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Frontiers in Cardiovascular Medicine 2024Transthyretin amyloidosis (ATTR) is a condition defined by accumulation of insoluble transthyretin amyloid deposits in multiple organs, especially in the peripheral... (Review)
Review
Transthyretin amyloidosis (ATTR) is a condition defined by accumulation of insoluble transthyretin amyloid deposits in multiple organs, especially in the peripheral nerve and heart muscle. ATTR may result from transthyretin mutations (variant ATTR or ATTRv) or may occur with normal transthyretin genotype (wild type ATTR or ATTRwt). ATTRwt was previously known as "senile amyloidosis" and causes cardiomyopathy which may lead to heart failure with a preserved ejection fraction, affecting predominantly elderly men. The exact prevalence of ATTRwt in the general population remains unclear, but its occurrence may be underestimated in women. It was observed that a proportion of ATTRwt cardiomyopathy patients may develop slowly progressing neuropathy that is milder and indolent in comparison with typical progressive neuropathy associated with ATTRv. Furthermore, the causality of neuropathy is often uncertain in patients with ATTRwt. Neuropathy symptoms, including distal sensory loss, unsteadiness and (neuropathic) pain are common in elderly patients with multiple potential causes, and as ATTRwt patients are typically older, relatively high prevalence of peripheral neuropathy is expected with frequent comorbidities. Relatively high prevalence of ATTRwt in elderly population contrasts few documented cases of neuropathy caused by ATTRwt, and there is uncertainty whether ATTRwt neuropathy is an infrequent occurrence or a significant manifestation of multisystemic ATTRwt. We review neurologic and musculoskeletal manifestations of ATTRwt and present clinical features of a single center cohort of ATTRwt patients with suspected peripheral neuropathy.
PubMed: 38410247
DOI: 10.3389/fcvm.2024.1345608 -
Circulation. Cardiovascular Imaging Jul 2023Apo AI amyloidosis (AApoAI) and Apo AIV amyloidosis (AApoAIV) are rare but increasingly recognized causes of cardiac amyloidosis (CA). We sought to define the cardiac...
BACKGROUND
Apo AI amyloidosis (AApoAI) and Apo AIV amyloidosis (AApoAIV) are rare but increasingly recognized causes of cardiac amyloidosis (CA). We sought to define the cardiac phenotype in AApoAI and AApoAIV using multimodality imaging.
METHODS
We identified all patients with AApoAI and AApoAIV assessed at our center between 2000 and 2021, and 2 cohorts of patients with immunoglobulin light-chain amyloidosis (AL) and transthyretin amyloidosis matched for age, sex, and cardiac involvement.
RESULTS
Forty-five patients had AApoAI, 13 (29%) of whom had cardiac involvement, 32 (71%) renal involvement, 28 (62%) splenic involvement, 27 (60%) hepatic involvement, and 7 (16%) laryngeal involvement. AApoAI-CA commonly presented with heart failure (n=8, 62%) or dysphonia (n=7, 54%). The Arg173Pro variant universally caused cardiac and laryngeal involvement (n=7, 100%). AApoAI-CA was associated with right-sided involvement, with a thicker right ventricular free wall (8.6±1.9 versus 6.3±1.3 mm versus 7.7±1.2 mm, =0.004), greater incidence of tricuspid stenosis (4 [31%] versus 0 [0%] versus 0 [0%], =0.012) and tricuspid regurgitation (6 [46%] versus 1 [8%] versus 2 [15%], =0.048) than AL-CA and transthyretin CA. Twenty-one patients had AApoAIV, and cardiac involvement was more common than in AApoAI (15 [71%] versus 13 [29%], =0.001). AApoAIV-CA most commonly presented with heart failure (n=12, 80%), and a lower median estimated glomerular filtration rate than AL-CA and transthyretin CA (36 mL/[min·1.73 m²] versus 65 mL/[min·1.73 m²] versus 63 mL/[min·1.73 m²], <0.001). All AApoAIV-CA patients had classical CA features on echocardiography/cardiac magnetic resonance, including an apical-sparing strain pattern, which was less common in AApoAI-CA (15 [100%] versus 7 [54%], =0.003), whereas cardiac uptake on bone scintigraphy was less common in AApoAIV-CA than AApoAI-CA (all grade 1) (14% versus 82%, <0.001). Patients with AApoAI and AApoAIV had a good prognosis (median survival >172 and >30 months, respectively), and a lower risk of mortality than matched patients with AL-amyloidosis (AL versus AApoAI: hazard ratio, 4.54 [95% CI, 2.02-10.14]; <0.001; AL versus AApoAIV: hazard ratio, 3.07 [95% CI, 1.27-7.44]; =0.013).
