Digoxin use in systemic light-chain (AL) amyloidosis: contra-indicated or cautious use?

Arrhythmias and Device Therapies in Cardiac Amyloidosis

Cardiac amyloidosis is caused by amyloid fibrils that deposit in the myocardial interstitium, causing restrictive cardiomyopathy and eventually death. The electromechanical, inflammatory, and autonomic changes due to amyloid deposition result in arrhythmias. Atrial fibrillation is by far the most common arrhythmia. The rate control strategy is generally poorly tolerated due to restrictive filling physiology and heart rate dependance, favoring adoption of the rhythm control strategy. Anticoagulation for stroke prophylaxis is warranted, irrespective of CHA2DS2-VASc score in patients with a favorable bleeding profile; data on left appendage closure devices are still insufficient. Ventricular arrhythmias are also not uncommon, and the role of implantable cardioverter-defibrillator in cardiac amyloidosis is controversial. There is no evidence of improvement in outcomes when used for primary prevention in these patients. Bradyarrhythmia is most commonly associated with sudden cardiac death in cardiac amyloidosis. Pacemaker implantation can help provide symptomatic relief but does not confer mortality benefit.

Perioperative implications of amyloidosis and amyloid cardiomyopathy: A review for anesthesiologists

It is well recognized that amyloid protein can infiltrate many regions of the body. This can include the peripheral nerves, the liver, kidney, spleen, the gastrointestinal tract, and most importantly the myocardium. The amyloid proteins that cause cardiomyopathy may come from genetically altered liver genes (transthyretin amyloid, ATTR) or from the bone marrow with malignant plasma cells (light chain amyloid, AL) generating the aberrant protein. These two types of amyloidosis cause significant damaging effects on both the myocardial cells as well as the conduction system of the heart. The resultant changes can produce dyspnea and exercise intolerance which is thought to be secondary to diastolic dysfunction and reduced stroke volume. This subclinical decompensation poses a significant problem for members of a care team as it often goes unrecognized. In the operating room patients are exposed to dramatic hemodynamic changes and may have difficult airways, autonomic dysfunction, and conduction abnormalities. Although the topic of amyloidosis is well described in cardiology literature, it is underdiagnosed. The purpose of this review is to describe some of the pathophysiology behind the principle proteins that cause cardiac amyloidosis and to comprehensively describe perioperative considerations for anesthesia providers.

World Heart Federation Consensus on Transthyretin Amyloidosis Cardiomyopathy (ATTR-CM)

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and fatal condition that requires early diagnosis, management, and specific treatment. The availability of new disease-modifying therapies has made successful treatment a reality. Transthyretin amyloid cardiomyopathy can be either age-related (wild-type form) or caused by mutations in the TTR gene (genetic, hereditary forms). It is a systemic disease, and while the genetic forms may exhibit a variety of symptoms, a predominant cardiac phenotype is often present. This document aims to provide an overview of ATTR-CM amyloidosis focusing on cardiac involvement, which is the most critical factor for prognosis. It will discuss the available tools for early diagnosis and patient management, given that specific treatments are more effective in the early stages of the disease, and will highlight the importance of a multidisciplinary approach and of specialized amyloidosis centres. To accomplish these goals, the World Heart Federation assembled a panel of 18 expert clinicians specialized in TTR amyloidosis from 13 countries, along with a representative from the Amyloidosis Alliance, a patient advocacy group. This document is based on a review of published literature, expert opinions, registries data, patients' perspectives, treatment options, and ongoing developments, as well as the progress made possible via the existence of centres of excellence. From the patients' perspective, increasing disease awareness is crucial to achieving an early and accurate diagnosis. Patients also seek to receive care at specialized amyloidosis centres and be fully informed about their treatment and prognosis.

Cardiac amyloidosis: evolving pathogenesis, multimodal diagnostics, and principles of treatment

Amyloidosis is a protein deposition disorder in which insoluble fibril structures accumulate in the bodily tissues damaging the organ function. Cardiac amyloidosis is a severe but under-reported medical condition characterized by the accumulation of amyloid in the extracellular area of the myocardium, which results in thickening and stiffening of ventricular walls. Cardiac amyloidosis has recently gained much attention with its slowly surging incidence. With this study, we seek to comprehensively compile the pathophysiology and clinical picture of cardiac amyloidosis subtypes, extending a clinically oriented, up-to-date clinical approach to diagnosis and therapy. Cardiac amyloidosis can be caused by rare genetic mutations which may be inherited or acquired. The growing incidence can be attributed to advancements in imaging methods and other diagnostic modalities. Most occurrences of cardiac amyloidosis result from two forms of precursor protein: transthyretin [TTR] amyloid and immunoglobulin-derived light-chain amyloid. Prompt identification of cardiac amyloidosis can facilitate the implementation of evolving therapeutic interventions to enhance the outcomes. The modalities for the management of CA have evolved significantly in the last ten years. Apart from therapies for modifying disease and heart failure, a myriad of novel therapeutic approaches that target specific aspects of the disease, including gene therapies, are being researched. These aim at impeding its progression and improving clinical outcomes. See also Figure 1(Fig. 1).

