Comparison of Utilization Trends, Indications, and Complications of Endomyocardial Biopsy in Native Versus Donor Hearts (from the Nationwide Inpatient Sample 2002 to 2014)

Diagnostic accuracy, clinical characteristics, and prognostic differences of patients with acute myocarditis according to inclusion criteria

INTRODUCTION

The diagnosis of acute myocarditis (AM) is complex due to its heterogeneity and typically is defined by either Electronic Healthcare Records (EHRs) or advanced imaging and endomyocardial biopsy, but there is no consensus. We aimed to investigate the diagnostic accuracy of these approaches for AM.

METHODS

Data on ICD 10th Revision(ICD-10) codes corresponding to AM were collected from two hospitals and compared to cardiac magnetic resonance (CMR)-confirmed or clinically suspected (CS)-AM cases with respect to diagnostic accuracy, clinical characteristics, and all-cause mortality. Next, we performed a review of published AM studies according to inclusion criteria.

RESULTS

We identified 291 unique admissions with ICD-10 codes corresponding to AM in the first three diagnostic positions. The positive predictive value of ICD-10 codes for CMR-confirmed or CS-AM was 36%, and patients with CMR-confirmed or CS-AM had a lower all-cause mortality than those with a refuted diagnosis (P = 0.019). Using an unstructured approach, patients with CMR-confirmed and CS-AM had similar demographics, comorbidity profiles and survival over a median follow-up of 52 months (P = 0.72). Our review of the literature confirmed our findings. Outcomes for patients included in studies using CMR-confirmed criteria were favourable compared to studies with endomyocardial biopsy-confirmed AM cases.

CONCLUSION

ICD-10 codes have poor accuracy in identification of AM cases and should be used with caution in clinical research. There are important differences in management and outcomes of patients according to the selection criteria used to diagnose AM. Potential selection biases must be considered when interpreting AM cohorts and requires standardization of inclusion criteria for AM studies.

Autoimmune Myocarditis, Old Dogs and New Tricks

Autoimmunity significantly contributes to the pathogenesis of myocarditis, underscored by its increased frequency in autoimmune diseases such as systemic lupus erythematosus and polymyositis. Even in cases of myocarditis caused by viral infections, dysregulated immune responses contribute to pathogenesis. However, whether triggered by existing autoimmune conditions or viral infections, the precise antigens and immunologic pathways driving myocarditis remain incompletely understood. The emergence of myocarditis associated with immune checkpoint inhibitor therapy, commonly used for treating cancer, has afforded an opportunity to understand autoimmune mechanisms in myocarditis, with autoreactive T cells specific for cardiac myosin playing a pivotal role. Despite their self-antigen recognition, cardiac myosin-specific T cells can be present in healthy individuals due to bypassing the thymic selection stage. In recent studies, novel modalities in suppressing the activity of pathogenic T cells including cardiac myosin-specific T cells have proven effective in treating autoimmune myocarditis. This review offers an overview of the current understanding of heart antigens, autoantibodies, and immune cells as the autoimmune mechanisms underlying various forms of myocarditis, along with the latest updates on clinical management and prospects for future research.

Advances in injectable hydrogels for radiation-induced heart disease

Radiological heart damage (RIHD) is damage caused by unavoidable irradiation of the heart during chest radiotherapy, with a long latency period and a progressively increasing proportion of delayed cardiac damage due to conventional doses of chest radiotherapy. There is a risk of inducing diseases such as acute/chronic pericarditis, myocarditis, delayed myocardial fibrosis and damage to the cardiac conduction system in humans, which can lead to myocardial infarction or even death in severe cases. This paper details the pathogenesis of RIHD and gives potential targets for treatment at the molecular and cellular level, avoiding the drawbacks of high invasiveness and immune rejection due to drug therapy, medical device implantation and heart transplantation. Injectable hydrogel therapy has emerged as a minimally invasive tissue engineering therapy to provide necessary mechanical support to the infarcted myocardium and to act as a carrier for various bioactive factors and cells to improve the cellular microenvironment in the infarcted area and induce myocardial tissue regeneration. Therefore, this paper combines bioactive factors and cellular therapeutic mechanisms with injectable hydrogels, presents recent advances in the treatment of cardiac injury after RIHD with different injectable gels, and summarizes the therapeutic potential of various types of injectable hydrogels as a potential solution.

Chinese Society of Cardiology guidelines on the diagnosis and treatment of adult fulminant myocarditis

Fulminant myocarditis is an acute diffuse inflammatory disease of myocardium. It is characterized by acute onset, rapid progress and high risk of death. Its pathogenesis involves excessive immune activation of the innate immune system and formation of inflammatory storm. According to China's practical experience, the adoption of the "life support-based comprehensive treatment regimen" (with mechanical circulation support and immunomodulation therapy as the core) can significantly improve the survival rate and long-term prognosis. Special emphasis is placed on very early identification,very early diagnosis,very early prediction and very early treatment.

