Arrhythmic Manifestations and Outcomes of Definite and Probable Cardiac Sarcoidosis

BACKGROUND

The 2014 HRS consensus statement defines histological (definite) and clinical (probable) diagnostic categories of cardiac sarcoidosis (CS), but few studies have compared their arrhythmic phenotypes and outcomes.

OBJECTIVE

Evaluate the electrophysiologic/arrhythmic phenotype and outcomes of patients with definite and probable CS.

METHODS

We analyzed the arrhythmic/electrophysiologic phenotype in a single-center North American cohort of 388 patients (median age 56 years, 39% female) diagnosed with definite (n=58) or probable (n=330) CS (2000-2022). The primary composite outcome was survival to first ventricular tachycardia/fibrillation (VT/VF) or sudden cardiac death (SCD). Key secondary outcomes were also assessed.

RESULTS

At index evaluation, in situ cardiac implantable electronic devices and antiarrhythmic drug use were more common in definite CS. At median follow-up 3.1 years, the primary outcome occurred in 22 (38%) definite and 127 (38%) probable CS patients (log-rank p=0.55). In multivariable analysis, only higher 18F-FDG SUVmax myocardium:SUVmax blood pool ratio (HR 1.09 [95% CI 1.03, 1.15], p=0.003, per 1 unit increase) was associated with the primary outcome. During follow-up, definite CS patients had higher burden of device-treated VT/VF events (mean 2.86 vs 1.56 per patient-year) and higher rate of progression to heart transplant/left ventricular assist device implantation, but no difference in all-cause mortality compared to probable CS patients.

CONCLUSION

Definite and probable CS patients had similarly high risks of first sustained VT/VF/SCD and all-cause death though definite CS patients had a higher overall arrhythmic burden. Both CS diagnostic groups as defined by the 2014 HRS criteria require an aggressive approach to prevent arrhythmic complications.

Exercise After Acute Myocarditis: When and How to Return to Sports

Myocarditis is an inflammatory disease of the myocardium secondary to infectious and noninfectious insults. The most feared consequence of myocarditis is sudden cardiac death owing to electrical instability and arrhythmia. Typical presenting symptoms include chest pain, dyspnea, palpitations and/or heart failure. Diagnosis is usually made with history, electrocardiogram, biomarkers, echocardiogram, and cardiac MRI (CMR). Application of the Lake Louise criteria to CMR results can help identify cases of myocarditis. Treatment is usually supportive with medical therapy, and patients are recommended to abstain from exercise for 3 to 6 months. Exercise restrictions may be lifted after normalization on follow-up testing.

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.

Sex differences in left-ventricular strain in a murine model of coxsackievirus B3 myocarditis

Myocarditis is typically caused by viral infections, but most cases are thought to be subclinical. Echocardiography is often used for initial assessment of myocarditis patients but is poor at detecting subtle changes in cardiac dysfunction. Cardiac strain, such as global longitudinal strain (GLS) and global circumferential strain (GCS), represents an increasingly used set of measurements which can detect these subtle changes. Using a murine model of coxsackievirus B3 myocarditis, we characterized functional changes in the heart using echocardiography during myocarditis and by sex. We found that 2D GLS, 4D mode, and 4D strains detected a significant reduction in ejection fraction and GLS during myocarditis compared to baseline and in males compared to females. Furthermore, worse GLS correlated to increased levels of CD45+, CD11b+, and CD3+ immune cells. Our findings closely resemble published reports of GLS in patients with myocarditis indicating the usefulness of this animal model for translational studies of myocarditis.

Reconstituted Extracellular Vesicles from Human Platelets Decrease Viral Myocarditis in Mice

Patients with viral myocarditis are at risk of sudden death and may progress to dilated cardiomyopathy (DCM). Currently, no disease-specific therapies exist to treat viral myocarditis. Here it is examined whether reconstituted, lyophilized extracellular vesicles (EVs) from platelets from healthy men and women reduce acute or chronic myocarditis in male mice. Human-platelet-derived EVs (PEV) do not cause toxicity, damage, or inflammation in naïve mice. PEV administered during the innate immune response significantly reduces myocarditis with fewer epidermal growth factor (EGF)-like module-containing mucin-like hormone receptor-like 1 (F4/80) macrophages, T cells (cluster of differentiation molecules 4 and 8, CD4 and CD8), and mast cells, and improved cardiac function. Innate immune mediators known to increase myocarditis are decreased by innate PEV treatment including Toll-like receptor (TLR)4 and complement. PEV also significantly reduces perivascular fibrosis and remodeling including interleukin 1 beta (IL-1β), transforming growth factor-beta 1, matrix metalloproteinase, collagen genes, and mast cell degranulation. PEV given at days 7-9 after infection reduces myocarditis and improves cardiac function. MicroRNA (miR) sequencing reveals that PEV contains miRs that decrease viral replication, TLR4 signaling, and T-cell activation. These data show that EVs from the platelets of healthy individuals can significantly reduce myocarditis and improve cardiac function.

Myocardial Recovery in Recent Onset Dilated Cardiomyopathy: Role of CDCP1 and Cardiac Fibrosis

BACKGROUND

Dilated cardiomyopathy (DCM) is a major cause of heart failure and carries a high mortality rate. Myocardial recovery in DCM-related heart failure patients is highly variable, with some patients having little or no response to standard drug therapy. A genome-wide association study may agnostically identify biomarkers and provide novel insight into the biology of myocardial recovery in DCM.

METHODS

A genome-wide association study for change in left ventricular ejection fraction was performed in 686 White subjects with recent-onset DCM who received standard pharmacotherapy. Genome-wide association study signals were subsequently functionally validated and studied in relevant cellular models to understand molecular mechanisms that may have contributed to the change in left ventricular ejection fraction.