Epidemiology, Mechanisms, and Management of Atrial Fibrillation in Cardiac Amyloidosis

Cardiac amyloidosis (CA) is a restrictive disease that results from intramyocardial amyloid deposition due to immunoglobulin light chain or transthyretin proteins. Up to two-third of CA patients have atrial fibrillation (AF) due to electromechanical, autonomic, and hemodynamic disturbances. AF in CA carries particularly increased risk of thromboembolism, prompting anticoagulation therapy irrespective of CHA₂DS₂VASc score. However, CA is also associated with enhanced bleeding risk that warrants thorough assessment of bleeding profile before initiation of anticoagulation. Management of AF in CA is challenging because these patients poorly tolerate rate control agents, while cardiomyopathy precludes most antiarrhythmic agents, leaving amiodarone as the preferred antiarrhythmic drug. The effectiveness of direct current cardioversion in restoring sinus rhythm in CA is comparable with that in the general population, although intraprocedural complication rates could be higher. Transesophageal echocardiogram should be performed prior to direct current cardioversion, given high incidence of intracardiac thrombus in these patients. Finally, the data on catheter ablation is limited.

Arrhythmic Manifestations of Cardiac Amyloidosis: Challenges in Risk Stratification and Clinical Management

Amylodiosis is a systemic disease characterized by extracellular deposits of insoluble amyloid in various tissues and organs. Cardiac amyloidosis is a frequent feature of the disease, causing a progressive, restrictive type of cardiomyopathy, and is associated with adverse clinical outcomes and increased mortality. The typical clinical presentation in patients with cardiac amyloidosis is heart failure (HF) with preserved ejection fraction. Most patients present with typical symptoms and signs of HF, such as exertional dyspnea, pretibial edema, pleural effusions and angina pectoris due to microcirculatory dysfunction. However, patients may also frequently encounter various arrhythmias, such as atrioventricular nodal block, atrial fibrillation and ventricular tachyarrhythmias. The management of arrhythmias in cardiac amyloidosis patients with drugs and devices is often a clinical challenge. Moreover, predictors of life-threatening arrhythmic events are not well defined. This review intends to give a deepened insight into the arrhythmic features of cardiac amyloidosis by discussing the pathogenesis of these arrhythmias, addressing the challenges in risk stratification and strategies for management in these patients.

Atrial amyloidosis: mechanisms and clinical manifestations

Cardiac amyloidosis (CA) is now recognized as an important cause of heart failure. Increased wall thickness and diastolic dysfunction of the left ventricle are the most easily detectable manifestations of CA, but amyloid accumulates in all cardiac structures. Involvement of the left and right atria may be due to the haemodynamic effects of ventricular diastolic dysfunction, the effects of amyloid infiltration into the atrial wall, and the cardiotoxic damage of atrial cardiomyocytes by amyloid precursors. Atrial amyloidosis is an early manifestation of CA, and is associated with an increased risk of atrial fibrillation and thromboembolic events. Furthermore, atrial amyloidosis can be found even in the absence of systemic disease and ventricular involvement. This condition is named isolated atrial amyloidosis and is due to a local overproduction of atrial natriuretic peptide. In this review we summarize the evidence on the mechanisms and clinical relevance of atrial amyloidosis.

Electrical cardioversion of atrial arrhythmias with cardiac amyloidosis in the era of direct oral anticogulants

AIMS

Atrial fibrillation (AF)/atrial flutter is common during cardiac amyloidosis (CA). Electrical cardioversion (EC) is a strategy to restore sinus rhythm (SR). However, left atrial thrombus (LAT) represents a contraindication for EC. CA patients with AF/atrial flutter have a high prevalence of LAT. We aimed to evaluate EC characteristics, LAT prevalence and risk factors, and AF/atrial flutter outcome in CA patients undergoing EC, predominantly treated with direct oral anticoagulants (DOACs).

METHODS AND RESULTS

All patients with CA and AF/atrial flutter referred for the first time to our national referral centre of amyloidosis for EC from June 2017 to February 2021 were included in this study. In total, 66 patients (median age 74.5 [70;80.75] years, 67% male) were included with anticoagulation consisted of DOAC in 74% of cases. All patients underwent cardiac imaging before EC to rule out LAT. EC was cancelled due to LAT in 14% of cases. Complete thrombus resolution was observed in only 17% of cases. The two independent parameters associated with LAT were creatinine [hazard ratio (HR) = 1.01; confidence interval (CI) = 1.00-1.03, P = 0.036] and the use of antiplatelet agents (HR = 13.47; CI = 1.85-98.02). EC acute success rate was 88%, and we observed no complication after EC. With 64% of patients under amiodarone, AF/atrial flutter recurrence rate following EC was 51% after a mean follow-up of 30 ± 27 months.

CONCLUSIONS

Left atrial thrombus was observed in 14% of CA patients listed for EC and mainly treated with DOAC. The acute EC success rate was high with no complication. The long-term EC success rate was acceptable (49%).

[Cardiac amyloidosis: State of art in 2022]

The 3 main types of cardiac amyloidosis are linked to two protein precursors: AL amyloidosis secondary to free light chain deposits in the context of monoclonal gammopathy (mainly of undetermined significance or myeloma) and transthyretin amyloidosis (ATTR), comprising wild-type transthyretin amyloidosis (ATTRwt for wild type) and hereditary transthyretin amyloidosis (ATTRv for variant). These diseases are underdiagnosed and highly prevalent in common cardiac phenotypes in recent studies (heart failure with preserved ejection fraction, severe aortic stenosis, hypertrophic cardiomyopathy). Myocardial amyloid infiltration affects all cardiac structures and clinically promotes predominantly heart failure, conductive disorders and cardioembolic events. The search for extracardiac signs makes it possible to arouse diagnostic suspicion. Electrocardiogram, echocardiography and cardiac MRI can suspect cardiac amyloidosis. The diagnostic confirmation follows a simple algorithm including a systematic search for monoclonal gammapathy and a disphosphonate scintigraphy. Histological proof is necessary in case of AL or ATTR amyloidosis with concomitant monoclonal gammopathy in order to initiate specific treatment. Due to the late disease onset in ATTRv, genetic testing must be routine in all cases of ATTR. These diseases are no longer perceived as incurable since recent therapeutic innovations. A better knowledge of the disease is more than ever necessary.

