Diagnostic approach of myocarditis: strike the golden mean

Detection of Parvovirus B19 genome in human heart tissue samples

OBJECTIVE

Identifying viral genomes in human heart tissues is critical for disease diagnosis and assessment of cardiovascular damage. Human heart tissue samples obtained during a biopsy procedure are routinely used to test for the presence of viruses, as guided by clinical manifestations and prognosis. Furthermore, heart tissue samples obtained post-mortem or during a cardiac transplant procedure serve as a valuable research tool, as they allow for an in-depth assessment of cardiac pathology that can aid in our understanding of molecular pathways associated with disease. Because viral nucleic acid constitutes only a small portion of each sample's genetic material, appropriate methods are necessary for positive viral genome identification.

RESULTS

Snap-frozen heart tissue samples obtained either post-mortem or during a cardiac transplant procedure were used to develop conditions for detection of Parvovirus B19. Briefly, total DNA was isolated from the heart tissue under varying conditions. A PCR-based assay with Parvovirus B19 specific primers was implemented to detect the presence of the viral genome, followed by Sanger Sequencing. The mechanical disruption of the heart tissue, as well as the cardiac tissue processing methods, had a significant effect on the DNA quality and the ability to detect the Parvovirus B19 genome.

COVID-19 Associated Fulminant Myocarditis in a Fully-Vaccinated Female: A Case Report with Clinical Follow-up

Background

Myocarditis is considered a serious adverse event after COVID-19 infection. The risk and severity of myocarditis after COVID-19 disease decreased significantly in the vaccinated population. We present a case of cardiac magnetic resonance proven fulminant myocarditis following COVID-19 disease in a young female who was previously vaccinated with 2 doses of the BIBP (Sinopharm) vaccine.

Case summary

A 29-year-old female was referred to the hospital with acute chest pain, dyspnea, and nausea. Her electrocardiogram revealed ST-segment elevation in anterolateral leads with reciprocal changes in inferior leads. She was primarily diagnosed with ST-elevation myocardial infarction following spontaneous coronary artery dissection (SCAD) according to her age and gender. Her coronary angiography was normal. RT-PCR nasopharyngeal swab was positive for SARS-COV-2 infection. According to her history and excluding coronary artery diseases, she was clinically diagnosed with myocarditis and received corticosteroids, IVIG, and colchicine. She was discharged in a favorable condition after 11 days of hospitalization. Cardiac magnetic resonance imaging confirmed the diagnosis of myocarditis according to the updated lake Louise criteria. On her 4-month follow-up, she was asymptomatic, and her echocardiography showed improvement in biventricular function.

Discussion

The diagnosis of myocarditis caused by COVID-19 infection may be challenging as the symptoms of myocarditis, and COVID-19 disease may overlap. It should be considered when patients have acute chest pain, palpitation, elevated cardiac biomarkers, and new abnormalities in ECG or echocardiography. Cardiac MRI is a non-invasive gold standard modality for diagnosing and follow-up of myocarditis and should be used in clinically suspected myocarditis. The long-term course of myocarditis following COVID-19 disease is still unclear, but some evidence suggests it may have a favorable mid-term outcome.

Immunopathogenesis of Immune Checkpoint Inhibitor Induced Myocarditis: Insights from Experimental Models and Treatment Implications

Despite the extraordinary success of immune checkpoint inhibitors (ICIs) in cancer treatment, their use is associated with a high incidence of immune-related adverse events (IRAEs), resulting from therapy-related autoimmunity against various target organs. ICI-induced myocarditis is one of the most severe forms of IRAE, which is associated with risk of hemodynamic compromise and mortality. Despite increasing recognition and prompt treatment by clinicians, there remain significant gaps in knowledge regarding the pathophysiology, diagnosis and treatment of ICI-induced myocarditis. As the newly emerged disease entity is relatively rare, it is challenging for researchers to perform studies involving patients at scale. Alternatively, mouse models have been developed to facilitate research understanding of the pathogenesis of ICI-induced myocarditis and drug discovery. Transgenic mice with immune checkpoint genes knocked out allow induction of myocarditis in a highly reproducible manner. On the other hand, it has not been possible to induce ICI-induced myocarditis in wild type mice by injecting ICIs monotherapy alone. Additional interventions such as combinational ICI, tumor inoculation, cardiac sarcomere immunization, or cardiac irradiation are necessary to mimic the underlying pathophysiology in human cancer patients and to induce ICI-induced myocarditis successfully. This review focuses on the immunopathogenesis of ICI-induced myocarditis, drawing insights from human studies and animal models, and discusses the potential implications for treatment.

