Immunosuppression in inflammatory cardiomyopathy and parvovirus B19 persistence

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.

Biomarkers in Acute Myocarditis and Chronic Inflammatory Cardiomyopathy: An Updated Review of the Literature

Myocarditis is a disease caused by cardiac inflammation that can progress to dilated cardiomyopathy, heart failure, and eventually death. Several etiologies, including autoimmune, drug-induced, and infectious, lead to inflammation, which causes damage to the myocardium, followed by remodeling and fibrosis. Although there has been an increasing understanding of pathophysiology, early and accurate diagnosis, and effective treatment remain challenging due to the high heterogeneity. As a result, many patients have poor prognosis, with those surviving at risk of long-term sequelae. Current diagnostic methods, including imaging and endomyocardial biopsy, are, at times, expensive, invasive, and not always performed early enough to affect disease progression. Therefore, the identification of accurate, cost-effective, and prognostically informative biomarkers is critical for screening and treatment. The review then focuses on the biomarkers currently associated with these conditions, which have been extensively studied via blood tests and imaging techniques. The information within this review was retrieved through extensive literature research conducted on major publicly accessible databases and has been collated and revised by an international panel of experts. The biomarkers discussed in the article have shown great promise in clinical research studies and provide clinicians with essential tools for early diagnosis and improved outcomes.

COVID myocarditis: a review of the literature

Myocarditis is a potentially fatal complication of coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. COVID-19 myocarditis appears to have distinct inflammatory characteristics that distinguish it from other viral etiologies. COVID-19 myocarditis can present with symptoms ranging from dyspnea and chest pain to acute heart failure and death. It is critical to detect any cases of myocarditis, especially fulminant myocarditis, which can be characterized by signs of heart failure and arrhythmias. Serial troponins, echocardiography, and electrocardiograms should be performed as part of the initial workup for suspected myocarditis. The second step in detecting myocarditis is cardiac magnetic resonance imaging and endomyocardial biopsy. Treatment for COVID-19 myocarditis is still debatable; however, combining intravenous immunoglobulins and corticosteroids may be effective, especially in cases of fulminant myocarditis. Overall, more research is needed to determine the incidence of COVID-19 myocarditis , and the use of intravenous immunoglobulins and corticosteroids in combination requires large randomized controlled trials to determine efficacy. The purpose of this review is to summarize current evidence on the subject. This review aims to summarise current evidence on this topic.

State-of-the-art document on optimal contemporary management of cardiomyopathies

Cardiomyopathies represent significant contributors to cardiovascular morbidity and mortality. Over the past decades, a progress has occurred in characterization of the genetic background and major pathophysiological mechanisms, which has been incorporated into a more nuanced diagnostic approach and risk stratification. Furthermore, medications targeting core disease processes and/or their downstream adverse effects have been introduced for several cardiomyopathies. Combined with standard care and prevention of sudden cardiac death, these novel and emerging targeted therapies offer a possibility of improving the outcomes in several cardiomyopathies. Therefore, the aim of this document is to summarize practical approaches to the treatment of cardiomyopathies, which includes the evidence-based novel therapeutic concepts and established principles of care, tailored to the individual patient aetiology and clinical presentation of the cardiomyopathy. The scope of the document encompasses contemporary treatment of dilated, hypertrophic, restrictive and arrhythmogenic cardiomyopathy. It was based on an expert consensus reached at the Heart Failure Association online Workshop, held on 18 March 2021.

Comparative Efficacy and Safety of Mycophenolate Mofetil and Azathioprine in Combination with Corticosteroids in the Treatment of Lymphocytic Myocarditis

AIMS

This paper aimed to study the efficacy and safety of mycophenolate mofetil (MM) in combination with corticosteroids in the treatment of lymphocytic myocarditis (LM) when compared to the standard combination of corticosteroids and azathioprine.

METHODS

The study included 50 adult patients (47.8 ± 10.8 y.o.) in a NYHA III functional class due to LM who were verified using endomyocardial biopsy. The main group included 29 patients who received MM at 2 g/day. The comparison group comprised 21 patients who received azathioprine at 150 [50; 150] mg/day. Both groups were administered with methylprednisolone. The average follow-up period was 30 [22; 35] months, but no less than 6 months.

