Cardiac Amyloidosis: Evolving Approach to Diagnosis and Management

The systemic amyloidoses are a group of heterogeneous disorders characterized by extracellular deposition of misfolded fibrillar protein that results in organ dysfunction. Involvement of the heart (cardiac amyloidosis) is manifest by increased cardiac wall thickness and impairment of myocardial diastolic and systolic properties, changes that result in heart failure, dysrhythmia, and death. Amyloidosis is classified by precursor protein, with light-chain (AL) and transthyretin (TTR) disease being most common in the United States. TTR amyloid can result from misfolding of variant TTR, a genetically inherited disease, or wild-type TTR, an acquired form of disease (termed senile systemic amyloidosis). In recent years, advances in the diagnosis and treatment of cardiac amyloidosis include identification and validation of disease biomarkers, new imaging techniques, and consensus treatment guidelines. Elevations of B-type natriuretic peptide and cardiac troponins can identify cardiac amyloidosis with a high degree of precision and confer important prognostic information. Non-invasive cardiac imaging techniques, such as cardiac magnetic resonance imaging and echocardiography with strain quantification, afford the ability to diagnose cardiac amyloidosis most often without the need for a confirmatory heart biopsy. Treatment of heart failure resulting from cardiac amyloidosis differs in many respects from most other etiologies of cardiomyopathy. The mainstay of treatment involves volume control with diuretics, low dose β-adrenergic antagonists or amiodarone for dysrhythmia, and warfarin to prevent thromboembolism. Although widely held to have a dismal prognosis, modern treatments such as high-dose melphalan with stem cell transplantation (HDM/SCT) for AL disease achieve a complete hematologic response in nearly half of eligible patients and yield long-term survival. For patients with advanced AL cardiac amyloidosis, cardiac transplantation followed by HDM/SCT is also an option that has proven highly effective. For familial amyloid derived from variant TTR, liver transplantation is the one validated treatment; however, small molecule therapeutic agents now in clinical trials appear capable of slowing or halting TTR amyloid deposition.     

Clinical experience with cardiac amyloidosis

OBJECTIVE: Amyloidosis is a systemic disease potentially afflicting the heart. In this study we retrospectively studied patients presenting with major cardiac amyloidotic involvement. METHODS AND RESULTS: From 1997 until 2000, eight patients with major cardiac involvement of amyloidosis resulting in heart failure were diagnosed. All patients presented with heart failure. Diagnostic work-up, clinical, electrocardiographic, echocardiographic characteristics and treatment modalities are presented. Seven patients with acquired (both primary AL and postinflammatory AA) amyloidosis out of a total of eight patients died within one year after diagnosis, as a result of intractable cardiac failure due to both systolic and diastolic left ventricular dysfunction despite state-of-the-art medical treatment of heart failure. Only one patient with hereditary amyloidosis undergoing liver transplantation survived. CONCLUSIONS: Despite optimal medical cardiac failure treatment, acquired cardiac amyloidosis carries an ominous prognosis probably because patients are already in a very advanced stage of the disease at presentation.     

Diagnostic and prognostic value of cardiac imaging in amyloidosis

Amyloidosis is an infiltrative disease caused by extracellular protein deposition that has accumulated a lot of scientific production in recent years. Different types of amyloidosis can affect the heart. Transthyretin amyloidosis and light chain amyloidosis are the two most common types of cardiac amyloidosis. These entities have a poor prognosis, so accurate diagnostic techniques are imperative for determining an early therapeutic approach. Recent advances in cardiac imaging and diagnostic strategies show that these tools are safe and can avoid the use of invasive diagnostic techniques to histological confirmation, such as endomyocardial biopsy. We performed a review on the diagnostic and prognostic implications of different cardiac imaging techniques in cardiac amyloidosis. We mainly focus on reviewing echocardiography, cardiac magnetic resonance, computed tomography and nuclear imaging techniques and the different safety measurements that can be done with each of them.     

Cardiac amyloidosis: the heart of the matter

Amyloidosis comprises a unique group of diseases that share in common the extracellular deposition of insoluble fibrillar proteins in organs and tissue including the heart. Cardiac amyloidosis could be primary a part of systemic acquired amyloidosis, or a result of heredofamilial amyloidosis. Although the infiltration of the heart from different types of amyloid results in restrictive cardiomyopathy that manifests with refractory congestive heart failure and conduction abnormalities, unequivocal identification of the deposited amyloidogenic protein is mandatory in order to avoid misdiagnosis and inappropriate treatment. Recent developments in imaging techniques and extracardiac tissue biopsy have minimized the need for invasive endomyocardial biopsy for amyloidosis. Despite advances in treatment, the prognosis of a patient with amyloidosis is still poor and depends upon the underlying disease, and the type and degree of dysfunction of the involved organs. Thus, early diagnosis is mandatory because patients with advanced disease are usually too ill for intensive therapy. This review outlines current approaches to diagnosis, assessment of disease severity, and treatment of cardiac amyloidosis.     