Heart failure in children and adolescents: an update on diagnostic approaches and management

Cardiac failure is a clinical syndrome that may develop in children owing to cardiac dysfunction or underlying structural heart diseases. Considering the differences in diagnostic and therapeutic approaches for pediatric heart failure (PHF) and adult heart failure, we have reviewed the current literature on PHF. Relevant studies were extracted from MEDLINE/PubMed, Google Scholar, and Clinical Trial Registries using the terms "pediatric heart failure" or "heart failure in children" and "management" or "decongestive therapy." Recent advances in diagnostic approaches, such as cardiac magnetic resonance, speckle-tracking echocardiography, tissue Doppler imaging, and molecular diagnostic techniques, have increased our under -standing of PHF. It is imperative that clinicians evaluate the interrelated factors responsible for the develop ment of PHF, including myocardial function, pulmonary and systemic blood flow, heart rhythm, valve function, and nutritional status. Although recent advances have demon strated the efficacy of many new drugs in adult heart failure trials, it cannot be concluded that these drugs will show similar efficacy in children, considering the heterogeneous nature of the underlying mechanisms and variable pharmacody-namics and pharmacokinetics. Therefore, the underlying pathophysiology of PHF and the mechanisms of action of different drugs should be considered when selecting appropriate therapies. Further trials are needed to establi sh the efficacy and safety of these drugs, and a combined mul-ti disciplinary strategy will help enhance PHF outcomes.

Early and Accurate Detection of Radiation-induced Heart Damage by Cardiodynamicsgram

Cardiodynamicsgram (CDG) has emerged recently as a noninvasive spatiotemporal electrocardiographic method for subtle cardiac dynamics information analysis within electrocardiogram (ECG). This study explored the feasibility of CDG for detecting radiation-induced heart damage (RIHD) in a rat model. A single radiation dose of 40 Gy was delivered to the cardiac apex of female Wistar rats. First, CDG was generated through dynamic modeling of ECG signals using the deterministic learning algorithm. Furthermore, CDG indexes were calculated using the wavelet transform and entropy. In this model, CDG entropy indexes decreased significantly after radiotherapy. The shape of CDG changed significantly after radiotherapy (irregular shape) compared with controls (regular shape). Macrophage and fibrosis in myocardium of rats increased significantly after radiotherapy. CDG changes after radiotherapy were significantly correlated with histopathological changes and occurred significantly earlier than histopathological changes. This study provides an experimental basis for the clinical application of CDG for the early detection of RIHD.

Red Flags in Acute Myocarditis

Acute myocarditis is an inflammatory disease of the heart that may occur in the setting of infection, immune system activation or exposure to certain drugs. Often, it is caused by viruses, whereby the clinical course is usually benign; however, it may also present with rapidly progressive fulminant myocarditis, which is associated with high morbidity and mortality. This review highlights the critical red flags - from the clinical, biochemical, imaging and histopathological perspectives - that should raise the index of suspicion of acute myocarditis. We also present an illustrative case of a young female patient with rapidly progressive cardiogenic shock requiring veno-arterial extracorporeal membrane oxygenation as a bridge to orthotopic heart transplantation. The patient showed no clinical or echocardiographic recovery signs and eventually underwent orthotopic heart transplantation. Furthermore, we elaborate on the classifications of acute myocarditis based on clinical presentation and histopathology classifications, focusing on identifying key red flags that will inform early diagnosis and appropriate management in such challenging cases.

A nationwide trend analysis on the usage of endomyocardial biopsy

BACKGROUND

Endomyocardial biopsy (EMB) is a safe procedure performed in diagnostic work-up of cardiac disease.

HYPOTHESIS

Data regarding temporal trends of total numbers, characteristics, in-hospital outcomes, and complications of patients undergoing EMB are sparse.

METHODS

The nationwide German inpatient sample (2005-2019) was used for this analysis. Patient cases of EBM during the 5-year cycles from 2005 to 2009, 2010 to 2014, and 2015 to 2019 were compared, and temporal trends regarding total numbers and presumable major and minor EMB-associated complications were investigated.

RESULTS

Overall, 67 745 EMB were performed in Germany 2005-2019. Total number of EMB increased from 3083 in 2005 to 5646 in 2019 (β 0.40 [95% confidence interval [CI] 0.37-0.43], p < .001). Among these EMB, 19 083 (28.2%) were performed during the period 2005-2009, 22 867 (33.7%) 2010-2014, and 25 795 (38.1%) between 2015 and 2019. The proportion of patients aged ≥70 years was highest 2015-2019 (2005-2009: 9.3%; 2010-2014: 13.8%; 2015-2019: 16.1%, p < .001) and the most aggravated comorbidity profile (Charlson Comorbidity Index 2.25 ± 1.93; 2.67 ± 2.14; 3.01 ± 2.29, p < .001) was also detected 2015-2019. Major complications occurred less often in the period 2015-2019 compared to 2005-2009 (odds ratio [OR] 0.921 [95% CI 0.893-0.950], p < .001), whereas minor complications were more frequently observed between 2015 and 2019 (OR 1.067 [95% CI 1.042-1.093], p < .001). While a decrease in major complications was detected irrespective of age, an increase in minor complications was identified only in patients between 30-59 years.

CONCLUSIONS

Annual numbers of EMB increased significantly in Germany 2005-2019. Patients who underwent EMB in recent years were older and showed an aggravated comorbidity profile accompanied by fewer major complications, underscoring safety of the procedure.

Fulminant myocarditis proven by early biopsy and outcomes

BACKGROUND AND AIMS

While endomyocardial biopsy (EMB) is recommended in adult patients with fulminant myocarditis, the clinical impact of its timing is still unclear.

