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.

Where is the right ventricle? Accurate diagnosis with cardiovascular multimodality imaging.

Endomyocardial fibrosis (EMF) is a globally unattended disease with significant rates of morbidity and mortality. It has a higher prevalence in tropical and subtropical countries compared to the rest of the world. Endomyocardial fibrosis can affect the atrioventricular valves, along with all four chambers of the heart, but spares the myocardium. Patients currently undergo symptomatic treatment with diuretics and vasodilators to enhance quality of life, although medical therapy alone is associated with poor prognosis. Hence, patients with severe symptoms prefer surgical treatment. Modern multimodality imaging, however, can help these definitions to be made more accurately.

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.

Cardiac magnetic resonance in arrhythmogenic cardiomyopathies.

Over the past few years, the approach to the 'arrhythmic patient' has profoundly changed. An early clinical presentation of arrhythmia is often accompanied by non-specific symptoms and followed by inconclusive electrocardiographic findings. In this scenario, cardiac magnetic resonance (CMR) has been established as a clinical tool of fundamental importance for a correct prognostic stratification of the arrhythmic patient. This technique provides a high-spatial-resolution tomographic evaluation of the heart, which allows studying accurately the ventricular volumes, identifying even segmental kinetic anomalies and properly detecting diffuse or focal tissue alterations through an excellent tissue characterization, while depicting different patterns of fibrosis distribution, myocardial edema or fatty substitution. Through these capabilities, CMR has a pivotal role for the adequate management of the arrhythmic patient, allowing the identification of those phenotypic manifestations characteristic of structural heart diseases. Therefore, CMR provides valuable information to reclassify the patient within the wide spectrum of potentially arrhythmogenic heart diseases, the definition of which remains the major determinants for both an adequate treatment and a poor prognosis. The purpose of this review study was to focus on the role of CMR in the evaluation of the main cardiac clinical entities associated with arrhythmogenic phenomena and to present a brief debate on the main pathophysiological mechanisms involved in the arrhythmogenesis process.

Cardiovascular magnetic resonance (CMR) in restrictive cardiomyopathies.

The restrictive cardiomyopathies constitute a heterogeneous group of myocardial diseases with a different pathogenesis and overlapping clinical presentations. Diagnosing them frequently poses a challenge. Echocardiography, electrocardiograms and laboratory tests may show non-specific changes. In this context, cardiac magnetic resonance (CMR) may play a crucial role in defining the diagnosis and guiding treatments, by offering a robust myocardial characterization based on the inherent magnetic properties of abnormal tissues, thus limiting the use of endomyocardial biopsy. In this review article, we explore the role of CMR in the assessment of a wide range of myocardial diseases causing restrictive patterns, from iron overload to cardiac amyloidosis, endomyocardial fibrosis or radiation-induced heart disease. Here, we emphasize the incremental value of novel relaxometric techniques such as T1 and T2 mapping, which may recognize different storage diseases based on the intrinsic magnetic properties of the accumulating metabolites, with or without the use of gadolinium-based contrast agents. We illustrate the importance of these CMR techniques and their great support when contrast media administration is contraindicated. Finally, we describe the useful role of cardiac computed tomography for diagnosis and management of restrictive cardiomyopathies when CMR is contraindicated.

Association between diffuse myocardial fibrosis and diastolic dysfunction in sickle cell anemia.