Is technetium-99 m-pyrophosphate scintigraphy valuable in the diagnosis of cardiac amyloidosis?

Amyloidosis is a systemic disease frequently involving the myocardium and leading to functional disturbances of the heart. Amyloidosis can mimic other cardiac diseases. A conclusive clinical diagnosis of cardiac involvement can only be made by a combination of different diagnostic methods. In 7 patients with myocardial amyloidosis we used a combined first-pass and static scintigraphy with technetium-99 m-pyrophosphate. There was only insignificant myocardial uptake of the tracer. The first-pass studies however revealed reduced systolic function in 4/7 patients and impaired diastolic function in 6/7 patients. Therefore, although cardiac amyloid could not be demonstrated in the static scintigraphy due to amyloid fibril amount and composition, myocardial functional abnormalities were seen in the first-pass study.     

Cardiac Amyloidosis: An Updated Review With Emphasis on Diagnosis and Future Directions

Cardiac amyloidosis occurs because of abnormal protein (amyloid) deposition in the cardiac tissue. Even with advanced diagnostic techniques and treatments, the prognosis of amyloidosis remains poor. The diagnosis of cardiac amyloidosis particularly needs to be in the differential in patients presenting with heart failure with preserved ejection fraction. This entity remains underdiagnosed due to lack of suspicion on the part of many clinicians. Involvement of cardiac tissue is the utmost determinant factor for available treatment options and prognosis. Many cases of cardiac amyloidosis usually remain undiagnosed or diagnosed only in advanced stages when treatment options are limited and associated with poor survival. Hence, early recognition of cardiac amyloidosis is indispensable in halting the disease process before irreversible changes occur. The purpose of this review is to summarize the recent updates in the evaluation and management of cardiac amyloidosis and to discuss potential future treatments options.     

伴心肌肌钙蛋白I持续升高和心绞痛症状的系统性淀粉样变性

系统性淀粉样变性相对少见,累及心脏时,可出现多种临床表现,极易造成误诊和漏诊。本例报道了一位66岁女性,表现为持续性肌钙蛋白I升高和反复发作的胸痛,根据心脏影像学检查,结合单克隆免疫球蛋白试验及骨髓细胞学和骨髓活检,最终诊断为“系统性淀粉样变性（心脏受累）”。因此,对于射血分数保留的不能解释原因的心衰、肌钙蛋白升高、心脏影像学异常或存在系统性疾病,均应警惕有无淀粉样变可能。     

Current therapeutic strategies in cardiac amyloidosis

Optional statement Amyloidosis is a systemic disease in which clinical manifestations are caused by the replacement of normal tissue with insoluble amyloid fibrils. Cardiac involvement causes a restrictive cardiomyopathy and is associated with poor functional outcomes. Cardiac magnetic resonance imaging and measurement of B-type natriuretic peptide are particularly helpful in distinguishing restrictive cardiomyopathy from constrictive pericarditis, but a tissue biopsy is required to make the diagnosis of amyloidosis. Although standard treatment options for congestive heart failure may provide symptomatic relief in cardiac amyloidosis, prognosis remains dismal. Judicious diuretic use remains the mainstay of therapy, but achieving optimal fluid balance is difficult because patients are usually “preload dependent.” Angiotensin-converting enzyme inhibitors in low doses are often helpful but may lead to orthostatic hypotension, particularly in patients who also have involvement of the autonomic nervous system. β Blockers may be useful if given relatively early in the disease process, but should be used with caution in patients with advanced disease because they may exacerbate symptoms. Therapy aimed at the underlying disease process in primary systemic amyloidosis is based on treatment regimens used in multiple myeloma, such as melphalan and prednisone. These offer limited benefit when cardiac involvement is significant, but newer treatments, including the novel anthracycline 4′-iodo-4′-deoxydoxorubicin, potentially combined with autologous stem cell transplantation, offer some hope for the future.     

Diagnosis of cardiac amyloidosis using magnetic resonance imaging: a new reliable, non-invasive technique to be validated

Introduction

Amyloidosis is characterised by extracellular tissue deposition of insoluble fibrillar protein in various organs. Cardiac involvement is associated with the worse prognosis and the main cause of death. It needs a prompt diagnosis, which could be sometimes difficult to obtain. Endomyocardial biopsy remains the gold standard diagnostic technique, but recent studies on cardiac magnetic resonance imaging (MRI) indicate that this imaging procedure may be useful to the diagnosis of amyloidosis.

