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.

[Tropical endomyocardial fibrosis: Perspectives]. / Fibrose endomyocardique tropicale : perspectives.

Tropical endomyocardial fibrosis (FET) is a leading cause of heart failure and the most common restrictive cardiomyopathy worldwide. Extensive fibrosis of the ventricular endocardium causing architectural distortion, impaired filling and valvular insufficiency define the disease. Confined to peculiar and limited geographical areas, the aetiology remains blurred and it carries a grim prognosis. The changing burden reported recently in some endemic areas and the refinement of diagnostic tools have emphasized alternative routes for understanding and treatment of the disease.

Geographical variation in the clinical presentation of endomyocardial fibrosis in India?

OBJECTIVES: To compare the clinical presentation, clinical profile and survival of two groups of endomyocardial fibrosis patients. METHODS: The study was a prospective cohort study, or a prospective case series, comparing all consecutive echocardiographically proven patients with endomyocardial fibrosis seen in Medical College Trivandrum with the patients seen in Medical College Hospital, Alappuzha(Alleppey) (or TD Medical College). In all patients the clinical details like age, sex, type of endomyocardial fibrosis, the presence of anaemia, eosinophilia, neutrophilia and type of rhythm(Sinus or atrial fibrillation) etc were compared by both simple X2 and by Kaplan Meier survival curves. RESULTS: The mean age and the sex distribution was same in both places Briefly the incidence of biventricular endomyocardial fibrosis was more from Trivandrum than Alleppey, 64.9% vs 14.3% (p<0.0.001), the incidence of atrial fibrillation was more in Trivandrum 44.2% vs 16.3%. (p<0.001)The overall survival of Trivandrum patients was poorer (p<0.0001). The six year survival was 61% in the Trivandrum population whereas it was 91.5% in the Alleppey population. CONCLUSIONS: These differences may have been due to the better nutrition of the Alleppey patients due to a higher exposure to fish compared to the Trivandrum population. Better nutrition would protect against Magnesium deficiency and prevent the absorption of Cerium in the patients from Alleppey, compared to those from Trivandrum.

Endomyocardial fibrosis in Sudan: clinical and echocardiographic features.

OBJECTIVE: Endomyocardial fibrosis (EMF) is a rare disease and is often an underdiagnosed and forgotten cardiomyopathy. The objective of this study was to document the current frequency of EMF in Sudan by defining and selecting cases from patients attending the echocardiography laboratory. Additionally we aimed to create an EMF registry for Sudan. METHODS: The study started in January 2007 and is on-going. All the patients attending our echocardiography clinics in four different hospitals in Khartoum, Sudan, were included. Transthoracic echocardiography was used as the main diagnostic and selection tool. The diagnosis of EMF was based on predefined criteria and definitions, and was further supported by additional clinical, ECG, laboratory and chest X-ray findings. RESULTS: Out of 4 332 cases studied, 23 (0.5%) were found to have features of EMF. Females constituted 52% and the age range was 24 to 67 years. All patients presented with dyspnoea grades III-IV. Advanced heart failure with gross fluid overload was seen in 54% of cases and ascites was seen in 30%. EMF was biventricular in 53%, left ventricular in 29% and right ventricular in 18% of cases. Apical and ventricular wall fibrosis was found in all cases, followed by atrial enlargement, atrioventricular valve incompetence, ventricular cavity obliteration, restrictive flow pattern and pericardial effusion. Additional echocardiographic features are defined and discussed. CONCLUSION: Although a rare disease, cases of EMF can be identified in Sudan if a high index of suspicion is observed. New echocardiographic features of ventricular wall layering, endocardial fibrous shelf and endomyocardiopericarial fibrosis were identified and are discussed.

Diagnosis and Management of Endomyocardial Fibrosis.

Endomyocardial fibrosis (EMF) remains an important cause of restrictive cardiomyopathy worldwide. Patients cluster in specific geographic locations and are almost universally living in extreme poverty. Specific etiology remains elusive and is likely multifactorial. Untreated EMF has a very poor prognosis. Medical management can mitigate symptoms for a time but has no curative benefit. Early surgical interventions may improve survival but are not readily available in most EMF-endemic regions. Increased awareness, advocacy, and research are needed to further understand this neglected tropical cardiomyopathy and to improve survival of those affected.

Tropical Endomyocardial Fibrosis: Natural History, Challenges, and Perspectives.