RESULTS

The genome-wide association study identified a highly suggestive locus that mapped to the 5'-flanking region of the CDCP1 (CUB [complement C1r/C1s, Uegf, and Bmp1] domain containing protein 1) gene (rs6773435; P=7.12×10-7). The variant allele was associated with improved cardiac function and decreased CDCP1 transcription. CDCP1 expression was significantly upregulated in human cardiac fibroblasts (HCFs) in response to the PDGF (platelet-derived growth factor) signaling, and knockdown of CDCP1 significantly repressed HCF proliferation and decreased AKT (protein kinase B) phosphorylation. Transcriptomic profiling after CDCP1 knockdown in HCFs supported the conclusion that CDCP1 regulates HCF proliferation and mitosis. In addition, CDCP1 knockdown in HCFs resulted in significantly decreased expression of soluble ST2 (suppression of tumorigenicity-2), a prognostic biomarker for heart failure and inductor of cardiac fibrosis.

CONCLUSIONS

CDCP1 may play an important role in myocardial recovery in recent-onset DCM and mediates its effect primarily by attenuating cardiac fibrosis.

Cardiac fludeoxyglucose-18 positron emission tomography in genotype-positive arrhythmogenic cardiomyopathy

BACKGROUND

Myocardial inflammation contributes to the pathogenesis of arrhythmogenic cardiomyopathy (ACM), a clinically and genetically heterogenous disorder. Due to phenotypic overlap, some patients with genetic ACM may be evaluated for an underlying inflammatory cardiomyopathy. However, the cardiac fludeoxyglucose (FDG) positron emission tomography (PET) findings in ACM patients have not been elucidated.

METHODS

All genotype-positive patients in the Mayo Clinic ACM registry (n = 323) who received a cardiac FDG PET were included in this study. Pertinent data were extracted from the medical record.

RESULTS

Collectively, 12/323 (4%; 67% female) genotype-positive ACM patients received a cardiac PET FDG scan as part of their clinical evaluation (median age at scan 49 ± 13 years). Amongst these patients, pathogenic/likely pathogenic variants were detected in LMNA (n = 7), DSP (n = 3), FLNC (n = 1) and PLN (n = 1). Of note, 6/12 (50%) had abnormal myocardial FDG uptake, including diffuse (entire myocardium) uptake in 2/6 (33%), focal (1-2 segments) uptake in 2/6 (33%) and patchy (3+ segments) in 2/6 (33%). Median myocardial standardized uptake value ratio was 2.1. Interestingly, LMNA-positive patients accounted for 3 out of 6 (50%) positive studies (diffuse uptake in 2 and focal uptake in 1).

CONCLUSION

Abnormal myocardial FDG uptake is common in genetic ACM patients undergoing cardiac FDG PET. This study further supports the role of myocardial inflammation in ACM. Further investigation is needed to determine role of FDG PET in diagnosis and management of ACM and investigate the role of inflammation in ACM.

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.

COVID-19, Myocarditis and Pericarditis

Viral infections are a leading cause of myocarditis and pericarditis worldwide, conditions that frequently coexist. Myocarditis and pericarditis were some of the early comorbidities associated with SARS-CoV-2 infection and COVID-19. Many epidemiologic studies have been conducted since that time concluding that SARS-CoV-2 increased the incidence of myocarditis/pericarditis at least 15× over pre-COVID levels although the condition remains rare. The incidence of myocarditis pre-COVID was reported at 1 to 10 cases/100 000 individuals and with COVID ranging from 150 to 4000 cases/100 000 individuals. Before COVID-19, some vaccines were reported to cause myocarditis and pericarditis in rare cases, but the use of novel mRNA platforms led to a higher number of reported cases than with previous platforms providing new insight into potential pathogenic mechanisms. The incidence of COVID-19 vaccine-associated myocarditis/pericarditis covers a large range depending on the vaccine platform, age, and sex examined. Importantly, the findings highlight that myocarditis occurs predominantly in male patients aged 12 to 40 years regardless of whether the cause was due to a virus-like SARS-CoV-2 or associated with a vaccine-a demographic that has been reported before COVID-19. This review discusses findings from COVID-19 and COVID-19 vaccine-associated myocarditis and pericarditis considering the known symptoms, diagnosis, management, treatment, and pathogenesis of disease that has been gleaned from clinical research and animal models. Sex differences in the immune response to COVID-19 are discussed, and theories for how mRNA vaccines could lead to myocarditis/pericarditis are proposed. Additionally, gaps in our understanding that need further research are raised.

Myocardial Inflammation as a Manifestation of Genetic Cardiomyopathies: From Bedside to the Bench

Over recent years, preclinical and clinical evidence has implicated myocardial inflammation (M-Infl) in the pathophysiology and phenotypes of traditionally genetic cardiomyopathies. M-Infl resembling myocarditis on imaging and histology occurs frequently as a clinical manifestation of classically genetic cardiac diseases, including dilated and arrhythmogenic cardiomyopathy. The emerging role of M-Infl in disease pathophysiology is leading to the identification of druggable targets for molecular treatment of the inflammatory process and a new paradigm in the field of cardiomyopathies. Cardiomyopathies constitute a leading cause of heart failure and arrhythmic sudden death in the young population. The aim of this review is to present, from bedside to bench, the current state of the art about the genetic basis of M-Infl in nonischemic cardiomyopathies of the dilated and arrhythmogenic spectrum in order to prompt future research towards the identification of novel mechanisms and treatment targets, with the ultimate goal of lowering disease morbidity and mortality.

18F-FDG/13N-ammonia cardiac PET findings in ATTR cardiac amyloidosis

18F-flurodeoxyglycose (FDG)/13N-ammonia positron emission tomography/computed tomography (PET/CT) is frequently utilized to evaluate cardiac sarcoidosis (CS) but findings can reflect other forms of myocardial inflammation or altered myocardial metabolic activity. Herein, we present five cases where cardiac PET findings suggested CS, but right ventricular endomyocardial biopsy samples revealed ATTR-type cardiac amyloidosis.

Sex and age differences in sST2 in cardiovascular disease

Aims

The goal of this study was to determine whether sex and age differences exist for soluble ST2 (sST2) for several cardiovascular diseases (CVDs).