RESULTS

The groups were comparable in the baseline parameters and standard drug therapy. In both groups, there was a comparable significant increase in the ejection fraction (from 30.6 ± 7.7% to 44.0 ± 9.4% vs. 29.2 ± 7.7% to 46.2 ± 11.8%, p < 0.001), and a decrease in systolic pressure in the pulmonary artery and the dimensions of the left ventricle and atrium. The frequency of death was two (6.9%) and two (9.5%), transplantation was one (3.4%) and one (4.8%) patient and the "death + transplantation" endpoint was three (10.3%) and three (14.3%) without differences between the groups. The presence of the parvovirus B19 in the myocardium in 6/5 patients did not affect the results. The incidence of infectious complications was comparable. The most severe infectious complications were pneumonia and fatal purulent encephalitis (both cases in the azathioprine group), leptospirosis meningitis (in the mycophenolate mofetil group).

CONCLUSIONS

In the patients with LM, the combination of corticosteroids with MM at a dose of 2 g/day was at least no less effective than with azathioprine. There was a tendency toward a better tolerance using MM.

Myocarditis: Etiology, Pathogenesis, and Their Implications in Clinical Practice

Myocarditis is an inflammatory disease of the myocardium caused by infectious or non-infectious agents. It can lead to serious short-term and long-term sequalae, such as sudden cardiac death or dilated cardiomyopathy. Due to its heterogenous clinical presentation and disease course, challenging diagnosis and limited evidence for prognostic stratification, myocarditis poses a great challenge to clinicians. As it stands, the pathogenesis and etiology of myocarditis is only partially understood. Moreover, the impact of certain clinical features on risk assessment, patient outcomes and treatment options is not entirely clear. Such data, however, are essential in order to personalize patient care and implement novel therapeutic strategies. In this review, we discuss the possible etiologies of myocarditis, outline the key processes governing its pathogenesis and summarize best available evidence regarding patient outcomes and state-of-the-art therapeutic approaches.

Leitlinie Myokarditis der Deutschen Gesellschaft für Pädiatrische Kardiologie

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

Successful treatment of fulminant myocarditis with intra-aortic balloon pump counterpulsation combined with immunoglobulin and glucocorticoid in a young male adult

Background

Fulminant myocarditis (FM) is a serious non-specific inflammatory disease of the myocardium. FM tends to occur in adolescents and the course of the disease progresses rapidly. It is prone to cardiogenic shock (CGS) and multiple organ failure (MOF) with high mortality. We report a case of FM with CGS and MOF in a young male who was successfully treated with intra-aortic balloon pump counterpulsation (IABP) combined with intravenous immunoglobulin (IVIG) and glucocorticoid (GC).

Case summary

A 21-year-old previously healthy man presented with fever, headache, and chest tightness. He came to the hospital for emergency treatment. The laboratory data showed that the levels of serum cardiac troponin I (cTnI), N-terminal B-type natriuretic peptide (NT-proBNP), myocardial zymogram, and neutrophils increased. Echocardiography showed pericardial effusion and decreased left ventricular systolic function. ECG showed diffuse ST-segment elevation. He was clinically diagnosed with FM and admitted to the intensive care unit for treatment. Within 48 h of admission, the clinical course of the patient deteriorated rapidly, with CGS accompanied by MOF, high atrioventricular block (AVB), and ventricular tachycardia (VT). After using mechanical circulatory support (MCS) therapy with IABP, IVIG, GC, continuous renal replacement therapy (CRRT), and mechanical ventilation complicated with a temporary cardiac pacemaker, he recovered normal cardiac function. He made a full recovery and was discharged home on day 21.

Discussion

For patients with FM, early diagnosis, close monitoring, timely use of MCS devices, and active comprehensive treatment are very important. MCS devices such as IABP can become lifesaving tools for the treatment of FM.