Supportive Care and Symptom Management for Patients With Immunoglobulin Light Chain (AL) Amyloidosis

Immunoglobulin light chain (AL) amyloidosis is a disorder of clonal plasma cells characterized by deposition of amyloid fibrils in a variety of tissues, leading to end-organ injury. Renal or cardiac involvement is most common, though any organ outside the central nervous system can develop amyloid deposition, and symptomatic presentations may consequently vary. The variability and subtlety of initial clinical presentations may contribute to delayed diagnoses, and organ involvement is often quite advanced and symptomatic by the time a diagnosis is established. Additionally, while organ function can improve with plasma-cell-directed therapy, such improvement lags behind hematologic response. Consequently, highly effective supportive care, including symptom management, is essential to improve quality of life and to maximize both tolerance of therapy and likelihood of survival. Considering the systemic nature of the disease, close collaboration between clinicians is essential for effective management.

Multidisciplinary supportive care in systemic light chain amyloidosis

The immunoglobulin light-chain amyloidosis is a multisystemic disease which manifests by damage to the vital organs by light chain-derived amyloid fibril. Traditionally, the treatment has been directed to the underlying plasma cell clone with or without high dose chemotherapy followed by autologous stem cell transplantation using melphalan based conditioning. Now with the approval of highly tolerable anti-CD38 monoclonal antibody daratumumab based anti-plasma cell therapy in 2021, high rates of hematologic complete responses are possible even in patients who are otherwise deemed not a candidate for autologous stem cell transplantation. However, despite the progress, there remains a limitation in the strategies to improve symptoms particularly in patients with advanced cardiac involvement, those with nephrotic syndrome and autonomic dysfunction due to underlying systemic AL amyloidosis. The symptoms can be an ordeal for the patients and their caregivers and effective strategies are urgently needed to address them. The supportive care is aimed to counteract the symptoms of the disease and the effects of the treatment on involved organs’ function and preserve patients’ quality of life. Here we discuss multidisciplinary approach in a system-based fashion to address the symptom management in this dreadful disease. In addition to achieving excellent anti-plasma cell disease control, using treatment directed to remove amyloid from the vital organs can theoretically hasten recovery of the involved organs thereby improving symptoms at a faster pace. Ongoing phase III clinical trials of CAEL-101 and Birtamimab will address this question.

Critical Comparison of Documents From Scientific Societies on Cardiac Amyloidosis: JACC State-of-the-Art Review

Over the last year, 5 national or international scientific societies have issued documents regarding cardiac amyloidosis (CA) to highlight the emerging clinical science, raise awareness, and facilitate diagnosis and management of CA. These documents provide useful guidance for clinicians managing patients with CA, and all include: 1) an algorithm to establish a diagnosis; 2) an emphasis on noninvasive diagnosis with the combined use of bone scintigraphy and the exclusion of a monoclonal protein; and 3) indications for novel disease-modifying therapies for symptomatic CA, either with or without peripheral neuropathy. Nonetheless, the documents diverge on specific details of diagnosis, risk stratification, and treatment. Highlighting the similarities and differences of the documents by the 5 scientific societies with respect to diagnosis, risk stratification, and treatment offers useful insight into the knowledge gaps and unmet needs in the management of CA. An analysis of these documents, therefore, highlights "gray zones" requiring further investigation.

Management of Cardiac Symptoms in Amyloidosis

Cardiac amyloidosis (CA) results in symptoms of heart failure, atrial and ventricular arrhythmias, conduction disturbances, and profound autonomic dysfunction. These symptoms present unique management challenges as compared with patients without CA, and can be very debilitating. Thus, management of the cardiovascular symptoms of these patients plays a central role in their care. This review presents an overview of the typical cardiovascular manifestations encountered in patients with CA and highlights the key management considerations for each.

Cardiac Amyloidosis Treatment

Cardiac amyloidosis (CA) is a restrictive cardiomyopathy with a traditionally poor prognosis. Until recently, CA treatment options were limited and consisted predominantly of managing symptoms and disease-related complications. However, the last decade has seen significant advances in disease-modifying therapies, increased awareness of CA, and improved diagnostic methods resulting in earlier diagnoses. In this review, we provide an overview of current and experimental treatments for the predominant types of CA: transthyretin cardiac amyloidosis (ATTR-CA) and immunoglobulin light chain (AL)-mediated CA (AL-CA).

The mainstay of AL-CA treatment is proteasome inhibitor-based chemotherapy with daratumumab and, when feasible, autologous stem cell transplantation. For ATTR-CA, the stabilizer tafamidis is the only US Food and Drug Administration (FDA)-approved treatment. However, promising novel therapies on the horizon target various points in the ATTR-CA amyloidogenic cascade. These include transthyretin gene (TTR) silencing agents to prevent TTR formation, TTR tetramer stabilization and inhibition of oligomer aggregation to prevent fibril formation, anti-TTR fiber antibodies, and amyloid degradation. For end-stage CA, advanced interventions may need to be considered, including heart, heart-kidney, and, for hereditary ATTR-CA, heart-liver transplantation. Despite the evolution of treatment options, CA management remains complex due to patient frailty and therapeutic side effects or intolerance with advanced cardiac disease. This is particularly relevant for those with AL-CA, when active teamwork between the hematologist-oncologist and the cardiologist is critical for treatment success. Often, referral to an expert center is necessary for timely diagnosis, initiation of treatment, and participation in clinical trials.

