Tropical Endomyocardial Fibrosis: Natural History, Challenges, and Perspectives

Cardiovascular Diseases in Sub-Saharan Africa Compared to High-Income Countries: An Epidemiological Perspective

Non-communicable diseases (NCDs) are the second common cause of death in sub-Saharan Africa (SSA) accounting for about 35% of all deaths, after a composite of communicable, maternal, neonatal, and nutritional diseases. Despite prior perception of low NCDs mortality rates, current evidence suggests that SSA is now at the dawn of the epidemiological transition with contemporary double burden of disease from NCDs and communicable diseases. In SSA, cardiovascular diseases (CVDs) are the most frequent causes of NCDs deaths, responsible for approximately 13% of all deaths and 37% of all NCDs deaths. Although ischemic heart disease (IHD) has been identified as the leading cause of CVDs mortality in SSA followed by stroke and hypertensive heart disease from statistical models, real field data suggest IHD rates are still relatively low. The neglected endemic CVDs of SSA such as endomyocardial fibrosis and rheumatic heart disease as well as congenital heart diseases remain unconquered. While the underlying aetiology of heart failure among adults in high-income countries (HIC) is IHD, in SSA the leading causes are hypertensive heart disease, cardiomyopathy, rheumatic heart disease, and congenital heart diseases. Of concern is the tendency of CVDs to occur at younger ages in SSA populations, approximately two decades earlier compared to HIC. Obstacles hampering primary and secondary prevention of CVDs in SSA include insufficient health care systems and infrastructure, scarcity of cardiac professionals, skewed budget allocation and disproportionate prioritization away from NCDs, high cost of cardiac treatments and interventions coupled with rarity of health insurance systems. This review gives an overview of the descriptive epidemiology of CVDs in SSA, while contrasting with the HIC and highlighting impediments to their management and making recommendations.

Comprehensive Assessment of Endomyocardial Fibrosis with Cardiac MRI: Morphology, Function, and Tissue Characterization

Endomyocardial fibrosis (EMF) affects approximately 12 million persons worldwide and is an important cause of restrictive cardiomyopathy in the developing world, with the highest prevalence reported in sub-Saharan Africa, South Asia, and South America. EMF is characterized by apical filling with fibrotic tissue of one or both ventricles, often associated with thrombus, calcification, and atrioventricular valve regurgitation, leading to typical symptoms of restrictive heart failure. Transthoracic echocardiography (TTE) is the first-line modality for assessment of EMF, basically owing to its widespread availability. However, in recent years cardiac MRI has emerged as a powerful tool for assessment of cardiac morphology and function, with higher accuracy than TTE, along with the unique advantage of being able to provide comprehensive noninvasive tissue characterization. Delayed enhancement (DE) imaging is the cornerstone of cardiac MRI tissue characterization and allows accurate identification of myocardial fibrosis, conveying valuable additional diagnostic and prognostic information. The typical DE pattern in EMF, described as the "double V" sign, consists of a three-layered pattern of normal myocardium, thickened enhanced endomyocardium, and overlying thrombus at the apex of the affected ventricle; it has excellent correlation with histopathologic findings and plays an important role in differentiating EMF from other cardiomyopathies. Conversely, fibrous tissue deposition quantified using DE imaging, when indexed to body surface area, has been shown to be a strong independent predictor of mortality. The aim of this review is to summarize state-of-the-art applications of cardiac MRI for diagnostic and prognostic assessment of patients with suspected or confirmed EMF. Online supplemental material is available for this article. ^©RSNA, 2020.

A case report of a 40-year-old woman with endomyocardial fibrosis in a non-tropical area: from initial presentation to high urgent heart transplantation

Background

Endomyocardial fibrosis (EMF) represents the most common cause of restrictive cardiomyopathy worldwide. Despite a high prevalence in tropical regions, it occasionally occurs in patients who have never visited these areas. While researches have proposed various possible triggers for EMF, etiology and pathogenesis remain largely unknown. Diagnosis is based on patient history, heart failure symptoms, and echocardiographic signs of restrictive ventricular filling, atrioventricular valve regurgitation and frequently apical thrombus. Following is a case report of an Austrian patient with EMF who eventually had to undergo a heart transplant. This case report strives to promote awareness for this in non-tropical areas uncommon but nevertheless detrimental disease.

