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Global Heart 2023Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and fatal condition that requires early diagnosis, management, and specific treatment. The availability... (Review)
Review
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.
Topics: Humans; Consensus; Prealbumin; Amyloid Neuropathies, Familial; Cardiomyopathies
PubMed: 37901600
DOI: 10.5334/gh.1262 -
The Lancet. Neurology Nov 2023Hereditary transthyretin (TTR) amyloid polyneuropathy is an autosomal dominant life-threatening disorder. TTR is produced mainly by the liver but also by the choroid... (Review)
Review
Hereditary transthyretin (TTR) amyloid polyneuropathy is an autosomal dominant life-threatening disorder. TTR is produced mainly by the liver but also by the choroid plexus and retinal pigment epithelium. Detailed clinical characterisation, identification of clinical red flags for misdiagnosis, and use of biomarkers enable early diagnosis and treatment. In addition to liver transplantation and TTR stabilisers, three other disease-modifying therapies have regulatory approval: one antisense oligonucleotide (inotersen) and two small interfering RNAs (siRNAs; patisiran and vutrisiran). The siRNAs have been shown to stop progression of neuropathy and improve patients' quality of life. As none of the disease-modifying therapies can cross the blood-brain barrier, TTR deposition in the CNS, which can cause stroke and cognitive impairment, remains an important unaddressed issue. CRISPR-Cas9-based one-time TTR editing therapy is being investigated in a phase 1 clinical study. Identification of the earliest stages of pathogenesis in TTR variant carriers is a major challenge that needs addressing for optimal management.
Topics: Humans; Amyloid Neuropathies, Familial; Prealbumin; Quality of Life; Amyloid Neuropathies; Biomarkers
PubMed: 37863593
DOI: 10.1016/S1474-4422(23)00334-4 -
Amyloid : the International Journal of... Sep 2022The recent approval of three drugs for the treatment of amyloid transthyretin (ATTR) amyloidosis, both hereditary and wild-type, has opened a new era in the care of...
The recent approval of three drugs for the treatment of amyloid transthyretin (ATTR) amyloidosis, both hereditary and wild-type, has opened a new era in the care of these diseases. ATTR amyloidosis is embedded in its pathophysiology, and the drugs target critical steps of the amyloid cascade. In addition to liver transplant, which removes the pathogenic variants, the introduction of gene silencers has allowed the suppression of both wild type and mutant transthyretin (TTR), thus extending the potential therapeutic range to wild-type cardiac amyloidosis. The kinetic stabilisation of TTR using small molecules has proved to be clinically effective both for amyloid neuropathy and cardiomyopathy. Gene silencers and kinetic stabilizers were recently approved on the basis of the outcome of phase III trials; however, comparative trials have not been performed, making it difficult to draw recommendations. Indications for liver transplantation have narrowed considerably. Here, guidelines for therapy are proposed based on expert consensus, acknowledging that the several drugs currently undergoing clinical trials will probably change in the near future the therapeutic armamentarium and, consequently, the therapeutic strategy. Indications for monitoring disease progression and drug efficacy are also provided for the management of these complexes, but now very treatable, diseases.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Humans; Liver Transplantation; Prealbumin
PubMed: 35652823
DOI: 10.1080/13506129.2022.2052838 -
JACC. Heart Failure Aug 2019Transthyretin amyloid cardiomyopathy (ATTR-CM) is a life-threatening, progressive, infiltrative disease caused by the deposition of transthyretin amyloid fibrils in the... (Review)
Review
Transthyretin amyloid cardiomyopathy (ATTR-CM) is a life-threatening, progressive, infiltrative disease caused by the deposition of transthyretin amyloid fibrils in the heart, and can often be overlooked as a common cause of heart failure. Delayed diagnosis due to lack of disease awareness and misdiagnosis results in a poorer prognosis. Early accurate diagnosis is therefore key to improving patient outcomes, particularly in the context of both the recent approval of tafamidis in some countries (including the United States) for the treatment of ATTR-CM, and of other promising therapies under development. With the availability of scintigraphy as an inexpensive, noninvasive diagnostic tool, the rationale to screen for ATTR-CM in high-risk populations of patients is increasingly warranted. Here the authors propose a framework of clinical scenarios in which screening for ATTR-CM is recommended, as well as diagnostic "red flags" that can assist in its diagnosis among the wider population of patients with heart failure.