CONCLUSIONS
Dysphonia, multisystem involvement, or right-sided cardiac disease should raise suspicion of AApoAI-CA. AApoAIV-CA presents most commonly with heart failure and always displays classical CA imaging features, mimicking common forms of CA. Both AApoAI and AApoAIV are associated with a good prognosis and a lower risk of mortality than matched patients with AL-amyloidosis.
Topics: Humans; Apolipoprotein A-I; Dysphonia; Prealbumin; Amyloid Neuropathies, Familial; Immunoglobulin Light-chain Amyloidosis; Heart Failure; Echocardiography; Cardiomyopathies
PubMed: 37431665
DOI: 10.1161/CIRCIMAGING.123.015259 -
Therapeutics and Clinical Risk... 2023Variant transthyretin amyloidosis (ATTRv) is an autosomal dominant inherited genetic disorder that affects 5000-10,000 people worldwide. It is caused by mutations in... (Review)
Review
Variant transthyretin amyloidosis (ATTRv) is an autosomal dominant inherited genetic disorder that affects 5000-10,000 people worldwide. It is caused by mutations in the transthyretin (TTR) gene and results in amyloid deposition in a variety of organs due to abnormal accumulation of TTR protein fibrils. Although this is a multisystem disorder, the heart and peripheral nerves are the preferentially affected organs. Over 150 TTR gene mutations have been associated with this disease and the clinical phenotype can vary significantly. Severe forms of the disorder can be fatal. Fortunately, the oligonucleotide-based therapy era has resulted in the development of several novel treatment options. Patisiran is a small interfering RNA (siRNA) encapsulated in a lipid nanoparticle that targets both mutant and wild-type TTR and results in significant reductions of the TTR protein in the serum and in tissue deposits. Patisiran has been approved for treatment of adults with polyneuropathy due to hereditary TTR-mediated amyloidosis in both the United States (US) and European Union (EU). In this review, we will discuss the development of patisiran, the clinical trials that lead to treatment approval, and provide guideline parameters for use in clinical practice. .
PubMed: 38047038
DOI: 10.2147/TCRM.S361706 -
ESC Heart Failure Feb 2024Whether sodium-glucose co-transporter 2 inhibitors are effective for heart failure caused by ATTR-CA (transthyretin cardiac amyloidosis) remains uncertain. The aim of...
AIMS
Whether sodium-glucose co-transporter 2 inhibitors are effective for heart failure caused by ATTR-CA (transthyretin cardiac amyloidosis) remains uncertain. The aim of this study is to investigate the cardiovascular prognosis in ATTR-CA mice model with dapagliflozin treatment.
METHODS AND RESULTS
Humanized RBP4/TTR and RBP4/TTR mice models were constructed with clustered regularly interspaced short palindromic repeats and associated Cas9 endonuclease (CRISPR-Cas9) techniques and multiple generations breeding. A total of 6 RBP4/TTR mice received placebo treatment, when 12 RBP4/TTR received dapagliflozin (1 mg/kg/day, 6 mice) and placebo (6 mice) treatment. Fasting glucose, intraperitoneal glucose tolerance test, and plasma brain natriuretic peptide (BNP) concentration were measured at Day 0, Week 2, and Week 4. BNP, transforming growth factor-beta (TGF-β), collagen type I alpha 1 (COL1A1) protein levels, and Cola1, TGFβ1, TNFα, IL-1β, BNP relative quantities in cardiac, along with cardiac pathology examination including right ventricular collagen percentage, ventricular septum thickness, left ventricular wall thickness, and left ventricular internal diameter were measured at Week 4 after treatment procedure. All 18 mice completed the experiment. The baseline characteristics were balanced among three treatment groups. In placebo-treated mice, the cardiac BNP relative quantity was significantly higher in RBP4/TTR mice than RBP4/TTR mice (RBP4[KI/KI], TTR [KI/KI]: 0.72 ± 0.46, RBP4[KI/KI], TTR [KI/KI]: 1.44 ± 0.60, P = 0.043), indicating more significant heart failure progression in ATTR-CA mice than normal mice. In ATTR-CA mice, the cardiovascular prognosis measurements including heart failure (plasma BNP concentration and relative quantities of BNP), cardiac inflammation (relative quantities of Cola1, TGFβ1, TNFα, and IL-1β), and pathological changes (right ventricular collagen percentage, ventricular septum thickness, left ventricular wall thickness, and left ventricular internal diameter) were statistically comparable between those under dapagliflozin and placebo treatment.
