Sex-Related Risk of Cardiac Involvement in Hereditary Transthyretin Amyloidosis: Insights From THAOS

A systematic review and meta-analysis of mortality in chronic Chagas cardiomyopathy versus other cardiomyopathies: higher risk or fiction?

INTRODUCTION AND OBJECTIVES

Although multiple studies suggest that chronic Chagas cardiomyopathy (CCC) has higher mortality than other cardiomyopathies, the absence of meta-analyses supporting this perspective limits the possibility of generating robust conclusions. The aim of this study was to systematically evaluate the current evidence on mortality risk in CCC compared with that of other cardiomyopathies.

METHODS

PubMed/Medline and EMBASE were searched for studies comparing mortality risk between patients with CCC and those with other cardiomyopathies, including in the latter nonischemic cardiomyopathy (NICM), ischemic cardiomyopathy, and non-Chagas cardiomyopathy (nonCC). A random-effects meta-analysis was performed to combine the effects of the evaluated studies.

RESULTS

A total of 37 studies evaluating 17 949 patients were included. Patients with CCC had a significantly higher mortality risk compared with patients with NICM (HR, 2.04; 95%CI, 1.60-2.60; I2, 47%; 8 studies) and non-CC (HR, 2.26; 95%CI, 1.65-3.10; I2, 71%; 11 studies), while no significant association was observed compared with patients with ischemic cardiomyopathy (HR, 1.72; 95%CI, 0.80-3.66; I2, 69%; 4 studies) in the adjusted-measures meta-analysis.

CONCLUSIONS

Patients with CCC have an almost 2-fold increased mortality risk compared with individuals with heart failure secondary to other etiologies. This finding highlights the need for effective public policies and targeted research initiatives to optimally address the challenges of CCC.

Safety assessment of Tafamidis: a real-world pharmacovigilance study of FDA adverse event reporting system (FAERS) events

OBJECTIVE

Tafamidis-associated adverse events (AEs) were investigated retrospectively by data mining the US Food and Drug Administration Adverse Event Reporting System (FAERS) to inform clinical safety.

METHODS

Data were gathered from the FAERS database, which spans the second quarter of 2019 to the fourth quarter of 2023. A total number of 8532 reports of Tafamidis-related adverse events were detected after evaluating 8,432,351 data. Disproportionality analyses were used to quantify the signal and assess the significance of Tafamidis-associated AEs using four algorithms, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the multi-item gamma Poisson shrinker (MGPS) and the Bayesian confidence propagation neural network (BCPNN).

RESULTS

Among the 8532 reports of AEs with Tafamidis as the primary suspected drug, Tafamidis-induced AEs were identified as occurring in 27 system organ classes (SOC). A total of 207 Tafamidis-induced AEs were detected which simultaneously complied with the four algorithms. Our analysis also identified new adverse reactions including Hypoacusis, Deafness, and Essential hypertension. The median onset of adverse reactions associated with Tafamidis was 180 days (interquartile range [IQR] 51-419 days).

CONCLUSION

Tafamidis is a drug that has shown favorable safety and tolerability results in clinical trials. However, a number of adverse reactions associated with Tafamidis have been identified through analysis of the FAERS database. In clinical applications, it is recommended to closely monitor patients' hearing while using Tafamidis. In addition, it is hoped that further experimental and clinical studies will be conducted in the future to understand the mechanism of occurrence between Tafamidis and adverse reactions such as primary hypertension, hyperlipidemia, and height reduction.

Hereditary transthyretin amyloidosis: a myriad of factors that influence phenotypic variability

Hereditary transthyretin-related amyloidosis (ATTRv amyloidosis) is a rare and progressively debilitating disease characterized by the deposition of transthyretin (TTR) amyloid fibrils in various organs and tissues, most commonly in the heart and peripheral nerves. This pathological deposition can lead to significant organ dysfunction and, ultimately, organ failure. ATTRv amyloidosis exhibits a broad range of clinical presentations, from purely neurological symptoms to purely cardiac manifestations, as well as mixed phenotypes which result from both neurological and cardiac implications. This wide phenotypical spectrum realistically challenges disease diagnosis and prognosis, especially in individuals without or with an unknown family history. Multiple factors are thought to contribute to this variability, including genetic, epigenetic, and even environmental influences. Understanding these factors is crucial, as they can significantly affect disease expression and progression. This review aims to summarize each of these contributing factors, to help elucidate the current knowledge on the phenotypical variability of ATTRv amyloidosis.

