Endomyocardial fibrosis: past, present, and future

Myocardial Late Gadolinium Enhancement (LGE) in Cardiac Magnetic Resonance Imaging (CMR)-An Important Risk Marker for Cardiac Disease

Cardiovascular magnetic resonance (CMR) has significantly revolutionized the comprehension and diagnosis of cardiac diseases, particularly through the utilization of late gadolinium enhancement (LGE) imaging for tissue characterization. LGE enables the visualization of expanded extracellular spaces in conditions such as fibrosis, fibrofatty tissue, or edema. The growing recognition of LGE's prognostic capacity underscores its importance, evident in the increasing explicit recommendations within guidelines. Notably, the contemporary characterization of cardiomyopathies relies on LGE-based scar assessment by CMR to a large extent. This review describes the pattern and prognostic value of LGE in detail for various cardiac diseases. Despite its merits, establishing LGE as a reliable risk marker encounters challenges. Limitations arise from the fact that not all diseases show LGE, and it should always be analyzed in the context of all CMR sequences and the patient's medical history. In summary, LGE stands as a robust indicator of adverse outcomes in diverse cardiovascular diseases. Its further integration into routine practice is desirable, necessitating widespread availability and application to accumulate both individual and scientific experience.

Endomyocardiofibrosis in the Americas Collaborative Study: The EMF-SIAC Registry

Endomyocardiofibrosis (EMF) is a restrictive cardiomyopathy characterized by subendocardial fibrosis due to eosinophilic myocardial infiltration. EMF may commonly present with heart failure (HF) or atrial fibrillation (AF). Immunosuppression can be effective in early stages, but not in the chronic phase. Our objective was to describe the characteristics of EMF patients in the Americas. This registry is a retrospective multicenter cross-sectional study including patients ≥18 years-old with EMF diagnosed by imaging methods, according to the Mocumbi criteria. Clinical, biochemical, and imaging variables were analyzed. On the 54 patients included, 28 (52%) were male with an age of 47 years. The etiology was idiopathic in 47 (87%) patients, familial in 4 (7%), and secondary to chemotherapy in 2 (3.5%). We detected a history of HF in 41 patients (76%), AF in 19 (35%), and ischemic stroke in 8 (15%). The diagnosis was made by echocardiography in all patients, and 38% had Cardiac Resonance or Computed Tomography. Thirty-five patients (65%) presented a left ventricular ejection fraction ≥50%, 11 (21%) severe mitral regurgitation, and 18 (33%) severe tricuspid regurgitation. In 17 patients (32%) the diagnosis was confirmed by endomyocardial biopsy. Among medical therapy, 72% received beta-blockers, 63% vasodilators, 65% mineralocorticoid antagonists, 7.4% SGLT2 inhibitors, and 11% corticosteroids. Subendocardial resection was performed in 9 (16%) patients and mitral valve replacement in 11 (20%) patients. In conclusion, EMF patients had a high prevalence of HF, AF, and embolic events. The diagnosis was frequently made in an advanced stage when HF management and surgery were the only effective treatments.

Left ventricle endomyocardial fibrosis: a case report

BACKGROUND

Endomyocardial fibrosis is a grim disease. It is the most common restrictive cardiomyopathy worldwide, but the exact etiology and pathogenesis both remain unknown. Endomyocardial fibrosis is recurrently associated with chronic eosinophilia and probable dietary, environmental, and infectious factors, which contribute not only to the onset of the disease (an inflammatory process) but also to its progression and maintenance (endomyocardial damage and scar formation). The trademark of the disease is the fibrotic obliteration of the affected ventricle. The combination of such processes produces focal or diffuse endocardial thickening and fibrosis, which leads to restrictive physiology. Endomyocardial fibrosis affects the apices of the right and the left ventricle in around 50% of cases and most often extends to the posterior leaflet of the mitral valve. Sometimes it involves the papillary muscle and chordae tendineae, causing atrioventricular valve dysfunction. The fibrosis does not affect extracardiac organs. This cardiomyopathy is most recurrent in tropical areas of the world.

CASE PRESENTATION

A 67-year-old Black male with past medical history of schistosomiasis infection in childhood presented with progressive dyspnea, lower extremity edema, and weakness for 2 years. He was diagnosed with endomyocardial fibrosis. The echocardiogram showed an increased thickness in the septum (17 mm) and free left ventricular wall (15 mm), obliteration of the left ventricular apex and inflow tract, and mitral valve regurgitation. Cardiac magnetic resonance imaging revealed apical left ventricle wall thickening with left ventricular apical obliteration associated with enlargement of the respective atrium. Delayed enhancement imaging showed endomyocardium enhancement involving left ventricular apex, mitral valve regurgitation due to annulus dilation, and a thrombus at left ventricular apex. He underwent open heart surgery with mitral valve replacement, endocardial decortication, endomyocardiectomy, and two-vessel coronary artery bypass grafting as preoperative coronary angiogram showed mild right coronary artery and proximal left anterior descending artery severe lesions. Postoperative course was uncomplicated, and he was discharged successfully from the hospital. Six months after surgery, he was New York Heart Association functional class I.

