diseases resulting from these viral infections.Additionally, it identifies areas requiring further research to comprehensively grasp the impact of this crucial innate immune signaling pathway on the pathogenesis of these prevalent viruses.

Diagnostic challenges and forensic implications in a case of infantile fatal myocarditis

We present the case of a 23-month-old child who died less than 24 h after the onset of cardiac symptoms, despite being admitted to the hospital 72 h earlier. Autopsy revealed no significant macroscopic changes, and histologic examination revealed focal lymphocytic myocarditis with myocyte disruption, diffuse alveolar damage in the exudative phase, and generalized lymphocytic immune activation in other organs. Ante-mortem and post-mortem microbiological exams did not clearly prove a causative role of infectious agents. The peculiarity of this case was characterized by the contrast between the severe clinical features and the mild cardiac histological findings. This discrepancy, coupled with the suspicion of a viral causative role based on both ante-mortem and post-mortem microbiological examinations, presented significant challenges in reaching an etiological diagnosis. This case also confirms that the diagnosis of myocarditis in children cannot be made solely on the basis of histological cut-offs or microbiological results. Using abductive reasoning, various diagnostic hypotheses were formulated and evaluated to arrive at the final diagnosis of fatal myocarditis of viral or post-viral origin. Data from post-mortem examination are often the only source of information that is available to the experts, especially in cases of sudden infant death syndrome. In such cases, the forensic pathologists should accurately evaluate findings that may appear to indicate a different etiology, and, in the absence of clinical or radiological data, interpret post-mortem data in a logically correct manner. The autopsy is the first essential step to evaluate the cause of death and must be integrated with the results of ante- and post-mortem diagnostic tests in a holistic approach, which is crucial to allow forensic pathologists to provide an appropriate and relevant opinion.

DRESS syndrome with multiorgan involvement and HHV-6 reactivation in the absence of a drug trigger

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe drug reaction where patients present with fever, morbilliform rash and multiorgan manifestations, which may include acute renal failure, acute respiratory distress syndrome and eosinophilic myocarditis. We present a case of a 60-year-old woman with acute heart failure, DRESS syndrome features and human herpesvirus 6 reactivation in the absence of a drug trigger. She was diagnosed with eosinophilic myocarditis and successfully treated with corticosteroid therapy.

The inflammatory spectrum of cardiomyopathies

Infiltration of the myocardium with various cell types, cytokines and chemokines plays a crucial role in the pathogenesis of cardiomyopathies including inflammatory cardiomyopathies and myocarditis. A more comprehensive understanding of the precise immune mechanisms involved in acute and chronic myocarditis is essential to develop novel therapeutic approaches. This review offers a comprehensive overview of the current knowledge of the immune landscape in cardiomyopathies based on etiology. It identifies gaps in our knowledge about cardiac inflammation and emphasizes the need for new translational approaches to improve our understanding thus enabling development of novel early detection methods and more effective treatments.

HHV-6 Myocarditis Progressing to Ventricular Standstill Requiring Cardiac Transplant

Human herpesvirus-6 (HHV-6) is an increasingly recognized cause of myocarditis. We present the case of a 46-year-old woman who presented with fulminant HHV-6 myocarditis requiring heart transplantation. (Level of Difficulty: Advanced.).

Leitlinie Myokarditis der Deutschen Gesellschaft für Pädiatrische Kardiologie

This consensus statement presents updated recommendations on diagnosis and treatment of myocarditis in childhood.

Persistent viral infections and their role in heart disease

Viral infections are the culprit of many diseases, including inflammation of the heart muscle, known as myocarditis. Acute myocarditis cases have been described in scientific literature, and viruses, such as parvovirus B19, coxsackievirus B3, or more recently, SARS-CoV-2, were the direct cause of cardiac inflammation. If not treated, myocarditis could progress to dilated cardiomyopathy, which permanently impairs the heart and limits a person's lifespan. Accumulated evidence suggests that certain viruses may persist in cardiac tissue after the initial infection, which could open up the door to reactivation under favorable conditions. Whether this chronic infection contributes to, or initiates, cardiac damage over time, remains a pressing issue in the field of virus-induced heart pathology, and it is directly tied to patients' treatment. Previously, large case studies found that a few viruses: parvovirus B19, coxsackievirus, adenovirus, human herpesvirus 6, cytomegalovirus and Epstein-Barr virus, are most commonly found in human endomyocardial biopsy samples derived from patients experiencing cardiac inflammation, or dilated cardiomyopathy. SARS-CoV-2 infection has also been shown to have cardiovascular consequences. This review examines the role of viral persistence in cardiac inflammation and heart disease, and discusses its implications for patients' outcomes.