Navigating the penetrance and phenotypic spectrum of inherited cardiomyopathies

Inherited cardiomyopathies are genetic diseases that can lead to heart failure and sudden cardiac death. These conditions tend to run in families, following an autosomal dominant pattern where first-degree relatives have a 50% chance of carrying the pathogenic variant. Despite significant advancements and increased accessibility of genetic testing, accurately predicting the phenotypic expression of these conditions remains challenging due to the inherent variability in their clinical manifestations and the incomplete penetrance observed. This poses challenges in providing patient care and effectively communicating the potential risk of future disease to patients and their families. To address these challenges, this review aims to synthesize the available evidence on penetrance, expressivity, and factors influencing disease expression to improve communication and risk assessment for patients with inherited cardiomyopathies and their family members.

Epidemiological Changes in Transthyretin Cardiac Amyloidosis: Evidence from In Vivo Data and Autoptic Series

Cardiac amyloidosis is an infiltrative disease that causes progressive myocardial impairment secondary to amyloid fibril deposition in the extracellular space of the myocardium. Many amyloid precursors, including transthyretin protein, are known to determine cardiac damage by aggregating and precipitating in cardiac tissue. Transthyretin cardiac amyloidosis may be either caused by rare genetic mutations of the transthyretin gene in the hereditary variant, or may arise as a consequence of age-related mechanisms in the acquired form. Although it has been labeled as a rare disease, in recent years, transthyretin cardiac amyloidosis has stood out as an emerging cause of aortic stenosis, unexplained left ventricular hypertrophy and heart failure with preserved ejection fraction, particularly in the elderly. Indeed, the integration of data deriving from both in vivo imaging techniques (whose advancement in the last years has allowed to achieve an easier and more accessible non-invasive diagnosis) and forensic studies (showing a prevalence of amyloid deposition in cardiac tissue of elderly patients up to 29%) suggests that cardiac amyloidosis is a more common disease than traditionally considered. Thanks to all the improvements in non-invasive diagnostic techniques, along with the development of efficacious therapies offering improvements in survival rates, transthyretin cardiac amyloidosis has been transformed from an incurable and infrequent condition to a relatively more diffuse and treatable disease, which physicians should take into consideration in the differential diagnostic processes in daily clinical practice.

Age- and Sex-Related Differences in Patients With Wild-Type Transthyretin Amyloidosis: Insights From THAOS

Background

Wild-type transthyretin amyloidosis (ATTRwt amyloidosis) is primarily diagnosed in elderly men but diagnoses in younger patients and women have recently increased.

Objectives

The purpose of this study was to examine age- and sex-related differences in patients with ATTRwt amyloidosis enrolled in the THAOS (Transthyretin Amyloidosis Outcomes Survey).

Methods

THAOS was a global, longitudinal, observational survey of patients with transthyretin amyloidosis, including both hereditary and wild-type disease, and asymptomatic carriers of pathogenic transthyretin gene variants. Patient characteristics at enrollment were analyzed by age at enrollment and sex (data cutoff date: August 1, 2022).

Results

Of 1,251 patients with ATTRwt amyloidosis, 13.7%, 49.1%, 34.5%, and 2.8% were aged <70 years, 70 to 79 years, 80 to 89 years, and ≥90 years, respectively. The proportion of women increased with age, from 4.1% in patients aged <70 years to 14.3% in patients aged ≥90 years. In the respective age groups, median time from symptom onset to diagnosis overall (male, female) was 1.7 (1.3, 5.2), 2.0 (2.0, 2.2), 1.8 (1.9, 0.8), and 0.7 (0.6, 2.5) years. A Karnofsky Performance Status score ≤70 was observed in 17.1%, 30.1%, 46.1%, and 44.4% of patients aged <70 years, 70 to 79 years, 80 to 89 years, and ≥90 years, respectively.

Conclusions

In this THAOS analysis of patients with ATTRwt amyloidosis, patients were diagnosed an average of 2 years after symptom onset, with the greatest diagnostic delay in women aged <70 years at 5 years. Patients were predominantly men, but the proportion of women increased with age. A substantial proportion of patients had significant functional impairment regardless of age. (Transthyretin Amyloidosis Outcome Survey [THAOS]; NCT00628745).

