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Circulation. Heart Failure Sep 2019Cardiomyopathy is a manifestation of transthyretin amyloidosis (ATTR), which is an underrecognized systemic disease whereby the transthyretin protein misfolds to form... (Review)
Review
Cardiomyopathy is a manifestation of transthyretin amyloidosis (ATTR), which is an underrecognized systemic disease whereby the transthyretin protein misfolds to form fibrils that deposit in various tissues and organs. ATTR amyloidosis is debilitating and associated with poor life expectancy, especially in those with cardiac dysfunction, but a variety of treatment options have recently become available. Considered a rare disease, ATTR amyloidosis may be more prevalent than thought, particularly in older persons. Diagnosis is often delayed because of a lack of disease awareness and the heterogeneity of symptoms at presentation. Given the recent availability of effective treatments, early recognition and diagnosis are especially critical because treatment is likely more effective earlier in the disease course. The Amyloidosis Research Consortium recently convened a group of experts in ATTR amyloidosis who, through an iterative process, agreed on best practices for suspicion, diagnosis, and characterization of disease. This review describes these consensus recommendations for ATTR associated with cardiomyopathy as a resource to aid cardiologists and others in the recognition and diagnosis of ATTR associated with cardiomyopathy. Included in this review is an overview of red flag signs and symptoms and a recommended diagnostic approach, including testing for monoclonal protein, scintigraphy, or biopsy and, if ATTR associated with cardiomyopathy is identified, TTR genotyping.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Consensus; Humans; Practice Guidelines as Topic
PubMed: 31480867
DOI: 10.1161/CIRCHEARTFAILURE.119.006075 -
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 -
Trends in Cardiovascular Medicine Jan 2018The amyloidoses are a group of systemic diseases characterized by organ deposition of misfolded protein fragments of diverse origins. The natural history of the disease,... (Review)
Review
The amyloidoses are a group of systemic diseases characterized by organ deposition of misfolded protein fragments of diverse origins. The natural history of the disease, involvement of other organs, and treatment options vary significantly based on the protein of origin. In AL amyloidosis, amyloid protein is derived from immunoglobulin light chains, and most often involves the kidneys and the heart. ATTR amyloidosis is categorized as mutant or wild-type depending on the genetic sequence of the transthyretin (TTR) protein produced by the liver. Wild-type ATTR amyloidosis mainly involves the heart, although the reported occurrence of bilateral carpal tunnel syndrome, spinal stenosis and biceps tendon rupture in these patients speaks to more generalized protein deposition. Mutant TTR is marked by cardiac and/or peripheral nervous system involvement. Cardiac involvement is associated with symptoms of heart failure, and dictates the clinical course of the disease. Cardiac amyloidosis can be diagnosed noninvasively by echocardiography, cardiac MRI, or nuclear scintigraphy. Endomyocardial biopsy may be needed in the case of equivocal imaging findings or discordant data. Treatment is aimed at relieving congestive symptoms and targeting the underlying amyloidogenic process. This includes anti-plasma cell therapy in AL amyloidosis, and stabilization of the TTR tetramer or inhibition of TTR protein production in ATTR amyloidosis. Cardiac transplantation can be considered in highly selected patients in tandem with therapy aimed at suppressing the amyloidogenic process, and appears associated with durable long-term survival.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathy, Restrictive; Genetic Markers; Genetic Predisposition to Disease; Humans; Mutation; Phenotype; Predictive Value of Tests; Risk Factors; Treatment Outcome
PubMed: 28739313
DOI: 10.1016/j.tcm.2017.07.004 -
Cleveland Clinic Journal of Medicine Dec 2017Cardiac amyloidosis (CA), once thought to be a rare disease, is increasingly recognized due to enhanced clinical awareness and better diagnostic imaging. CA is becoming... (Review)
Review
Cardiac amyloidosis (CA), once thought to be a rare disease, is increasingly recognized due to enhanced clinical awareness and better diagnostic imaging. CA is becoming of heightened interest to the cardiology community given more effective treatment strategies for light chain amyloidosis (AL), as well as emerging therapies for transthyretin amyloidosis (ATTR). Furthermore, reversing amyloid deposition in affected organs using monoclonal antibodies is actively being tested in clinical trials. A high index of suspicion and a systematic approach to the diagnosis of CA can lead to referral to a center of expertise for timely treatment.
Topics: Amyloid Neuropathies, Familial; Heart Diseases; Humans
PubMed: 29257735
DOI: 10.3949/ccjm.84.s3.02 -
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 -
European Heart Journal Jun 2023To perform evaluation of widely embraced bone scintigraphy-based non-biopsy diagnostic criteria (NBDC) for ATTR amyloid cardiomyopathy (ATTR-CM) in clinical practice,...
AIMS
To perform evaluation of widely embraced bone scintigraphy-based non-biopsy diagnostic criteria (NBDC) for ATTR amyloid cardiomyopathy (ATTR-CM) in clinical practice, and to refine serum free light chain (sFLC) ratio cut-offs that reliably exclude monoclonal gammopathy (MG) in chronic kidney disease.
METHODS AND RESULTS
A multi-national retrospective study of 3354 patients with suspected or histologically proven cardiac amyloidosis (CA) referred to specialist centres from 2015 to 2021; evaluations included radionuclide bone scintigraphy, serum and urine immunofixation, sFLC assay, eGFR measurement and echocardiography. Seventy-nine percent (1636/2080) of patients with Perugini grade 2 or 3 radionuclide scans fulfilled NBDC for ATTR-CM through absence of a serum or urine monoclonal protein on immunofixation together with a sFLC ratio falling within revised cut-offs incorporating eGFR; 403 of these patients had amyloid on biopsy, all of which were ATTR type, and their survival was comparable to non-biopsied ATTR-CM patients (p = 0.10). Grade 0 radionuclide scans were present in 1091 patients, of whom 284 (26%) had CA, confirmed as AL type (AL-CA) in 276 (97%) and as ATTR-CM in only one case with an extremely rare TTR variant. Among 183 patients with grade 1 radionuclide scans, 122 had MG of whom 106 (87%) had AL-CA; 60/61 (98%) without MG had ATTR-CM.