Case presentation

A 40-year-old woman was presented at our emergency department with chest pain and fever up to 38.1° Celsius. Plasma troponin-T levels and inflammatory markers were slightly elevated, but the echocardiogram was without pathological findings. The patient was hospitalized on the suspicion of acute myocarditis and discharged soon after improvement. Eight months later, she was presented again with chest pain and symptoms of heart failure. The echocardiogram showed normal systolic left ventricular (LV) function with LV wall thickening and severe restrictive mitral regurgitation as well as aortic and tricuspid regurgitation. Coronary angiogram was normal but right heart catheterization showed pulmonary hypertension due to left heart disease. Further diagnostic workup with cardiac magnetic resonance imaging revealed subendocardial late enhancement and apical thrombus formation in the left ventricle compatible with the diagnosis of EMF. A comprehensive diagnostic workup showed no evidence of infection, systemic immunologic or hematological disease, in particular hypereosinophilic syndrome. After a multidisciplinary consideration of several therapeutic options, the patient was listed for heart transplantation. On the waiting list, she deteriorated rapidly due to progressive heart failure and finally underwent a heart transplantation. Histological examination confirmed the diagnosis of EMF. Six years after her heart transplantation, the patient was presented in an excellent clinical condition.

Conclusions

Even in non-tropical regions, the diagnosis of EMF should always be considered in restrictive cardiomyopathy. Knowledge of the distinct phenotype of EMF facilitates diagnosis, but comprehensive workup and therapeutic management remain challenging and require a multidisciplinary approach.

Endomyocardial fibrosis of the right ventricle: A case report of successful surgery

AIMS

The case we report, shows a successful treatment of right ventricle endomyocardial fibrosis.

MATERIALS AND METHODS

Surgical therapy by endocardial decortication seems to be beneficial for many patients with advanced disease who are in functional-therapeutic class III or IV. The operative mortality rate is high, but successful surgery has a clear benefit on symptoms and seems to favourably affect survival as well.

Endomyocardial Fibrosis: an Update After 70 Years

PURPOSE OF REVIEW

This review aims at highlighting the need to better understand the pathogenesis and natural history of endomyocardial fibrosis when set against its changing endemicity and disease burden, improvements in diagnosis, and new options for clinical management.

RECENT FINDINGS

Progress in imaging diagnostic techniques and availability of new targets for drug and surgical treatment of heart failure are contributing to earlier diagnosis and may lead to improvement in patient survival. Endomyocardial fibrosis was first described in Uganda by Davies more than 70 years ago (1948). Despite its poor prognosis, the etiology of this neglected tropical restrictive cardiomyopathy still remains enigmatic nowadays. Our review reflects on the journey of scientific discovery and construction of the current guiding concepts on this mysterious and fascinating condition, bringing to light the contemporary knowledge acquired over these years. Here we describe novel tools for diagnosis, give an overview of the improvement in clinical management, and finally, suggest research themes that can help improve patient outcomes focusing (whenever possible) on novel players coming into action.

[Cardiac manifestations of tropical diseases]

Due to an increase in global mobility, international travel and migration, tropical diseases are more frequently observed in Germany. Some tropical diseases can also affect the heart, cause cardiac symptoms and may require inclusion in differential diagnostic work-ups. The most important tropical diseases with cardiac involvement are Chagas' disease and echinococcosis. Other tropical diseases such as schistosomiasis, tropical endomyocardial fibrosis or sleeping sickness can affect the heart. The suspicion of a tropical disease as the cause of cardiac symptoms is based on the patient history of travel, migration and social setting. This CME article describes the diagnostic and therapeutic approach to tropical parasitic diseases with cardiac involvement.

Isolated Right-Sided Endomyocardial Fibroelastosis Resulting in Sudden Cardiac Death

Restrictive cardiomyopathy, atrial fibrillation, and cardiac thrombi have been reported with endomyocardial fibroelastosis. This case report examines a unique case of focal endomyocardial fibroelastosis localized to the right ventricle that resulted in sudden cardiac death in an otherwise healthy 21-year-old adult and discusses cardiac magnetic resonance imaging findings in this disease. (Level of Difficulty: Beginner.)

Heart diseases and echocardiography in rural Tanzania: Occurrence, characteristics, and etiologies of underappreciated cardiac pathologies

BACKGROUND

Little is known about heart diseases and their treatment in rural sub-Saharan Africa. This study aimed to describe the occurrence, characteristics, and etiologies of heart diseases, and the medication taken before and prescribed after echocardiography in a rural referral Hospital in Tanzania.

METHODS

This prospective descriptive cohort study included all adults and children referred for echocardiography. Clinical and echocardiographic data were collated for analysis.