Distinctive Deposition Patterns of Sporadic Transthyretin-Derived Amyloidosis in the Atria: A Forensic Autopsy-Based Study

Left-to-right differences in the histopathologic patterns of transthyretin-derived amyloid (ATTR) deposition in the atria of older adults have not yet been investigated. Hence, this study evaluated heart specimens from 325 serial autopsy subjects. The amount of ATTR deposits in the seven cardiac regions, including both sides of atria and atrial appendages, was evaluated semiquantitatively. Using digital pathology, we quantitatively evaluated the immunohistochemical deposition burden of ATTR in the myocardium. We identified 20 sporadic ATTR cardiac amyloidosis cases (nine males). All patients had ATTR deposition in the left atrial regions of the myocardium. In the semiquantitative analysis, 14 of the 20 cases showed more severe ATTR deposition on the left atrial regions than on the right side, with statistically significant differences in the pathology grading (p < 0.01 for both the atrium and atrial appendage). Quantitative analysis further supported the difference. Moreover, six had ATTR deposition in the epineurium and/or neural fibers of the atria. Cluster analysis revealed that ATTR deposition in the myocardium was significantly more severe in males than in females. The heterogeneous distribution of amyloid deposits between atria revealed in this study may impair the orderly transmission of the cardiac conduction system and induce arrhythmias, which may be further aggravated by additional neuropathy in the advanced phase. This impairment could be more severe among males. These findings emphasize that atrial evaluation is important for individuals with sporadic ATTR cardiac amyloidosis, particularly for early detection.

Diagnostic Pitfall and Clinical Characteristics of Variant Versus Wild-Type Transthyretin Amyloid Cardiomyopathy in Asian Population: The Korean Nationwide Cohort Study

BACKGROUND

Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an under-recognized cause of heart failure (HF) with clinical phenotypes that vary across regions and genotypes. We sought to characterize the clinical characteristics of ATTR-CM in Asia.

METHODS

Data from a nationwide cohort of patients with ATTR-CM from six major tertiary centres in South Korea were analysed between 2010 and 2021. All patients underwent clinical evaluation, biochemical laboratory tests, echocardiography, and transthyretin (TTR) genotyping at the time of diagnosis. The study population comprised 105 Asian ATTR-CM patients (mean age: 69 years; male: 65.7%, wild-type ATTR-CM: 41.9%).

RESULTS

Among our cohort, 18% of the patients had a mean left ventricular (LV) wall thickness < 12 mm. The diagnosis of ATTR-CM increased notably during the study period (8 [7.6%] during 2010-2013 vs. 22 [21.0%] during 2014-2017 vs. 75 [71.4%] during 2018-2021). Although the duration between symptom onset and diagnosis did not differ, the proportion of patients with HF presenting mild symptoms increased during the study period (25% NYHA class I/II between 2010-2013 to 77% between 2018-2021). In contrast to other international registry data, male predominance was less prominent in wild-type ATTR-CM (68.2%). The distribution of TTR variants was also different from Western countries and from Japan. Asp38Ala was the most common mutation.

CONCLUSION

A nationwide cohort of ATTR-CM exhibited less male predominance, a proportion of patients without increased LV wall thickness, and distinct characteristics of genetic mutations, compared to cohorts in other parts of the world. Our results highlight the ethnic variation in ATTR-CM and may contribute to improving the screening process for ATTR-CM in the Asian population.

Disease features and management of cardiomyopathies in women

Over the last years, there has been a growing interest in the clinical manifestations and outcomes of cardiomyopathies in women. Peripartum cardiomyopathy is the only women-specific cardiomyopathy. In cardiomyopathies with X-linked transmission, women are not simply healthy carriers of the disorder, but can show a wide spectrum of clinical manifestations ranging from mild to severe manifestations because of heterogeneous patterns of X-chromosome inactivation. In mitochondrial disorders with a matrilinear transmission, cardiomyopathy is part of a systemic disorder affecting both men and women. Even some inherited cardiomyopathies with autosomal transmission display phenotypic and prognostic differences between men and women. Notably, female hormones seem to exert a protective role in hypertrophic cardiomyopathy (HCM) and variant transthyretin amyloidosis until the menopausal period. Women with cardiomyopathies holding high-risk features should be referred to a third-level center and evaluated on an individual basis. Cardiomyopathies can have a detrimental impact on pregnancy and childbirth because of the associated hemodynamic derangements. Genetic counselling and a tailored cardiological evaluation are essential to evaluate the likelihood of transmitting the disease to the children and the possibility of a prenatal or early post-natal diagnosis, as well as to estimate the risk associated with pregnancy and delivery, and the optimal management strategies.