Case reports

We report three patients with systemic amyloidosis who underwent cardiac MRI for the diagnosis or the follow-up of their disease. In addition to poorly specific signs of restrictive cardiomyopathy, cardiac MRI showed, after gadolinium enhancement that was considered characteristic of amyloidosis.

Conclusion

Cardiac MRI is a useful diagnostic tool in cardiac amyloidosis, as it was shown in recent studies. Compared to endomyocardial biopsy it is a non-invasive technique that is now more readily accessible and that seems to have an acceptable specificity.     

Case Report: Isolated Cardiac Amyloidosis: An Enigma Unravelled

Amyloidosis is a rare, multisystem disease characterized by deposition of fibrils in extracellular tissue involving kidney, liver, heart, autonomic nervous system, and several other organs. This report discusses a 75-year-old male who presented with worsening dyspnea on exertion, orthopnea, and lower-extremity edema. On physical exam, he had elevated jugular venous pressure and lowerextremity edema. Electrocardiogram depicted low voltage in limb leads and a prolonged PR interval. Echocardiogram revealed left ventricular hypertrophy, severe biatrial dilatation, and restrictive filling physiology. Coronary angiography showed absence of significant epicardial coronary artery disease. On right heart catheterization, a “dip-and-plateau sign” was noted on right ventricular pressure tracings. A diagnosis of cardiac amyloidosis was considered, but a complete hematology work-up for systemic amyloidosis was negative. Cardiac magnetic resonance imaging was pursued, showing delayed gadolinium enhancement, and this ultimately led to the myocardial biopsy confirming the diagnosis of isolated cardiac amyloidosis. Further genetic analyses confirmed isolated cardiac amyloid caused by mutant transthyretin protein (Val-122-Ile). Isolated cardiac amyloidosis is an extremely rare entity, and diagnosis may be difficult despite the use of multimodality imaging. If the index of suspicion is high, then myocardial biopsy should be considered.     

Hiding in Plain Sight: Cardiac Amyloidosis,an Emerging Epidemic

Amyloidosis is a term used to describe a group of rare heterogeneous diseases that ultimately result in the deposition and accumulation of misfolded proteins. These misfolded proteins, known as amyloids, are associated with a variety of precursor proteins that have amyloidogenic potential. Ultimately, the specific type of amyloidosis is dependent on multiple factors including genetic variability of precursor proteins and the tissue or organ in which the amyloid accumulates. Several types of amyloid have a predilection for the heart and thus contribute to cardiac amyloidosis, a major cause of restrictive cardiomyopathy. Individuals with cardiac amyloidosis present clinically with heart failure with preserved ejection fraction. Although improved diagnostics and increased awareness of cardiac amyloidosis have led to a relative increase in diagnosis, cardiac amyloidosis remains an underrecognized and underdiagnosed cause of heart failure with preserved ejection fraction. It is essential to properly identify cases of cardiac amyloidosis and determine the pathology responsible for the formation of amyloid to appropriately provide management. This review aims to encourage physician awareness of cardiac amyloidosis by focusing on clinical presentation and the distinctions between types. Furthermore, epidemiology is central to understanding the affected demographics and sometimes hereditary nature of the disease. Improved understanding of cardiac amyloidosis will ideally lead to earlier diagnosis and interventions to improve patient outcomes.     

Management of Cardiac Amyloidosis: Do’s and Don’ts

Cardiac amyloidosis is a potentially deadly disease characterized by progressive infiltration of amyloid fibrils, and it is increasingly recognized as an underdiagnosed but important cause of heart failure. Given its unique pathogenesis, there are key differences in the management of cardiac amyloidosis compared with other forms of heart failure. Moreover, the 2 common forms of cardiac amyloidosis, transthyretin and light-chain amyloidosis, are distinct entities with varying clinical manifestations and prognoses, leading to the need for tailored approaches to management. In the past decade, there have been many significant advances in the diagnosis and treatment of both forms of cardiac amyloidosis. For example, in selected cases, transthyretin cardiac amyloidosis can be diagnosed noninvasively with the use of bone scintigraphy imaging, avoiding the need for a biopsy. Effective, more targeted therapies have been developed for both transthyretin and light-chain amyloidosis. However, these treatments are much more effective in early stages of disease before significant end-organ amyloid deposition has occurred. Consequently, it is increasingly imperative that clinicians aggressively screen at-risk groups, identify early signs of disease, and initiate treatment. Finally, once thought to be ill advised, heart transplantation should be considered in carefully selected patients with end-stage cardiac amyloidosis, because transplant outcomes in these patients is now similar to other those for other cardiomyopathies. Given these and other recent changes in clinical practice, this article discusses several key considerations for the clinical care of patients with cardiac amyloidosis.     