Two Decades of Cardiac Amyloidosis: A Danish Nationwide Study

Background

Cardiac amyloidosis (CA) has been associated with poor outcomes. Screening studies suggest that CA is overlooked-especially in the elderly. Recent advances in treatment have brought attention to the disease, but data on temporal changes in CA epidemiology are sparse.

Objectives

The aim of this work was to describe all patients with CA in Denmark, examining changes in patient characteristics from 1998 to 2017.

Methods

All patients with any form of amyloidosis diagnosed from 1998 to 2017, as well as their comorbidities and pharmacotherapy, were identified in Danish nationwide registries. CA was defined as any diagnosis code for amyloidosis combined with a diagnosis code for heart failure, cardiomyopathy, or atrial fibrillation or a procedural code for pacemaker implantation, regardless of the order. The index date was defined as the date of meeting those criteria. Patients were divided into 5-year periods by index date. For comparison, we also included control subjects (1:4 ratio) from the general population.

Results

CA criteria were met by 619 patients. Comparing 1998-2002 vs 2013-2017, the median age at baseline increased from 67.4 years (interquartile range [IQR]: 53.9-75.2 years) to 72.3 years (IQR: 66.0-79.3 years). The frequency of male patients increased from 62.1% to 66.2%. The incidence of CA rose from 0.88 to 3.56 per 100,000 person-years in the Danish population aged ≥65 years, and the 2-year mortality decreased from 82.6% (IQR: 69.9%-90.5%) to 50.2% (IQR: 43.1%-56.9%). Compared with control subjects, the mortality among CA patients was significantly higher (log-rank test: P < 0.0001).

Conclusions

CA, as defined in this study, was increasingly diagnosed on a national scale. The increasing frequency of male patients and median age suggest that wild-type transthyretin amyloidosis is driving this increase. Greater recognition of earlier, less advanced cases might explain decreasing mortality.

Clinical management of amyloid cardiomyopathy

Clinical heart failure, restrictive cardiomyopathy, and arrhythmias are hallmark features of amyloid cardiomyopathy. In contrast to the advancements in targeted therapies, there is a general lack of evidence-based practice guidelines for clinical management of amyloid cardiomyopathy. In this review, we review the role of routine medical therapy in amyloid cardiomyopathy, from heart failure management to orthostatic hypotension, atrial arrhythmias, thromboembolic complications, and prevention of sudden death. We conclude by discussing approaches to patients with end-stage disease.

Progress and challenges in the treatment of cardiac amyloidosis: a review of the literature

Cardiac amyloidosis is a restrictive cardiomyopathy determined by the accumulation of amyloid, which is represented by misfolded protein fragments in the cardiac extracellular space. The main classification of systemic amyloidosis is determined by the amyloid precursor proteins causing a very heterogeneous disease spectrum, but the main types of amyloidosis involving the heart are light chain (AL) and transthyretin amyloidosis (ATTR). AL, in which the amyloid precursor is represented by misfolded immunoglobulin light chains, can involve almost any system carrying the worst prognosis among amyloidosis patients. This has however dramatically improved in the last few years with the increased usage of the novel therapies such as proteasome inhibitors and haematopoietic cell transplantation, in the case of timely diagnosis and initiation of treatment. The treatment for AL is directed by the haematologist working closely with the cardiologist when there is a significant cardiac involvement. Transthyretin (TTR) is a protein that is produced by the liver and is involved in the transportation of thyroid hormones, especially thyroxine and retinol binding protein. ATTR results from the accumulation of transthyretin amyloid in the extracellular space of different organs and systems, especially the heart and the nervous system. Specific therapies for ATTR act at various levels of TTR, from synthesis to deposition: TTR tetramer stabilization, oligomer aggregation inhibition, genetic therapy, amyloid fibre degradation, antiserum amyloid P antibodies, and antiserum TTR antibodies. Treatment of systemic amyloidosis has dramatically evolved over the last few years in both AL and ATTR, improving disease prognosis. Moreover, recent studies revealed that timely treatment can lead to an improvement in clinical status and in a regression of amyloid myocardial infiltration showed by imaging, especially by cardiac magnetic resonance, in both AL and ATTR. However, treating cardiac amyloidosis is a complex task due to the frequent association between systemic congestion and low blood pressure, thrombo-embolic and haemorrhagic risk balance, patient frailty, and generally poor prognosis. The aim of this review is to describe the current state of knowledge regarding cardiac amyloidosis therapy in this constantly evolving field, classified as treatment of the cardiac complications of amyloidosis (heart failure, rhythm and conduction disturbances, and thrombo-embolic risk) and the disease-modifying therapy.

Treatment of AL Amyloidosis: Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) Consensus Statement 2020 Update

Immunoglobulin light chain (AL) amyloidosis is a clonal plasma cell disorder leading to progressive and life-threatening organ failure. The heart and the kidneys are the most commonly involved organs, but almost any organ can be involved. Because of the nonspecific presentation, diagnosis delay is common, and many patients are diagnosed with advanced organ failure. In the era of effective therapies and improved outcomes for patients with AL amyloidosis, the importance of early recognition is further enhanced as the ability to reverse organ dysfunction is limited in those with a profound organ failure. As AL amyloidosis is an uncommon disorder and given patients' frailty and high early death rate, management of this complex condition is challenging. The treatment of AL amyloidosis is based on various anti-plasma cell therapies. These therapies are borrowed and customized from the treatment of multiple myeloma, a more common disorder. However, a growing number of phase 2/3 studies dedicated to the AL amyloidosis population are being performed, making treatment decisions more evidence-based. Supportive care is an integral part of management of AL amyloidosis because of the inherent organ dysfunction, limiting the delivery of effective therapy. This extensive review brings an updated summary on the management of AL amyloidosis, sectioned into the 3 pillars for survival improvement: early disease recognition, anti-plasma cell therapy, and supportive care.