CONCLUSION
The NBDC for ATTR-CM are highly specific [97% (95% CI 0.91-0.99)] in clinical setting, and diagnostic performance was further refined here using new cut-offs for sFLC ratio in patients with CKD. A grade 0 radionuclide scan all but excludes ATTR-CM but occurs in most patients with AL-CA. Grade 1 scans in patients with CA and no MG are strongly suggestive of early ATTR-type, but require urgent histologic corroboration.
Topics: Humans; Amyloid Neuropathies, Familial; Retrospective Studies; Radionuclide Imaging; Amyloid; Echocardiography; Cardiomyopathies
PubMed: 36946431
DOI: 10.1093/eurheartj/ehad139 -
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 -
The Mount Sinai Journal of Medicine,... 2012Peripheral neuropathy is a common complication of many of the systemic amyloidoses. Although the cause of neuropathy is not entirely clear, it is likely related to... (Review)
Review
Peripheral neuropathy is a common complication of many of the systemic amyloidoses. Although the cause of neuropathy is not entirely clear, it is likely related to amyloid deposition within the nerve. This may lead to focal, multifocal, or diffuse neuropathies involving sensory, motor and/or autonomic fibers. The presenting symptoms depend on the distribution of nerves affected. One of the most common phenotypes is sensorimotor polyneuropathy, which is characterized by symptoms of neuropathic pain, numbness, and in advanced cases weakness. Symptoms begin in the feet and ultimately progress to the proximal legs and hands. The most common focal neuropathy is a median neuropathy at the wrist, clinically known as carpal tunnel syndrome. Carpal tunnel symptoms may include pain and sensory disturbances in the lateral palm and fingers; hand weakness may ensue if the focal neuropathy is severe. Autonomic neuropathy may affect a variety of organ systems such as the cardiovascular, gastrointestinal, and genitourinary systems. Symptoms may be non-specific making the diagnosis of autonomic neuropathy more difficult to identify. However, it is important to recognize and distinguish autonomic neuropathy from diseases of the end-organs themselves. This article reviews the inherited and acquired amyloidoses that affect the peripheral nervous system including familial amyloid polyneuropathy, and primary, secondary and senile amyloidosis. We emphasize the clinical presentation of the neurologic aspects of these diseases, physical examination findings, appropriate diagnostic evaluation, treatment and prognosis.
Topics: Age Factors; Amyloid Neuropathies; Amyloid Neuropathies, Familial; Combined Modality Therapy; Humans; Physical Examination; Prognosis; Risk Factors
PubMed: 23239211
DOI: 10.1002/msj.21352 -
Neurology Aug 2012To evaluate the efficacy and safety of 18 months of tafamidis treatment in patients with early-stage V30M transthyretin familial amyloid polyneuropathy (TTR-FAP). (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To evaluate the efficacy and safety of 18 months of tafamidis treatment in patients with early-stage V30M transthyretin familial amyloid polyneuropathy (TTR-FAP).
METHODS
In this randomized, double-blind trial, patients received tafamidis 20 mg QD or placebo. Coprimary endpoints were the Neuropathy Impairment Score-Lower Limbs (NIS-LL) responder analysis (<2-point worsening) and treatment-group difference in the mean change from baseline in Norfolk Quality of Life-Diabetic Neuropathy total score (TQOL) in the intent-to-treat (ITT) population (n = 125). These endpoints were also evaluated in the efficacy-evaluable (EE; n = 87) population. Secondary endpoints, including changes in neurologic function, nutritional status, and TTR stabilization, were analyzed in the ITT population.
RESULTS
There was a higher-than-anticipated liver transplantation dropout rate. No differences were observed between the tafamidis and placebo groups for the coprimary endpoints, NIS-LL responder analysis (45.3% vs 29.5% responders; p = 0.068) and change in TQOL (2.0 vs 7.2; p = 0.116) in the ITT population. In the EE population, significantly more tafamidis patients than placebo patients were NIS-LL responders (60.0% vs 38.1%; p = 0.041), and tafamidis patients had better-preserved TQOL (0.1 vs 8.9; p = 0.045). Significant differences in most secondary endpoints favored tafamidis. TTR was stabilized in 98% of tafamidis and 0% of placebo patients (p < 0.0001). Adverse events were similar between groups.
CONCLUSIONS
Although the coprimary endpoints were not met in the ITT population, tafamidis was associated with no trend toward more NIS-LL responders and a significant reduction in worsening of most neurologic variables, supporting the hypothesis that preventing TTR dissociation can delay peripheral neurologic impairment.
CLASSIFICATION OF EVIDENCE
This study provides Class II evidence that 20 mg tafamidis QD was associated with no difference in clinical progression in patients with TTR-FAP, as measured by the NIS-LL and the Norfolk QOL-DN score. Secondary outcomes demonstrated a significant delay in peripheral neurologic impairment with tafamidis, which was well tolerated over 18 months.
Topics: Adolescent; Adult; Aged; Amyloid Neuropathies, Familial; Benzoxazoles; Double-Blind Method; Humans; Male; Middle Aged; Neuroprotective Agents; Polymorphism, Single Nucleotide; Prealbumin; Quality of Life; Severity of Illness Index
PubMed: 22843282
DOI: 10.1212/WNL.0b013e3182661eb1