CONCLUSION

The purpose of this case report is to illustrate the aspects of endomyocardial fibrosis by reporting a case of this entity. In conclusion, progress in imaging techniques and treatment in a reference institution for cardiac diseases contribute to earlier diagnosis and survival in patients with endomyocardial fibrosis.

p53 and Myofibroblast Apoptosis in Organ Fibrosis

Organ fibrosis represents a dysregulated, maladaptive wound repair response that results in progressive disruption of normal tissue architecture leading to detrimental deterioration in physiological function, and significant morbidity/mortality. Fibrosis is thought to contribute to nearly 50% of all deaths in the Western world with current treatment modalities effective in slowing disease progression but not effective in restoring organ function or reversing fibrotic changes. When physiological wound repair is complete, myofibroblasts are programmed to undergo cell death and self-clearance, however, in fibrosis there is a characteristic absence of myofibroblast apoptosis. It has been shown that in fibrosis, myofibroblasts adopt an apoptotic-resistant, highly proliferative phenotype leading to persistent myofibroblast activation and perpetuation of the fibrotic disease process. Recently, this pathological adaptation has been linked to dysregulated expression of tumour suppressor gene p53. In this review, we discuss p53 dysregulation and apoptotic failure in myofibroblasts and demonstrate its consistent link to fibrotic disease development in all types of organ fibrosis. An enhanced understanding of the role of p53 dysregulation and myofibroblast apoptosis may aid in future novel therapeutic and/or diagnostic strategies in organ fibrosis.

Complications of Endomyocardial fibrosis and their physiological compromise: A review

Endomyocardial fibrosis (EMF) is an endemic idiopathic cardiomyopathy denoted by restricted and fibrous myocardium and endocardium. Apical fibrosis may cause thickening of the myocardium and extend from the ventricular apices through to the valves, thereby, restricting inflow. EMF is a critical condition that is predominant in the young population. However, it may also be associated with older individuals. Identified areas recorded with cases include the under-developed populations i.e. the tropics of Africa- Uganda, Mozambique; South Asia, and South America. Unlike in the preceded years, further studies are currently on focus to completely evaluate this medical condition. Additionally, this review encompasses the complications that arise from EMF as studied and reported from case studies, clinical trials, experiments and research including heart failure, atrioventricular valves regurgitations, arrhythmias, serous cavities'effusions, circulatory shock, stroke, myocardial ischemic syndromes, hepatic and end-organ dysfunctions. Complications like heart failure may be very fatal to its victims. Moreover, left ventricular thrombosis may probably impose systemic or cerebral thromboembolism, which would risk the probability of a stroke. All in all, suggestions in the management strategies that have proved effective and advances in cardiac transplantation and of recently proposed therapeutic targets equally take part of this review and may form a foundation to diminishing the remaining inch of EMF and its outcomes.

A rare case of sudden death due to endomyocardial fibrosis in Italy: A differential diagnosis with other causes of restrictive cardiomyopathy

A 45-years-old Indonesian woman was admitted to the hospital with nausea, vomiting, abdominal pain and tachyarrhythmia. Atrial fibrillation was found at ECG, blood tests showed mild hepatic function alterations. Radiological exams showed bilateral pleural effusions, ascites, hepatomegaly. Systolic and diastolic functions of the left ventricle were found to be strongly compromised at US. Physical conditions and laboratory results worsened rapidly, followed by multi organ failure. Death occurred 28 hours after admission. An autopsy was performed to clarify the cause of death and investigated medical malpractice. External examination showed jaundice skin and at internal examination bilateral pleural and pericardial effusions, ascites, mild cardiomegaly, ventricular endocardial fibrosis, a thrombus in tight junction to the left ventricular wall and hepatic necrosis were observed. Histological investigations revealed a massive endomyocardial fibrosis, detected through Azan-Mallory and Verhoef-Van-Gieson stain, and confirmed the presence of hepatic and renal necrosis. Toxicological and microbiological investigations were negative. The cause of death was a global cardiac dysfunction caused by a restrictive cardiomyopathy in an Indonesian woman affected by an undiagnosed and asymptomatic endomyocardial fibrosis. In this case, autopsy and histopathological investigations were fundamental to diagnose an occult endomyocardial fibrosis, which is an idiopathic disorder of tropical and subtropical regions of the world. The not common incidence of this disease in our country and its unusual clinical onset were at first perceived as a medical malpractice from the relatives. Consequently, the clinical aspects of the case intertwine with the medicolegal implications concerning the undiagnosed disease and the causality with the patient's death.