Viral Myocarditis: Classification, Diagnosis, and Clinical Implications

Myocarditis is an inflammatory disease of the myocardium with focal or diffuse involvement. Viral infections are the most common cause of myocarditis, especially in Western countries. A recent viral illness with gastroenteric or upper respiratory symptoms often precedes myocarditis. The absence of specific pathognomonic features in conjunction with the wide spectrum of clinical manifestations that range from subclinical cases to sudden cardiac death (SCD) makes myocarditis diagnosis particularly challenging. Moreover, myocarditis might represent a cause of initially unexplained dilated cardiomyopathy (DCM) and heart failure (HF), especially among children and young adults. Cardiac magnetic resonance imaging (CMR) is crucial for myocarditis diagnosis, because of its ability to detect interstitial edema during acute inflammation. Assessment of subepicardial or mid-myocardial fibrosis by late gadolinium enhancement (LGE) is typical for myocarditis. Cardiac arrhythmias are frequent events that may arise especially in more severe myocarditis cases. The most common form of arrhythmia is atrial fibrillation, followed by ventricular tachycardia. Documented arrhythmias have been reported more commonly with HIV myocarditis than other more common infections such as Adenovirus, Parvovirus B19, human Herpes virus 6, and Enterovirus. The mechanisms of arrhythmogenesis in myocardial inflammation are not fully understood; in the acute phase, the spectrum of arrhythmogenesis ranges from a direct effect on cardiomyocytes that leads to electrical instability and ion channel impairment to ischemia from coronary macro- or microvascular disease. In chronic myocarditis, instead, myocardial replacement with fibrosis promotes scar-mediated re-entrant ventricular arrhythmias. Observational data suggested the important role of CMR, with LGE being the strongest independent predictor of SCD, cardiac, and all-cause mortality. In acute myocarditis, the most common localization of subepicardial LGE dwells in the lateral wall. Patients with myocarditis that develop HF and arrhythmias usually show a larger LGE distribution involving several myocardial segments. Moreover, a mid-layer LGE in the interventricular septum is more frequent in acute myocarditis than in acute coronary syndromes cases. The risk of SCD in patients with wide areas of LGE is significant, and a shared decision-making approach is warranted. Nevertheless, there is no formal consensus about the extension of LGE to justify implantable cardioverter defibrillator (ICD) implantation in primary prevention.

Immunomodulating Therapies in Acute Myocarditis and Recurrent/Acute Pericarditis

The field of inflammatory disease of the heart or "cardio-immunology" is rapidly evolving due to the wider use of non-invasive diagnostic tools able to detect and monitor myocardial inflammation. In acute myocarditis, recent data on the use of immunomodulating therapies have been reported both in the setting of systemic autoimmune disorders and in the setting of isolated forms, especially in patients with specific histology (e.g., eosinophilic myocarditis) or with an arrhythmicburden. A role for immunosuppressive therapies has been also shown in severe cases of coronavirus disease 2019 (COVID-19), a condition that can be associated with cardiac injury and acute myocarditis. Furthermore, ongoing clinical trials are assessing the role of high dosage methylprednisolone in the context of acute myocarditis complicated by heart failure or fulminant presentation or the role of anakinra to treat patients with acute myocarditis excluding patients with hemodynamically unstable conditions. In addition, the explosion of immune-mediated therapies in oncology has introduced new pathophysiological entities, such as immune-checkpoint inhibitor-associated myocarditis and new basic research models to understand the interaction between the cardiac and immune systems. Here we provide a broad overview of evolving areas in cardio-immunology. We summarize the use of new imaging tools in combination with endomyocardial biopsy and laboratory parameters such as high sensitivity troponin to monitor the response to immunomodulating therapies based on recent evidence and clinical experience. Concerning pericarditis, the normal composition of pericardial fluid has been recently elucidated, allowing to assess the actual presence of inflammation; indeed, normal pericardial fluid is rich in nucleated cells, protein, albumin, LDH, at levels consistent with inflammatory exudates in other biological fluids. Importantly, recent findings showed how innate immunity plays a pivotal role in the pathogenesis of recurrent pericarditis with raised C-reactive protein, with inflammasome and IL-1 overproduction as drivers for systemic inflammatory response. In the era of tailored medicine, anti-IL-1 agents such as anakinra and rilonacept have been demonstrated highly effective in patients with recurrent pericarditis associated with an inflammatory phenotype.

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.

Interferon-β Suppresses Transcriptionally Active Parvovirus B19 Infection in Viral Cardiomyopathy: A Subgroup Analysis of the BICC-Trial