RESULTS

From December 2015 to October 2017, a total of 1'243 echocardiograms were performed. A total of 815 adults and 59 children ≤15 years had abnormal echocardiographic findings; in adults 537/815 (66%) had hypertension, with 230/537(43%) on antihypertensive drugs, and 506/815 (62%) were not on regular cardiac medication; 346/815 (42%) had severe eccentric or concentric left ventricular hypertrophy, and 182/815 (22%) had severe systolic heart failure. Only 44% demonstrated normal left ventricular systolic function. The most frequent heart diseases were hypertensive heart disease (41%), valvular heart disease (18%), coronary heart disease (18%), peripartum cardiomyopathy (7%), and other non-hypertensive dilated cardiomyopathies (6%) in adults, and congenital heart disease (34%) in children. Following echocardiography, 802/815 (98%) adults and 40/59 (68%) children had an indication for cardiac medication, 70/815 (9%) and 2/59 (3%) for oral anticoagulation, and 35/815 (4%) and 23/59 (39%) for cardiac surgery, respectively.

CONCLUSION

Hypertension is the leading etiology of heart diseases in rural Tanzania. Most patients present with advanced stages of heart disease, and the majority are not treated before echocardiography. There is an urgent need for increased awareness, expertise and infrastructure to detect and treat hypertension and heart failure in rural Africa.

Endomyocardial fibrosis and myocardial infarction leading to diastolic and systolic dysfunction requiring transplantation

Endomyocardial fibrosis (EMF) is an endemic disease in tropical areas, characterized by restrictive physiology due to endocardial fibrous thickening of the ventricular chambers. We report the case of a 25-year-old man of African origin who presented with end-stage heart failure due to both diastolic and systolic dysfunction and extensive endocavitary thrombosis as proven by echocardiography and cardiac magnetic resonance. EMF diagnosis was confirmed by endomyocardial biopsy and the patient had eventually cardiac transplantation. The explanted heart revealed, besides features consistent with EMF, transmural post- myocardial infarction scarring, in the absence of significant coronary artery disease, most probably thromboembolic in origin.

Eosinophilia to endomyocardial fibrosis: Documentation of a case

Endomyocardial fibrosis (EMF) is an important cause of restrictive cardiomyopathy in tropical countries. The etiopathogenesis of EMF remains obscure. The role of eosinophilia in the etiopathogenesis of EMF has been debated extensively, but remains unproven. Accordingly, we present a case wherein a patient with documented eosinophilia and heart failure at the age of three-and-a-half years presented with endomyocardial fibrosis at the age of nine years. Such documentation is important to highlight the central role of eosinophils in the pathogenesis of EMF.

Acquired heart disease in low-income and middle-income countries

The burden of illness associated with acquired cardiac disease in children in low-income and middle-income countries (LMIC) is significant and may be equivalent to that of congenital heart disease. Rheumatic heart disease, endomyocardial fibrosis, cardiomyopathy (including HIV cardiomyopathy) and tuberculosis are the most important causes. All are associated with poverty with the neediest children having the least access to care. The associated mortality and morbidity is high. There is an urgent need to improve cardiac care in LMIC, particularly in sub-Saharan Africa and parts of Southeast Asia where the burden is highest.

Cardiomyopathies: An Overview

The nonischemic cardiomyopathies are a diverse group of cardiac disorders that frequently cause heart failure and death and are now recognized with increasing frequency. There has been substantial progress in the clinical recognition and understanding of the natural history of these conditions. Well-established and new techniques of cardiac imaging are also helpful in this regard. Basic scientists are elucidating the pathogenesis and pathobiology of individual cardiomyopathies. In this compendium, some of the most important advances in this field are reviewed. Scientific opportunities to enhance further collaborative research to accelerate progress are identified.

Cardiac manifestations of parasitic diseases

The heart may be affected directly or indirectly by a variety of protozoa and helminths. This involvement may manifest in different ways, but the syndromes resulting from impairment of the myocardium and pericardium are the most frequent. The myocardium may be invaded by parasites that trigger local inflammatory response with subsequent myocarditis or cardiomyopathy, as occurs in Chagas disease, African trypanosomiasis, toxoplasmosis, trichinellosis and infection with free-living amoebae. In amoebiasis and echinococcosis, the pericardium is the structure most frequently involved with consequent pericardial effusion, acute pericarditis, cardiac tamponade or constrictive pericarditis. Chronic hypereosinophilia due to helminth infections, especially filarial infections, has been associated with the development of tropical endomyocardial fibrosis, a severe form of restrictive cardiomyopathy. Schistosomiasis-associated lung vasculature involvement may cause pulmonary hypertension (PH) and cor pulmonale Tropical pulmonary eosinophilia, which is characterised by progressive interstitial fibrosis and restrictive lung disease, may lead to PH and its consequences may occur in the course of filarial infections. Intracardiac rupture of an Echinococcus cyst can cause membrane or secondary cysts embolisation to the lungs or organs supplied by the systemic circulation. Although unusual causes of cardiac disease outside the endemic areas, heart involvement by parasites should be considered in the differential diagnosis especially of myocardial and/or pericardial diseases of unknown aetiology in both immunocompetent and immunocompromised individuals. In this review, we updated and summarised the current knowledge on the major heart diseases caused by protozoan and metazoan parasites, which either involve the heart directly or otherwise influence the heart adversely.