Sickle cell anemia (SCA)-related cardiomyopathy is characterized by diastolic dysfunction and hyperdynamic features. Diastolic dysfunction portends early mortality in SCA. Diastolic dysfunction is associated with microscopic myocardial fibrosis in SCA mice, but the cause of diastolic dysfunction in humans with SCA is unknown. We used cardiac magnetic resonance measurements of extracellular volume fraction (ECV) to discover and quantify diffuse myocardial fibrosis in 25 individuals with SCA (mean age, 23 ± 13 years) and determine the association between diffuse myocardial fibrosis and diastolic dysfunction. ECV was calculated from pre- and post-gadolinium T1 measurements of blood and myocardium, and diastolic function was assessed by echocardiography. ECV was markedly increased in all participants compared with controls (0.44 ± 0.08 vs 0.26 ± 0.02, P < .0001), indicating the presence of diffuse myocardial fibrosis. Seventeen patients (71%) had diastolic abnormalities, and 7 patients (29%) met the definition of diastolic dysfunction. Participants with diastolic dysfunction had higher ECV (0.49 ± 0.07 vs 0.37 ± 0.04, P = .01) and N-terminal pro-brain natriuretic peptide (NT-proBNP; 191 ± 261 vs 33 ± 33 pg/mL, P = .04) but lower hemoglobin (8.4 ± 0.3 vs 10.9 ± 1.4 g/dL, P = .004) compared with participants with normal diastolic function. Participants with the highest ECV values (≥0.40) were more likely to have diastolic dysfunction (P = .003) and increased left atrial volume (57 ± 11 vs 46 ± 12 mL/m2, P = .04) compared with those with ECV <0.4. ECV correlated with hemoglobin (r = -0.46, P = .03) and NT-proBNP (r = 0.62, P = .001). In conclusion, diffuse myocardial fibrosis, determined by ECV, is a common and previously underappreciated feature of SCA that is associated with diastolic dysfunction, anemia, and high NT-proBNP. Diffuse myocardial fibrosis is a novel mechanism that appears to underlie diastolic dysfunction in SCA.

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.

A case presentation of patient from northern China with endomyocardial fibrosis.

BACKGROUND: Endomyocardial fibrosis (EMF) is a rare condition and a major cause of death in tropical countries. The etiology of EMF remains elusive, and no specific treatment has been developed yet, therefore it carries poor prognosis. CASE PRESENTATION: An 81-year-old male Chinese patient with a history of long-standing exertional breathlessness, presented with worsening symptoms rapidly evolving to orthopnea. A proper specific treatment was prescribed to the patient in the following days, including diuretics, angiotensin-converting-enzyme inhibitor and beta blockers. The patient died of progressive multiple organ failure. CONCLUSION: Echocardiography is technically limited due to the acoustic shadowing as a result of the calcification. Chest computed tomography is a more accurate diagnostic tool to examine the anatomic distribution and extent of endomyocardial calcification in this rare case.

Echocardiography in Indigenous Populations and Resource Poor Settings.

The majority of global cardiovascular disease burden occurs in low- and middle-income countries (LMIC) and indigenous populations. Although common diseases, such as ischaemic heart disease, cause significant burden, there are also neglected diseases. Forgotten by many, these diseases-including rheumatic heart disease, endomyocardial fibrosis and Chagas cardiomyopathy-continue to take a tremendous toll on a large proportion of the world's population. Whilst the technology of echocardiography continues to evolve in many high-income countries, low resource countries are working out how to make this vital tool available and affordable for the most remote and poorest populations. This paper aims to highlight the neglected cardiovascular diseases and their echocardiographic features. It also highlights the latest research in relation to portable echocardiography, task shifting and disease screening. The authors make recommendations in relation to future directions, including making echocardiography an affordable and accessible tool for all.

Predictive Values of Apelin for Myocardial Fibrosis in Hypertrophic Cardiomyopathy.