CONCLUSIONS
Dapagliflozin did not improve cardiovascular prognosis including the progression of heart failure, cardiac inflammation, and pathological changes in ATTR-CA mice compared with placebo. The results of this study were not in support of dapagliflozin's therapeutic effects for ATTR-CA. More pre-clinical and clinical researches to validate these findings and demonstrate the underlying mechanisms are still required.
Topics: Animals; Mice; Prealbumin; Amyloid Neuropathies, Familial; Tumor Necrosis Factor-alpha; Myocardium; Heart Failure; Collagen; Glucose; Inflammation; Benzhydryl Compounds; Glucosides
PubMed: 37877450
DOI: 10.1002/ehf2.14567 -
European Journal of Internal Medicine May 2024Transthyretin amyloid cardiomyopathy (ATTR-CM) has been traditionally considered a rare and inexorably fatal condition. ATTR-CM now is an increasingly recognized cause... (Review)
Review
Transthyretin amyloid cardiomyopathy (ATTR-CM) has been traditionally considered a rare and inexorably fatal condition. ATTR-CM now is an increasingly recognized cause of heart failure (HF) and mortality worldwide with effective pharmacological treatments. Advances in non-invasive diagnosis, coupled with the development of effective treatments, have transformed the diagnosis of ATTR-CM, which is now possible without recourse to endomyocardial biopsy in ≈70 % of cases. Many patients are now diagnosed at an earlier stage. Echocardiography and cardiac magnetic resonance have enabled identification of patients with possible ATTR-CM and more accurate prognostic stratification. Although radionuclide scintigraphy with 'bone' tracers has an established diagnostic value, the diagnostic performance of the bone tracers validated for non-invasive confirmation of ATTR-CM may not be equal. Characterising the wider clinical phenotype of patients with ATTR-CM has enabled identification of features with potential for earlier diagnosis such as carpal tunnel syndrome. Therapies able to slow or halt ATTR-CM progression and increase survival are now available and there is also evidence that patients may benefit from specific conventional HF medications. Cutting-edge research in the field of antibody-mediated removal of ATTR deposits compellingly suggest that ATTR-CM is a truly reversible disorder, bringing hope for patients even with advanced disease. A wide horizon of possibilities is unfolding and awaits discovery.
Topics: Humans; Cardiomyopathies; Amyloid Neuropathies, Familial; Heart Failure; Echocardiography; Prealbumin; Magnetic Resonance Imaging
PubMed: 38184468
DOI: 10.1016/j.ejim.2024.01.001 -
JAMA Cardiology Aug 2023Hereditary transthyretin cardiac amyloidosis is an increasingly recognized cause of heart failure (HF) with distinct treatment. The amyloidogenic pV142I (V122I) variant...
IMPORTANCE
Hereditary transthyretin cardiac amyloidosis is an increasingly recognized cause of heart failure (HF) with distinct treatment. The amyloidogenic pV142I (V122I) variant is present in 3% to 4% of Black individuals in the US and increases the risk for atrial fibrillation (AF), HF, and mortality. Since hereditary transthyretin cardiac amyloidosis demonstrates age-dependent anatomic penetrance, evaluation later in life may identify survivors at particularly high risk.
OBJECTIVE
To estimate age-dependent risks for cardiovascular events with the variant.
DESIGN, SETTINGS, AND PARTICIPANTS
This cohort study analyzed Black participants from the Atherosclerosis Risk in Communities (ARIC) study attending visit 1 (1987-1989) (followed up until 2019; median follow-up, 27.6 years). Data analyses were completed from June 2022 to April 2023.