Endomyocardial involvement in asymptomatic sub-Saharan immigrants with helminth-related eosinophilia

Background

Among immigrants of sub-Saharan origin, parasitic infection is the leading cause of eosinophilia, which is generally interpreted as a defense mechanism. A side effect of the inflammatory mediators released by eosinophils is damage to host organs, especially the heart. The main objectives of this study were to i) assess cardiac involvement in asymptomatic sub-Saharan immigrants with eosinophilia, ii) relate the presence of lesions with the degree of eosinophilia, and iii) study the relationship between cardiac involvement and the type of causative parasite.

Methodology/Principle findings

In total, the study included 50 black immigrants (37 patients and 13 controls) from sub-Saharan Africa. In all subjects, heart structure and function were evaluated in a blinded manner using Sonos 5500 echocardiographic equipment. The findings were classified and described according to established criteria. The diagnostic criteria for helminthosis were those reported in the literature. Serum eosinophil-derived neurotoxin levels were measured using enzyme-linked immunosorbent assay. A significant association was found between the presence of eosinophilia and structural alterations (mitral valve thickening). However, the lack of an association between the degree of eosinophilia and heart valve disease and the absence of valve involvement in some patients with eosinophilia suggest the role of other factors in the appearance of endocardial lesions. There was also no association between the type of helminth and valve involvement.

Conclusions

We, therefore, suggest that transthoracic echocardiography be performed in every sub-Saharan individual with eosinophilia in order to rule out early heart valve lesions.

Endomyocardial fibrosis is characterized by fibrosis of the apical endocardium of the right ventricle, left ventricle, or both. Epidemiological studies of endomyocardial fibrosis indicate a predominance in tropical regions, with young people and men being affected predominantly. Little is known about the natural history and pathogenic factors of this condition. One of the most important factors is the presence of eosinophilia, which is mainly related to helminth infections. The aim of the study was to evaluate cardiac involvement in patients with absolute eosinophilia. We performed an echocardiographic study in asymptomatic sub-Saharan immigrants with eosinophilia and compared them with a group of control patients from the same region and of the same age. Our results suggest that eosinophilia associated with helminth infection (regardless of the causative microorganism) contributes to the asymptomatic phases of endomyocardial involvement. Treatment of these infections is simple, effective, and economical. Therefore, we suggest that all immigrant patients with eosinophilia undergo etiologic study and causal treatment as well as transthoracic echocardiography in order to rule out early damage.

Cardiac surgery in Africa: a thirty-five year experience on open heart surgery in Cote d'Ivoire

BACKGROUND

Few centers for open heart surgery (OHS) are in Sub-Saharan Africa. Lack of OHS results is also noted. By reporting our African experience on OHS, the aim of this study was to fill the gap.

METHODS

It is a retrospective study on 2,612 patients who were subject to an OHS between 1978 and 2013. Data were collected from demographical, clinical, investigative studies, surgical and outcomes parameters.

RESULTS

There were 1,475 cases of rheumatic heart diseases (RHD), 126 endomyocardial fibrosis (EMF), 741 congenital heart diseases (CHDs) and 270 various affections. Related to rheumatic valvular surgery we enumerated 1,175 monovalvular (mitral n=778, aortic n=336, tricuspid n=61); 280 bivalvular (mitral + aortic n=150, mitral + tricuspid n=130) and 20 trivalvular. For RHD, average age was 26±10.1 years (4-69 years) and 60% of our patients presented a functional class III or IV according to New York Heart Association (NYHA) classification. A total of 1,481 valvular replacements (bioprostheses n=489, mechanical prostheses n=992) and 445 valvular repair were carried out with a global and late mortality surgery respectively at 7% and 8%. One hundred and twenty-six [126] cases of EMF with right sided form 39, left sided form 40, and bilateral form 47 were colligated. Average age was 12±0.6 years (2-15 years). All patients with EMF underwent surgery; an endocardectomy in all patients combined with valvular reconstruction (n=36) or valvular replacement (n=90) was carried out with a hospital mortality at 16% (n=20). Concerning CHD, the most frequent were ventricular septal defect (VSD) (n=240), atrial septal defect (ASD) (n=200), partial atrio-ventricular sepal defect (n=30) and tetralogy of Fallot (T4F) (n=220), a total correction was performed for those CHD with an early mortality at 6.4% (n=44).

CONCLUSIONS

OHS in Cote d'Ivoire was successfully performed in most of our patients, the spectrum of acquired valvular heart diseases and CHDs in our country is similar to others in Sub-Saharan Africa.