Apelin was proved to attenuate cardiac interstitial fibrosis. However, the association between apelin level and myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) is still unclear.This study aims to determine whether apelin is associated with myocardial fibrosis in HCM and investigate the predictive values of apelin for myocardial fibrosis in HCM.One hundred sixteen patients with HCM were enrolled in this study. Plasma apelin-13 and high-sensitivity cardiac troponin I (cTNI) were measured. The cardiac systolic and diastolic functions were evaluated by echocardiography, and the presence and extent of cardiac fibrosis were assessed by cardiac magnetic resonance. All statistical data were analyzed by SPSS version 21.0.The percentage of late gadolinium enhancement (LGE) was negatively correlated with apelin and positively correlated with cTNI, maximum wall thickness (MWT), and left ventricular mass index in the overall patients with HCM and LGE. Apelin, cTNI, MWT, and left ventricular ejection fraction were independent predictors of the presence of LGE. The cutoff values of apelin, cTNI, and MWT were 1.24 pg/mL, 0.031 ng/mL, and 19 mm, respectively, for the prediction of LGE. The combined measurements of MWT ≥ 19 mm and/or apelin ≤ 1.24 pg/mL, as well as the combined measurements of MWT ≥ 19 mm and/or cTNI ≥ 0.031 ng/mL, obtained higher specificity and higher sensitivity, thus, indicating the presence of LGE.Plasma apelin and cTNI are independent predictors of myocardial fibrosis. The combined measurements of serum apelin and MWT, as well as cTNI and MWT, showed higher predictive values for predicting myocardial fibrosis in patients with HCM.

Endocardial Fibrotic Lesions Have a Greater Effect on Peak Longitudinal Strain than Epicardial Fibrotic Lesions in Hypertrophic Cardiomyopathy Patients.

Peak longitudinal strain (PLS) of the left ventricular (LV) myocardium by transthoracic echocardiogram (TTE) is useful to detect LV myocardial damage. We hypothesized that myocardial fibrosis (MF) in the LV myocardium may influence PLS. Eighteen hypertrophic cardiomyopathy (HCM) patients (14 males; 58 ± 17 years old) underwent 1.5 Tesla cardiac magnetic resonance (CMR) and TTE. Patients with previous myocardial infarction were excluded. We used TTE to assess whole-layer PLS in an American Heart Association-defined 17-segment LV model. Whole-layer PLS was calculated using Echo PAC, version 113 (GE Healthcare). MF was assessed by T1-weighted CMR of the LV endocardial layer, the LV epicardial layer, or both the LV endocardial and epicardial layers for each lesion. Of the 306 segments, MF was detected in the LV endocardial layer only (13 segments), in the LV epicardial layer only (9 segments), or in both LV endocardial and epicardial layers (59 segments). PLS values were significantly lower in segments with MF affecting only the LV endocardial layer (7% ± 4%) (P < 0.05) and where MF was observed in both the LV endocardial and epicardial layers (9% ± 5%) (P = 0.001) compared with segments without MF (13% ± 7%). No significant difference in PLS values was detected between the MF segments for the LV epicardial layer only (10% ± 6%) and those without MF (13% ± 7%) (P > 0.05). In HCM patients, fibrotic lesions in the LV endocardium have a greater adverse effect on PLS than those in the LV epicardium. Our results are significant for HCM patients with fibrotic lesions within the LV endocardium.

Quantitative Differentiation of LV Myocardium with and without Layer-Specific Fibrosis Using MRI in Hypertrophic Cardiomyopathy and Layer-Specific Strain TTE Analysis.

To achieve further risk stratification in hypertrophic cardiomyopathy (HCM) patients, we localized and quantified layer-specific LVM fibrosis on MRI in HCM patients using regional layer-specific peak longitudinal strain (PLS) and peak circumferential strain (PCS) in LV myocardium (LVM) on speckle tracking transthoracic echocardiography (TTE). A total of 18 HCM patients (14 males; 58 ± 17 years) underwent 1.5T-MRI and TTE. PLS and PCS in each layer of the LVM (endocardium, epicardium, and whole-layer myocardium) were calculated for 17 AHA-defined lesions. MRI assessment showed that fibrosis was classified as endocardial, epicardial, or whole-layer (= either or both of these). Regional PLS was smaller in fibrotic endocardial lesions than in non-fibrotic endocardial lesions (P = 0.004). To detect LV endocardial lesions with fibrosis, ROC curves of regional PLS revealed an area under the curve (AUC) of 0.609 and a best cut-off point of 13.5%, with sensitivity of 65.3% and specificity of 54.3%. Regional PLS was also smaller in fibrotic epicardial lesions than in non-fibrotic epicardial lesions (P < 0.001). To detect LV epicardial lesions with fibrosis, ROC curves of PLS revealed an AUC of 0.684 and a best cut-off point of 9.5%, with sensitivity of 73.5% and specificity of 55.5%. Using whole-layer myocardium analysis, PLS was smaller in fibrotic lesions than in non-fibrotic lesions (P < 0.001). To detect whole-layer LV lesions with fibrosis, ROC curves of regional PLS revealed an AUC of 0.674 and a best cut-off point of 12.5%, with sensitivity of 79.0% and specificity of 50.7%. There were no significant differences in PCS of LV myocardium (endocardium, epicardium, and whole-layer) between fibrotic and non-fibrotic lesions. Quantitative regional PLS but not PCS in LV endocardium, epicardium, and whole-layer myocardium provides useful non-invasive information for layer-specific localization of fibrosis in HCM patients.