Methods

We examined sST2 levels using an ELISA kit for myocarditis (n = 303), cardiomyopathy (n = 293), coronary artery disease (CAD) (n = 239), myocardial infarct (MI) (n = 159), and congestive heart failure (CHF) (n = 286) and compared them to controls that did not have CVDs (n = 234).

Results

Myocarditis occurred in this study in relatively young patients around age 40 while the other CVDs occurred more often in older individuals around age 60. We observed a sex difference in sST2 by age only in myocarditis patients (men aged 38, women 46, p = 0.0002), but not for other CVDs. Sera sST2 levels were significantly elevated compared to age-matched controls for all CVDs: myocarditis (p ≤ 0.0001), cardiomyopathy (p = 0.0009), CAD (p = 0.03), MI (p = 0.034), and CHF (p < 0.0001) driven by elevated sST2 levels in females for all CVDs except myocarditis, which was elevated in both females (p = 0.002) and males (p ≤ 0.0001). Sex differences in sST2 levels were found for myocarditis and cardiomyopathy but no other CVDs and were higher in males (myocarditis p = 0.0035; cardiomyopathy p = 0.0047). sST2 levels were higher in women with myocarditis over 50 years of age compared to men (p = 0.0004) or women under 50 years of age (p = 0.015). In cardiomyopathy and MI patients, men over 50 had significantly higher levels of sST2 than women (p = 0.012 and p = 0.043, respectively) but sex and age differences were not detected in other CVDs. However, women with cardiomyopathy that experienced early menopause had higher sST2 levels than those who underwent menopause at a natural age range (p = 0.02).

Conclusion

We found that sex and age differences in sera sST2 exist for myocarditis, cardiomyopathy, and MI, but were not observed in other CVDs including CAD and CHF. These initial findings in patients with self-reported CVDs indicate that more research is needed into sex and age differences in sST2 levels in individual CVDs.

Sex and gender differences in myocarditis and dilated cardiomyopathy: An update

In the past decade there has been a growing interest in understanding sex and gender differences in myocarditis and dilated cardiomyopathy (DCM), and the purpose of this review is to provide an update on this topic including epidemiology, pathogenesis and clinical presentation, diagnosis and management. Recently, many clinical studies have been conducted examining sex differences in myocarditis. Studies consistently report that myocarditis occurs more often in men than women with a sex ratio ranging from 1:2-4 female to male. Studies reveal that DCM also has a sex ratio of around 1:3 women to men and this is also true for familial/genetic forms of DCM. Animal models have demonstrated that DCM develops after myocarditis in susceptible mouse strains and evidence exists for this progress clinically as well. A consistent finding is that myocarditis occurs primarily in men under 50 years of age, but in women after age 50 or post-menopause. In contrast, DCM typically occurs after age 50, although the age that post-myocarditis DCM occurs has not been investigated. In a small study, more men with myocarditis presented with symptoms of chest pain while women presented with dyspnea. Men with myocarditis have been found to have higher levels of heart failure biomarkers soluble ST2, creatine kinase, myoglobin and T helper 17-associated cytokines while women develop a better regulatory immune response. Studies of the pathogenesis of disease have found that Toll-like receptor (TLR)2 and TLR4 signaling pathways play a central role in increasing inflammation during myocarditis and in promoting remodeling and fibrosis that leads to DCM, and all of these pathways are elevated in males. Management of myocarditis follows heart failure guidelines and there are currently no disease-specific therapies. Research on standard heart failure medications reveal important sex differences. Overall, many advances in our understanding of the effect of biologic sex on myocarditis and DCM have occurred over the past decade, but many gaps in our understanding remain. A better understanding of sex and gender effects are needed to develop disease-targeted and individualized medicine approaches in the future.

Myocarditis and pericarditis recovery following smallpox vaccine 2002-2016: A comparative observational cohort study in the military health system

OBJECTIVES

(1) Characterize the initial clinical characteristics and long-term outcomes of smallpox vaccine-associated hypersensitivity myocarditis and pericarditis (MP) in United States service members. (2) Describe the process of case identification and adjudication using the 2003 CDC nationally defined myocarditis/pericarditis epidemiologic case definitions to include consideration of case-specific diversity and evolving evidence.

BACKGROUND

Between 2002 and 2016, 2.546 million service members received a smallpox Vaccinia vaccine. Acute MP is associated with vaccinia, but the long-term outcomes have not been studied.

METHODS

Records of vaccinia-associated MP reported to the Vaccine Adverse Event Reporting System by vaccination date were adjudicated using the 2003 MP epidemiologic case definitions for inclusion in a retrospective observational cohort study. Descriptive statistics of clinical characteristics, presentation, cardiac complications, and time course of clinical and cardiac recovery were calculated with comparisons by gender, diagnosis and time to recovery.

RESULTS

Out of over 5000 adverse event reports, 348 MP cases who survived the acute illness, including 276 myocarditis (99.6% probable/confirmed) and 72 pericarditis (29.2% probable/confirmed), were adjudicated for inclusion in the long-term follow-up. Demographics included a median age of 24 years (IQR 21,30) and male predominance (96%). Compared to background military population, the myocarditis and pericarditis cohort had a higher percentage of white males by 8.2% (95% CI: 5.6, 10.0) and age <40 years by 4.2% (95% CI: 1.7,5.8). Long-term follow-up documented full recovery in 267/306 (87.3%) with 74.9% recovered in less than a year (median ~3 months). Among patients with myocarditis, the percentage who had a delayed time to recovery at time of last follow-up was 12.8% (95% CI: 2.1,24.7) higher in those with an acute left ventricular ejection fraction (EF) of ≤50% and 13.5% (95% CI: 2.4,25.7) higher in those with hypokinesis. Patient complications included 6 ventricular arrhythmias (2 received implanted defibrillators) and 14 with atrial arrhythmias (2 received radiofrequency ablation). Three of 6 patients (50%) diagnosed with cardiomyopathy had clinical recovery at their last follow-up date.