METHODS

Data were collected from 419 adult patients with clinically suspected fulminant myocarditis admitted to intensive care units across 36 tertiary centres in 15 countries worldwide. The diagnosis of myocarditis was histologically proven in 210 (50%) patients, either by EMB (n = 183, 44%) or by autopsy/explanted heart examination (n = 27, 6%), and clinically suspected cardiac magnetic resonance imaging confirmed in 96 (23%) patients. The primary outcome of survival free of heart transplantation (HTx) or left ventricular assist device (LVAD) at 1 year was specifically compared between patients with early EMB (within 2 days after intensive care unit admission, n = 103) and delayed EMB (n = 80). A propensity score-weighted analysis was done to control for confounders.

RESULTS

Median age on admission was 40 (29-52) years, and 322 (77%) patients received temporary mechanical circulatory support. A total of 273 (65%) patients survived without HTx/LVAD. The primary outcome was significantly different between patients with early and delayed EMB (70% vs. 49%, P = .004). After propensity score weighting, the early EMB group still significantly differed from the delayed EMB group in terms of survival free of HTx/LVAD (63% vs. 40%, P = .021). Moreover, early EMB was independently associated with a lower rate of death or HTx/LVAD at 1 year (odds ratio of 0.44; 95% confidence interval: 0.22-0.86; P = .016).

CONCLUSIONS

Endomyocardial biopsy should be broadly and promptly used in patients admitted to the intensive care unit for clinically suspected fulminant myocarditis.

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.

Prostaglandin E2 and myocarditis; friend or foe?

This review article summarizes the role of prostaglandin E2 (PGE2) and its receptors (EP1-EP4) as it relates to the inflammatory cardiomyopathy, myocarditis. During the COVID-19 pandemic, the onset of myocarditis in a subset of patients prompted a debate on the use of nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen, which act to inhibit the actions of prostaglandins. This review aims to further understanding of the role of PGE2 in the pathogenesis or protection of the myocardium in myocarditis. Inflammatory cardiomyopathies encompass a broad spectrum of disorders, all characterized by cardiac inflammation. Therefore, for the purpose of this review, the authors have placed particular emphasis on etiologies of myocarditis where effects of PGE2 have been documented.

Viral Myocarditis and Dilated Cardiomyopathy as a Consequence-Changing Insights from Advanced Imaging

Advancements in quantitative cardiac magnetic resonance (CMR) have revolutionized the diagnosis and management of viral myocarditis. With the addition of T1 and T2 mapping parameters in the updated Lake Louise Criteria, CMR can diagnose myocarditis with superior diagnostic accuracy compared with endomyocardial biopsy, especially in stable patients. Additionally, the unique value of CMR tissue characterization continues to improve the diagnosis and risk stratification of myocarditis. This review will discuss new and ongoing developments in cardiovascular imaging and its application to noninvasive diagnosis, prognostication, and management of viral myocarditis and its complications.

Myocarditis post-COVID-19 vaccination

There has been much interest in the possible adverse events associated with available anti-coronavirus disease of 2019 (COVID-19) vaccines, given the rapid pace at which they had to be developed during the pandemic. One such adverse event is myocarditis post-COVID-19 vaccination. Several pathophysiological mechanisms have been proposed that might help us understand the relationship between the messenger ribonucleic acid (mRNA) vaccine and the occurrence of myocarditis, though we are yet to ascertain the causal link between them. Although the actual absolute incidence of myocarditis post-COVID-19 vaccination remains low among the large, general population that has been vaccinated, there has been a high relative incidence of this adverse event. We aim to review the existing literature and bring to light what we have so far understood with respect to the association between COVID-19 vaccination and myocarditis. This will help in better understanding the burden of the pathology along with alleviating apprehensions associated with it.

KEY MESSAGES

Diagnostic Approach for Suspected Acute Myocarditis: Considerations for Standardization and Broadening Clinical Spectrum

Myocarditis is most recognized in patients with moderate to severe, recent-onset heart failure. However, less typical presentations including myocardial infarction with normal coronary arteries and arrhythmias are important manifestations but less commonly recognized to be caused by myocarditis. Most cases of myocarditis can be self-limiting without specific treatment; however, appropriate identification of risk during the diagnostic process of myocarditis and once a diagnosis is established is of primordial importance to identify patients in need for more specific follow-up and management. We propose a flexible, multitiered approach to the diagnostic process, allowing for capturing of the spectrum of myocarditis at an early time-point, individualized use of diagnostic resources through disease severity phenotyping, and providing structured follow-up care once myocarditis is confirmed. Such diagnostic processes allow for identification of specific etiologies with potential therapeutic consequences or allows for the comprehension of disease chronicity by understanding genetic contributions or elements of persistent immune dysregulation and degree of cardiac damage. The article highlights the evolving field of immunophenotyping in myocarditis, generating a potential for the development of targeted therapeutic approaches. Currently long-term follow-up should be titrated to the refined risk assessments of patients with a diagnosis of myocarditis and includes arrhythmia monitoring and imaging when the results will likely impact management. Genetic testing should be considered in selected cases, and histologic diagnosis may be considered in nonresponders even at later stages.