Tropical endomyocardial fibrosis (EMF) is a neglected disease of poverty that afflicts rural populations in tropical low-income countries, with some certain high-prevalence areas. Tropical EMF is characterized by the deposition of fibrous tissue in the endomyocardium, leading to restrictive physiology. Since the first descriptions in Uganda in 1948, high-frequency areas for EMF have included Africa, Asia, and South America. Although there is no clear consensus on a unified hypothesis, it seems likely that dietary, environmental, and infectious factors may combine in a susceptible individual to give rise to an inflammatory process leading to endomyocardial damage and scar formation. The natural history of EMF includes an active phase with recurrent flare-ups of inflammation evolving to a chronic phase leading to restrictive heart failure. In the chronic phase, biventricular involvement is the most common presentation, followed by isolated right-sided heart disease. Marked ascites out of proportion to peripheral edema usually develops as a typical feature of EMF. EMF carries a very poor prognosis. In addition to medical management of heart failure, early open heart surgery (endocardectomy and valve repair/replacement) appears to improve outcomes to some extent; however, surgery is technically challenging and not available in most endemic areas. Increased awareness among health workers and policy makers is the need of the hour for the unhindered development of efficient preventive and therapeutic strategies.

Coronary microvascular rarefaction and myocardial fibrosis in heart failure with preserved ejection fraction.

BACKGROUND: Characterization of myocardial structural changes in heart failure with preserved ejection fraction (HFpEF) has been hindered by the limited availability of human cardiac tissue. Cardiac hypertrophy, coronary artery disease (CAD), coronary microvascular rarefaction, and myocardial fibrosis may contribute to HFpEF pathophysiology. METHODS AND RESULTS: We identified HFpEF patients (n=124) and age-appropriate control subjects (noncardiac death, no heart failure diagnosis; n=104) who underwent autopsy. Heart weight and CAD severity were obtained from the autopsy reports. With the use of whole-field digital microscopy and automated analysis algorithms in full-thickness left ventricular sections, microvascular density (MVD), myocardial fibrosis, and their relationship were quantified. Subjects with HFpEF had heavier hearts (median, 538 g; 169% of age-, sex-, and body size-expected heart weight versus 335 g; 112% in controls), more severe CAD (65% with ≥1 vessel with >50% diameter stenosis in HFpEF versus 13% in controls), more left ventricular fibrosis (median % area fibrosis, 9.6 versus 7.1) and lower MVD (median 961 versus 1316 vessels/mm(2)) than control (P<0.0001 for all). Myocardial fibrosis increased with decreasing MVD in controls (r=-0.28, P=0.004) and HFpEF (r=-0.26, P=0.004). Adjusting for MVD attenuated the group differences in fibrosis. Heart weight, fibrosis, and MVD were similar in HFpEF patients with CAD versus without CAD. CONCLUSIONS: In this study, patients with HFpEF had more cardiac hypertrophy, epicardial CAD, coronary microvascular rarefaction, and myocardial fibrosis than controls. Each of these findings may contribute to the left ventricular diastolic dysfunction and cardiac reserve function impairment characteristic of HFpEF.

Prevalence of myocardial fibrosis patterns in patients with systolic dysfunction: prognostic significance for the prediction of sudden cardiac arrest or appropriate implantable cardiac defibrillator therapy.

BACKGROUND: Late gadolinium enhancement-cardiac magnetic resonance is increasingly performed in patients with systolic dysfunction. Numerous patterns of fibrosis are commonly reported among this population. However, the relative prevalence and prognostic significance of these findings remains uncertain. METHODS AND RESULTS: Three hundred eighteen consecutive patients referred for late gadolinium enhancement-cardiac magnetic resonance and a left ventricular ejection fraction <55% were followed up for the primary end point of sudden cardiac arrest or appropriate implantable cardiac defibrillator therapy. Late gadolinium enhancement images were blindly interpreted for the presence of 6 distinct pattern(s) of myocardial fibrosis in addition to signal threshold-based quantification of total fibrosis volume. The mean age and left ventricular ejection fraction of participants were 62.0±12.9 years and 32.6±11.9%, respectively. Any pattern of myocardial fibrosis was seen in 248 patients (78%) with ≥2 patterns present in 25% of patients. During follow-up (median of 467 days), 49 patients (15%) had a primary outcome. After adjustment for left ventricular ejection fraction, cardiomyopathy pathogenesis, and total fibrosis volume, the presence of a midwall striae pattern of fibrosis was an independent predictor of sudden cardiac arrest or appropriate implantable cardiac defibrillator therapy with a hazard ratio of 2.4 (95% confidence interval, 1.2-4.6; P=0.01); this finding is present in 30% of patients with nonischemic and 15% of patients with ischemic cardiomyopathy. Cumulative event rate was significantly higher among those with midwall striae, particularly among those with a left ventricular ejection fraction >35% (40% versus 6%; P=0.005). CONCLUSIONS: Patients with systolic dysfunction frequently demonstrate multiple patterns of myocardial fibrosis. Of these, a midwall striae pattern of fibrosis is the strongest independent predictor of sudden cardiac arrest or appropriate implantable cardiac defibrillator therapy.