Practical recommendations for the diagnosis and management of transthyretin cardiac amyloidosis

Cardiac amyloidosis (CA) is an infiltrative restrictive cardiomyopathy caused by accumulation in the heart interstitium of amyloid fibrils formed by misfolded proteins. Most common CA types are light chain amyloidosis (AL) caused by monoclonal immunoglobulin light chains and transthyretin amyloidosis (ATTR) caused by either mutated or wild-type transthyretin aggregates. Previously considered a rare disease, CA is increasingly recognized among patients who may be misdiagnosed as undifferentiated heart failure with preserved ejection fraction (HFPEF), paradoxical low-flow/low-gradient aortic stenosis, or otherwise unexplained left ventricular hypertrophy. Progress in diagnosis has been due to the refinement of cardiac echocardiographic techniques (speckle tracking imaging) and magnetic resonance (T1 mapping) and mostly due to the advent of bone scintigraphy that has enabled noninvasive diagnosis of ATTR, limiting the need for endomyocardial biopsy. Importantly, proper management of CA starts from early recognition of suspected cases among high prevalence populations, followed by advanced diagnostic evaluation to confirm diagnosis and typing, preferentially in experienced amyloidosis centers. Differentiating ATTR from other types of amyloidosis, especially AL, is critical. Emerging targeted ATTR therapies offer the potential to improve outcomes of these patients previously treated only palliatively.

Updates in the Diagnosis and Management of AL Amyloidosis

PURPOSE OF REVIEW

Light chain (AL) amyloidosis is an insidious progressive disease which results in significant morbidity and inevitable mortality if not diagnosed and treated promptly. This review will highlight recent developments and summarize critical clinical points and updated practice changes for the clinician in 2020.

RECENT FINDINGS

Comparative analyses of staging systems, updated prognostic tools, and treatment response criteria now allow for improved patient stratification and treatment decisions; the role of minimal residual disease in response assessment is still being assessed. Clinical and genetic predictors for long-term survivors have been highlighted. Standard-of-care front-line bortezomib and the integration of anti-CD38 monoclonal antibodies in the relapsed disease have transformed treatment approach in recent years. Various clinical trials in the pipeline include novel anti-plasma cell therapies and therapies directed against amyloid deposits which promise to further advance the treatment landscape. Diagnosis, response assessment, and treatment paradigms for AL amyloidosis have evolved significantly in the past 15 years, translating into superior outcomes and increased chances of long-term survival for AL amyloidosis.

2019 HRS expert consensus statement on evaluation, risk stratification, and management of arrhythmogenic cardiomyopathy: Executive summary

Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.

Cardiac Amyloidosis: Overlooked, Underappreciated, and Treatable

Cardiac amyloidosis (CA) is an infiltrative and restrictive cardiomyopathy that leads to heart failure, reduced quality of life, and death. The disease has two main subtypes, transthyretin cardiac amyloidosis (ATTR-CA) and immunoglobulin light chain cardiac amyloidosis (AL-CA), characterized by the nature of the infiltrating protein. ATTR-CA is further subdivided into wild-type (ATTRwt-CA) and variant (ATTRv-CA) based on the presence or absence of a mutation in the transthyretin gene. CA is significantly underdiagnosed and increasingly recognized as a cause of heart failure with preserved ejection fraction. Advances in diagnosis that employ nuclear scintigraphy to diagnose ATTR-CA without a biopsy and the emergence of effective treatments, including transthyretin stabilizers and silencers, have changed the landscape of this field and render early and accurate diagnosis critical. This review summarizes the epidemiology, pathophysiology, diagnosis, prognosis, and management of CA with an emphasis on the significance of recent developments and suggested future directions.

Advances in pharmacotherapy for cardiac amyloidosis

INTRODUCTION

Amyloidosis is a group of progressive and devastating disorders resulting from extracellular deposition of misfolded proteins into tissues. When deposition of fibrils occurs in cardiac tissues, this systemic disease can lead to a very poor prognosis. Systemic amyloidosis can be acquired [light chain (AL) amyloidosis; AA amyloidosis], or hereditary [transthyretin (ATTR) amyloidosis]. Cardiac disease in amyloidosis is usually secondary to a systemic disease. The diagnosis of cardiac involvement is often delayed and yields an adverse prognosis.

AREAS COVERED

in this review, the authors report current literature on advances in pharmacotherapy for cardiac amyloidosis, mainly focused on AL and ATTR amyloidosis treatment.

EXPERT OPINION

Most pharmacological trials in amyloidosis patients, both AL and TTR, are directed to study the effects of drugs on polyneuropathy. However, since cardiac involvement carries a prominent negative survival impact in amyloidosis patients, future research should be more focused on amyloidosis cardiomyopathy as primary endpoint. Additionally, in AL amyloidosis therapies are mainly derived from experience on multiple myeloma treatment. In this specific setting, possible future research could particularly focus on immunotherapeutic agents able to optimize the standard chemotherapy results and, thus, allowing a larger population of patients to be treated by bone marrow stem cell transplantation.