Human parvovirus B19 (B19V) is the predominant virus currently detected in endomyocardial biopsies (EMBs). Recent findings indicate that, specifically, transcriptionally active B19V with detectable viral RNA is of prognostic relevance in inflammatory viral cardiomyopathy. We aimed to evaluate B19V replicative status (viral RNA) and beneficial effects in a sub-collective of the prospective randomized placebo-controlled phase II multi-center BICC-Trial (Betaferon In Chronic Viral Cardiomyopathy) after interferon beta-1b (IFN-β) treatment. EMBs of n = 64 patients with B19V mono-infected tissue were retrospectively analyzed. Viral RNA could be detected in n = 18/64 (28.1%) of B19V DNA positive samples (mean age 51.7 years, 12 male), of whom n = 13 had been treated with IFN-ß. Five patients had received placebo. PCR analysis confirmed in follow-up that EMBs significantly reduced viral RNA loads in n = 11/13 (84.6%) of IFN-ß treated patients (p = 0.001), independently from the IFN-ß dose, in contrast to the placebo group, where viral RNA load was not affected or even increased. Consequently, a significant improvement of left ventricular ejection fraction (LVEF) after treatment with IFN-ß was observed (LVEF mean baseline 51.6 ± 14.1% vs. follow-up 61.0 ± 17.5%, p = 0.03). In contrast, in the placebo group, worsening of LVEF was evaluated in n = 4/5 (80.0%) of patients. We could show for the first-time the beneficial effects from treatment with IFN-ß, suppressing B19V viral RNA and improving the hemodynamic course. Our results need further verification in a larger prospective randomized controlled trial.

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

Introduction: This study investigated the spontaneous clinical course of patients with endomyocardial biopsy (EMB)-proven lymphocytic myocarditis and cardiac human herpesvirus 6 (HHV6) DNA presence, and the effectiveness of steroid-based intervention in HHV6-positive patients. Results: 756 heart failure (HF) patients underwent an EMB procedure to determine the underlying cause of unexplained HF. Low levels of HHV6 DNA, detectable by nested PCR only, were found in 10.4% of the cases (n = 79) of which 62% (n = 49) showed myocardial inflammation. The spontaneous course of patients with EMB-proven HHV6 DNA-associated lymphocytic myocarditis (n = 26) showed significant improvements in the left ventricular ejection fraction (LVEF) and clinical symptoms, respectively, in 15/26 (60%) patients, 3–12 months after disease onset. EMB mRNA expression of components of the NLRP3 inflammasome pathway and protein analysis of cardiac remodeling markers, analyzed by real-time PCR and MALDI mass spectrometry, respectively, did not differ between HHV6-positive and -negative patients. In another cohort of patients with ongoing symptoms related to lymphocytic myocarditis associated with cardiac levels of HHV6-DNA copy numbers <500 copies/µg cardiac DNA, quantified by real-time PCR, the efficacy and safety of steroid-based immunosuppression for six months was investigated. Steroid-based immunosuppression improved the LVEF (≥5%) in 8/10 patients and reduced cardiac inflammation in 7/10 patients, without an increase in cardiac HHV6 DNA levels in follow-up EMBs. Conclusion: Low HHV6 DNA levels are frequently detected in the myocardium, independent of inflammation. In patients with lymphocytic myocarditis with low levels of HHV6 DNA, the spontaneous clinical improvement is nearby 60%. In selected symptomatic patients with cardiac HHV6 DNA copy numbers less than 500 copies/µg cardiac DNA and without signs of an active systemic HHV6 infection, steroid-based therapy was found to be effective and safe. This finding needs to be further confirmed in large, randomized trials.

Viral Myocarditis-From Pathophysiology to Treatment

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.

Update on acute myocarditis

Acute myocarditis (AM), a recent-onset inflammation of the heart, has heterogeneous clinical presentations, varying from minor symptoms to high-risk cardiac conditions with severe heart failure, refractory arrhythmias, and cardiogenic shock. AM is moving from being a definitive diagnosis based on histological evidence of inflammatory infiltrates on cardiac tissue to a working diagnosis supported by high sensitivity troponin increase in association with specific cardiac magnetic resonance imaging (CMRI) findings. Though experts still diverge between those advocating for histological definition versus those supporting a mainly clinical definition of myocarditis, in the real-world practice the diagnosis of AM has undoubtedly shifted from being mainly biopsy-based to solely CMRI-based in most of clinical scenarios. It is thus important to clearly define selected settings where EMB is a must, as information derived from histology is essential for an optimal management. As in other medical conditions, a risk-based approach should be promoted in order to identify the most severe AM cases requiring appropriate bundles of care, including early recognition, transfer to tertiary centers, aggressive circulatory supports with inotropes and mechanical devices, histologic confirmation and eventual immunosuppressive therapy. Despite improvements in recognition and treatment of AM, including a broader use of promising mechanical circulatory supports, severe forms of AM are still burdened by dismal outcomes. This review is focused on recent clinical studies and registries that shed new insights on AM. Attention will be paid to contemporary outcomes and predictors of prognosis, the emerging entity of immune checkpoint inhibitors-associated myocarditis, updated CMRI diagnostic criteria, new data on the use of temporary mechanical circulatory supports in fulminant myocarditis. The role of viruses as etiologic agents will be reviewed and a brief update on pediatric AM is also provided. Finally, we summarize a risk-based approach to AM, based on available evidence and clinical experience.