[Clinical differences between transthyretin cardiac amyloidosis and hypertensive heart disease]

INTRODUCTION

A significant percentage of patients eventually diagnosed with cardiac transthyretin amyloidosis (TTRA) was previously diagnosed with hypertensive heart disease (HHD), since both conditions usually present with heart failure (HF) with preserved ejection fraction (HFpEF) and ventricular hypertrophy. Our objectives were to evaluate the clinical, electrocardiographic and echocardiographic differences, and to analyse whether there exists a differential prognosis between these two nosological entities.

MATERIALS AND METHODS

We retrospectively included all patients with HHD for whom a cardiac scintigraphy with 99mTc-diphosphonate (GDPD) and a free light chains test in blood and urine were ordered for ATTR screening in our centre, in the period between 2016 and 2021. Those diagnosed with other types of amyloidosis were excluded from the analysis.

RESULTS

A total of 72 patients were analyzed: 33 were finally diagnosed with TTRA and 39 with CHTA. Patients with TTRA had higher levels of ultrasensitive troponin I (TnI-US) and N-terminal brain natriuretic propeptide (NT-ProBNP); in electrocardiography (ECG) they presented a pseudo-infarction pattern more frequently as well as conduction disturbances; in echocardiography (TTE) they presented a higher degree of ventricular hypertrophy, left ventricular dysfunction and worse diastolic function parameters, with elevated filling pressures. In the 4-year follow-up, the ATTR group showed greater need for pacemaker (PCM), with no evidence regarding mortality, development of atrial fibrillation (AF), or more admissions for heart failure (HF).

CONCLUSIONS

In our series, patients with TTRA showed clinical, electrocardiographic and echocardiographic differences compared to patients with HHD, with increased risk of need for PCM.

Sex differences in transthyretin cardiac amyloidosis

Transthyretin cardiac amyloidosis (ATTR-CA) is a progressive disease characterized by the deposition of abnormal transthyretin protein fibrils in the heart, leading to cardiac dysfunction. Recent evidence suggests that sex differences may play a significant role in various steps of ATTR-CA, including clinical presentation, diagnostic challenges, disease progression, and treatment outcomes. ATTR-CA predominantly affects men, whereas women are older at presentation. Women generally present with a history of heart failure with preserved ejection fraction and/or carpal tunnel syndrome. When indexed, left ventricular (LV) wall thickness is equal, or even increased, than men. Women also have smaller LV cavities, more preserved ejection fractions, and apparently a slightly worse right ventricular and diastolic function. Given the under-representation on women in clinical trials, no data regarding sex influence on the treatment response are currently available. Finally, it seems there are no differences in overall prognosis, even if premenopausal women may have a certain level of myocardial protection. Genetic variations, environmental factors, and hormonal changes are considered as potential contributors to observed disparities. Understanding sex differences in ATTR-CA is vital for accurate diagnosis and management. By considering these differences, clinicians can improve diagnostic accuracy, tailor treatments, and optimize outcomes for both sexes with ATTR-CA.

Screening for Occult Transthyretin Amyloidosis in Patients with Severe Aortic Stenosis and Amyloid Red Flags

AIMS

The optimal strategy to identify transthyretin-type cardiac amyloidosis (ATTR-CA) in patients with aortic stenosis (AS) is still unclear. This study aimed to investigate if targeted screening for ATTR-CA in patients with severe AS and amyloid red flags is associated with higher detection rates.