Transthyretin amyloid cardiomyopathy

Transthyretin (TTR) cardiac amyloidosis is a severe, progressive, infiltrative disease caused by the deposition of TTR at cardiac level. It may be due to a genetic alteration in its hereditary form (ATTRv) or as a consequence of an age-related degenerative process (ATTRwt). Thanks to advances in imaging techniques and the possibility of achieving a non-invasive diagnosis, we now know that ATTR is more frequent than traditionally considered and that it is particularly relevant in patients over 65 years with heart failure or with aortic stenosis. With the appearance of several treatment options capable of modifying the natural history of ATTR, it is necessary for clinicians to be familiar with the diagnostic process and treatment of this disease. This review will cover the clinical spectrum of presentation of ATTR, its diagnosis and treatment.

Supportive Care for Patients with Systemic Light Chain Amyloidosis

Light chain amyloidosis is a disease in which clonal plasma cells produce toxic immunoglobulin light chains that form amyloid fibrils with deposition in organs, most commonly the heart and kidneys, but also the nervous system, gastrointestinal tract, and soft tissues. Treatment directed at the clonal cells eliminates light chain production and further deposition and may enable organ improvement and decrease the risk of organ failure. Supportive care manages the symptoms of organ involvement and the side effects of treatment. Supportive care also addresses the psychological and social issues that may arise in patients with light chain amyloidosis.

Treatment of cardiac transthyretin amyloidosis: an update

Transthyretin (TTR) is a tetrameric protein synthesized mostly by the liver. As a result of gene mutations or as an ageing-related phenomenon, TTR molecules may misfold and deposit in the heart and in other organs as amyloid fibrils. Cardiac involvement in TTR-related amyloidosis (ATTR) manifests typically as left ventricular pseudohypertrophy and/or heart failure with preserved ejection fraction. ATTR is an underdiagnosed disorder as well as a crucial determinant of morbidity and mortality, thus justifying the current quest for a safe and effective treatment. Therapies targeting cardiac damage and its direct consequences may yield limited benefit, mostly related to dyspnoea relief through diuretics. For many years, liver or combined heart and liver transplantation have been the only available treatments for patients with mutations causing ATTR, including those with cardiac involvement. The therapeutic options now include several pharmacological agents that inhibit hepatic synthesis of TTR, stabilize the tetramer, or disrupt fibrils. Following the positive results of a phase 3 trial on tafamidis, and preliminary findings on patisiran and inotersen in patients with ATTR-related neuropathy and cardiac involvement, we provide an update on this rapidly evolving field, together with practical recommendations on the management of cardiac involvement.

Digoxin Use in Cardiac Amyloidosis

Despite limited options for rate control of atrial fibrillation and for low-output heart failure seen in cardiac amyloidosis (CA), digoxin use is discouraged due to a reported increased risk of sensitivity and toxicity. We present our experience with digoxin use in patients with CA and report the event rate of suspected digoxin-related arrhythmias and toxicity. This is a retrospective study of patients with CA seen at our institution between November 1995 and October 2018. Patients were screened for a history of ≥7 days of continuous digoxin use and stratified based on amyloid precursor protein-transthyretin (ATTR) and immunoglobulin light chain (AL). Medical records were used to identify suspected digoxin-related arrhythmias and toxicity events. Digoxin was used in 69 patients (42 ATTR, 27 AL) for a median duration of 6 months (IQR, 1 to 16). Indication for use was rate control in 64% of patients and symptomatic heart failure management in 36%. Suspected digoxin-related arrhythmias and toxicity events occurred in 12% of patients. No deaths were attributed to digoxin use or toxicity, but 11 patients died while on digoxin-most due to progressive heart failure in the setting of CA. In conclusion, digoxin may be a therapeutic option for rate and symptom control for some patients with AL-CA and ATTR-CA. Rigorous patient selection is recommended, and patients should be closely monitored during digoxin administration.

Impact of Genetic Testing in Transthyretin (ATTR) Cardiac Amyloidosis

PURPOSE OF REVIEW

The review's main focus centers on the genetics of hereditary cardiac amyloidosis, highlighting the opportunities and challenges posed by the widespread availability of genetic screening and diagnostic cardiac imaging.

RECENT FINDINGS

Advancements in cardiac imaging, heightened awareness of the ATTR amyloidosis diagnosis, and greater access to genetic testing have all led to an increased appreciation of the prevalence of ATTR cardiac amyloidosis. Elucidation of the TTR molecular structure and effect of mutations on TTR function have allowed for novel TTR therapy development leading to clinical implementation of transthyretin stabilizers and transthyretin gene silencers. The transthyretin amyloidoses are a diverse group of protein misfolding disorders with cardiac and peripheral/autonomic nervous system manifestations due to protein deposition. Genetic screening allows for the early identification of asymptomatic TTR mutation carriers. With the advent of TTR-specific therapeutics, clinical guidance is necessary for the management of individuals with mutations in the TTR gene without evidence of disease.

Amyloidosis in Heart Failure

PURPOSE

Amyloidosis represents an increasingly recognized but still frequently missed cause of heart failure. In the light of many effective therapies for light chain (AL) amyloidosis and promising new treatment options for transthyretin (ATTR) amyloidosis, awareness among caregivers needs to be raised to screen for amyloidosis as an important and potentially treatable differential diagnosis. This review outlines the diversity of cardiac amyloidosis, its relation to heart failure, the diagnostic algorithm, and therapeutic considerations that should be applied depending on the underlying type of amyloidosis.