[Long-term treatment of morphologically verified myocarditis: successes and probable errors. Case report]

Diagnosis and treatment of myocarditis can be challenging, including determining indications for heart transplantation. We present a 6-year medical history of a 54 years old patient with severe morphologically verified viral-negative lymphocytic myocarditis and systemic manifestations (onset of hemorrhagic vasculitis) combined with moderate coronary atherosclerosis, which regressed according to repeated coronary angiography. For 5 years, the patient received immunosuppressive therapy with methylprednisolone and azathioprine with a significant improvement. Repeated relapses of atrial fibrillation required correction of basic therapy and plasmapheresis. The disease was complicated by thyrotoxicosis and multi-organ dysfunction; the autopsy showed persistent myocarditis activity. The myocarditis is a chronic condition and requires a review of the treatment strategy at each stage.

Fulminant Myocarditis: When One Size Does Not Fit All - A Critical Review of the Literature

Fulminant myocarditis, rather than being a distinct form of myocarditis, is instead a peculiar clinical presentation of the disease. The definition of fulminant myocarditis has varied greatly in the last 20 years, leading to conflicting reports on prognosis and treatment strategies, mainly because of varied inclusion criteria in different studies. The main conclusion of this review is that fulminant myocarditis may be due to different histotypes and aetiologies that can be diagnosed only by endomyocardial biopsy and managed by aetiology-directed treatment. This life-threatening presentation requires rapid, targeted management both in the short term (mechanical circulatory support, inotropic and antiarrhythmic treatment and endomyocardial biopsy) and in the long term (including prolonged follow-up). Fulminant presentation has also recently been identified as a risk factor for worsened prognosis, even long after the resolution of the acute phase of myocarditis.

Multimodality imaging in acute myocarditis

The diagnosis of acute myocarditis often involves several noninvasive techniques that can provide information regarding volumes, ejection fraction, and tissue characterization. In particular, echocardiography is extremely helpful for the evaluation of biventricular volumes, strain and ejection fraction. Cardiac magnetic resonance, beyond biventricular volumes, strain, and ejection fraction allows to characterize myocardial tissue providing information regarding edema, hyperemia, and fibrosis. Contemporary cardiac computed tomography angiography (CCTA) can not only be extremely important for the assessment of coronary arteries, pulmonary arteries and aorta but also tissue characterization using CCTA can be an additional tool that can explain chest pain with a diagnosis of myocarditis.

Clinical Manifestations, Monitoring, and Prognosis: A Review of Cardiotoxicity After Antitumor Strategy

The development of various antitumor drugs has significantly improved the survival of patients with cancer. Many first-line chemotherapy drugs are cytotoxic and the cardiotoxicity is one of the most significant effects that could leads to poor prognosis and decreased survival rate. Cancer treatment include traditional anthracycline drugs, as well as some new targeted drugs such as trastuzumab and ICIs. These drugs may directly or indirectly cause cardiovascular injury through different mechanisms, and lead to increasing the risk of cardiovascular disease or accelerating the development of cardiovascular disease. Cardiotoxicity is clinically manifested by arrhythmia, decreased cardiac function, or even sudden death. The cardiotoxicity caused by traditional chemotherapy drugs such as anthracyclines are significantly known. The cardiotoxicity of some new antitumor drugs such like immune checkpoint inhibitors (ICIs) is also relatively clear and requiring further observation and verification. This review is focused on major three drugs with relatively high incidence of cardiotoxicity and poor prognosis and intended to provide an update on the clinical complications and outcomes of these drugs, and we innovatively summarize the monitoring status of survivors using these drugs and discuss the biomarkers and non-invasive imaging features to identify early cardiotoxicity. Finally, we summarize the prevention that decreasing antitumor drugs-induced cardiotoxicity.

Fulminant myocarditis in adults: a narrative review

Fulminant myocarditis (FM) is an uncommon syndrome characterized by sudden and severe hemodynamic compromise secondary to acute myocardial inflammation, often presenting as profound cardiogenic shock, life-threatening ventricular arrhythmias and/or electrical storm. FM may be refractory to conventional therapies and require mechanical circulatory support (MCS). The immune system has been recognized as playing a pivotal role in the pathophysiology of myocarditis, leading to an increased focus on immunosuppressive treatment strategies. Recent data have highlighted not only the fact that FM has significantly worse outcomes than non-FM, but that prognosis and management strategies of FM are heavily dependent on histological subtype, placing greater emphasis on the role of endomyocardial biopsy in diagnosis. The impact of subtype on severity and prognosis will likewise influence how aggressively the myocarditis is managed, including whether MCS is warranted. Many patients with refractory cardiogenic shock secondary to FM end up requiring MCS, with venoarterial extracorporeal membrane oxygenation demonstrating favorable survival rates, particularly when initiated prior to the development of multiorgan failure. Among the challenges facing the field are the need to more precisely identify immunopathophysiological pathways in order to develop targeted therapies, and the need to better optimize the timing and management of MCS to minimize complications and maximize outcomes.

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.