CONCLUSIONS

Hypersensitivity myocarditis/pericarditis following the smallpox vaccine is associated with full clinical and functional ventricular recovery in over 87% of cases (74.9% <1 year). A minority of MP cases experienced prolonged or incomplete recovery beyond 1 year.

Extracellular vesicles as personalized medicine

Extracellular vesicles (EVs) are released from all cells in the body, forming an important intercellular communication network that contributes to health and disease. The contents of EVs are cell source-specific, inducing distinct signaling responses in recipient cells. The specificity of EVs and their accumulation in fluid spaces that are accessible for liquid biopsies make them highly attractive as potential biomarkers and therapies for disease. The duality of EVs as favorable (therapeutic) or unfavorable (pathological) messengers is context dependent and remains to be fully determined in homeostasis and various disease states. This review describes the use of EVs as biomarkers, drug delivery vehicles, and regenerative therapeutics, highlighting examples involving viral infections, cancer, and neurological diseases. There is growing interest to provide personalized therapy based on individual patient and disease characteristics. Increasing evidence suggests that EV biomarkers and therapeutic approaches are ideal for personalized medicine due to the diversity and multifunctionality of EVs.

Inflammation on Endomyocardial Biopsy Predicts Risk of MACE in Undefined Left Ventricular Arrhythmogenic Cardiomyopathy

BACKGROUND

Predictors of major adverse cardiovascular events (MACE) in patients with undefined left ventricular arrhythmogenic cardiomyopathy (ULVACM) have not been described.

OBJECTIVES

The purpose of this study was to investigate the prognostic value of genetic testing and histology in a cohort of ULVACM patients.

METHODS

We identified 313 patients with ULVACM defined by new-onset ventricular arrhythmia (VA), nonischemic pattern of late gadolinium enhancement limited to the left ventricle (LV), and no severe dilated cardiomyopathy (LV ejection fraction ≥40%) from a retrospective multicenter registry. Patients undergoing next generation sequencing (NGS) for cardiomyopathy genes and endomyocardial biopsy (EMB) were compared with subjects without these studies. The primary endpoint was the occurrence of MACE, defined as the composite of cardiac death, heart transplantation, and malignant VA (ventricular tachycardia, ventricular fibrillation, appropriate implantable cardioverter-defibrillator treatment), at 60 months after clinical presentation.

RESULTS

Of the whole cohort (age 46 ± 14 years, 63% men, LV ejection fraction 55% ± 7%), 160 (51%) and 198 patients (63%), respectively, underwent NGS and EMB. NGS identified pathogenic or likely-pathogenic cardiomyopathy variants (pathogenic variants/likely pathogenic variants) in 25 of 160 cases (16%). EMB showed active myocardial inflammation (AM) in 102 of 198 patients (52%), 47 of whom (46%) received immunosuppressive therapy. After 58-month median follow-up, 93 of 313 patients (30%) experienced MACE. On multivariable analysis, presentation with malignant VA and EMB-proven AM were positively associated with the primary endpoint (HR: 2.8; 95% CI: 1.4-5.5; P = 0.003; and HR: 3.9; 95% CI: 1.9-7.5; P < 0.001, respectively), whereas immunosuppressive therapy showed a reverse association with MACE at 60 months (HR: 0.10; 95% CI: 0.05-0.40; P < 0.001).

CONCLUSIONS

Presentation with malignant VA or AM associates with MACE in ULVACM patients.

Myocarditis following COVID-19 vaccine: incidence, presentation, diagnosis, pathophysiology, therapy, and outcomes put into perspective. A clinical consensus document supported by the Heart Failure Association of the European Society of Cardiology (ESC) and the ESC Working Group on Myocardial and Pericardial Diseases

Over 10 million doses of COVID-19 vaccines based on RNA technology, viral vectors, recombinant protein, and inactivated virus have been administered worldwide. Although generally very safe, post-vaccine myocarditis can result from adaptive humoral and cellular, cardiac-specific inflammation within days and weeks of vaccination. Rates of vaccine-associated myocarditis vary by age and sex with the highest rates in males between 12 and 39 years. The clinical course is generally mild with rare cases of left ventricular dysfunction, heart failure and arrhythmias. Mild cases are likely underdiagnosed as cardiac magnetic resonance imaging (CMR) is not commonly performed even in suspected cases and not at all in asymptomatic and mildly symptomatic patients. Hospitalization of symptomatic patients with electrocardiographic changes and increased plasma troponin levels is considered necessary in the acute phase to monitor for arrhythmias and potential decline in left ventricular function. In addition to evaluation for symptoms, electrocardiographic changes and elevated troponin levels, CMR is the best non-invasive diagnostic tool with endomyocardial biopsy being restricted to severe cases with heart failure and/or arrhythmias. The management beyond guideline-directed treatment of heart failure and arrhythmias includes non-specific measures to control pain. Anti-inflammatory drugs such as non-steroidal anti-inflammatory drugs, and corticosteroids have been used in more severe cases, with only anecdotal evidence for their effectiveness. In all age groups studied, the overall risks of SARS-CoV-2 infection-related hospitalization and death are hugely greater than the risks from post-vaccine myocarditis. This consensus statement serves as a practical resource for physicians in their clinical practice, to understand, diagnose, and manage affected patients. Furthermore, it is intended to stimulate research in this area.

Genetic Architecture of Acute Myocarditis and the Overlap With Inherited Cardiomyopathy

BACKGROUND

Acute myocarditis is an inflammatory condition that may herald the onset of dilated cardiomyopathy (DCM) or arrhythmogenic cardiomyopathy (ACM). We investigated the frequency and clinical consequences of DCM and ACM genetic variants in a population-based cohort of patients with acute myocarditis.

METHODS

This was a population-based cohort of 336 consecutive patients with acute myocarditis enrolled in London and Maastricht. All participants underwent targeted DNA sequencing for well-characterized cardiomyopathy-associated genes with comparison to healthy controls (n=1053) sequenced on the same platform. Case ascertainment in England was assessed against national hospital admission data. The primary outcome was all-cause mortality.