METHODS

The study prospectively enrolled patients ≥65 years with severe AS. Patients who fulfilled ≥1 major (carpal tunnel syndrome (CTS), ruptured biceps tendon, spinal stenosis, N-terminal pro B-type natriuretic peptide ≥1000 pg/mL, cardiac troponin >99th percentile) or ≥2 minor criteria (diastolic dysfunction ≥2 grade/lateral e' <10 cm/s, atrial fibrillation, atrioventricular conduction disease/pacemaker) received bone scintigraphy and biochemical analysis for light chain amyloidosis. Hypertensive patients (>140/90 mmHg) and those with interventricular septal thickness (IVSd) ≤13 mm were excluded.

RESULTS

Overall, 264 patients were screened, of whom 85 were included in the analysis. Tracer uptake Perugini grade ≥1 was detected in nine patients (11%). An endomyocardial biopsy was additionally performed in four of nine patients, yielding a prevalence of 7% (n = 6). All patients with dual AS-ATTR were male. Syncope was more commonly reported in AS-ATTR patients (50% vs. 6%, p = 0.010), who also tended to have more severe hypertrophy (IVSd of 18 vs. 16 mm, p = 0.075). Pericardial effusion and CTS were more common in patients with dual pathology (67% vs. 8%, p < 0.001, and 83% vs. 24%, p = 0.003, respectively).

CONCLUSION

Targeted screening for ATTR-CA in patients with AS and amyloid red flags does not yield higher detection rates than those reported previously in all comers with AS.

A 15-year consolidated overview of data in over 6000 patients from the Transthyretin Amyloidosis Outcomes Survey (THAOS)

BACKGROUND

Transthyretin amyloidosis (ATTR amyloidosis) is a progressive, multisystemic, life-threatening disease resulting from the deposition of variant or wild-type (ATTRwt amyloidosis) transthyretin amyloid fibrils in various tissues and organs.

METHODS

Established in 2007, the Transthyretin Amyloidosis Outcomes Survey (THAOS) is the largest ongoing, global, longitudinal, observational study of patients with ATTR amyloidosis, including both hereditary and wild-type disease, and asymptomatic carriers of pathogenic TTR mutations. This analysis describes the baseline characteristics of symptomatic patients and asymptomatic gene carriers enrolled in THAOS since its inception in 2007 (data cutoff: August 1, 2022), providing a consolidated overview of 15-year data from the THAOS registry.

RESULTS

This analysis included 4428 symptomatic patients and 1707 asymptomatic gene carriers. The majority of symptomatic patients were male (70.8%) with a mean (standard deviation [SD]) age at symptom onset of 56.6 (17.9) years. Compared with the 14-year analysis, V30M remained the most prevalent genotype in Europe (62.2%), South America (78.6%), and Japan (74.2%) and ATTRwt remained most common in North America (56.2%). Relative to the 14-year analysis, there was an increase of mixed phenotype (from 16.6 to 24.5%) and a reduction of predominantly cardiac phenotype (from 40.7 to 31.9%). The proportion of patients with predominantly neurologic phenotype remained stable (from 40.1 to 38.7%). Asymptomatic gene carriers were 58.5% female with a mean age at enrollment of 41.9 years (SD 15.5).

CONCLUSIONS

This overview of > 6000 patients enrolled over 15 years in THAOS represents the largest registry analysis of ATTR amyloidosis to date and continues to emphasize the genotypic and phenotypic heterogeneity of the disease. Nearly a quarter of the symptomatic population within THAOS was mixed phenotype, underscoring the need for multidisciplinary management of ATTR amyloidosis.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00628745.

A simple ATTR-CM score to identify transthyretin amyloid cardiomyopathy burden in HFpEF patients

BACKGROUND

Transthyretin amyloid cardiomyopathy (ATTR-CM) is often found in patients with heart failure with preserved ejection fraction (HFpEF). However, the evidence regarding ATTR-CM and prognosis in HFpEF remains scarce. This study sought to determine whether the ATTR-CM burden was associated with clinical outcomes in HFpEF patients.

METHODS

We evaluated the associations of baseline ATTR-CM score with adverse outcomes in HFpEF patients from the TOPCAT trial using the Cox proportional hazards model or the competing risk regression model. The discriminatory ability of the ATTR-CM score was assessed using the area under the time-dependent receiver operating characteristic curve (AUC).