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.

Myocarditis Induced by Immunotherapy in Metastatic Melanoma—Review of Literature and Current Guidelines

Immunotherapy is a widely used treatment modality in oncology. Immune checkpoint inhibitors, as a part of immunotherapy, caused a revolution in oncology, especially in melanoma therapy, due to the significant prolongation of patients’ overall survival. These drugs act by activation of inhibited immune responses of T lymphocytes against cancer cells. The mechanism responsible for the therapy’s high efficacy is also involved in immune tolerance of the patient’s own tissues. The administration of ICI therapy to a patient can cause severe immune reactions against non-neoplastic cells. Among them, cardiotoxicity seems most important due to the high mortality rate. In this article, we present the history of a 79 year-old patient diagnosed with melanoma who died due to myocarditis induced by ICI therapy, despite the fast administration of recommended immunosuppressive therapy, as an illustration of possible adverse events of ICI. Additionally, we summarize the mechanism, risk factors, biomarkers, and clinical data from currently published guidelines and studies about ICI-related myocarditis. The fast recognition of this fatal adverse effect of therapy may accelerate the rapid introduction of treatment and improve patients’ outcomes.

Clinical Characteristics of Patients with Myocarditis following COVID-19 mRNA Vaccination: A Systematic Review and Meta-Analysis

COVID-19 mRNA vaccinations have recently been implicated in causing myocarditis. Therefore, the primary aim of this systematic review and meta-analysis was to investigate the clinical characteristics of patients with myocarditis following mRNA vaccination. The secondary aims were to report common imaging and laboratory findings, as well as treatment regimes, in these patients. A literature search was performed from December 2019 to June 2022. Eligible studies reported patients older than 18 years vaccinated with mRNA, a diagnosis of myocarditis, and subsequent outcomes. Pooled mean or proportion were analyzed using a random-effects model. Seventy-five unique studies (patient n = 188, 89.4% male, mean age 18-67 years) were included. Eighty-six patients had Moderna vaccines while one hundred and two patients had Pfizer-BioNTech vaccines. The most common presenting symptoms were chest pain (34.5%), fever (17.1%), myalgia (12.4%), and chills (12.1%). The most common radiologic findings were ST-related changes on an electrocardiogram (58.7%) and hypokinesia on cardiac magnetic resonance imaging or echocardiography (50.7%). Laboratory findings included elevated Troponin I levels (81.7%) and elevated C-reactive protein (71.5%). Seven patients were admitted to the intensive care unit. The most common treatment modality was non-steroid anti-inflammatory drugs (36.6%) followed by colchicine (28.5%). This meta-analysis presents novel evidence to suggest possible myocarditis post mRNA vaccination in certain individuals, especially young male patients. Clinical practice must therefore take appropriate pre-cautionary measures when administrating COVID-19 mRNA vaccinations.

A Case of Myocarditis Presenting With a Hyperechoic Nodule After the First Dose of COVID-19 mRNA Vaccine

Myocarditis and/or pericarditis have been reported as adverse events following coronavirus disease 2019 (COVID-19) messenger RNA vaccination, with most cases occurring within 1 week after the second dose. We report a rare case of myocarditis after the first dose of the BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine in a 17-year-old boy. Here, we describe the laboratory, electrocardiographic, and imaging findings of myocarditis.