Progressive chronic SARS-CoV-2-positive giant cell myoendocarditis with atrial standstill and sudden cardiac death

Giant cell myocarditis (GCM) is a rare condition. Its association with SARS‐CoV‐2 has not been described before. The 46‐year‐old female patient was admitted to the clinic on September 2020. She had 7 year adrenal insufficiency history and infarct‐like debut of myocardial disease in November 2019. After COVID‐19 in April 2020, cardiac disease progressed. The examination showed low QRS voltage, QS complexes in V₁–V₅ leads, atrial standstill, left ventricular systolic and restrictive dysfunction, elevated anti‐heart antibodies, and subepicardial late gadolinium enhancement by magnetic resonance imaging. Endomyocardial biopsy and pacemaker implantation were performed, but the patient died suddenly due to ventricular tachycardia or ventricular fibrillation (the resuscitation was ineffective). The autopsy revealed GCM, SARS‐CoV‐2, and Parvovirus B19 were detected in the myocardium. The role of SARS‐CoV‐2 in the pathogenesis of autoimmune myocarditis is discussed.

Effectiveness of myocarditis therapy depending on the diagnosis approach (with or without myocardial biopsy)

Aim. To evaluate the effectiveness of myocarditis therapy depending on the diagnosis approach (with or without myocardial biopsy).

Material and methods. The study included 83 patients ≥18 years old with severe and moderate myocarditis (25 women and 58 men; mean age, 45,7±11,7 years), established by myocardial biopsy (group 1, n=36) or by a non-invasive diagnostic algorithm (group 2, n=47), for which immunosuppressive therapy (IST) was carried out. Inclusion criteria were left ventricular (LV) end-diastolic dimension >5,5 cm and ejection fraction (EF) <50%. An endomyocardial (n=31) or intraoperative (n=5) biopsy with a study of the viral genome and level of anticardiac antibodies were performed. Coronary angiography (29%), cardiac multislice computed tomography (75%), cardiac magnetic resonance imaging (41%), and 99mTc-MIBI scintigraphy (35%) were also carried out. The mean follow-up period was 3 years (36 [12; 65] months). The study was approved by the Intercollegiate Ethics Committee.

Results. The groups were completely comparable in age, baseline parameters (class III [2,25; 3] and III [2; 3] heart failure (HF); end-diastolic LV dimension, 6,7±0,7 and 6,4±0,7 cm; EF, 29,9±8,7 and 31,4±9,3%), the extent of cardiac therapy (excluding the administration rate of в-blockers — 94,4 and 78,7%, p<0,05) and 1ST (methylprednisolone in 91,7 and 89,4% of patients at a mean dose of 24 [16; 32] and 20 [15; 32] mg/day, azathioprine in 50,0 and 46,8% of patients at a mean dose of 150 mg/day or mycophenolate mofetil 2,0 g/day in 30,6% in group 1, hydroxychloroquine 0,2 g/day in 27,8 and 23,4%). Biopsy in group 1 revealed active/borderline (61/39%) myocarditis, in 8 patients — viral genome in the myocardium, including parvovirus B19 in 7 of them. Both groups showed a comparable significant increase in EF after 6 months up to 37,6±8,1 and 42,6±11,5% (p<0,001) and after 27 [12; 54] months up to 43,4±9,6 and 45,5±12,3% (p<0,001), as well as a significant decrease in HF class to 2 [1; 2] in both groups. An increase in EF by ≥10% was recorded in 70 and 72% of patients, respectively. The mortality rate was 13,9 and 12,8%. Taking into account the only transplantation in group 2, the death+transplantation endpoints reached 13,9 and 14,9% of patients (without significant differences between the groups).

Conclusion. In patients with severe and moderate myocarditis diagnosed with and without myocardial biopsy, the effectiveness of combined therapy, including IST, was comparable. If it is impossible to perform a biopsy, complex non-invasive strategy makes it possible to diagnose myocarditis with different probability rate and conduct an effective IST, the refusal of which mostly is not justified.

