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Heart Failure Reviews Mar 2024Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is an underrecognized cause of heart failure due to misfolded wild-type transthyretin (TTRwt) myocardial... (Review)
Review
Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is an underrecognized cause of heart failure due to misfolded wild-type transthyretin (TTRwt) myocardial deposition. The development of wild-type TTR amyloid fibrils is a complex pathological process linked to the deterioration of homeostatic mechanisms owing to aging, plausibly implicating multiple molecular mechanisms. The components of amyloid transthyretin often include serum amyloid P, proteoglycans, and clusterin, which may play essential roles in the localization and elimination of amyloid fibrils. Oxidative stress, impaired mitochondrial function, and perturbation of intracellular calcium dynamics induced by TTR contribute to cardiac impairment. Recently, tafamidis has been the only drug approved by the U.S. Food and Drug Administration (FDA) for the treatment of ATTRwt-CM. In addition, small interfering RNAs and antisense oligonucleotides for ATTR-CM are promising therapeutic approaches and are currently in phase III clinical trials. Newly emerging therapies, such as antibodies targeting amyloid, inhibitors of seed formation, and CRISPR‒Cas9 technology, are currently in the early stages of research. The development of novel therapies is based on progress in comprehending the molecular events behind amyloid cardiomyopathy. There is still a need to further advance innovative treatments, providing patients with access to alternative and effective therapies, especially for patients diagnosed at a late stage.
Topics: Humans; Amyloid Neuropathies, Familial; Prealbumin; Heart Failure; Myocardium; Cardiomyopathies
PubMed: 38233673
DOI: 10.1007/s10741-023-10380-9 -
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 -
Revista Espanola de Cardiologia... Jun 2024
Topics: Humans; Amyloid Neuropathies, Familial; Male; Female; Middle Aged; Aged; Mass Screening; Adult; Spain; Prealbumin; Genetic Testing
PubMed: 38220055
DOI: 10.1016/j.rec.2023.12.006 -
Journal of the American Heart... Jan 2024Hereditary transthyretin amyloid cardiomyopathy (hATTR-CM) is a progressive and fatal disease. Recent evidence indicates that bone scintigraphy may serve as a tool to...
Use of Technetium-99m-Pyrophosphate Single-Photon Emission Computed Tomography/Computed Tomography in Monitoring Therapeutic Changes of Eplontersen in Patients With Hereditary Transthyretin Amyloid Cardiomyopathy.
BACKGROUND
Hereditary transthyretin amyloid cardiomyopathy (hATTR-CM) is a progressive and fatal disease. Recent evidence indicates that bone scintigraphy may serve as a tool to monitor the effectiveness of hATTR-CM treatment. The objective of this study was to examine how eplontersen therapy influences the semiquantitative uptake of technetium-99m-pyrophosphate in individuals diagnosed with hATTR-CM.
METHODS AND RESULTS
We retrospectively analyzed a prospective cohort from the NEURO-TTRansform trial, including patients with hATTR-CM receiving eplontersen (45 mg/4 weeks). A control group comprised patients with hATTR-CM who had not received eplontersen, inotersen, tafamidis, or patisiran. Technetium-99m-pyrophosphate single-photon emission computed tomography/computed tomography was conducted at baseline and during follow-up. Thirteen patients with hATTR-CM were enrolled, with 6 receiving eplontersen and 7 serving as the control group. The median follow-up time was 544 days. The eplontersen group exhibited a significant decrease in volumetric heart and lung ratio (3.774 to 2.979, =0.028), whereas the control group showed no significant change (4.079 to 3.915, =0.237). Patients receiving eplontersen demonstrated a significantly greater reduction in volumetric heart and lung ratio compared with the control group (-20.7% versus -3.4%, =0.007).
CONCLUSIONS
The volumetric heart and lung ratio used to quantify technetium-99m-pyrophosphate uptake showed a significant reduction subsequent to eplontersen treatment in individuals diagnosed with hATTR-CM. These findings suggest the potential efficacy of eplontersen in treating hATTR-CM and highlight the value of technetium-99m-pyrophosphate single-photon emission computed tomography/computed tomography as a tool for monitoring therapeutic effectiveness.
Topics: Humans; Amyloid Neuropathies, Familial; Cardiomyopathies; Prealbumin; Prospective Studies; Retrospective Studies; Technetium Tc 99m Pyrophosphate; Tomography, X-Ray Computed
PubMed: 38214277
DOI: 10.1161/JAHA.123.030512 -
ESC Heart Failure Apr 2024Transthyretin amyloid cardiomyopathy (ATTR-CM) is characterized by increased wall thickness, diastolic dysfunction and progressive heart failure symptoms. The disease...