Topics: Age Factors; Amyloid Neuropathies, Familial; Benzoxazoles; Cardiomyopathies; Delayed Diagnosis; Diagnostic Errors; Early Diagnosis; Early Medical Intervention; Heart Failure; Humans; Stroke Volume
PubMed: 31302046
DOI: 10.1016/j.jchf.2019.04.010 -
Heart Failure Reviews May 2022Amyloid transthyretin (ATTR) amyloidosis is a clinically heterogeneous and fatal disease that results from deposition of insoluble amyloid fibrils in various organs and... (Review)
Review
Amyloid transthyretin (ATTR) amyloidosis is a clinically heterogeneous and fatal disease that results from deposition of insoluble amyloid fibrils in various organs and tissues, causing progressive loss of function. The objective of this review is to increase awareness and diagnosis of ATTR amyloidosis by improving recognition of its overlapping conditions, misdiagnosis, and multiorgan presentation. Cardiac manifestations include heart failure, atrial fibrillation, intolerance to previously prescribed antihypertensives, sinus node dysfunction, and atrioventricular block, resulting in the need for permanent pacing. Neurologic manifestations include progressive sensorimotor neuropathy (e.g., pain, weakness) and autonomic dysfunction (e.g., erectile dysfunction, chronic diarrhea, orthostatic hypotension). Non-cardiac red flags often precede the diagnosis of ATTR amyloidosis and include musculoskeletal manifestations (e.g., carpal tunnel syndrome, lumbar spinal stenosis, spontaneous rupture of the distal tendon biceps, shoulder and knee surgery). Awareness and recognition of the constellation of symptoms, including cardiac, neurologic, and musculoskeletal manifestations, will help with early diagnosis of ATTR amyloidosis and faster access to therapies, thereby slowing the progression of this debilitating disease.
Topics: Amyloid; Amyloid Neuropathies, Familial; Diagnostic Errors; Humans; Male; Prealbumin
PubMed: 33609196
DOI: 10.1007/s10741-021-10080-2 -
Heart, Lung & Circulation Apr 2020Amyloid cardiomyopathy is emerging as an important and under-recognised cause of heart failure and cardiac arrhythmias, especially in older adults. This disorder is... (Review)
Review
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.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Genetic Predisposition to Disease; Genetic Testing; Humans; Prealbumin
PubMed: 32001152
DOI: 10.1016/j.hlc.2019.11.019 -
Herz May 2020Cardiac amyloidosis is a heterogeneous group of diseases characterized by extracellular deposition of amyloid fibrils in many different organs finally resulting in... (Review)
Review
Cardiac amyloidosis is a heterogeneous group of diseases characterized by extracellular deposition of amyloid fibrils in many different organs finally resulting in organ failure. Cardiac involvement is common for immunoglobulin light chain amyloidosis (AL) or transthyretin amyloidosis (ATTR); the latter is caused by a transthyretin gene variant or wild-type protein. Precise diagnostic assessment including laboratory tests, electrocardiography, echocardiography, cardiac magnetic resonance imaging, biopsy, and/or bone scintigraphy is mandatory for definition of the amyloid type and finally for treatment initiation. Treatment of cardiac amyloidosis includes symptomatic therapy of heart failure as well as the underlying disease. Causative treatment of AL amyloidosis is according to regimens used for multiple myeloma. For many years, orthotopic liver transplantation was the only treatment available for hereditary ATTR amyloidosis, but important advances have been made after approval of a novel class of medication, namely, RNA silencers. However, currently no treatment is available to remove amyloid deposited in the tissue. Thus, early diagnosis is still critical to afford the best efficacy of available therapies.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Echocardiography; Electrocardiography; Heart; Humans
PubMed: 32107564
DOI: 10.1007/s00059-020-04904-4 -
Current Cardiology Reports Dec 2019While morbidity and mortality remain high for amyloid cardiomyopathy (AC), increased awareness, earlier diagnosis, and advances in treatment have improved patient... (Review)
Review
PURPOSE OF REVIEW
While morbidity and mortality remain high for amyloid cardiomyopathy (AC), increased awareness, earlier diagnosis, and advances in treatment have improved patient outcomes. This review will discuss the pathophysiology, contemporary diagnostic strategies, and novel and investigational therapeutic strategies for light-chain (AL) and transthyretin (ATTR) AC.