Safety evaluation of high-risk myocardial micro-biopsy in a swine model

The objective of the study was to investigate the safety profile of high-risk micro-endomyocardial biopsy (micro-EMB) compared to conventional EMB in a large animal model. Twenty pigs were subjected to a maximum of 30 consecutive biopsies, including sampling from the free ventricular wall, with either micro-EMB (n = 10) or conventional EMB (n = 10). There were no major complications in the micro-EMB group (0/10), compared to six major complications in the EMB group (6/10; p = 0.003). Survival analysis further highlighted these differences (p = 0.004). There were significantly higher volumes of pericardial effusion in the EMB group (p = 0.01). The study shows a safety advantage of micro-EMB compared to standard EMB in the experimental high-risk circumstances investigated in this animal study. These results indicate enhanced possibilities to collect samples from sensitive areas by using the micro-EMB technique instead of standard EMB.

Acute myocarditis: aetiology, diagnosis and management

Acute myocarditis is a serious, likely underdiagnosed condition affecting people of all ages and for which the number of UK hospital admissions is rising. A primary diagnosis of myocarditis accounted for 0.04% (36.5 per 100,000) of all hospital admissions in England between 1998 and 2017, although this is likely to be an underestimate of the true burden of myocarditis. The aetiology is broad, including infective and inflammatory conditions as well as exposure to toxic agents. Clinical features are varied and overlap with other acute cardiac conditions making diagnosis a challenge. Cardiovascular magnetic resonance imaging currently serves as the gold standard non-invasive diagnostic modality. If an underlying aetiological process is identified, then therapy may be directed at the cause; however, for most, treatment is supportive and aimed at managing any complications such as heart failure or arrhythmias. There is emerging evidence for immunosuppressive therapy in certain cases. Prognosis is generally good with recovery in most; however, up to 30% with biopsy-proven myocarditis progress to develop a dilated cardiomyopathy and its potential associated complications. All-cause mortality in the UK for patients presenting to hospital with acute myocarditis is approximately 4%.

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.

Expression profiles and functional analysis of plasma tRNA-derived small RNAs in children with fulminant myocarditis

Aim: Fulminant myocarditis (FM) has neither validated biomarkers nor well-established therapy. Roles of tRNA-derived small RNAs (tsRNAs) in FM remain unknown. Materials & methods: Small RNA sequencing was conducted in plasma from children with FM during acute and convalescent phase and matched healthy volunteers. Data were validated by quantitative real-time PCR in larger sample-sized groups and in vitro. Functional analysis was performed to explore the roles. Results: tiRNA-Gln-TTG-001 was overexpressed in children with FM during acute phase, and the generation and extracellular release of tiRNA-Gln-TTG-001 were higher after myocarditis-mimicked activity in vitro. Several pathways might participate in the pathogenesis of FM. Conclusion: tsRNAs may play an important role in FM, and tiRNA-Gln-TTG-001 might represent a novel and promising biomarker and therapeutic target.

Heart Failure Association of the ESC, Heart Failure Society of America and Japanese Heart Failure Society Position statement on endomyocardial biopsy

Endomyocardial biopsy (EMB) is an invasive procedure, globally most often used for the monitoring of heart transplant (HTx) rejection. In addition, EMB can have an important complementary role to the clinical assessment in establishing the diagnosis of diverse cardiac disorders, including myocarditis, cardiomyopathies, drug-related cardiotoxicity, amyloidosis, other infiltrative and storage disorders, and cardiac tumours. Improvements in EMB equipment and the development of new techniques for the analysis of EMB samples have significantly improved diagnostic precision of EMB. The present document is the result of the Trilateral Cooperation Project between the Heart Failure Association of the European Society of Cardiology, the Heart Failure Society of America, and the Japanese Heart Failure Society. It represents an expert consensus aiming to provide a comprehensive, up-to-date perspective on EMB, with a focus on the following main issues: (i) an overview of the practical approach to EMB, (ii) an update on indications for EMB, (iii) a revised plan for HTx rejection surveillance, (iv) the impact of multimodality imaging on EMB, and (v) the current clinical practice in the worldwide use of EMB.

Heart Failure Association, Heart Failure Society of America, and Japanese Heart Failure Society Position Statement on Endomyocardial Biopsy

Endomyocardial biopsy (EMB) is an invasive procedure, globally most often used for the monitoring of heart transplant rejection. In addition, EMB can have an important complementary role to the clinical assessment in establishing the diagnosis of diverse cardiac disorders, including myocarditis, cardiomyopathies, drug-related cardiotoxicity, amyloidosis, other infiltrative and storage disorders, and cardiac tumors. Improvements in EMB equipment and the development of new techniques for the analysis of EMB samples has significantly improved the diagnostic precision of EMB. The present document is the result of the Trilateral Cooperation Project between the Heart Failure Association of the European Society of Cardiology, Heart Failure Society of America, and the Japanese Heart Failure Society. It represents an expert consensus aiming to provide a comprehensive, up-to-date perspective on EMB, with a focus on the following main issues: (1) an overview of the practical approach to EMB, (2) an update on indications for EMB, (3) a revised plan for heart transplant rejection surveillance, (4) the impact of multimodality imaging on EMB, and (5) the current clinical practice in the worldwide use of EMB.

