Viral Myocarditis—From Pathophysiology to Treatment

Abstract

The diagnosis of acute and chronic myocarditis remains a challenge for clinicians. Characterization of this disease has been hampered by its diverse etiologies and heterogeneous clinical presentations. Most cases of myocarditis are caused by infectious agents. Despite successful research in the last few years, the pathophysiology of viral myocarditis and its sequelae leading to severe heart failure with a poor prognosis is not fully understood and represents a significant public health issue globally. Most likely, at a certain point, besides viral persistence, several etiological types merge into a common pathogenic autoimmune process leading to chronic inflammation and tissue remodeling, ultimately resulting in the clinical phenotype of dilated cardiomyopathy. Understanding the underlying molecular mechanisms is necessary to assess the prognosis of patients and is fundamental to appropriate specific and personalized therapeutic strategies. To reach this clinical prerequisite, there is the need for advanced diagnostic tools, including an endomyocardial biopsy and guidelines to optimize the management of this disease. The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has currently led to the worst pandemic in a century and has awakened a special sensitivity throughout the world to viral infections. This work aims to summarize the pathophysiology of viral myocarditis, advanced diagnostic methods and the current state of treatment options.

Cardiovascular Biomarkers for Prediction of in-hospital and 1-Year Post-discharge Mortality in Patients With COVID-19 Pneumonia

“…On the one hand, the lack of a clear association between high-sensitive TnI and in-hospital mortality may partly be explained by the collection of blood samples at the 1st day of hospitalization. However, virally- induced cardiac injury usually requires 1–2 weeks to develop until clinical manifestations and resultant high-sensitive TnI increases occur ( 5 , 45 ). This is further emphasized by a study of Zhou et al ( 5 ), in which serum high-sensitive TnI median concentrations increased from 57.6 to 290.6 pg/mL during the period between day 16 and day 22 after the onset of COVID-19 infection in non-survivors ( 5 ).…”

A Case Report on an Underappreciated Cause of Heart Failure: Chronic Viral Myocarditis

“…Furthermore, there are three possibilities that may result after the initial acute symptoms of viral myocarditis, including the following: the virus may be completely cleared, resulting in full recovery, the viral infection may persist, or the viral infection could lead to a persistent auto-immunemediated inflammatory process with long-term symptoms of heart failure [10]. Viral persistence in the myocardium is associated with progressive deterioration of left ventricular ejection fraction (LVEF) [11]. This was likely the case with our patient's new drop in ejection fraction from an LVEF of 60% to an LVEF of 10% over less than two years.…”

“…This was likely the case with our patient's new drop in ejection fraction from an LVEF of 60% to an LVEF of 10% over less than two years. Endomyocardial biopsy (EMB) is the gold standard method for diagnosing acute or chronic inflammatory heart disease [11]. However, EMB is used infrequently because of perceived risks and the lack of a widely accepted and sensitive histologic standard [6].…”

“…Liquid biopsy by monitoring circulating biomarkers, including microRNAs (miRNAs), has also been shown to have the potential to complement EMBs and provide the excellent diagnostic capability. A recent study revealed the ability to discriminate between patients with viral myocarditis, inflammatory cardiomyopathy, and healthy donors with a specificity of over 95% based on expression levels of miRNAs [11]. However, further studies would be needed to elevate the routine use of miRNA-panel in addition to further guidelines to help optimize the management of this disease.…”

New Insights in Human Myocarditis

“…When infectious myocarditis is suspected, the application of polymerase chain reaction to frozen endomyocardial samples allows for the identification of the causative inflammatory agent and how to manage it. In this regard, viral genomes are the most commonly involved agents, and nowadays, a specific strategy for their treatment is available [5].…”