RECENT FINDINGS
Diagnostic strategies for AC now include cardiac magnetic resonance imaging and bone scintigraphy. Proteosome inhibitor therapy is now front-line therapy for AL AC followed by autologous stem cell transplantation. Emerging disease-modifying strategies for ATTR AC include the recently FDA-approved TTR-stabilizer, tafamadis. ATTR gene-silencing therapy and amyloid fibril degradation therapy are two other strategies under investigation. Heart transplantation and durable mechanical circulatory support remain a final potential option; however, contemporary outcomes are improving with better patient selection. Patient outcomes for AC are expected to improve as increased awareness leads to earlier diagnosis and prompt treatment with emerging pharmacotherapy or advanced heart therapies.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Female; Hematopoietic Stem Cell Transplantation; Humans; Male; Middle Aged; Mutation; Pedigree; Prealbumin; Transplantation, Autologous
PubMed: 31792619
DOI: 10.1007/s11886-019-1230-9 -
Journal of the Peripheral Nervous... Dec 2022Transthyretin-mediated amyloidosis (ATTR) is a rare, under-recognized, progressively debilitating, fatal disease caused by the aggregation and extracellular deposition... (Review)
Review
Transthyretin-mediated amyloidosis (ATTR) is a rare, under-recognized, progressively debilitating, fatal disease caused by the aggregation and extracellular deposition of amyloid transthyretin (TTR) fibrils in multiple organs and tissues throughout the body. TTR is predominantly synthesized by the liver and normally circulates as a homotetramer, while misfolded monomers aggregate to form amyloid fibrils. One strategy to treat ATTR amyloidosis is to reduce the amount of TTR produced by the liver using drugs that directly target the TTR mRNA or gene. This narrative review focuses on how TTR gene silencing tools act to reduce TTR production, describing strategies for improved targeted delivery of these agents to hepatocytes where TTR is preferentially expressed. Antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs), termed RNA silencers, cause selective degradation of TTR mRNA, while a TTR gene editing tool reduces TTR expression by introducing nonsense mutations into the TTR gene. Two strategies to facilitate tissue-specific delivery of these nucleic acid-based drugs employ endogenous receptors expressed by hepatocytes. Lipid nanoparticles (LNPs) that recruit apolipoprotein E support low-density lipoprotein receptor-mediated uptake of unconjugated siRNA and are now used for CRISPR gene editing tools. Additionally, conjugating N-acetylgalactosamine (GalNAc) moieties to ASOs or siRNAs facilitates receptor-mediated uptake by the asialoglycoprotein receptor. In summary, ATTR is a progressive disease with various clinical manifestations due to TTR aggregation, deposition, and amyloid formation. Receptor-targeted ligands (eg, GalNAc) and nanoparticle encapsulation (eg, LNPs) are technologies to deliver ASOs, siRNAs, and gene editing tools to hepatocytes, the primary location of TTR synthesis.
Topics: Humans; Amyloid Neuropathies, Familial; Liposomes; Liver; Prealbumin; RNA, Messenger; RNA, Small Interfering
PubMed: 36345805
DOI: 10.1111/jns.12519 -
European Journal of Heart Failure Sep 2022Systematic evidence on the prevalence and clinical outcome of transthyretin amyloidosis (ATTR) is missing. We explored: (i) the prevalence of cardiac amyloidosis in... (Meta-Analysis)
Meta-Analysis
AIM
Systematic evidence on the prevalence and clinical outcome of transthyretin amyloidosis (ATTR) is missing. We explored: (i) the prevalence of cardiac amyloidosis in various patient subgroups, (ii) survival estimates for ATTR subtypes, and (iii) the effects of novel therapeutics on the natural course of disease.
METHODS AND RESULTS
A systematic review of literature published in MEDLINE before 31 December 2021 was performed for the prevalence of cardiac amyloidosis and all-cause mortality of ATTR patients. Extracted data included sample size, age, sex, and all-cause mortality at 1, 2, and 5 years. Subgroup analyses were performed for ATTR subtype, that is, wild-type ATTR (wtATTR) versus hereditary ATTR (hATTR), hATTR genotypes, and treatment subgroups. We identified a total of 62 studies (n = 277 882 individuals) reporting the prevalence of cardiac amyloidosis, which was high among patients with a hypertrophic cardiomyopathy phenotype, heart failure with preserved ejection fraction, and the elderly with aortic stenosis. Data on ATTR mortality were extracted from 95 studies (n = 18 238 ATTR patients). Patients with wtATTR were older (p = 7 × 10 ) and more frequently male (p = 5 × 10 ) versus hATTR. The 2-year survival of ATTR was 73.3% (95% confidence interval [CI] 70.9-75.7); for non-subtyped ATTR 70.4% (95% CI 66.9-73.9), for wtATTR 76.0% (95% CI 73.0-78.9]) and for hATTR 77.2% (95% CI 74.0-80.4); in meta-regression analysis, wtATTR was associated with higher survival after adjusting for confounders. There was an interaction between survival and hATTR genotypes (p = 10 , Val30Met having the lowest and Val122Ile/Thr60Ala the highest mortality). ATTR 2-year survival was higher on tafamidis/patisiran compared to natural disease course (79.9%, 95% CI 74.4-85.3 vs. 72.4%, 95% CI 69.8-74.9, p < 0.05).
CONCLUSIONS
We report the prevalence of ATTR in various population subgroups and provide survival estimates for the natural course of disease and the effects of novel therapeutics. Important gaps in worldwide epidemiology research in ATTR were identified.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Heart Failure; Humans; Male; Prevalence
PubMed: 35730461
DOI: 10.1002/ejhf.2589