Parvovirus B19 DNA detectable in hearts of patients with dilated cardiomyopathy, but absent or inactive in blood

Aims

Parvovirus B19 (B19V) is often assumed to be a cause of dilated cardiomyopathy (DCM), based on the quantification of B19V DNA in endomyocardial biopsies (EMB). Whether the presence of B19V DNA correlates with active infection is still debated. Application of the enzyme endonuclease to blood samples results in degradation of B19V DNA remnants but leaves viral particles intact, which enables differentiation between active and past infection. In this study, the susceptibility to degradation by endonuclease of B19V DNA in blood was compared between DCM patients and a control group of recent B19V infections.

Methods and results

Twenty blood samples from 20 adult patients with DCM, who previously tested positive for B19V DNA in EMB and/or blood, were tested with B19V PCR before and after application of endonuclease to the samples. Six blood samples tested positive for B19V DNA with a mean viral load of 2.3 × 10⁴ IU/mL. In five samples, B19V DNA became undetectable after endonuclease (100% load reduction); in one sample DNA load showed a 23% log load reduction (viral load before endonuclease: 9.1 × 10⁴ IU/mL; after: 6.5 × 10³ IU/mL). Presence of cardiac inflammation did not differ between patients with B19V DNAemia (1/4) and patients without B19V DNAemia (6/14) (P value = 1.0). In all 18 control samples of proven recent B19V infections, DNA remained detectable after application of endonuclease, showing only a mean log load reduction of 2.3% (mean viral load before endonuclease: 8.1 × 10¹¹ IU/mL; after: 8.0 × 10¹¹ IU/mL). Load reduction differed significantly between the DCM group and the control group; indicating the presence of intact viral particles in the control group with proven active infection and the presence of DNA remnants in the DCM group (P value = 0.000).

Conclusion

During recent B19V infection, viral DNA levels in blood were unaffected by endonuclease. In contrast, B19V DNA in blood in patients with DCM became undetectable or strongly reduced after application of endonuclease. Circulating viral DNA in this subset of patients with presumed parvovirus‐associated DCM does not consist of intact viral particles. Viral replicative activity cannot be assumed from demonstrating B19V DNA in cardiac tissue or in blood in DCM patients.

Myocardial Inflammation, Sports Practice, and Sudden Cardiac Death: 2021 Update

Myocardial inflammation is an important cause of cardiovascular morbidity and sudden cardiac death in athletes. The relationship between sports practice and myocardial inflammation is complex, and recent data from studies concerning cardiac magnetic resonance imaging and endomyocardial biopsy have substantially added to our understanding of the challenges encountered in the comprehensive care of athletes with myocarditis or inflammatory cardiomyopathy (ICM). In this review, we provide an overview of the current knowledge on the epidemiology, pathophysiology, diagnosis, and treatment of myocarditis, ICM, and myopericarditis/perimyocarditis in athletes, with a special emphasis on arrhythmias, patient-tailored therapies, and sports eligibility issues.

Intravenous immunoglobulin therapy in adult patients with idiopathic chronic cardiomyopathy and cardiac parvovirus B19 persistence: a prospective, double-blind, randomized, placebo-controlled clinical trial

AIMS

Previous uncontrolled studies suggested a possible benefit of intravenous immunoglobulin (IVIg) in parvovirus B19 (B19V)-related dilated cardiomyopathy (DCM). This randomized, double-blind, placebo-controlled, single-centre trial investigated the benefits of IVIg beyond conventional therapy in idiopathic chronic DCM patients with B19V persistence.

METHODS AND RESULTS

Fifty patients (39 men; mean age 54 ± 11 years) with idiopathic chronic (>6 months) DCM on optimal medical therapy, left ventricular ejection fraction (LVEF) <45%, and endomyocardial biopsy (EMB) B19V load of >200 copies/µg DNA were blindly randomized to either IVIg (n = 26, 2 g/kg over 4 days) or placebo (n = 24). The primary outcome was change in LVEF at 6 months after randomization. Secondary outcomes were change in functional capacity assessed by 6-min walk test (6MWT), quality of life [Minnesota Living with Heart Failure Questionnaire (MLHFQ)], left ventricular end-diastolic volume (LVEDV), and EMB B19V load at 6 months after randomization. LVEF significantly improved in both IVIg and placebo groups (absolute mean increase 5 ± 9%, P = 0.011 and 6 ± 10%, P = 0.008, respectively), without a significant difference between groups (P = 0.609). Additionally, change in 6MWT [median (interquartile range) IVIg 36 (13;82) vs. placebo 32 (5;80) m; P = 0.573], MLHFQ [IVIg 0 (-7;5) vs. placebo -2 (-6;6), P = 0.904] and LVEDV (IVIg -16 ± 49 mL/m² vs. placebo -29 ± 40 mL/m² ; P = 0.334) did not significantly differ between groups. Moreover, despite increased circulating B19V antibodies upon IVIg administration, reduction in cardiac B19V did not significantly differ between groups.