Myocardial Galectin-3 Expression Is Associated with Remodeling of the Pressure-Overloaded Heart and May Delay the Hypertrophic Response without Affecting Survival, Dysfunction, and Cardiac Fibrosis.

The ß-galactoside-binding animal lectin galectin-3 is predominantly expressed by activated macrophages and is a promising biomarker for patients with heart failure. Galectin-3 regulates inflammatory and fibrotic responses; however, its role in cardiac remodeling remains unclear. We hypothesized that galectin-3 may be up-regulated in the pressure-overloaded myocardium and regulate hypertrophy and fibrosis. In normal mouse myocardium, galectin-3 was constitutively expressed in macrophages and was localized in atrial but not ventricular cardiomyocytes. In a mouse model of transverse aortic constriction, galectin-3 expression was markedly up-regulated in the pressure-overloaded myocardium. Early up-regulation of galectin-3 was localized in subpopulations of macrophages and myofibroblasts; however, after 7 to 28 days of transverse aortic constriction, a subset of cardiomyocytes in fibrotic areas contained large amounts of galectin-3. In vitro, cytokine stimulation suppressed galectin-3 synthesis by macrophages and cardiac fibroblasts. Correlation studies revealed that cardiomyocyte- but not macrophage-specific galectin-3 localization was associated with adverse remodeling and dysfunction. Galectin-3 knockout mice exhibited accelerated cardiac hypertrophy after 7 days of pressure overload, whereas female galectin-3 knockouts had delayed dilation after 28 days of transverse aortic constriction. However, galectin-3 loss did not affect survival, systolic and diastolic dysfunction, cardiac fibrosis, and cardiomyocyte hypertrophy in the pressure-overloaded heart. Despite its potential role as a prognostic biomarker, galectin-3 is not a critical modulator of cardiac fibrosis but may delay the hypertrophic response.

Endogenous assessment of diffuse myocardial fibrosis in patients with T1ρ -mapping.

PURPOSE: Recently, it was shown that a significantly higher T1ρ is found in compact myocardial fibrosis after chronic myocardial infarction. In this study, we investigated the feasibility of native T1ρ -mapping for the detection of diffuse myocardial fibrosis in patients with dilated cardiomyopathy (DCM). MATERIALS AND METHODS: T1ρ -mapping was performed on three explanted hearts from DCM patients at 3 Tesla (T). Histological fibrosis quantification was performed, and compared with the T1ρ -relaxation times in the heart. Furthermore, twenty DCM patients underwent an MRI at 1.5T. Native T1ρ -maps, native T1 -maps, and extracellular volume (ECV)-maps were acquired. Additionally, eight healthy volunteers were scanned for reference values. RESULTS: A significant correlation (Pearson r = 0.49; P = 0.005) was found between ex vivo T1ρ -values and fibrosis fraction from histology. Additionally, a significantly higher T1ρ -relaxation time (55.2 ± 2.7 ms) was found in DCM patients compared with healthy control subjects (51.5 ± 1.2 ms) (P = 0.0024). The relation between in vivo T1ρ -values and ECV-values was significant (Pearson r = 0.66). No significant relation was found between native T1 - and ECV-values in this study (P = 0.89). CONCLUSION: This study showed proof of principle for the endogenous detection of diffuse myocardial fibrosis with T1ρ -MRI. Ex vivo and in vivo experiments showed promising results that T1ρ -MRI can be used to measure the extent of diffuse myocardial fibrosis in the myocardium. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:132-138.