Recent advances in the epidemiology, diagnosis and treatment of endomyocardial fibrosis in Africa.

Endomyocardial fibrosis (EMF) continues to be an important and disabling disease in many parts of Africa, although its prevalence has declined in some parts of the continent. Increased access to medical care in general and increased availability of echocardiography in some parts of the continent have led to recognition of the disease in areas in which the disease had not been previously reported, and this has given new insights into its natural history. However, the early manifestations of EMF continue to elude clinicians and researchers, and no progress has been made in defining its aetiology. Advances have, however, been made in establishing the epidemiology and improving clinical diagnosis and management, through modern medical therapy and improved surgical techniques. Research is still required to define clinical, biological and echocardiographic markers of early stages of EMF, so that advances in the knowledge of its pathogenesis and pathophysiology can be made. This will hopefully determine preventive measures and avoid the burden of this debilitating condition in this continent.

Fibrosis endomiocárdica tropical en nuestro medio / Tropical endomyocardial fibrosis in Spain

La fibrosis endomiocárdica es una miocardiopatía restrictiva de etiología desconocida, prevalente en regiones tropicales. Se caracteriza por la obliteración fibrótica del ápex de uno o ambos ventrículos, que puede extenderse a la cámara de entrada ventricular. Afecta predominantemente a niños y adultos jóvenes. No existe un tratamiento específico y suele tener un pobre pronóstico. No es una entidad frecuente en nuestro medio pero debido a la inmigración estamos presenciando un auge de la misma. Presentamos 4 casos clínicos de fibrosis endomiocárdica en niños diagnosticados y tratados en nuestro medio, y realizamos una revisión de la misma (AU)

Endomyocardial fibrosis is a restrictive cardiomyopathy of unknown etiology prevalent in tropical regions. It is characterized by fibrotic obliteration of the apex of one or both ventricles, which can be extended to the ventricular inlet chamber. It predominantly affects children and young adults. There is no specific treatment and usually has a poor prognosis. It is uncommon in Spain, but due to immigration, it appears to be increasing. Four cases of endomyocardial fibrosis in children diagnosed and treated in Spain are presented, as a well as a review of this disease (AU)

Heart failure in sub-Saharan Africa.

The heart failure syndrome has been recognized as a significant contributor to cardiovascular disease burden in sub-Saharan African for many decades. Seminal knowledge regarding heart failure in the region came from case reports and case series of the early 20th century which identified infectious, nutritional and idiopathic causes as the most common. With increasing urbanization, changes in lifestyle habits, and ageing of the population, the spectrum of causes of HF has also expanded resulting in a significant burden of both communicable and non-communicable etiologies. Heart failure in sub-Saharan Africa is notable for the range of etiologies that concurrently exist as well as the healthcare environment marked by limited resources, weak national healthcare systems and a paucity of national level data on disease trends. With the recent publication of the first and largest multinational prospective registry of acute heart failure in sub-Saharan Africa, it is timely to review the state of knowledge to date and describe the myriad forms of heart failure in the region. This review discusses several forms of heart failure that are common in sub-Saharan Africa (e.g., rheumatic heart disease, hypertensive heart disease, pericardial disease, various dilated cardiomyopathies, HIV cardiomyopathy, hypertrophic cardiomyopathy, endomyocardial fibrosis, ischemic heart disease, cor pulmonale) and presents each form with regard to epidemiology, natural history, clinical characteristics, diagnostic considerations and therapies. Areas and approaches to fill the remaining gaps in knowledge are also offered herein highlighting the need for research that is driven by regional disease burden and needs.

Valvular heart diseases in the developing world: developmental biology takes center stage.

Heart valve disease is a significant and increasing global problem of which, in the developing world, the primary sufferers are the children and young adults regarded as the critical 'engine' of future economic growth. Yet, up to 10 times the current number of known sufferers remain undiagnosed in these countries. Among the most prevalent and neglected diseases are rheumatic heart disease and endomyocardial fibrosis. The etiologies of these diseases can be described in part as a dysregulation or reactivation of developmental biology pathways. Consequently, connecting mechanisms of valvulogenesis and disease etiology may represent an excellent strategy to identify therapeutic targets. These local diseases require local solutions tailored to local resources; therefore, collaboration with experienced research groups should be encouraged as a way of accelerating the creation of relevant knowledge, and its clinical translation.