RESULTS

We included 870 HFpEF patients, 18.9% of which had an ATTR-CM score ≥6. Per 1 increment in the ATTR-CM score was significantly associated with an increased risk of the primary outcome (adjusted hazard ratio [HR] 1.19, 95% confidence interval [CI] 1.12-1.27) with an AUC of 0.652 (0.594-0.711), whereas patients with ATTR-CM score ≥6 presented higher risks of the primary outcome (adjusted HR 2.20, 95% CI 1.65-2.95). Similar results were observed toward the secondary outcomes.

CONCLUSIONS

The simple ATTR-CM score identified an 18.9% ATTR-CM burden in HFpEF patients, and a higher ATTR-CM burden might predict adverse outcomes with moderate discriminatory abilities in HFpEF.

A multicentric study of the disease risks and first manifestations in hereditary transthyretin amyloidosis (ATTRv): insights for an earlier diagnosis

BACKGROUND

In hereditary transthyretin amyloidosis (ATTRv), early manifestation and age at onset (AO) may vary strikingly. We assessed the disease'risk (penetrance), AO and initial features in ATTRv families to gain insights on the early disease presentation.

METHODS

Genealogical information, AO and first disease manifestations were collected in ATTRv families, from Sweden, Italy (Sicily), Spain (Mallorca), France, Turkey, Brazil. Penetrance was computed using a non-parametric survival method.

RESULTS

We analysed 258 TTRV30M kindreds and 84 carrying six other variants (TTRT49A, F64L, S77Y, S77F, E89Q, I107V). In ATTRV30M families, the earliest disease risk was found at age 20 years in the Portuguese and Mallorcan families and at age 30-35 years, in the French and Swedish groups. The risks were higher in men and in carriers of maternal descent. In families carrying TTR-nonV30M variants, the earliest disease risk ranged from 30 y-o in TTRT49A to 55 y-o in TTRI107V families. Peripheral neuropathy symptoms were the most frequent initial manifestations. Among patients carrying TTRnonV30M variants, about 25% had an initial cardiac phenotype, one third a mixed phenotype.

CONCLUSION

Our work provided solid data on the risks and early features of ATTRv in a spectrum of families to enhance an early diagnosis and treatment.

The contribution of amyloid deposition in the aortic valve to calcification and aortic stenosis

Calcific aortic valve disease (CAVD) and stenosis have a complex pathogenesis, and no therapies are available that can halt or slow their progression. Several studies have shown the presence of apolipoprotein-related amyloid deposits in close proximity to calcified areas in diseased aortic valves. In this Perspective, we explore a possible relationship between amyloid deposits, calcification and the development of aortic valve stenosis. These amyloid deposits might contribute to the amplification of the inflammatory cycle in the aortic valve, including extracellular matrix remodelling and myofibroblast and osteoblast-like cell proliferation. Further investigation in this area is needed to characterize the amyloid deposits associated with CAVD, which could allow the use of antisense oligonucleotides and/or isotype gene therapies for the prevention and/or treatment of CAVD.

Risk stratification in transthyretin-related cardiac amyloidosis

Transthyretin related cardiac amyloidosis (TTR-CA) is an infiltrative cardiomyopathy that cause heart failure with preserved ejection fraction, mainly in aging people. Due to the introduction of a non invasive diagnostic algorithm, this disease, previously considered to be rare, is increasingly recognized. The natural history of TTR-CA includes two different stages: a presymptomatic and a symptomatic stage. Due to the availability of new disease-modifying therapies, the need to reach a diagnosis in the first stage has become impelling. While in variant TTR-CA an early identification of the disease may be obtained with a genetic screening in proband's relatives, in the wild-type form it represents a challenging issue. Once the diagnosis has been made, in order to identifying patients with a higher risk of cardiovascular events and death it is necessary to focus on risk stratification. Two prognostic scores have been proposed both based on biomarkers and laboratory findings. However, a multiparametric approach combining information from electrocardiogram, echocardiogram, cardiopulmonary exercise test and cardiac magnetic resonance may be warranted for a more comprehensive risk prediction. In this review, we aim at evaluating a step by step risk stratification, providing a clinical diagnostic and prognostic approach for the management of patients with TTR-CA.

Ser77Tyr transthyretin amyloidosis in Israel: Initial manifestations and diagnostic features

OBJECTIVE

Amyloidosis due to the transthyretin Ser77Tyr mutation (ATTRS77Y) is a rare autosomal-dominant disorder, characterized by carpal-tunnel syndrome, poly- and autonomic-neuropathy, and cardiomyopathy. However, related symptoms and signs are often nonspecific and confirmatory tests are required. We describe the age and frequency of early symptoms and diagnostic features among individuals of Jewish Yemenite descent in Israel.