Nutritional Heart Disease and Cardiomyopathies: JACC Focus Seminar 4/4

This JACC Focus Seminar provides an overview of and highlights recently published research on cardiomyopathies and nutritional heart disease that have a higher prevalence in tropical regions. The development of tropical cardiomyopathies and nutritional cardiovascular disease (CVD) is complicated by high rates of poverty, fragmented health care systems, and suboptimal access to health care because of socioeconomic inequalities, leading to the fact that children, adolescents, and young adults are disproportionally affected. Such tropical cardiomyopathies and nutritional CVD that have not been prevalent in high-income countries in the past decades are now reemerging. When treating migrants or refugees, it is important for attending physicians to consider the burden of endemic diseases in the countries of origin and the likelihood that such patients might be affected. In this review, the authors propose an approach for adequate diagnostic work-up leading to appropriate care for those with suspected or confirmed tropical cardiomyopathies and nutritional CVD.

Elucidating the role of circNFIB in myocardial fibrosis alleviation by endogenous sulfur dioxide

BACKGROUND

To investigate the role of circNFIB in the alleviation of myocardial fibrosis by endogenous sulfur dioxide (SO₂).

METHODS

We stimulated cultured neonatal rat cardiac fibroblasts with transforming growth factor-β1 (TGF-β1) and developed an in vitro myocardial fibrosis model. Lentivirus vectors containing aspartate aminotransferase 1 (AAT1) cDNA were used to overexpress AAT1, and siRNA was used to silence circNFIB. The SO₂, collagen, circNFIB, Wnt/β-catenin, and p38 MAPK pathways were examined in each group.

RESULTS

In the in vitro TGF-β1-induced myocardial fibrosis model, endogenous SO₂/AAT1 expression was significantly decreased, and collagen levels in the cell supernatant and type I and III collagen expression, as well as α-SMA expression, were all significantly increased. TGF-β1 also significantly reduced circNFIB expression. AAT1 overexpression significantly reduced myocardial fibrosis while significantly increasing circNFIB expression. Endogenous SO₂ alleviated myocardial fibrosis after circNFIB expression was blocked. We discovered that circNFIB plays an important role in the alleviation of myocardial fibrosis by endogenous SO₂ by inhibiting the Wnt/β-catenin and p38 MAPK pathways.

CONCLUSION

Endogenous SO₂ promotes circNFIB expression, which inhibits the Wnt/β-catenin and p38 MAPK signaling pathways, consequently alleviating myocardial fibrosis.

Kardiale MRT bei nichtischämischen Kardiomyopathien

Hintergrund

Die in Deutschland angewandte Einteilung der Kardiomyopathien geht auf die Klassifikation der Europäischen Gesellschaft für Kardiologie (ESC) von 2008 zurück. Dort werden sie nach ihrem Phänotyp unterteilt, so dass die Magnetresonanztomographie (MRT) in der Lage ist, die unterschiedlichen Kardiomyopathien zu differenzieren.

Bildgebung und Differenzialdiagnostik

Die Stärke der MRT ist es, anhand der Möglichkeiten der Gewebsdifferenzierung nichtischämische Kardiomyopathien von anderen Erkrankungen mit ähnlichen morphofunktionellen Aspekten zu differenzieren. So gelingt im Fall der dilatativen Kardiomyopathie (DCM) eine Differenzierung zur inflammatorischen DCM. Im Fall der hypertrophen Kardiomyopathie (HCM) kann analog zur Echographie eine obstruktive und nichtobstruktive Form differenziert werden, aber auch die Detektion einer Amyloidose oder eines Morbus Fabry ist möglich. Die Evaluation der rechtsventrikulären Funktion gelingt im Rahmen einer arrhythmogenen rechtsventrikulären Kardiomyopathie (ARVC) zuverlässig. Außerdem ist die MRT in der Lage, die charakteristische fettige Ersatzfibrose direkt nachzuweisen. Bei den seltenen restriktiven Kardiomyopathien kann sie die Restriktion nachvollziehen und z. B. mittels T1-, T2- und T2*-Mapping die Sphingolipid-Akkumulation im Myokard bei einem Morbus Fabry oder eine Eisenüberladung bei Hämochromatose nachvollziehen.