Amyloid heart disease. New frontiers and insights in pathophysiology, diagnosis, and management

Amyloidosis comprises a unique group of diseases that share in common the extracellular deposition of insoluble fibrillar proteins in organs and tissues. Cardiovascular amyloidosis can be primary, a part of systemic amyloidosis, or a result of chronic systemic diseases elsewhere in the body. The most common presentations are congestive heart failure-mainly a restrictive infiltrative pattern--and conduction system disturbances. Recent developments in imaging techniques and extracardiac tissue sampling have minimized the need for invasive endomyocardial biopsy for amyloidosis. Despite advances in treatment, the prognosis for patients with amyloidosis is still poor and depends on the underlying disease type. Herein, we present new insights and recent advances in cardiovascular amyloidosis.     

Amyloidosis as a Systemic Disease in Context

The systemic amyloidoses are a group of diseases characterized by the deposition of amyloid, a material formed from misfolding of proteins, in one or more organs. The 2 commonest forms of amyloidosis are transthyretin amyloidosis (ATTR), derived from wild-type or mutant transthyretin, and light-chain (AL) amyloidosis, derived from abnormal circulating light chains produced by plasma cell dyscrasia. Both frequently involve the heart, producing an infiltrative cardiomyopathy with restrictive pathophysiology. Although advances in echocardiographic, magnetic resonance, and nuclear imaging have rendered diagnosis of cardiac amyloidosis easier, diagnosis is still often delayed. This review focuses on noncardiac manifestations of AL and TTR amyloidosis that may aid the cardiologist in making an earlier diagnosis of cardiac amyloidosis in a patient with cardiac symptoms (such as periorbital purpura in AL amyloidosis and a history of carpal tunnel syndrome and ruptured biceps tendon in ATTR). It also focuses on the unique challenges that treatment of cardiac amyloidosis poses owing to concomitant noncardiac disease, such as nephrotic syndrome–related edema and hypotension due to autonomic neuropathy, and stresses the importance of a precise typing of amyloidosis and a multidisciplinary approach to therapy.     

心脏淀粉样变性

淀粉样变性是以不可溶性的淀粉样物质沉积于器官或组织的细胞外区,导致相应的器官或组织功能障碍为特征的一组疾病。心脏是淀粉样变性常累及的器官。心脏淀粉样变性临床上通常按其病因分为原发性、家族性、老年性、继发性及透析相关性五种类型。其最常见的临床表现为限制性心肌病和顽固性心力衰竭,有时伴有传导阻滞。心肌活检可以确定诊断,近年来随着心外组织取样和显像技术的发展已大大减少了心内膜心肌活检的必要。尽管治疗上有所改进,但心脏淀粉样变性患者预后仍然较差,主要取决于原有疾病类型。     

The quintessential form of diastolic heart failure in older adults: Wild type transthyretin cardiac amyloidosis

Wild-type transthyretin cardiac amyloidosis (ATTRwt) is now recognized as a common cause of heart failure with preserved ejection fraction (HFpEF). In this review, we aim to describe the unique epidemiologic, pathophysiologic, and clinical features associated with ATTwt cardiac amyloidosis. Compared to other etiologies of HFpEF, ATTRwt cardiac amyloidosis affects almost exclusively older adults, demonstrating a characteristic age-dependent penetrance that impacts both the diagnosis and treatment of the disease. In addition, ATTR cardiac amyloidosis demonstrates a unique pathophysiology in contrast to other etiologies of HFpEF, which results in a characteristic phenotype that can raise suspicion for ATTRwt cardiac amyloid in the appropriate demographic. With these distinguishing features in mind, we aim to describe the specific signs, symptoms, and imaging characteristics associated with ATTRwt cardiac amyloidosis, including the role of nuclear scintigraphy that has essentially eliminated the need for biopsy in most patients with suspected disease. Finally, we review the evidence behind the available therapeutic agents, as well as those under investigation, which will change the way we manage older patients with ATTRwt cardiac amyloidosis in the coming years.     