Micro-biopsy for detection of gene expression changes in ischemic swine myocardium: A pilot study

Micro-endomyocardial biopsy (micro-EMB) is a novel catheter-based biopsy technique, aiming to increase flexibility and safety compared to conventional EMB. The technique was developed and evaluated in healthy swine. Therefore, the ability to detect disease related tissue changes could not be evaluated. The aim of the present pilot study was to investigate the ability to detect disease related gene expression changes using micro-EMB. Myocardial infarction was induced in three swine by coronary artery balloon occlusion. Micro-EMB samples (n = 164) were collected before, during, and after occlusion. RNA-sequencing was performed on 85 samples, and 53 of these were selected for bioinformatic analysis. A large number of responding genes was detected from the infarcted area (n = 1911). The early responding genes (n = 1268) were mostly related to apoptosis and inflammation. There were fewer responding genes two days after infarction (n = 6), which were related to extra-cellular matrix changes, and none after 14 days. In contrast to the infarcted area, samples harvested from a non-infarcted myocardial region showed considerably fewer regulated genes (n = 33). Deconvolution analysis, to estimate the proportion of different cell types, revealed a higher proportion of fibroblasts and a reduced proportion of cardiomyocytes two days after occlusion compared to baseline (p < 0.02 and p < 0.01, respectively. S5 File). In conclusion, this pilot study demonstrates the capabilities of micro-EMB to detect local gene expression responses at an early stage after ischemia, but not at later timepoints.

The State of the Heart Biopsy: A Clinical Review

Endomyocardial biopsy (EMB) is an invaluable and underused diagnostic tool for myocardial disease. The primary indications are surveillance of cardiac allograft rejection and the diagnosis of inflammatory and infiltrative cardiomyopathies. EMB is typically performed by sampling the right ventricular septum via the right internal jugular vein using fluoroscopic guidance. The diagnostic yield of EMB is improved by sampling both ventricles and with the use of guidance from imaging or electroanatomic mapping. The risk of major cardiac complications is operator dependent and < 1% in experienced centres. EMB is the gold standard and most common form of cardiac allograft rejection surveillance, whereas advanced cardiac imaging and donor-specific antibody quantification provide complementary information. Gene expression profiling is an alternative surveillance strategy to EMB for low-risk patients. EMB is recommended for myocarditis and can guide therapy for giant-cell myocarditis, necrotizing eosinophilic myocarditis, sarcoidosis, and immune checkpoint inhibitor myocarditis. There is growing interest in using EMB to guide therapy for viral myocarditis, although the uptake of this approach is limited to specialized centres. EMB has been replaced as a first-line test for infiltrative cardiomyopathy by nonbiopsy diagnostic techniques, but is still useful to clarify the diagnosis or disease subtype. The miniaturization of bioptomes and advances in laboratory techniques such as microarrays promises to improve the safety and yield of EMB. We review the contemporary use of EMB for cardiac allograft rejection, inflammatory cardiomyopathy, and infiltrative cardiomyopathy.

Trends in post-heart transplant biopsies for graft rejection versus nonrejection

With alternatives such as gene profiling available for surveillance after orthotopic heart transplantation, we sought to evaluate the utilization of endomyocardial biopsies (EMBs) for hospitalized patients after heart transplantation. Surveillance EMBs in patients with and without complications were evaluated from the 2004 to 2014 National Inpatient Sample. Over the study period, there was no significant change in the number of EMB procedures performed (P = 0.44). Of 37,955 EMBs, 2283 (6%) were in the setting of graft complications, while 35,672 EMBs were not related to graft complications. EMBs in graft complications did not show a significant increase in length of stay over time (P = 0.06), but had a significant increase in cost over time (P = 0.001). However, those with graft complications had an average of a 5-day longer length of stay (P < 0.001) and costs that were $88,816 (P < 0.001) more expensive compared with those without graft complications. In conclusion, the vast majority of in-hospital EMBs were not related to heart transplantation complications. Nevertheless, EMB hospitalizations with graft complications showed significantly greater length of stay and cost. With the COVID-19 pandemic, it seems more effective to use minimal-contact health surveillance methods rather than invasive EMBs.

Markers of Immune Function in Heart Transplantation: Implications for Immunosuppression and Screening for Rejection

PURPOSE OF REVIEW

Recent developments in high-throughput DNA and RNA sequencing technologies have facilitated the development of noninvasive assays to monitor heart transplant rejection. In this review, we summarize existing assays employed for the surveillance of allograft rejection, as well as promising future directions for such tests in the molecular biology field.

RECENT FINDINGS

The AlloMap genome expression profiling assay remains the only noninvasive test for rejection surveillance and is incorporated into the International Society of Heart and Lung Transplantation guidelines. Other efforts have focused on messenger RNA (mRNA), microRNA (miRNA), and donor-derived cell-free DNA (dd-cfDNA) as potential viable biomarkers. Mitochondrial pathways in allograft necroptosis and inflammation signaling may represent a novel direction for future research endeavors. Although endomyocardial biopsy remains the gold standard, several converging areas of molecular biology could soon yield successful alternative methods of heart transplant rejection monitoring, with the distinct advantage of avoiding procedural complications.

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.

Fulminant Versus Acute Nonfulminant Myocarditis in Patients With Left Ventricular Systolic Dysfunction

BACKGROUND

Fulminant myocarditis (FM) is a form of acute myocarditis characterized by severe left ventricular systolic dysfunction requiring inotropes and/or mechanical circulatory support. A single-center study found that a patient with FM had better outcomes than those with acute nonfulminant myocarditis (NFM) presenting with left ventricular systolic dysfunction, but otherwise hemodynamically stable. This was recently challenged, so disagreement still exists.