CONCLUSION

Intravenous immunoglobulin therapy does not significantly improve cardiac systolic function or functional capacity beyond standard medical therapy in patients with idiopathic chronic DCM and cardiac B19V persistence.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID NCT00892112.

Management of Acute Myocarditis and Chronic Inflammatory Cardiomyopathy: An Expert Consensus Document

Myocarditis is an inflammatory disease of the heart that may occur because of infections, immune system activation, or exposure to drugs. The diagnosis of myocarditis has changed due to the introduction of cardiac magnetic resonance imaging. We present an expert consensus document aimed to summarize the common terminology related to myocarditis meanwhile highlighting some areas of controversies and uncertainties and the unmet clinical needs. In fact, controversies persist regarding mechanisms that determine the transition from the initial trigger to myocardial inflammation and from acute myocardial damage to chronic ventricular dysfunction. It is still uncertain which viruses (besides enteroviruses) cause direct tissue damage, act as triggers for immune-mediated damage, or both. Regarding terminology, myocarditis can be characterized according to etiology, phase, and severity of the disease, predominant symptoms, and pathological findings. Clinically, acute myocarditis (AM) implies a short time elapsed from the onset of symptoms and diagnosis (generally <1 month). In contrast, chronic inflammatory cardiomyopathy indicates myocardial inflammation with established dilated cardiomyopathy or hypokinetic nondilated phenotype, which in the advanced stages evolves into fibrosis without detectable inflammation. Suggested diagnostic and treatment recommendations for AM and chronic inflammatory cardiomyopathy are mainly based on expert opinion given the lack of well-designed contemporary clinical studies in the field. We will provide a shared and practical approach to patient diagnosis and management, underlying differences between the European and US scientific statements on this topic. We explain the role of histology that defines subtypes of myocarditis and its prognostic and therapeutic implications.

Management perspectives from the 2019 Wuhan international workshop on fulminant myocarditis

Fulminant myocarditis (FM) is a form of acute myocardial inflammation leading to rapid-onset hemodynamic instability due to cardiogenic shock or life-threatening arrhythmias. As highlighted by recent registries, FM is associated with high rates of death and heart transplantation, regardless of the underlying histology. Because of a paucity of evidence-based management strategies exists for this disease, an International workshop on FM was held in Wuhan, China, in October 2019, in order to share knowledge on the disease and identify areas of consensus. The present report highlights both agreements and controversies in FM management across the world, focusing the attention on areas of opportunity, FM definition, the use of endomyocardial biopsy and viral identification on heart specimens, treatment algorithms including immunosuppression and the timing of circulatory support escalation. This report incorporates the most recent recommendations from national and international professional societies. Main areas of interest and aims of future prospective observational registries and randomized controlled trials were finally identified and suggested.

Myocarditis and inflammatory cardiomyopathy: current evidence and future directions

Inflammatory cardiomyopathy, characterized by inflammatory cell infiltration into the myocardium and a high risk of deteriorating cardiac function, has a heterogeneous aetiology. Inflammatory cardiomyopathy is predominantly mediated by viral infection, but can also be induced by bacterial, protozoal or fungal infections as well as a wide variety of toxic substances and drugs and systemic immune-mediated diseases. Despite extensive research, inflammatory cardiomyopathy complicated by left ventricular dysfunction, heart failure or arrhythmia is associated with a poor prognosis. At present, the reason why some patients recover without residual myocardial injury whereas others develop dilated cardiomyopathy is unclear. The relative roles of the pathogen, host genomics and environmental factors in disease progression and healing are still under discussion, including which viruses are active inducers and which are only bystanders. As a consequence, treatment strategies are not well established. In this Review, we summarize and evaluate the available evidence on the pathogenesis, diagnosis and treatment of myocarditis and inflammatory cardiomyopathy, with a special focus on virus-induced and virus-associated myocarditis. Furthermore, we identify knowledge gaps, appraise the available experimental models and propose future directions for the field. The current knowledge and open questions regarding the cardiovascular effects associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are also discussed. This Review is the result of scientific cooperation of members of the Heart Failure Association of the ESC, the Heart Failure Society of America and the Japanese Heart Failure Society.