RECENT FINDINGS

Non-biopsy diagnosis is feasible in ATTR amyloidosis in the absence of a monoclonal component resulting in higher detection rates of cardiac ATTR amyloidosis. Biomarker-guided staging systems have been updated to facilitate risk stratification according to currently available biomarkers independent of regional differences, but have not yet prospectively been tested. Novel therapies for hereditary and wild-type ATTR amyloidosis are increasingly available. The complex treatment options for AL amyloidosis are improving continuously, resulting in better survival and quality of life. Mortality in advanced cardiac amyloidosis remains high, underlining the importance of early diagnosis and treatment initiation. Cardiac amyloidosis is characterized by etiologic and clinical heterogeneity resulting in a frequently delayed diagnosis and an inappropriately high mortality risk. New treatment options for this hitherto partially untreatable condition have become and will become available, but raise challenges regarding their implementation. Referral to specialized centers providing access to extensive and targeted diagnostic investigations and treatment initiation may help to face these challenges.

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 Care of Patients with Cardiac Amyloidosis

Cardiac amyloidosis, the majority of cases of which are due to immunoglobulin light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR), affects different aspects of the heart and cardiovascular system. Amyloid-induced cardiomyopathy, clinically manifesting with heart failure and electrophysiological abnormalities, has distinct characteristics compared to non-amyloid cardiomyopathies. Accordingly, specific management strategies are required. This paper will review the cardiovascular manifestations of patients with cardiac amyloidosis and their suggested treatment strategies, emphasizing the importance of multidisciplinary care.

Advances in the Treatment of Cardiac Amyloidosis

OPINION STATEMENT

Cardiac amyloidosis is associated with a high mortality rate, a long delay between the first signs and the diagnosis but a short interval between diagnosis and death. This scenario has changed recently due to improved disease awareness among doctors and significant progress in diagnosis thanks to multimodal imaging and a multidisciplinary approach. Therefore, during the last few years, we have had access to specific therapies for those patients. Those therapies are quite different depending on the type of amyloidosis, but there has been real progress. Systemic light chain amyloidosis (AL) with cardiac involvement is the most common form of cardiac amyloidosis. The severity of heart disease dictates the prognosis in AL amyloidosis. Advances in chemotherapy and immunotherapy that suppress light chain production have improved the outcomes. These recent improvements in survival rates have enabled therapies such as implanted cardiac defibrillators and heart transplantation that were usually not indicated for patients with advanced light chain amyloid cardiomyopathy to now be applied in selected patients. For transthyretin amyloidosis (ATTR), the second most common form of amyloidosis with cardiac involvement, there is also significant progress in treatment. Until recently, we had no specific therapy for ATTR cardiomyopathy (ATTR-CM), though now disease-modifying therapies are available. Therapies that stabilize transthyretin, such as tafamidis, have been shown to improve outcomes for patients with ATTR-CM. Modern treatments that stop the synthesis of TTR through gene silencing, such as patisiran and inotersen, have shown positive results for patients with TTR amyloidosis. Significant progress has been made in the treatment of amyloid cardiomyopathy, and hopefully, we will see even more progress with the spread of those treatments. We now can be optimistic about patients with this disease.

Management of complications of cardiac amyloidosis: 10 questions and answers

Amyloidosis is a systemic disorder characterized by extracellular deposition of insoluble fibrils. The most common forms are amyloid light chain and amyloid transthyretin (ATTR) amyloidoses. Cardiac involvement may be found in both these forms, and is an important cause of morbidity and mortality. The clinical presentation of cardiac amyloidosis (CA) may be represented by congestive heart failure (HF), possibly progressing to end-stage HF, as well as atrial fibrillation with possible thromboembolic events, and also conduction disturbances related to amyloid infiltration of conduction fibres. Beyond therapies targeting the blood dyscrasia or the ATTR amyloidogenic cascade, a careful choice of drug therapies, need for device implantation, and possibly treatments for advanced HF is then warranted. In the present review, we try to provide a useful guide to clinicians treating patients with CA by enucleating 10 main questions and answering them based on the evidence available as well as expert opinion and our clinical experience.

Amyloid Cardiomyopathy

Amyloid cardiomyopathy is emerging as an important and under-recognised cause of heart failure and cardiac arrhythmias, especially in older adults. This disorder is characterised by extracellular deposition of amyloid fibrils that form due to misfolding of secreted light chains (AL) or transthyretin protein (ATTR). In ATTR, amyloid aggregates typically result from excessive accumulation of wild-type transthyretin (ATTRwt) or from protein structural defects caused by TTR gene variants (ATTRv). Amyloid fibril deposition may predominantly affect the heart or show multi-system involvement. Previously considered to be rare and inexorably progressive with no specific therapy, there has been enormous recent interest in ATTR cardiomyopathy due to upwardly-revised estimates of disease prevalence together with development of disease-modifying interventions. Because of this, there is a clinical imperative to have a high index of suspicion to identify potential cases and to be aware of contemporary diagnostic methods and treatment options. Genetic testing should be offered to all patients with proven ATTR to access the benefits of new therapies specific to ATTRv and allow predictive testing of family members. With heightened awareness of amyloid cardiomyopathy and expanded use of genetic testing, a substantial rise in the numbers of asymptomatic individuals who are carriers of pathogenic variants is expected, and optimal strategies for monitoring and treatment of these individuals at risk need to be determined. Pre-emptive administration of fibril-modifying therapies provides an unprecedented opportunity for disease prevention and promises to change amyloid cardiomyopathy from being a fatal to a treatable disorder.