Innovationen

Die quantitativen Verfahren des parametrischen Mappings bieten die Möglichkeit eines Therapiemonitorings; die klinische Relevanz dieses Monitorings ist aber noch Gegenstand aktueller Forschung. Die unklassifizierten Kardiomyopathien können sich klinisch mit ähnlicher Symptomatik wie ischämische oder inflammatorische Erkrankungen präsentieren, so dass im Fall eines Myokardinfarkts ohne verschlossene Koronararterien („myocardial infarction without obstructive coronary arteries“, MINOCA) in der Herzkatheteruntersuchung die MRT ein entscheidendes diagnostisches Instrument ist, um die tatsächlich zugrundeliegende Erkrankung festzustellen. Gleichermaßen kann sie bei neuen Kardiomyopathien wie der Non-compaction-Kardiomyopathie der Wegbereiter für eine morphologische Krankheitsdefinition sein.

Diagnosis and Management of Rare Cardiomyopathies in Adult and Paediatric Patients. A Position Paper of the Italian Society of Cardiology (SIC) and Italian Society of Paediatric Cardiology (SICP)

Cardiomyopathies (CMPs) are myocardial diseases in which the heart muscle is structurally and functionally abnormal in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to cause the observed myocardial abnormality. Thought for a long time to be rare diseases, it is now clear that most of the CMPs can be easily observed in clinical practice. However, there is a group of specific heart muscle diseases that are rare in nature whose clinical/echocardiographic phenotypes resemble those of the four classical morphological subgroups of hypertrophic, dilated, restrictive, arrhythmogenic CMPs. These rare CMPs, often but not solely diagnosed in infants and paediatric patients, should be more properly labelled as specific CMPs. Emerging consensus exists that these conditions require tailored investigation and management. Indeed, an appropriate understanding of these conditions is mandatory for early treatment and counselling. At present, however, the multisystemic and heterogeneous presentation of these entities is a challenge for clinicians, and time delay in diagnosis is a significant concern. The aim of this paper is to define practical recommendations for diagnosis and management of the rare CMPs in paediatric or adult age. A modified Delphi method was adopted to grade the recommendations proposed by each member of the writing committee.

Overview of Restrictive Cardiomyopathies

Restrictive cardiomyopathy (RCM) includes a heterogeneous group of diseases that cause increased myocardial stiffness, leading to impaired ventricular relaxation and severe diastolic dysfunction. Given that it is the least common type of cardiomyopathy, it can be a diagnostic challenge due to its varied pathogenesis, clinical presentation, and diagnostic evaluation. In this review, we provide an overview of different etiologies of RCM and examine the diagnostic and treatment approaches for various types.

[Cardiac imaging in infiltrative cardiomyopathies. What cardiovascular imaging modalities to propose in hypertrophic cardiomyopathies ?]

Infiltrative cardiomyopathies are abnormal accumulations or depositions of different substances in cardiac tissue leading to its dysfunction, first diastolic, then systolic. The different infiltrative cardiomyopathies are amyloidosis (both light chain amyloidosis and transthyretin amyloidosis variants), lysosomal and glycogen storage disorders (Fabry-Anderson disease), and iron overload (hemochromatosis and thalassemia associated with blood transfusions), as well as inflammatory diseases such as sarcoidosis. We also evoke hypereosinophilic syndrome associated with endomyocardial fibrosis. Echocardiography is the first essential step after interrogatory and clinical examination and may help the cardiologist as a screening tool. Cardiac MRI is the second fundamental step towards the diagnosis especially due to the late gadolinium enhancement and to the T1-mapping. Cardiac amyloidosis diagnosis also requires the use of nuclear imaging. Cardiac CT-Scan may be useful for estimating the amyloid load, identify potential cardiac thrombus and rule out associated coronaropathy.

Heart failure can affect everyone: the ESC Geoffrey Rose lecture

The principle of 'sick individuals vs. sick population', a concept pioneered by Geoffrey Rose 35 years ago, is particularly applicable to heart failure (HF). This perspective article summarizes and expands on the Geoffrey Rose lecture given at the European Society of Cardiology meeting held in conjunction with the World Congress of Cardiology, in Paris, 2019. This article focuses on the fact that, clearly, HF not only affects a large spectrum of the population globally, but it occurs in all ages and equally in both genders. Heart failure, in most parts of the world, is clearly not a disease of the elderly. There are multiple and complex pathways leading to HF which include various risk factors (including communicable diseases and exposure to indoor and environmental pollutants), poverty and overcrowding, as well as sub-optimal access to health care systems due to socioeconomic inequities. Reflecting on Geoffrey Rose's concept 35 years later motivates us to confront our global responsibility to address the population distribution of risk factors more effectively, instead of focusing solely on interventions that target high-risk individuals.