Viral presence-guided immunomodulation in lymphocytic myocarditis: an update

Latest statements from European and American societies recommend to rule out viral presence in endomyocardial biopsy (EMB) via polymerase chain reaction (PCR) analysis before starting immunosuppression or immunomodulation in acute lymphocytic myocarditis presenting with life‐threatening scenarios. However, recommendations in myocarditis are mostly based on heterogeneous studies enrolling patients with inflammatory cardiomyopathies and established heart failure rather than acute myocarditis. Thus, definitive evidence of a survival benefit from immunomodulation guided by viral presence is currently lacking. Finally, distinguishing innocent bystanders from causative agents among EMB‐detected viruses remain challenging and a major goal to achieve in the near future. Therefore, considerable divergence remains between official recommendations and clinical practice, including the possibility of starting immunosuppressive therapy empirically, without knowing viral PCR results. This review systematically discusses the unsolved issues of immunomodulation guided by viral presence in acute lymphocytic myocarditis, namely (i) virus epidemiology and prognosis, (ii) variability of viral presence rates, (iii) the role of potential viral bystander findings, and (iv) the main results of immunosuppression controlled trials in lymphocytic myocarditis. Furthermore, a practical approach for the critical use of viral presence analysis in guiding immunomodulation is provided, highlighting its importance before starting immunosuppression or immunomodulation. Future, multicentre studies are needed to address specific scenarios such as fulminant lymphocytic myocarditis and a virus‐tailored management as for parvovirus B19.

A Toolbox of Potential Immune-Related Therapies for Inflammatory Cardiomyopathy

Myocarditis is a multifactorial disorder, characterized by an inflammatory reaction in the myocardium, predominantly triggered by infectious agents, but also by antigen mimicry or autoimmunity in susceptible individuals. Unless spontaneously resolved, a chronic inflammatory course concludes with cardiac muscle dysfunction portrayed by ventricular dilatation, clinically termed inflammatory cardiomyopathy (Infl-CM). Treatment strategies aim to resolve chronic inflammation and preserve cardiac function. Beside standard heart failure treatments, which only play a supportive role in this condition, systemic immunosuppressants are used to diminish inflammatory cell function at the cost of noxious side effects. To date, the treatment protocols are expert-based without large clinical evidence. This review describes concept and contemporary strategies to alleviate myocardial inflammation and sheds light on potential inflammatory targets in an evidence-based order.

Myocarditis in athletes: A clinical perspective

Myocarditis is an important cause of arrhythmias and sudden cardiac death (SCD) in both physically active individuals and athletes. Elite athletes seem to have an increased risk for viral infection and subsequent myocarditis due to increased exposure to pathogens (worldwide traveling/international competition) or impaired immune system (continuing training during infections/resuming training early thereafter, strenuous exercise training or competition, and exercising in extreme weather conditions). Initial clinical presentation is variable, but athletes characteristically express non-specific symptoms of fatigue, muscle soreness, increased heart rate at rest, as well as during exercise and reduced overall exercise capacity. Beyond resting electrocardiogram (ECG), cardiac biomarkers, echocardiography, and 24-hour Holter ECG, diagnostic work-up should include cardiac magnetic resonance imaging (CMR) assessing inflammation, oedema, and fibrosis by late gadolinium enhancement (LGE), respectively, as these measures are crucial for prognosis and sports eligibility. For patients with insufficient cardiac recovery, endomyocardial biopsy is recommended to clarify differential diagnoses and initiate specific treatment options. In uncomplicated cases with normal left ventricular function during acute phase and absent LGE, eligibility for sports can be attested to three months after clinical recovery. In those with persistent pathological findings, even after six months, the risk for SCD remains increased and resuming exercise beyond recreational activities can only be recommended individually based on course of disease, left ventricular function, arrhythmias, pattern of LGE in CMR, as well as intensity and volume of exercise performed during training and competition. For all athletes, follow-up examination should be performed yearly.