EXPOSURE
pV142I carrier status.
MAIN OUTCOMES
The association between the variant and AF, HF hospitalization, mortality, and a composite of HF hospitalization or mortality was modeled by generating 10-year absolute risk differences for each year between ages 53 (the median age at visit 1) and 80 years, adjusting for the first 5 principal components of ancestry and sex. As an example, 5- and 10-year risk differences were specifically estimated for the composite outcome among participants surviving to age 80 years.
RESULTS
Among 3856 Black participants (including 124 carriers) at visit 1, 2403 (62%) were women, 2140 (56%) had hypertension, and 740 (20%) had diabetes, with no differences between groups. The 10-year absolute risk difference between ages 53 and 80 years increased over time for each outcome. Statistical significance for increased 10-year risk difference emerged near ages 65 years for AF, 70 years for HF hospitalization, and 75 years for mortality. Among participants surviving to age 80 years, carriers had a 20% (95% CI, 2%-37%) and 24% (95% CI, 1%-47%) absolute increased risk for HF hospitalization or death at 5 and 10 years, respectively. Thus, at age 80 years, only 4 carriers would need to be identified to attribute 1 HF hospitalization or death over the following decade to the variant.
CONCLUSIONS AND RELEVANCE
In this study, age-specific risks were provided for relevant outcomes with the pV142I variant. Despite a relatively benign course during earlier years, Black individuals who carry the pV142I variant surviving into later life may be particularly vulnerable. These data may inform timing for screening, risk counseling to patients, and potential strategies for early targeted therapy.
Topics: Aged, 80 and over; Female; Humans; Male; Amyloid Neuropathies, Familial; Atrial Fibrillation; Black or African American; Cohort Studies; Heart Failure; Prealbumin; Middle Aged; Aged
PubMed: 37212191
DOI: 10.1001/jamacardio.2023.1525 -
Journal of Clinical Medicine Mar 2024Light chain amyloidosis is a plasma-cell disorder with a poor prognosis. It is a progressive condition, causing worsening pain, disability, and life-limiting... (Review)
Review
Light chain amyloidosis is a plasma-cell disorder with a poor prognosis. It is a progressive condition, causing worsening pain, disability, and life-limiting complications involving multiple organ systems. The medical regimen can be complex, including chemotherapy or immunotherapy for the disease itself, as well as treatment for pain, gastrointestinal and cardiorespiratory symptoms, and various secondary symptoms. Patients and their families must have a realistic awareness of the illness and of the goals and limitations of treatments in making informed decisions about medical therapy, supportive management, and end-of-life planning. Palliative care services can thus improve patients' quality of life and may even reduce overall treatment costs. Light chain (AL) amyloidosis is a clonal plasma cell disorder characterized by the excessive secretion of light chains by an indolent plasma cell clone that gradually accumulates in vital organs as amyloid fibrils and leads to end-organ damage. With progressive disease, most patients develop diverse clinical symptoms and complications that negatively impact quality of life and increase mortality. Complications include cardiac problems including heart failure, hypotension, pleural effusions, renal involvement including nephrotic syndrome with peripheral edema, gastrointestinal symptoms leading to anorexia and cachexia, complex pain syndromes, and mood disorders. The prognosis of patients with advanced AL amyloidosis is dismal. With such a complex presentation, and high morbidity and mortality rates, there is a critical need for the establishment of a palliative care program in clinical management. This paper provides an evidence-based overview of the integration of palliative care in the clinical management of AL amyloidosis as a means of reducing ER visits, rehospitalizations, and in-hospital mortality. We also discuss potential future collaborative directions in various aspects of clinical care related to AL amyloidosis.