Fibroblast involvement in cardiac remodeling and repair under ischemic conditions

Cardiac fibroblasts play a main role in the physiological turnover of the extracellular matrix, as well as its pathological remodeling. A study was performed on a batch of 23 cases who died of various cardiac complications secondary to scarring myocardial infarctions. The aim of the study was to assess the fibroblast involvement in cardiac repair under ischemic conditions after myocardial infarction. Tissue myocardial samples from the left ventricle were taken from these cases for microscopy examination, in order to investigate the type and degree of fibrosis as well as the presence of cardiac interstitial fibroblasts. Multiple series of histological sections were also performed and examined, along with immunohistochemical analysis. The fibroblasts were diffusely distributed in the interstitium among the residual cardiomyocytes, showing variable expression of vimentin and smooth muscle actin. During cardiac remodeling, there was a successive interstitial deposition, first of reticulin fibers and then of collagen fibers, leading to interstitial fibrosis and myocardial replacement. There was a correlation between vimentin and smooth muscle actin expression and collagen deposition. Fibrosis with cardiac remodeling is based on maintaining proliferation capacity of the fibroblast and its capacity of protein synthesis in the extracellular matrix. Under hypoxic ischemic conditions, followed by myocardial infarction, the fibroblast switches phenotype and transdifferentiate into myofibroblast, contributing to the healing by secreting extracellular matrix proteins and collagen deposition, with subsequent cardiac remodeling and regulation of the micro-environment metabolism.

Testosterone, cardiomyopathies, and heart failure: a narrative review

Testosterone exerts an important regulation of cardiovascular function through genomic and nongenomic pathways. It produces several changes in cardiomyocytes, the main actor of cardiomyopathies, which are characterized by pathological remodeling, eventually leading to heart failure. Testosterone is involved in contractility, in the energy metabolism of myocardial cells, apoptosis, and the remodeling process. In myocarditis, testosterone directly promotes the type of inflammation that leads to fibrosis, and influences viremia with virus localization. At the same time, testosterone exerts cardioprotective effects that have been observed in different studies. There is increasing evidence that low endogenous levels of testosterone have a negative impact in some cardiomyopathies and a protective impact in others. This review focuses on the interrelationships between testosterone and cardiomyopathies and heart failure.

Endomyocardiofibrosis: A Systematic Review

Endomyocardiofibrosis was described first time in Uganda as an infrequent restrictive cardiomyopathy with a poor prognosis, characterized by fibrosis of the ventricular subendocardium and severe restrictive physiology leading to difficult therapeutic management and frequently associated with hypereosinophilic syndrome. Its higher prevalence in the tropics and its relationship in some cases with hypereosinophilic endocarditis has led to the search for genetic, infectious, autoimmune and nutritional causes, but its etiology remains unclear. It is a rare cardiomyopathy, difficult to diagnose and with a nonexistent effective treatment. Imaging methods such as echocardiography and cardiac magnetic resonance are essential for the initial diagnosis, although endomyocardial biopsy establishes the definitive diagnosis. Immunosuppressive treatment is only useful in the early stages of the disease and usually ineffective if installed late when signs of heart failure are present. Surgical treatment is generally palliative.

Cardiac Fibroblasts and Cardiac Fibrosis: Precise Role of Exosomes

Exosomes are a group of extracellular microvesicles that deliver biologically active RNAs, proteins, lipids and other signaling molecules to recipient cells. Classically, exosomes act as a vehicle by which cells or organs communicate with each other to maintain cellular/tissue homeostasis and to respond to pathological stress. Most multicellular systems, including the cardiovascular system, use exosomes for intercellular communication. In heart, endogenous exosomes from cardiac cells or stem cells aid in regulation of cell survival, cell proliferation and cell death; and thus tightly regulate cardiac biology and repair processes. Pathological stimulus in heart alters secretion and molecular composition of exosomes, thus influencing the above processes. The past decade has yielded increasing interest in the role of exosomes in the cardiovascular system and significant contribution of cardiac fibroblast (CF) and mediated cardiac fibrosis in heart failure, in this review we had overviewed the relevant literatures about fibroblast exosomes, its effect in the cardiovascular biology and its impact on cardiovascular disease (CVD). This review briefly describes the communication between fibroblasts and other cardiac cells via exosomes, the influence of such on myocardial fibrosis and remodeling, and the possibilities to use exosomes as biomarkers for acute and chronic heart diseases.