OBJECTIVES

This study sought to provide additional evidence on the outcome of FM and to ascertain whether patient stratification based on the main histologic subtypes can provide additional prognostic information.

METHODS

A total of 220 patients (median age 42 years, 46.3% female) with histologically proven acute myocarditis (onset of symptoms <30 days) all presenting with left ventricular systolic dysfunction were included in a retrospective, international registry comprising 16 tertiary hospitals in the United States, Europe, and Japan. The main endpoint was the occurrence of cardiac death or heart transplantation within 60 days from admission and at long-term follow-up.

RESULTS

Patients with FM (n = 165) had significantly higher rates of cardiac death and heart transplantation compared with those with NFM (n = 55), both at 60 days (28.0% vs. 1.8%, p = 0.0001) and at 7-year follow-up (47.7% vs. 10.4%, p < 0.0001). Using Cox multivariate analysis, the histologic subtype emerged as a further variable affecting the outcome in FM patients, with giant cell myocarditis having a significantly worse prognosis compared with eosinophilic and lymphocytic myocarditis. In a subanalysis including only adults with lymphocytic myocarditis, the main endpoints occurred more frequently in FM compared with in NFM both at 60 days (19.5% vs. 0%, p = 0.005) and at 7-year follow up (41.4% vs. 3.1%, p = 0.0004).

CONCLUSIONS

This international registry confirms that patients with FM have higher rates of cardiac death and heart transplantation both in the short- and long-term compared with patients with NFM. Furthermore, we provide evidence that the histologic subtype of FM carries independent prognostic value, highlighting the need for timely endomyocardial biopsy in this condition.

Myocardial micro-biopsy procedure for molecular characterization with increased precision and reduced trauma

Endomyocardial biopsy is a valuable tool in cardiac diagnostics but is limited by low diagnostic yield and significant complication risks. Meanwhile, recent developments in transcriptomic and proteomic technologies promise a wealth of biological data from minimal tissue samples. To take advantage of the minimal tissue amount needed for molecular analyses, we have developed a sub-millimeter endovascular biopsy device, considerably smaller than current clinical equipment, and devised a low-input RNA-sequencing protocol for analyzing small tissue samples. In in vivo evaluation in swine, 81% of biopsy attempts (n = 157) were successful. High quality RNA-sequencing data was generated from 91% of the sequenced cardiac micro-biopsy samples (n = 32). Gene expression signatures of samples taken with the novel device were comparable with a conventional device. No major complications were detected either during procedures or during 7 days' follow-up, despite acquiring a relatively large number of biopsies (median 30) in each animal. In conclusion, the novel device coupled with RNA-sequencing provides a feasible method to obtain molecular data from the myocardium. The method is less traumatic and has a higher flexibility compared to conventional methods, enabling safer and more targeted sampling from different parts of the myocardium.

Diagnostic value of myocardial strain using two-dimensional speckle-tracking echocardiography in acute cardiac allograft rejection: A systematic review and meta-analysis

BACKGROUND

Two-dimensional speckle-tracking echocardiography (2D STE) has been demonstrated to have certain diagnostic utility in heart transplantation (HTX) patients with acute cardiac allograft rejection (ACAR). The aim of the systematic review and meta-analysis was to evaluate the diagnostic value of common strain parameters for ACAR in HTX patients.

METHODS

After conducting a database search, we selected studies evaluating left ventricular global longitudinal strain (GLS), circumferential strain (CS), radial strain (RS), and free wall right ventricular longitudinal strain (RV FW) in rejection group vs rejection-free group.

RESULTS

After reviewing 886 publications, seven studies were finally included in the meta-analysis, representing the data of 1173 pairs of endomyocardial biopsy and echocardiographic examination. Heart transplantation patients with rejection had significantly lower GLS than rejection-free subjects (weighted mean difference -2.32 (95% CI, -3.41 to -1.23; P < .001). Heart transplantation patients with rejection had significantly lower CS than rejection-free subjects (weighted mean difference -2.49 (95% CI, -4.05 to -0.91; P = .0019). In addition, HTX patients with rejection also had significantly lower RV FW (weighted mean difference -4.90 (95% CI, -6.15 to -3.65; P < .001).

CONCLUSIONS

The meta-analysis and systematic review demonstrate that myocardial strain parameters derived from 2D STE may be useful in detecting ACAR in HTX patients. The present results provide encouraging evidence to consider the routine use of GLS, CS, and RV FW as markers of graft function involvement during ACAR.

Cardiac Interventional Procedures in Cardio-Oncology Patients

Comorbidities specific to the cardio-oncology population contribute to the challenges in the interventional management of patients with cancer and cardiovascular disease (CVD). Patients with cancer have generally been excluded from cardiovascular randomized clinical trials. Endovascular procedures may represent a valid option in patients with cancer with a range of CVDs because of their minimally invasive nature. Patients with cancer are less likely to be treated according to societal guidelines because of perceived high risk. This article presents the specific challenges that interventional cardiologists face when caring for patients with cancer and the modern tools to optimize care.

Non-typhoidal Salmonella myocarditis in an immunocompetent young adult with diarrhea

Myocarditis is the inflammation of the heart muscle and it is caused by a wide range of infectious and non-infectious conditions. Non-typhoidal Salmonella infection, a common foodborne illness worldwide, only rarely causes myocarditis. We describe a case of an immunocompetent adult with Salmonella enterica serovar Typhimurium myocarditis who had a favorable outcome due to early recognition of the causative factor and prompt initiation of appropriate treatment.