METHODS

Records of mutation carriers were retrospectively reviewed. ATTRS77Y diagnosis was defined by the presence of amyloid in tissue and/or amyloid-related cardiomyopathy.

RESULTS

We identified the Ser77Tyr mutation at the heterozygous state in 19 amyloidosis patients (mean age at diagnosis: 62 ± 5.7 years, range 49-70) and 30 amyloid-negative carriers. The probability for disease diagnosis increased from 4.4% at age 49 to 100% at 70 and occurred earlier in males. Initial symptoms preceded diagnosis by 5 ± 3.8 years (range 0-12) and were commonly sensory changes in the extremities. Erectile dysfunction predated these in 8/13 (62%) males. In two patients cardiac preceded neurological symptoms. Two patients declined symptoms. Electrophysiological studies near the time of diagnosis indicated a median neuropathy at the wrist in 18/19 (95%) and polyneuropathy in 13/19 (68%). Skin biopsy revealed epidermal denervation in 15/16 (94%) patients. Cardiomyopathy was identified in 16/19 (84%). Sensory complaints or epidermal denervations were present in 17/30 (57%) of amyloid-negative carriers and co-occurred in 10/30 (33%).

INTERPRETATION

ATTRS77Y symptoms commonly occur after age 50, but may begin earlier. Median neuropathy, skin denervation and cardiomyopathy are frequently identified. Symptoms may be absent in patients and common in amyloid-negative carriers.

Amyloid Disassembly: What Can We Learn from Chaperones?

Protein aggregation and subsequent accumulation of insoluble amyloid fibrils with cross-β structure is an intrinsic characteristic of amyloid diseases, i.e., amyloidoses. Amyloid formation involves a series of on-pathway and off-pathway protein aggregation events, leading to mature insoluble fibrils that eventually accumulate in multiple tissues. In this cascade of events, soluble oligomeric species are formed, which are among the most cytotoxic molecular entities along the amyloid cascade. The direct or indirect action of these amyloid soluble oligomers and amyloid protofibrils and fibrils in several tissues and organs lead to cell death in some cases and organ disfunction in general. There are dozens of different proteins and peptides causing multiple amyloid pathologies, chief among them Alzheimer's, Parkinson's, Huntington's, and several other neurodegenerative diseases. Amyloid fibril disassembly is among the disease-modifying therapeutic strategies being pursued to overcome amyloid pathologies. The clearance of preformed amyloids and consequently the arresting of the progression of organ deterioration may increase patient survival and quality of life. In this review, we compiled from the literature many examples of chemical and biochemical agents able to disaggregate preformed amyloids, which have been classified as molecular chaperones, chemical chaperones, and pharmacological chaperones. We focused on their mode of action, chemical structure, interactions with the fibrillar structures, morphology and toxicity of the disaggregation products, and the potential use of disaggregation agents as a treatment option in amyloidosis.

Characteristics of Patients with Hereditary Transthyretin Amyloidosis-Polyneuropathy (ATTRv-PN) in NEURO-TTRansform, an Open-label Phase 3 Study of Eplontersen

INTRODUCTION

Hereditary transthyretin (ATTRv) amyloidosis is a rare, severe, progressive, debilitating, and ultimately fatal disease caused by systemic deposition of transthyretin (TTR) amyloid fibrils. ATTRv amyloidosis occurs in both males and females. Eplontersen (ION-682884), a ligand-conjugated antisense oligonucleotide designed to degrade hepatic TTR mRNA, is being evaluated for the treatment of ATTRv amyloidosis with polyneuropathy (ATTRv-PN) in the phase 3, international, multicenter, open-label NEURO-TTRansform study (NCT04136184). To describe the study population of this pivotal trial, here we report the baseline characteristics of patients enrolled in the NEURO-TTRansform study.

METHODS

Patients eligible for NEURO-TTRansform were 18-82 years old with a diagnosis of ATTRv-PN and Coutinho stage 1 (ambulatory without assistance) or stage 2 (ambulatory with assistance) disease; documented TTR gene variant; signs and symptoms consistent with neuropathy associated with ATTRv; no prior liver transplant; and New York Heart Association (NYHA) functional class I or II.