RESULTS

Variants that would be considered pathogenic if found in a patient with DCM or ACM were identified in 8% of myocarditis cases compared with <1% of healthy controls (P=0.0097). In the London cohort (n=230; median age, 33 years; 84% men), patients were representative of national myocarditis admissions (median age, 32 years; 71% men; 66% case ascertainment), and there was enrichment of rare truncating variants (tv) in ACM-associated genes (3.1% of cases versus 0.4% of controls; odds ratio, 8.2; P=0.001). This was driven predominantly by DSP-tv in patients with normal LV ejection fraction and ventricular arrhythmia. In Maastricht (n=106; median age, 54 years; 61% men), there was enrichment of rare truncating variants in DCM-associated genes, particularly TTN-tv, found in 7% (all with left ventricular ejection fraction <50%) compared with 1% in controls (odds ratio, 3.6; P=0.0116). Across both cohorts over a median of 5.0 years (interquartile range, 3.9-7.8 years), all-cause mortality was 5.4%. Two-thirds of deaths were cardiovascular, attributable to worsening heart failure (92%) or sudden cardiac death (8%). The 5-year mortality risk was 3.3% in genotype-negative patients versus 11.1% for genotype-positive patients (Padjusted=0.08).

CONCLUSIONS

We identified DCM- or ACM-associated genetic variants in 8% of patients with acute myocarditis. This was dominated by the identification of DSP-tv in those with normal left ventricular ejection fraction and TTN-tv in those with reduced left ventricular ejection fraction. Despite differences between cohorts, these variants have clinical implications for treatment, risk stratification, and family screening. Genetic counseling and testing should be considered in patients with acute myocarditis to help reassure the majority while improving the management of those with an underlying genetic variant.

Acute Myocarditis Associated With Desmosomal Gene Variants

BACKGROUND

The risk of adverse cardiovascular events in patients with acute myocarditis (AM) and desmosomal gene variants (DGV) remains unknown.

OBJECTIVES

The purpose of this study was to ascertain the risk of death, ventricular arrhythmias, recurrent myocarditis, and heart failure (main endpoint) in patients with AM and pathogenic or likely pathogenetic DGV.

METHODS

In a retrospective international study from 23 hospitals, 97 patients were included: 36 with AM and DGV (DGV[+]), 25 with AM and negative gene testing (DGV[-]), and 36 with AM without genetics testing. All patients had troponin elevation plus findings consistent with AM on histology or at cardiac magnetic resonance (CMR). In 86 patients, CMR changes in function and structure were re-assessed at follow-up.

RESULTS

In the DGV(+) AM group (88.9% DSP variants), median age was 24 years, 91.7% presented with chest pain, and median left ventricular ejection fraction (LVEF) was 56% on CMR (P = NS vs the other 2 groups). Kaplan-Meier curves demonstrated a higher risk of the main endpoint in DGV(+) AM compared with DGV(-) and without genetics testing patients (62.3% vs 17.5% vs 5.3% at 5 years, respectively; P &lt; 0.0001), driven by myocarditis recurrence and ventricular arrhythmias. At follow-up CMR, a higher number of late gadolinium enhanced segments was found in DGV(+) AM.

CONCLUSIONS

Patients with AM and evidence of DGV have a higher incidence of adverse cardiovascular events compared with patients with AM without DGV. Further prospective studies are needed to ascertain if genetic testing might improve risk stratification of patients with AM who are considered at low risk.

Risk of Sudden Death in a General Unbiased Epidemiological Cohort of Sarcoidosis

Background

Sarcoidosis is an inflammatory, noncaseating, granulomatous disorder of unknown cause that can affect any body system and is associated with cardiovascular disease including sudden cardiac death (SCD). Cardiac involvement in sarcoidosis is associated with higher risk of SCD, but the SCD risk in the general sarcoidosis population is unknown. We aimed to determine the risk of SCD in people with sarcoidosis versus the matched general population.

Methods and Results

A population‐based cohort of sarcoidosis and age‐ and sex‐matched comparators from January 1, 1976 to December 31, 2013 was used; presence of other comorbidities in the comparator group was not an exclusion criterion. Mortality, including time, place, and cause of death were measured and manually adjudicated for SCD events. Incidence rates are reported per 100 000 person‐years, and Cox models were used for group comparisons. Of the 345 incident cases of sarcoidosis (171 men; 50%) there were 58 reported deaths; 10 were definite/probable SCD versus 57 all‐cause and 9 SCDs in comparators. Median follow‐up was 12.9 years (interquartile range, 6.0–23.4 years) . Incidence rate of SCD in sarcoidosis was 192 (95% CI, 92–352) versus 155 (95% CI, 71–294) in comparators (hazard ratio [HR], 1.28 (95% CI, 0.52–3.17). Nocturnal deaths were more frequent in sarcoidosis 57 (95% CI, 12–168) versus 17 (95% CI, 0.4–95) (HR, 3.76 [95% CI, 0.39–36.47]). No significant differences were detected between the groups by sex, age, calendar year of diagnosis, or disease duration.

Conclusions

In a population‐based cohort of patients with sarcoidosis, the risk for SCD compared with matched comparators was not increased. There were more nocturnal deaths among patients with sarcoidosis, yet this was statistically insignificant.

Precision Phenotyping of Dilated Cardiomyopathy Using Multidimensional Data

BACKGROUND

Dilated cardiomyopathy (DCM) is a final common manifestation of heterogenous etiologies. Adverse outcomes highlight the need for disease stratification beyond ejection fraction.

OBJECTIVES

The purpose of this study was to identify novel, reproducible subphenotypes of DCM using multiparametric data for improved patient stratification.

METHODS

Longitudinal, observational UK-derivation (n = 426; median age 54 years; 67% men) and Dutch-validation (n = 239; median age 56 years; 64% men) cohorts of DCM patients (enrolled 2009-2016) with clinical, genetic, cardiovascular magnetic resonance, and proteomic assessments. Machine learning with profile regression identified novel disease subtypes. Penalized multinomial logistic regression was used for validation. Nested Cox models compared novel groupings to conventional risk measures. Primary composite outcome was cardiovascular death, heart failure, or arrhythmia events (median follow-up 4 years).