Clinical Presentation and Outcome in a Contemporary Cohort of Patients With Acute Myocarditis: Multicenter Lombardy Registry

BACKGROUND

There is controversy about the outcome of patients with acute myocarditis (AM), and data are lacking on how patients admitted with suspected AM are managed. We report characteristics, in-hospital management, and long-term outcome of patients with AM based on a retrospective multicenter registry from 19 Italian hospitals.

METHODS

A total of 684 patients with suspected AM and recent onset of symptoms (<30 days) were screened between May 2001 and February 2017. Patients >70 years of age and those >50 years of age without coronary angiography were excluded. The final study population comprised 443 patients (median age, 34 years; 19.4% female) with AM diagnosed by either endomyocardial biopsy or increased troponin plus edema and late gadolinium enhancement at cardiac magnetic resonance.

RESULTS

At presentation, 118 patients (26.6%) had left ventricular ejection fraction <50%, sustained ventricular arrhythmias, or a low cardiac output syndrome, whereas 325 (73.4%) had no such complications. Endomyocardial biopsy was performed in 56 of 443 (12.6%), and a baseline cardiac magnetic resonance was performed in 415 of 443 (93.7%). Cardiac mortality plus heart transplantation rates at 1 and 5 years were 3.0% and 4.1%. Cardiac mortality plus heart transplantation rates were 11.3% and 14.7% in patients with complicated presentation and 0% in uncomplicated cases (log-rank P<0.0001). Major AM-related cardiac events after the acute phase (postdischarge death and heart transplantation, sustained ventricular arrhythmias treated with electric shock or ablation, symptomatic heart failure needing device implantation) occurred in 2.8% at the 5-year follow-up, with a higher incidence in patients with complicated forms (10.8% versus 0% in uncomplicated AM; log-rank P<0.0001). β-Adrenoceptor blockers were the most frequently used medications both in complicated (61.9%) and in uncomplicated forms (53.8%; P=0.18). After a median time of 196 days, 200 patients had follow-up cardiac magnetic resonance, and 8 of 55 (14.5%) with complications at presentation had left ventricular ejection fraction <50% compared with 1 of 145 (0.7%) of those with uncomplicated presentation.

CONCLUSIONS

In this contemporary study, overall serious adverse events after AM were lower than previously reported. However, patients with left ventricular ejection fraction <50%, ventricular arrhythmias, or low cardiac output syndrome at presentation were at higher risk compared with uncomplicated cases that had a benign prognosis and low risk of subsequent left ventricular systolic dysfunction.

Acute and Fulminant Myocarditis: a Pragmatic Clinical Approach to Diagnosis and Treatment

PURPOSE OF REVIEW

To review the clinical features of acute myocarditis, including its fulminant presentation, and present a pragmatic approach to the diagnosis and treatment, considering indications of American and European Scientific Statements and recent data derived by large contemporary registries.

RECENT FINDINGS

Patients presenting with acute uncomplicated myocarditis (i.e., without left ventricular dysfunction, heart failure, or ventricular arrhythmias) have a favorable short- and long-term prognosis: these findings do not support the indication to endomyocardial biopsy in this clinical scenario. Conversely, patients with complicated presentations, especially those with fulminant myocarditis, require an aggressive and comprehensive management, including endomyocardial biopsy and availability of advanced therapies for circulatory support. Although several immunomodulatory or immunosuppressive therapies have been studied and are actually prescribed in the real-world practice, their effectiveness has not been clearly demonstrated. Patients with specific histological subtypes of acute myocarditis (i.e., giant cell and eosinophilic myocarditis) or those affected by sarcoidosis or systemic autoimmune disorders seem to benefit most from immunosuppression. On the other hand, no clear evidence supports the use of immunosuppressive agents in patients with lymphocytic acute myocarditis, even though small series suggest a potential benefit. Acute myocarditis is a heterogeneous condition with distinct pathophysiological pathways. Further research is mandatory to identify factors and mechanisms that may trigger/maintain or counteract/repair the myocardial damage, in order to provide a rational for future evidence-based treatment of patients affected by this condition.

Feasibility of Performing Radiofrequency Catheter Ablation and Endomyocardial Biopsy in the Same Setting

In patients with unexplained cardiomyopathy, electroanatomical mapping can identify abnormal tissue to target during electrophysiology-guided endomyocardial biopsy (EP-guided EMB). The objective of this study is to determine whether catheter ablation performed in the same setting as EP-guided EMB increases procedural risk. Sixty-seven patients (mean age 54.4 ± 13.8, 57% male) undergoing EP-guided EMB were included. Radiofrequency catheter ablation was performed in 17 patients (25%) for ventricular arrhythmias and in 2 (3%) for typical atrial flutter. Femoral arterial access was obtained in 90% ablation patients and 40% biopsy-only patients; vascular access complications were more common in the ablation group than in the EMB-only group (p = 0.02). There were no significant differences in rate of tricuspid regurgitation, thromboembolism, or pericardial effusion, whether procedural anticoagulation was used. In conclusion, catheter ablation and procedural anticoagulation can be combined with EP-guided EMB with an increased risk of vascular access complications, but no significant increase in intracardiac complications.