AL Amyloidosis for the Cardiologist and Oncologist: Epidemiology, Diagnosis, and Management

AL amyloidosis results from clonal production of immunoglobulin light chains, most commonly arising from a clonal plasma cell disorder. Once considered a nearly uniformly fatal disease, prognosis has improved markedly over the past 15 years, predominantly because of advances in light chain suppressive therapies. Cardiac deposition of amyloid fibrils is common, and the severity of cardiac involvement remains the primary driver of prognosis. Improvements in chemotherapy/immunotherapy have prompted a reassessment of the role of advanced cardiac therapies previously considered contraindicated in most patients, including the role of implantable cardioverter-defibrillators and cardiac transplantation. This state-of-the-art review highlights the current state of the field, including diagnosis, prognosis, and hematologic- and cardiac-specific therapies.

Cardiac amyloidosis: An underdiagnosed/underappreciated disease

Cardiac amyloidosis or amyloid cardiomyopathy (ACM), commonly resulting from extracellular deposition of amyloid fibrils consisted of misfolded immunoglobulin light chain (AL) or transthyretin (TTR) protein, is an underestimated cause of heart failure and cardiac arrhythmias. Among the three types of cardiac amyloidosis (wild-type or familial TTR and light-chain), the wild-type (Wt) TTR-related amyloidosis (ATTR) is an increasingly recognized cause of heart failure with preserved ejection fraction (HFpEF), and amyloidosis should be considered in the differential diagnosis of this heart failure group of patients. Recent advances in the diagnosis and drug treatment of ACM have ushered in a new era in early disease detection and better management of these patients. Certain clues in cardiac and extracardiac manifestations of ACM may heighten clinical suspicion and guide further confirmatory testing. Newer noninvasive imaging methods (strain echocardiography, cardiac magnetic resonance and bone scintigraphy) may obviate the need for endomyocardial biopsy in ATTR patients, while newer targeted therapies may alter the adverse prognosis in these patients. Early recognition of ACM is crucial in halting the disease process before irreversible organ damage occurs. Chemotherapy and stem-cell transplantation combined with immunomodulatory therapy may also favorably affect the course and prognosis of light chain ACM. Finally, in select patients with end-stage disease, heart transplantation may render results comparable to non-ACM patients. All these issues are herein reviewed.

Diagnosis and treatment of heart failure in hereditary transthyretin amyloidosis

Amyloidosis describes a family of related disease states associated with the extracellular tissue deposition of fibrils composed of low-molecular-weight subunits of a variety of proteins circulating as constituents of plasma. Depending on the disease subtype, fibrillar deposits in a several organs including the heart, kidney, liver, and peripheral nerves cause organ dysfunction and associated morbidity and mortality. The most common amyloid fibril deposits associated with cardiac manifestations are of monoclonal light-chain or transthyretin (ATTR) types. This review will focus on the ATTR types of cardiac amyloidosis. ATTR amyloidosis may be associated with abnormal metabolism of wild-type transthyretin (previously called senile systemic amyloidosis) or with hereditary variants in the transthyretin gene. Cardiac amyloidosis is often under-recognized in its early stages, and when a diagnosis of cardiac amyloidosis is made, patients are often at the advanced stages of the disease. Treatments now available appear to exert their benefit predominantly in individuals with the early stages of disease. Increased awareness and early diagnosis of cardiac amyloidosis and continued discovery of effective therapies will increase opportunities to improve clinical outcomes in this patient population.

2019 HRS expert consensus statement on evaluation, risk stratification, and management of arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.

Systemic immunoglobulin light chain amyloidosis

Systemic immunoglobulin light chain amyloidosis is a protein misfolding disease caused by the conversion of immunoglobulin light chains from their soluble functional states into highly organized amyloid fibrillar aggregates that lead to organ dysfunction. The disease is progressive and, accordingly, early diagnosis is vital to prevent irreversible organ damage, of which cardiac damage and renal damage predominate. The development of novel sensitive biomarkers and imaging technologies for the detection and quantification of organ involvement and damage is facilitating earlier diagnosis and improved evaluation of the efficacy of new and existing therapies. Treatment is guided by risk assessment, which is based on levels of cardiac biomarkers; close monitoring of clonal and organ responses guides duration of therapy and changes in regimen. Several new classes of drugs, such as proteasome inhibitors and immunomodulatory drugs, along with high-dose chemotherapy and autologous haematopoietic stem cell transplantation, have led to rapid and deep suppression of amyloid light chain production in the majority of patients. However, effective therapies for patients with advanced cardiac involvement are an unmet need. Passive immunotherapies targeting clonal plasma cells and directly accelerating removal of amyloid deposits promise to further improve the overall outlook of this increasingly treatable disease.

Storage diseases with hypertrophic cardiomyopathy phenotype

Never judge a book by its cover, nor assume hypertrophic cardiomyopathy (HCM) as sarcomeric, as appearances can deceive. HCM phenocopies account for a 5–10% of the cases, mainly represented by storage diseases, flagged by the increasing prevalence of senile cardiac amyloid in developing countries. Multisystemic and heterogeneous presentation of these entities is a challenge for clinicians, and time delay in diagnosis is a major concern. Promising drugs and gene-specific tailored therapies are under development, therefore, more than ever, appropriate understanding of these conditions is mandatory for adequate early treatment and counselling.

In this review, storage disorders will be classified as extracellular and intracellular deposit storage diseases, focusing our attention on the most prevalent conditions from the cardiologist’s perspective.