RESULTS

In total, 3 novel DCM subtypes were identified: profibrotic metabolic, mild nonfibrotic, and biventricular impairment. Prognosis differed between subtypes in both the derivation (P < 0.0001) and validation cohorts. The novel profibrotic metabolic subtype had more diabetes, universal myocardial fibrosis, preserved right ventricular function, and elevated creatinine. For clinical application, 5 variables were sufficient for classification (left and right ventricular end-systolic volumes, left atrial volume, myocardial fibrosis, and creatinine). Adding the novel DCM subtype improved the C-statistic from 0.60 to 0.76. Interleukin-4 receptor-alpha was identified as a novel prognostic biomarker in derivation (HR: 3.6; 95% CI: 1.9-6.5; P = 0.00002) and validation cohorts (HR: 1.94; 95% CI: 1.3-2.8; P = 0.00005).

CONCLUSIONS

Three reproducible, mechanistically distinct DCM subtypes were identified using widely available clinical and biological data, adding prognostic value to traditional risk models. They may improve patient selection for novel interventions, thereby enabling precision medicine.

Prognostic role of myocardial inflammation in patients with undefined left ventricular arrhythmogenic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

Etiology identification and risk stratification represent major issues for patients presenting with undefined left ventricular arrhythmogenic cardiomyopathy (ULVACM).

Purpose

To investigate the role of genetics and histology for ULVACM classification, management, and risk assessment.

Methods

We retrospectively analyzed a multicenter cohort of patients (screened n=1037) with ULVACM defined by ventricular arrhythmia (VA) onset, nonischemic late gadolinium enhancement (LGE) limited to the LV, and no severe dilated cardiomyopathy (LVEF≥40%). We selected patients undergoing both next generation sequencing (NGS) screening and endomyocardial biopsy (EMB) for etiology definition. When feasible, immunosuppressive therapy (IST) was used to target active myocardial inflammation (AMI). The study endpoint was a composite of cardiac death, heart transplantation and malignant VAs (VT, VF, appropriate ICD treatment).

Results

The study cohort is composed by 135 ULVACM patients (age 43±14 years, 63% males, LVEF 55±7 %). NGS identified pathogenic or likely-pathogenic variants (PVs/LPVs) consistent with ACM in 21 cases (16%), whereas EMB showed AMI in 78 patients (58%), including 13/21 PVs/LPVs+ (62%). After reclassification of 86 patients (64%), only 49 (36%) remained ULVACM. IST was started in 41/78 AMI patients (53%), including 9/13 PVs/LPVs+ (69%). Twenty patients (15%) met the study endpoint by 12 months, and 36 (27%) by the end of the study (60±27 months). Beyond malignant VT onset, AMI was the only predictor of events by 12 months (HR 5.0, 95%CI 1.4-18.1, p=0.007). No prognostic role was found for PVs/LPVs, except for the subgroup (n=77) with nonsustained VT onset. Among AMI patients, those treated by IST had a significantly lower occurrence of events, both by 12-months (1/41 vs. 16/37, p&lt;0.001) and later (HR 0.05, 95%CI 0.01-0.21, p&lt;0.001). Results were independently confirmed in PVs/LPVs+ and PVs/LPVs- cases. Excluding the IST population, the association of multiple factors among VT onset, PVs/LPVs, and AMI, resulted in an improved discrimination of arrhythmic risk profiles.

Conclusion

The combined genetic and histological workup allowed reclassification of up to 64% ULVACM patients, and substantially contributed into prognostic assessment. Furthermore, EMB identified suitable candidates for IST, who showed better outcomes irrespectively of their genotype.

The Pathogenesis and Long-Term Consequences of COVID-19 Cardiac Injury

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COVID-19 myocardial injury results from immune and hypercoagulability responses.

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Long-term cardiac consequences of COVID-19 include structural and functional changes.

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Myocarditis after COVID-19 vaccination is uncommon (highest risk in teenage males).

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Larger population-based studies are necessary to validate these early results.

The mechanisms of coronavirus disease-2019 (COVID-19)–related myocardial injury comprise both direct viral invasion and indirect (hypercoagulability and immune-mediated) cellular injuries. Some patients with COVID-19 cardiac involvement have poor clinical outcomes, with preliminary data suggesting long-term structural and functional changes. These include persistent myocardial fibrosis, edema, and intraventricular thrombi with embolic events, while functionally, the left ventricle is enlarged, with a reduced ejection fraction and new-onset arrhythmias reported in a number of patients. Myocarditis post-COVID-19 vaccination is rare but more common among young male patients. Larger studies, including prospective data from biobanks, will be useful in expanding these early findings and determining their validity.

Myocarditis after COVID-19 mRNA vaccination: clinical observations and potential mechanisms

The risk of acute myocarditis associated with COVID-19 mRNA vaccination has garnered intense (social) media attention. However, myocarditis after COVID-19 mRNA vaccination is rare and usually resolves within days or weeks. Moreover, the risks of hospitalization and death associated with COVID-19 are greater than the risk associated with COVID-19 vaccination. Therefore, COVID-19 vaccination should be recommended in adolescents and adults.

Routine Laboratory Biomarkers As Prognostic Indicators of Cardiac Sarcoidosis Outcomes

Background

Biomarkers to monitor disease activity and predict major adverse cardiac events (MACE) in CS have not been described previously. We aimed to identify biomarkers to predict MACE in cardiac sarcoidosis (CS).

Methods

Patients (N=232) diagnosed with CS were retrospectively enrolled. Biomarkers including angiotensin-converting enzyme (ACE), N-terminal brain natriuretic peptide (NT-proBNP), troponin T, and creatinine levels were evaluated against a primary end point of left ventricular assist device implantation, heart transplantation, or death, and a secondary end point of cardiac hospitalization-free survival.