AIMS
Transthyretin amyloid cardiomyopathy (ATTR-CM) is characterized by increased wall thickness, diastolic dysfunction and progressive heart failure symptoms. The disease may infiltrate the conduction system leading to conduction disturbances requiring an implantation of permanent cardiac pacemaker (PM), but the extent is unknown. Here, we report the prevalence of ATTR-CM in patients ≥65 years with PM.
METHODS AND RESULTS
In this prospective, cross-sectional single-centre study patients were recruited from our out-patient pacemaker clinic. Eligibility criteria were age above 65 years, permanent cardiac pacemaker and competent to give informed consent. Patients underwent echocardiography at the pacemaker visit and were referred to Tc-DPD-scintigraphy (DPD) and blood samples if septum thickness was ≥12 mm, defined as left ventricular hypertrophy (LVH). Fifty eight of the 128 patients had LVH on echocardiography. Eleven patients had a DPD-scintigraphy based diagnosis of ATTR-CM, which represent 19% of patients with LVH and 9% of the total cohort. Patients diagnosed with ATTR-CM had higher concentrations of cardiac biomarkers (P < 0.001), higher E/E' (P = 0.001), and lower global longitudinal strain (P = 0.003) on echocardiography and more heart failure symptoms (P = 0.001).
CONCLUSIONS
The prevalence of ATTR-CM in elderly patients with PM and LVH on echocardiography was 19%.
Topics: Humans; Aged; Prealbumin; Amyloid Neuropathies, Familial; Prospective Studies; Prevalence; Cross-Sectional Studies; Cardiomyopathies; Heart Diseases; Heart Failure; Hypertrophy, Left Ventricular; Pacemaker, Artificial
PubMed: 38204282
DOI: 10.1002/ehf2.14645 -
Investigative Ophthalmology & Visual... Jan 2024Indocyanine green (ICG) is an albumin and lipoprotein binding dye absorbing in the far red used in angiography to visualize choroidal vessels (ICG angiography [ICGA])....
PURPOSE
Indocyanine green (ICG) is an albumin and lipoprotein binding dye absorbing in the far red used in angiography to visualize choroidal vessels (ICG angiography [ICGA]). To guide interpretation, ICG transport in the choroid, RPE, and retina of rats was studied.
METHODS
Two conditions were used: RPE/choroid organoculture, incubated for 45 minutes in DMEM medium, 1% fetal bovine serum containing 0.25 mg/mL ICG and RPE/choroid and neural retina flat-mounts at 1 and 6 hours after intravenous ICG injection. Early and late sequences of ICGA were recorded until 6 hours. Ultra-deep red confocal microscope was used to localize ICG in flat-mounts and immunohistochemistry was performed for caveolin-1, tryptase (mast cell marker), and tubulin β3 (a nerve marker).
RESULTS
In the organoculture, ICG penetrated homogeneously in the cytoplasm and stained the membranes of the RPE. At 1 hour after intravenous injection, ICG appeared in fine granules in RPE, partly labeled with caveolin-1 and decreasing at 6 hours. At 1 hour and 6 hours, ICG was found in the retinal vessels, faintly in the inner retina, and in the photoreceptor outer segments at 6 hours. In the choroid, ICG colocalized with mast cells, immunostained with tryptase, and accumulated along the large tubulin β3-labeled nerve bundles. The hypothesis was raised on the interpretation of late ICGA infrared photography in case of transthyretin amyloidosis with neuropathy.
CONCLUSIONS
Beside being a vascular dye, ICG is transported from the vessels to the RPE toward the outer retina. It stains mast cells and large choroidal nerves. These observations could help the analysis of ICGA images.
Topics: Animals; Rats; Indocyanine Green; Caveolin 1; Tryptases; Tubulin; Angiography; Retina; Choroid; Amyloid Neuropathies, Familial
PubMed: 38193758
DOI: 10.1167/iovs.65.1.25 -
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 -
Biomarkers of axonal damage to favor early diagnosis in variant transthyretin amyloidosis (A-ATTRv).Scientific Reports Jan 2024Early identification of ATTRv amyloidosis disease onset is still often delayed due to the lack of validated biomarkers of this disease. Light chain neurofilament (NfL)...