PubMed: 38610755
DOI: 10.3390/jcm13071991 -
Hellenic Journal of Cardiology : HJC =... 2023Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed disease associated with high mortality rates and the patient journey is characterized by increased... (Review)
Review
Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed disease associated with high mortality rates and the patient journey is characterized by increased complexities. Accurate and timely diagnosis and prompt initiation of disease-modifying treatment constitute the contemporary unmet need in ATTR-CM. ATTR-CM diagnosis is characterized by considerable delays and high rates of misdiagnosis. The majority of patients present themselves to primary care physicians, internists, and cardiologists, and many have undergone repeated medical evaluations before an accurate diagnosis has been made. The disease is diagnosed mainly after the development of heart failure symptoms, reflecting a long course of missed opportunities before diagnosis and disease-modifying treatment initiation. Early referral to experienced centers ensures prompt diagnosis and therapy. Early diagnosis, better care coordination, acceleration of digital transformation and reference networks, encouragement of patient engagement, and implementation of rare disease registries are the key pillars to improve the ATTR-CM patient pathway and achieve important benefits in ATTR-CM outcomes.
Topics: Humans; Amyloid Neuropathies, Familial; Greece; Heart Failure; Heart Diseases; Early Diagnosis; Cardiomyopathies
PubMed: 37201632
DOI: 10.1016/j.hjc.2023.05.004 -
Pharmacological Research Mar 2024Since its discovery in 1998, the use of small interfering RNA (siRNA) has been increasing in biomedical studies because of its ability to very selectively inhibit the... (Review)
Review
Since its discovery in 1998, the use of small interfering RNA (siRNA) has been increasing in biomedical studies because of its ability to very selectively inhibit the expression of any target gene. Thus, siRNAs can be used to generate therapeutic compounds for different diseases, including those that are currently 'undruggable'. This has led siRNA-based therapeutic compounds to break into clinical settings, with them holding the promise to potentially revolutionise therapeutic approaches. To date, the United States Food and Drug Administration (FDA) have approved 5 compounds for treating different diseases including hypercholesterolemia, transthyretin-mediated amyloidosis (which leads to polyneuropathy), hepatic porphyria, and hyperoxaluria. This current article presents an overview of the molecular mechanisms involved in the selective pharmacological actions of siRNA-based compounds. It also describes the ongoing clinical trials of siRNA-based therapeutic compounds for hepatic diseases, pulmonary diseases, atherosclerosis, hypertriglyceridemia, transthyretin-mediated amyloidosis, and hyperoxaluria, kidney diseases, and haemophilia, as well as providing a description of FDA-approved siRNA therapies. Because of space constraints and to provide an otherwise comprehensive review, siRNA-based compounds applied to cancer therapies have been excluded. Finally, we discuss how the use of lipid-based nanoparticles to deliver siRNAs holds promise for selectively targeting mRNA-encoding proteins associated with the genesis of different diseases. Thus, siRNAs can help reduce the cellular levels of these proteins, thereby contributing to disease treatment. As consequence, a marked increase in the number of marketed siRNA-based medicines is expected in the next two decades, which will likely open up a new era of therapeutics.
Topics: United States; Humans; RNA, Small Interfering; Prealbumin; Nanoparticles; Amyloid Neuropathies, Familial; Hyperoxaluria
PubMed: 38331236
DOI: 10.1016/j.phrs.2024.107102 -
Structural polymorphism of amyloid fibrils in ATTR amyloidosis revealed by cryo-electron microscopy.Nature Communications Jan 2024ATTR amyloidosis is caused by the deposition of transthyretin in the form of amyloid fibrils in virtually every organ of the body, including the heart. This systemic...
ATTR amyloidosis is caused by the deposition of transthyretin in the form of amyloid fibrils in virtually every organ of the body, including the heart. This systemic deposition leads to a phenotypic variability that has not been molecularly explained yet. In brain amyloid conditions, previous studies suggest an association between clinical phenotype and the molecular structures of their amyloid fibrils. Here we investigate whether there is such an association in ATTRv amyloidosis patients carrying the mutation I84S. Using cryo-electron microscopy, we determined the structures of cardiac fibrils extracted from three ATTR amyloidosis patients carrying the ATTRv-I84S mutation, associated with a consistent clinical phenotype. We found that in each ATTRv-I84S patient, the cardiac fibrils exhibited different local conformations, and these variations can co-exist within the same fibril. Our finding suggests that one amyloid disease may associate with multiple fibril structures in systemic amyloidoses, calling for further studies.
Topics: Humans; Amyloid; Amyloid Neuropathies, Familial; Cryoelectron Microscopy; Prealbumin; Heart; Brain Diseases
PubMed: 38233397
DOI: 10.1038/s41467-024-44820-3