Results

Troponin T (hazard ratio [HR], 1.06 per 0.01 ng/mL; P=.006), NT-proBNP (HR, 1.31 per 1,000 pg/mL; P<.001), and creatinine (HR, 4.02 per mg/dL; P=.01) were associated with the primary end point, even after adjusting for ejection fraction. NT-proBNP, B-type natriuretic peptide (BNP), creatinine, albumin, and calcium were associated with the secondary end point (P<.05). ACE levels were associated with presence of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging (mean difference, 14.7; P=.03); 1,25 dihydroxyvitamin D (1,25-OHVit-D) was associated with uptake on cardiac ¹⁸F-flurodeoxyglucose position emission tomography (FDG-PET, P=.03).

Conclusions

Troponin T, NT-proBNP, and creatinine predict clinically significant outcomes in CS. ACE levels correlated with LGE on CMR, and 1,25-OHVit-D levels correlated with FDG-PET activity.

Inflammation and Immune Response in Arrhythmogenic Cardiomyopathy: State-of-the-Art Review

Arrhythmogenic cardiomyopathy (ACM) is a primary disease of the myocardium, predominantly caused by genetic defects in proteins of the cardiac intercalated disc, particularly, desmosomes. Transmission is mostly autosomal dominant with incomplete penetrance. ACM also has wide phenotype variability, ranging from premature ventricular contractions to sudden cardiac death and heart failure. Among other drivers and modulators of phenotype, inflammation in response to viral infection and immune triggers have been postulated to be an aggravator of cardiac myocyte damage and necrosis. This theory is supported by multiple pieces of evidence, including the presence of inflammatory infiltrates in more than two-thirds of ACM hearts, detection of different cardiotropic viruses in sporadic cases of ACM, the fact that patients with ACM often fulfill the histological criteria of active myocarditis, and the abundance of anti-desmoglein-2, antiheart, and anti-intercalated disk autoantibodies in patients with arrhythmogenic right ventricular cardiomyopathy. In keeping with the frequent familial occurrence of ACM, it has been proposed that, in addition to genetic predisposition to progressive myocardial damage, a heritable susceptibility to viral infections and immune reactions may explain familial clustering of ACM. Moreover, considerable in vitro and in vivo evidence implicates activated inflammatory signaling in ACM. Although the role of inflammation/immune response in ACM is not entirely clear, inflammation as a driver of phenotype and a potential target for mechanism-based therapy warrants further research. This review discusses the present evidence supporting the role of inflammatory and immune responses in ACM pathogenesis and proposes opportunities for translational and clinical investigation.

Sarcoidosis-Related Cardiomyopathy: Current Knowledge, Challenges, and Future Perspectives State-of-the-Art Review

The prevalence of sarcoidosis-related cardiomyopathy is increasing. Sarcoidosis impacts cardiac function through granulomatous infiltration of the heart, resulting in conduction disease, arrhythmia, and/or heart failure. The diagnosis of cardiac sarcoidosis (CS) can be challenging and requires clinician awareness as well as differentiation from overlapping diagnostic phenotypes, such as other forms of myocarditis and arrhythmogenic cardiomyopathy. Clinical manifestations, extracardiac involvement, histopathology, and advanced cardiac imaging can all lend support to a diagnosis of CS. The mainstay of therapy for CS is immunosuppression; however, no prospective clinical trials exist to guide management. Patients may progress to developing advanced heart failure or ventricular arrhythmia, for which ventricular assist device therapies or heart transplantation may be considered. The existing knowledge gaps in CS call for an interdisciplinary approach to both patient care and future investigation to improve mechanistic understanding and therapeutic strategies.

Diagnosis and Management of Myocarditis in Children: A Scientific Statement From the American Heart Association

Myocarditis remains a clinical challenge in pediatrics. Originally, it was recognized at autopsy before the application of endomyocardial biopsy, which led to a histopathology-based diagnosis such as in the Dallas criteria. Given the invasive and low-sensitivity nature of endomyocardial biopsy, its diagnostic focus shifted to a reliance on clinical suspicion. With the advances of cardiac magnetic resonance, an examination of the whole heart in vivo has gained acceptance in the pursuit of a diagnosis of myocarditis. The presentation may vary from minimal symptoms to heart failure, life-threatening arrhythmias, or cardiogenic shock. Outcomes span full resolution to chronic heart failure and the need for heart transplantation with inadequate clues to predict the disease trajectory. The American Heart Association commissioned this writing group to explore the current knowledge and management within the field of pediatric myocarditis. This statement highlights advances in our understanding of the immunopathogenesis, new and shifting dominant pathogeneses, modern laboratory testing, and use of mechanical circulatory support, with a special emphasis on innovations in cardiac magnetic resonance imaging. Despite these strides forward, we struggle without a universally accepted definition of myocarditis, which impedes progress in disease-targeted therapy.

Proinflammatory TH17 cytokine activation, disease severity and outcomes in peripartum cardiomyopathy

BACKGROUND

Immune dysregulation is implicated in the development and clinical outcomes of peripartum cardiomyopathy (PPCM).

METHODS AND RESULTS

98 women with PPCM were enrolled and followed for 1 year postpartum (PP). LVEF was assessed at entry, 6-, and 12-months PP by echocardiography. Serum levels of soluble interleukin (IL)-2 receptor (sIL2R), IL-2, IL-4, IL-17, IL-22, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ were measured by ELISA at entry. Cytokine levels were compared between women with PPCM by NYHA class. Outcomes including myocardial recovery and event-free survival were compared by cytokine tertiles. For cytokines found to impact survival outcomes, parameters indicative of disease severity including baseline LVEF, medications, and use of inotropic and mechanical support were analyzed. Levels of proinflammatory cytokines including IL-17, IL-22, and sIL2R, were elevated in higher NYHA classes at baseline. Subjects with higher IL-22 levels were more likely to require inotropic or mechanical support. Higher levels of TNF-α and IL-22 were associated with poorer event-free survival. Higher TNF-α levels were associated with lower mean LVEF at entry and 12 months. In contrast, higher levels of immune-regulatory cytokines such as IL-4 and IL-2 were associated with higher LVEF during follow up.