Early identification of ATTRv amyloidosis disease onset is still often delayed due to the lack of validated biomarkers of this disease. Light chain neurofilament (NfL) have shown promising results in early diagnosis in this disease, but data is still needed, including with alternative measuring methods. Our aim was to study the levels of NfL measured by ELISA. Furthermore, interstitial matrix metalloproteinase type 1 (MMP-1) serum levels were measured as a potential new biomarker in ATTRv. Serum NfL and MMP-1 were measured using ELISA assays in 90 participants (29 ATTR-V30M patients, 31 asymptomatic V30M-TTR variant carriers and 30 healthy controls). Median NfL levels among ATTRv amyloidosis patients were significantly higher (116 pg/mL vs 0 pg/mL in both comparison groups). The AUC comparing ATTRv amyloidosis patients and asymptomatic carriers was 0.90 and the NfL concentration of 93.55 pg/mL yielded a sensitivity of 79% and a specificity of 87%. NfL levels had a significant positive correlation with NIS values among patients. We found a negative significant correlation between eGFR and NfL levels. Finally, MMP1 levels were not different between groups. Evidence of NfL use for early diagnosis of ATTR-PN amyloidosis is growing. ELISA seems a reliable and available technique for it quantification. Decreased GFR could influence NfL plasma levels.
Topics: Humans; Matrix Metalloproteinase 1; Amyloid Neuropathies, Familial; Early Diagnosis; Biomarkers
PubMed: 38182630
DOI: 10.1038/s41598-023-50212-2 -
Biochemical and Biophysical Research... Jan 2024The first small interfering RNA (siRNA) therapeutic received approval for hereditary transthyretin (ATTRv) amyloidosis, and the patients' lifespan extension by specific...
The first small interfering RNA (siRNA) therapeutic received approval for hereditary transthyretin (ATTRv) amyloidosis, and the patients' lifespan extension by specific inhibition of hepatic synthesis of transthyretin (TTR) is expected. However, ocular amyloidosis in these patients has been a crucial issue. This study aims to evaluate the efficacy and safety of intravitreal TTR siRNA conjugate injection into rabbit eyes. Rabbit (r) TTR siRNA is a screened TTR siRNA conjugate from 53 candidates. The intraocular pressure (IOP) immediately after injection was high despite the 65.9 % decrease of aqueous humor TTR protein levels in the rTTR siRNA group compared with those in the Control siRNA group 2 weeks after the 50 μL siRNA injection. The IOP spike was milder after the 30 μL siRNA injection, and aqueous humor TTR levels decreased by ∼50 % in the rTTR siRNA group, which is consistent with the mRNA levels in the retina. The parameters of dark-adapted, light-adapted, and light-adapted 30 Hz electroretinogram and the thickness of each retinal layer in histological analysis demonstrated no significant differences between the groups. In conclusion, we developed TTR siRNA conjugates for rabbit eyes, and the results indicate that intravitreal TTR siRNA conjugate injection could be a therapeutic option for ocular amyloidosis caused by ATTRv amyloidosis.
Topics: Animals; Humans; Rabbits; RNA, Small Interfering; Prealbumin; Intravitreal Injections; Amyloid Neuropathies, Familial
PubMed: 38157582
DOI: 10.1016/j.bbrc.2023.149397 -
ESC Heart Failure Apr 2024The prevalence of transthyretin-associated amyloidosis cardiomyopathy (ATTR-CM) has grown because of newer non-invasive diagnosis tools. Detecting the presence of... (Review)
Review
The prevalence of transthyretin-associated amyloidosis cardiomyopathy (ATTR-CM) has grown because of newer non-invasive diagnosis tools. Detecting the presence of extra-cardiac ATTR manifestations such as musculoskeletal pathologies considered 'red flags', when there is minimal or non-cardiac clinical involvement is primordial to carry out an early diagnosis. The aim of this systematic review is to examine the prevalence of musculoskeletal, ATTR-deposition-related co-morbidities in patients already diagnosed with ATTR-CM, specifically carpal tunnel syndrome, ruptured biceps tendon, spinal stenosis, and trigger finger. We performed a systematic review using PRISMA guidelines. Inclusion criteria were all studies in English and Spanish language and participants had to be patients diagnosed with ATTR-CM, by any diagnostic method, with the musculoskeletal co-morbidities subject of this review. The quality of the studies was based on the Risk of Bias Tool. This systematic review included 22 studies for final analysis. Carpal tunnel syndrome is reported in 21 studies, brachial biceps tendon rupture is reported in three, and spinal stenosis in eight studies. No articles that accomplished all the inclusion criteria for trigger finger were found. Regarding to the quality of the studies, all of them were categorized as being of high and moderate quality. The frequent association between ATTR-CM and carpal tunnel syndrome, ruptured biceps tendon, and lumbar spinal is confirmed, and the onset of these co-morbidities usually precedes the diagnosis of by years. This association defines them as red flags that should be search proactively due to the current treatment possibilities and the severity of the presentation of cardiac amyloidosis.
Topics: Humans; Prealbumin; Spinal Stenosis; Carpal Tunnel Syndrome; Trigger Finger Disorder; Amyloid Neuropathies, Familial; Cardiomyopathies; Morbidity
PubMed: 38130034
DOI: 10.1002/ehf2.14622