Utility of cardiac CT for evaluating delayed contrast enhancement in dilated cardiomyopathy.

BACKGROUND: The presence of myocardial fibrosis is associated with adverse outcome in dilated cardiomyopathy (DCM). Delayed contrast-enhanced cardiac magnetic resonance (DE-CMR) currently represents the gold standard in noninvasive evaluation of myocardial scarring. However, a significant number of patients are unable to undergo DE-CMR study for various reasons. We sought to determine the diagnostic accuracy of cardiac CT (CCT) compared with CMR in the investigation of the presence of delayed contrast enhancement (DCE) in subjects with DCM. METHODS: We prospectively enrolled 17 consecutive patients with DCM, who were initially referred to our institution because of recently manifested heart failure due to unexplained left ventricular systolic dysfunction. In all subjects, CCT and DE-CMR were performed within 1 week. RESULTS: CCT and DE-CMR showed satisfactory agreement in detecting DCE (agreement in 82% cases, κ = 0.56) with 50% sensitivity, 100% specificity, and a positive predictive value of 100%. CONCLUSION: CCT may be a valuable method for detecting DCE in patients with DCM. CCT thus might be considered as an alternative method to DE-CMR in the assessment of the presence and extent of myocardial fibrosis in subjects who are not suitable for DE-CMR examination.

Endomyocardial fibrosis: missing tricuspid valve and Fontan-like circulation.

Endomyocardial fibrosis (EMF) is a progressive type of obliterative/restrictive cardiomyopathy characterized by fibrosis of the apical endomyocardium of the ventricles. Although the prognosis of EMF patients is poor in tropical regions, the exact clinical course and pathogenesis of patients with EMF are not known. Here, we report the rare case with EMF in the seventh decade, who showed the disappearance of papillary muscles, chordae tendineae, and part of the tricuspid valves due to massive right ventricular thrombus. Because of those unusual findings of the isolated RV involvement, we observed continuous forward pulmonary artery flow, as occurring in a Fontan circulation.

A Challenging Differential Diagnosis: Distinguishing between Endomyocardial Fibrosis and Apical Hypertrophic Cardiomyopathy.

Endomyocardial fibrosis, which is a cause of restrictive cardiomyopathy, is characterized by the deposition of fibrous tissue in the apical region of 1 or both ventricles. The condition not only affects the diastolic dynamics of the ventricles, but also the function of the atrioventricular valves. The disease occurs predominantly in tropical regions worldwide and in sub-Saharan Africa. This condition is not well understood, with varied manifestations, from subclinical presentations to chronic and progressive edematous syndromes. Here, we present the challenging case of a patient with an indeterminate echocardiographic image, suggesting apical hypertrophy, plus severe aortic stenosis and fibrosis of the left ventricular outflow tract. An electrocardiogram revealed symmetrical T-wave inversion, which is a characteristic manifestation of apical hypertrophy. The importance of cardiac imaging examinations such as echocardiography and cardiac magnetic resonance for differentiating between endomyocardial fibrosis and apical hypertrophy is highlighted in this patient's case.

Multimodality imaging of eosinophilic myocarditis (loeffler's endocarditis) in a patient with idiopathic hypereosinophilic syndrome.

Eosinophilic myocarditis can result in endomyocardial fibrosis affecting both ventricles, leading to restrictive cardiomyopathy. Multimodality imaging is crucial for diagnosis, as demonstrated in this case of a patient presenting with symptoms of heart failure.