State-of-the-Art of Endomyocardial Biopsy on Acute Myocarditis and Chronic Inflammatory Cardiomyopathy

Purpose of Review

Histologic evidence of myocardial inflammatory infiltrate not secondary to an ischemic injury is required by current diagnostic criteria to reach a definite diagnosis of myocarditis. Endomyocardial biopsy (EMB) is therefore often indicated for the diagnosis of myocarditis, although it may lack sufficient sensitivity considering the limited possibility of myocardial sampling. Improving the diagnostic yield and utility of EMB is of high priority in the fields of heart failure cardiology and myocarditis in particular. The aim of the present review is to highlight indications, strengths, and shortcomings of current EMB techniques, and discuss innovations currently being tested in ongoing clinical studies, especially in the setting of acute myocarditis and chronic inflammatory cardiomyopathy.

Recent Findings

EMB provides unique diagnostic elements and prognostic information which can effectively guide the treatment of myocarditis. Issues affecting the diagnostic performance in the setting of acute myocarditis and chronic inflammatory cardiomyopathies will be discussed in this review in the light of recent expert consensus documents on the management of these conditions and on indication to EMB. Recent innovations using electroanatomic mapping (EAM)-guided EMB and fluoroscopic-guided EMB during temporary mechanical circulatory support have improved the utility of the procedure.

Summary

EMB remains an important diagnostic test whose results need to be interpreted in the context of (1) clinical pre-test probability, (2) timing of sampling, (3) quality of sampling (4) site of sampling, (5) histologic type of myocarditis, and (6) analytic methods that are applied. Herein we will review these caveats as well as perspectives and innovations related to the use of this diagnostic tool.

Targeting early stages of cardiotoxicity from anti-PD1 immune checkpoint inhibitor therapy

AIMS

Cardiac immune-related adverse events (irAEs) from immune checkpoint inhibition (ICI) targeting programmed death 1 (PD1) are of growing concern. Once cardiac irAEs become clinically manifest, fatality rates are high. Cardio-oncology aims to prevent detrimental effects before manifestation of severe complications by targeting early pathological changes. We therefore aimed to investigate early consequences of PD1 inhibition for cardiac integrity to prevent the development of overt cardiac disease.

METHODS AND RESULTS

We investigated cardiac-specific consequences from anti-PD1 therapy in a combined biochemical and in vivo phenotyping approach. Mouse hearts showed broad expression of the ligand PDL1 on cardiac endothelial cells as a main mediator of immune-crosstalk. Using a novel melanoma mouse model, we assessed that anti-PD1 therapy promoted myocardial infiltration with CD4+ and CD8+ T cells, the latter being markedly activated. Left ventricular (LV) function was impaired during pharmacological stress, as shown by pressure-volume catheterization. This was associated with a dysregulated myocardial metabolism, including the proteome and the lipidome. Analogous to the experimental approach, in patients with metastatic melanoma (n = 7) receiving anti-PD1 therapy, LV function in response to stress was impaired under therapy. Finally, we identified that blockade of tumour necrosis factor alpha (TNFα) preserved LV function without attenuating the anti-cancer efficacy of anti-PD1 therapy.

CONCLUSIONS

Anti-PD1 therapy induces a disruption of cardiac immune homeostasis leading to early impairment of myocardial functional integrity, with potential prognostic effects on the growing number of treated patients. Blockade of TNFα may serve as an approach to prevent the manifestation of ICI-related cardiotoxicity.

Dermatomyositis presenting as heart failure revealed a concealed cervical malignancy: an infrequent clinical nexus

Dermatomyositis (DM) belongs to the spectrum of inflammatory myopathies which are a heterogeneous group of acquired disorders in which dysregulated immune system is thought to play a major pathologic role. Patients with DM generally present with characteristic skin manifestations with or without muscle weakness and pain. Although subclinical myocardial involvement in DM is well reported in literature, heart failure (HF) as its principal manifestation is extremely rare. Recognition of DM, a known paraneoplastic syndrome, should prompt clinicians to search for underlying malignancy. While gynaecological malignancies are common in association with DM, cervical cancer has rarely been heard of as an aetiology of paraneoplastic DM. We are reporting a case of DM in a postmenopausal woman presenting with advanced decompensated congestive HF with hidden squamous cell carcinoma of cervix.