Cardiac Amyloidosis in Patients Undergoing TAVR: Why We Need to Think About It

Systemic amyloidosis encompasses a variety of diseases characterized by extracellular deposition of protein-derived fibrils in different tissues and organs. Immunoglobulin light-chain (AL) and transthyretin (ATTR) amyloid are the two types that more commonly affect the heart and in both subtypes cardiac involvement is the main determinant of prognosis. Recently, several studies have suggested that Cardiac Amyloidosis (CA) and Aortic Stenosis (AS) can coexist more frequently than previously suspected with prevalence ranging from 5,6% to 16% in different cohorts. The unexpected high prevalence of CA in AS and the availability of potentially effective treatment in CA should push us to carefully investigate elderly patients with aortic valve stenosis in order to identify those with coexistent amyloidosis. While the motivation to exclude amyloidosis was in the past their exclusion from active treatment of the valve disease, judged as futile because of their poor unavoidable prognosis, the improved therapeutic options available challenges this conservative approach. Aim of this review is to identify the triggers to investigate AS patients at risk of having concomitant ATTR-CA, to propose a diagnostic path to reach diagnosis and to discuss the changes in the therapeutic strategy caused by this discovery in the era of TAVR and active pharmacological treatments to slow down disease progression.     

Cardiac amyloidosis - experience in a tertiary cardiac referral centre

Amyloidosis is an uncommon systemic disease characterized by deposition of insoluble fibrillar protein in different organs and the prognosis is poor if the heart is involved. Experience with management of cardiac amyloidosis is difficult because of its rare occurrence, late presentation and ineffective treatment. Since 1995, we have encountered and prospectively followed up 16 cases of cardiac amyloidosis in our cardiac centre. We believe this is the largest series of cardiac amyloidosis reported in Chinese patients. The 1-year, 3-year and 5-year survival rates were 40%, 25% and 17%, respectively. The major cause of death was cardiac-related. Those patients with overt heart failure or with untreated amyloidosis had a dismal prognosis (mean survival of 2.2 months and 3.5 months, respectively). Those who received specific treatment for the underlying amyloidosis had a better outcome with an average survival of 33.4 months.     

Amyloidosis. Also a heart disease

The term cardiac amyloidosis refers to the involvement of the heart as a result of amyloid deposition in heart tissue either in the context of a systemic disease or as a localized form. Several proamyloid proteins can produce amyloid deposits in the heart. Each of these amyloidoses has characteristic clinical (cardiac and extracardiac) features, its own course, and a specific diagnosis and treatment. Since cardiac involvement may be the first-manifestation of amyloidosis, the cardiologist may be the first healthcare professional to see the patient and must always consider this diagnosis. In this review, we consider the amyloidosis characteristics that may present with cardiac involvement, from the cardiologist's viewpoint and in light of our experience. We review in detail when and how to establish the diagnosis and how to treat these patients’ cardiac involvement and the underlying amyloid disease.Full English text available from: www.revespcardiol.org     

Rheumatic heart disease associated with secondary renal amyloidosis

Introduction: Amyloidosis is a disorder of protein folding in which normally soluble proteins undergo conformational changes and are deposited in the extracellular space in an abnormal fibrillar form. Accumulation of these fibrils causes progressive disruption of the structure and function of tissues and organs, and the systemic forms of amyloidosis are frequently fatal. The conditions that underlie amyloid deposition may be either acquired or hereditary. Amyloid-A (AA) amyloidosis is the most common form of systemic amyloidosis worldwide, AA amyloidosis occurs in the course of chronic inflammatory diseases, hereditary periodic fevers, and with certain neoplasms such as Hodgkin disease and renal cell carcinoma. Amyloidosis due to rheumatic heart disease (RHD) is not common but can be seen. We report here a patient with RHD and AA renal amyloidosis. Case Report: we present a 30 year-old Egyptian male with a history of RHD, accidently discovered to have nephrotic range proteinuria and rising serum creatinine. Serology studies were negative or normal, including antinuclear antibody (ANA) and antineutrophil cytoplasmic antibody (ANCA). C3 and C4 complement levels were normal. Kidney biopsy revealed AA renal amyloidosis. CT chest and abdomen revealed bilateral hilar and mediastinal lymphadenopathy and para-aortic lymph nodes. Endobronchial biopsy and bronchoalveolar lavage revealed non-specific chronic inflammatory changes. The patient's secondary amyloidosis was presumed to be related to the long standing RHD after exclusion of other causes of secondary amyloidosis. The patient finally died due to heart failure and acute pulmonary edema. Conclusion: Long standing RHD can lead to secondary AA amyloidosis. Keywords: AA Amyloidosis; Kidney Biopsy; Rheumatic Heart Disease; Renal Amyloidosis.