CONCLUSION

Proinflammatory cytokines IL-22 and TNF-α were associated with adverse event-free survival. IL-17 and IL-22 were associated with more severe disease. In contrast, higher levels of IL-2 and IL-4 corresponded with higher subsequent LVEF. Increased production of TH17 type cytokines in PPCM correlated with worse disease and outcomes, while an increased immune-regulatory response seems to be protective.

Myocarditis Following Immunization With mRNA COVID-19 Vaccines in Members of the US Military

Importance

Myocarditis has been reported with COVID-19 but is not clearly recognized as a possible adverse event following COVID-19 vaccination.

Objective

To describe myocarditis presenting after COVID-19 vaccination within the Military Health System.

Design, Setting, and Participants

This retrospective case series studied patients within the US Military Health System who experienced myocarditis after COVID-19 vaccination between January and April 2021. Patients who sought care for chest pain following COVID-19 vaccination and were subsequently diagnosed with clinical myocarditis were included.

Exposure

Receipt of a messenger RNA (mRNA) COVID-19 vaccine between January 1 and April 30, 2021.

Main Outcomes and Measures

Clinical diagnosis of myocarditis after COVID-19 vaccination in the absence of other identified causes.

Results

A total of 23 male patients (22 currently serving in the military and 1 retiree; median [range] age, 25 [20-51] years) presented with acute onset of marked chest pain within 4 days after receipt of an mRNA COVID-19 vaccine. All military members were previously healthy with a high level of fitness. Seven received the BNT162b2-mRNA vaccine and 16 received the mRNA-1273 vaccine. A total of 20 patients had symptom onset following the second dose of an appropriately spaced 2-dose series. All patients had significantly elevated cardiac troponin levels. Among 8 patients who underwent cardiac magnetic resonance imaging within the acute phase of illness, all had findings consistent with the clinical diagnosis of myocarditis. Additional testing did not identify other etiologies for myocarditis, including acute COVID-19 and other infections, ischemic injury, or underlying autoimmune conditions. All patients received brief supportive care and were recovered or recovering at the time of this report. The military administered more than 2.8 million doses of mRNA COVID-19 vaccine in this period. While the observed number of myocarditis cases was small, the number was higher than expected among male military members after a second vaccine dose.

Conclusions and Relevance

In this case series, myocarditis occurred in previously healthy military patients with similar clinical presentations following receipt of an mRNA COVID-19 vaccine. Further surveillance and evaluation of this adverse event following immunization is warranted. Potential for rare vaccine-related adverse events must be considered in the context of the well-established risk of morbidity, including cardiac injury, following COVID-19 infection.

Myocarditis After BNT162b2 and mRNA-1273 Vaccination

Supplemental Digital Content is available in the text.

Rationale and design of the African Cardiomyopathy and Myocarditis Registry Program: The IMHOTEP study

BACKGROUND

Heart failure (HF), the dominant form of cardiovascular disease in Africans, is mainly due to hypertension, rheumatic heart disease and cardiomyopathy. Cardiomyopathies pose a great challenge because of poor prognosis and high prevalence in low- and middle-income countries (LMICs). Little is known about the etiology and outcome of cardiomyopathy in Africa. Specifically, the role of myocarditis and the genetic causes of cardiomyopathy are largely unidentified in Africans.

METHOD

The African Cardiomyopathy and Myocarditis Registry Program (the IMHOTEP study) is a pan-African multi-centre, hospital-based cohort study, designed with the primary aim of describing the clinical characteristics, genetic causes, prevalence, management and outcome of cardiomyopathy and myocarditis in children and adults. The secondary aim is to identify barriers to the implementation of evidence-based care and provide a platform for trials and other intervention studies to reduce morbidity and mortality in cardiomyopathy. The registry consists of a prospective cohort of newly diagnosed (i.e., incident) cases and a retrospective (i.e., prevalent) cohort of existing cases from participating centres. Patients with cardiomyopathy and myocarditis will be subjected to a standardized 3-stage diagnostic process. To date, 750 patients have been recruited into the multi-centre pilot phase of the study.

CONCLUSION

The IMHOTEP study will provide comprehensive and novel data on clinical features, genetic causes, prevalence and outcome of African children and adults with all forms of cardiomyopathy and myocarditis in Africa. Based on these findings, appropriate strategies for management and prevention of the cardiomyopathies in LMICs are likely to emerge.

Cancer Mortality Rates Increasing vs Cardiovascular Disease Mortality Decreasing in the World: Future Implications

Objective

To highlight the current global trends in mortality for cardiovascular disease and cancer.

Methods

The World Health Organization and the World Bank DataBank databases were used to analyze mortality rates for cancer and cardiovascular disease by calculating age-standardized mortality rates (ASRs) from 2000 to 2015 for high-income, upper-middle-income, and lower-middle-income countries. Data for cancer mortality and population for 43 countries representing 5 of the 7 continents (except Australia and Antarctica) were analyzed.

Results

From 2000 to 2015, there was an increase in the ASR for cancer for both men and women irrespective of a country’s income status, representing an overall 7% increase in cancer ASR (Pearson r, +0.99; P<.00001). We report a higher ASR for cancer in high-income countries than in upper-middle-income and lower-middle-income countries specifically; high-income countries saw a 3% increase in cancer ASR vs +31% for upper-middle-income and +19% for lower-middle-income countries (P<.01). There has been a decrease in the ASR for cardiovascular disease for the 15 years analyzed (P<.00001). In addition, high-income countries had a higher ASR for cardiovascular disease than upper-middle-income countries during the 15-year period (P<.05).

Conclusion

We suspect that because of early detection and targeted interventions, cardiovascular disease mortality rates have decreased during the past decade. On the basis of our results, cancer mortality rates continue to rise, with the projection of surpassing cardiovascular disease mortality rates in the near future.

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.