RESULTS

The NEURO-TTRansform study enrolled 168 patients across 15 countries/territories (North America, 15.5%; Europe, 38.1%; South America/Australia/Asia, 46.4%). At baseline, the study cohort had a mean age of 52.8 years, 69.0% of patients were male, and 78.0% of patients were White. The V30M variant was most prevalent (60.1% of patients), and prevalence varied by region. Overall, 56.5% and 17.3% of patients had received previous treatment with tafamidis or diflunisal, respectively. A majority of patients (79.2%) had Coutinho stage 1 disease (unimpaired ambulation) and early (before age 50) disease onset (53.0%). Time from diagnosis to enrollment was 46.6 (57.4) months (mean [standard deviation]). Most patients had a baseline polyneuropathy disability (PND) score of I (40.5%) or II (41.1%), and the mean modified Neuropathy Impairment Score + 7 (mNIS + 7) was 79.0.

CONCLUSION

The recruited population in the ongoing NEURO-TTRansform study has global representation characteristic of contemporary clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04136184.

Sex differences among patients with transthyretin amyloid cardiomyopathy - from diagnosis to prognosis

AIMS

Transthyretin amyloid cardiomyopathy (ATTR-CM) is predominantly diagnosed in men. The few available studies suggest affected women have a more favourable cardiac phenotype. We aimed to characterize sex differences among consecutive patients with non-hereditary and two prevalent forms of hereditary (h)ATTR-CM diagnosed over a 20-year period.

METHODS AND RESULTS

Analysis of deep phenotyping at presentation, changes on serial echocardiography and overall prognosis were evaluated. In total, 1732 consecutive patients were studied, comprising: 1095 with wild-type (wt)ATTR-CM; 206 with T60A-hATTR-CM; and 431 with V122I-hATTR-CM. Female prevalence was greater in T60A-hATTR-CM (29.6%) and V122I-hATTR-CM (27.8%) compared to wtATTR-CM (6%). At presentation, females were 3.3 years older than males (wtATTR-CM: 81.9 vs. 77.8 years; T60A-hATTR-CM: 68.7 vs. 65.1 years; V122I-hATTR-CM: 77.1 vs. 74.9 years). Body size significantly influenced measures of disease severity; when indexed, overall structural and functional phenotype was similar between sexes, the few significant differences suggested a mildly worse phenotype in females. No significant differences were observed in both disease progression on serial echocardiography and mortality across the overall population (p = 0.459) and when divided by genotype (wtATTR-CM: p = 0.730; T60A-hATTR-CM: p = 0.161; V122I-hATTR-CM: p = 0.056).

CONCLUSION

This study of a well-characterized large cohort of ATTR-CM patients did not demonstrate overall differences between sexes in either clinical phenotype, when indexed, or with respect to disease progression and prognosis. Non-indexed wall thickness measurements may have contributed to both under-representation and delays in diagnosis for affected females and highlights the potential role of utilizing indexed echocardiographic parameters for a more accurate assessment of patients at diagnosis and for disease prognostication.

A natural history analysis of asymptomatic TTR gene carriers as they develop symptomatic transthyretin amyloidosis in the Transthyretin Amyloidosis Outcomes Survey (THAOS)

BACKGROUND

Hereditary transthyretin amyloidosis (ATTRv amyloidosis) results from pathogenic mutations in the transthyretin (TTR) gene. This analysis aimed to better understand ATTRv amyloidosis development in asymptomatic TTR gene carriers.

METHODS

The Transthyretin Amyloidosis Outcomes Survey (THAOS) is an ongoing, global, longitudinal, observational survey of patients with transthyretin amyloidosis, including both inherited and wild-type disease, and asymptomatic TTR gene carriers. Asymptomatic TTR gene carriers were assessed longitudinally to identify those who developed ATTRv amyloidosis after enrolment in THAOS (data cut-off: 1 August 2021).

RESULTS

Of 740 asymptomatic TTR gene carriers, 268 (36.2%) (Val30Met, 212/613 [34.6%]; non-Val30Met, 48/111 [43.2%]) developed ATTRv amyloidosis within a median 2.2 years after enrolment. The most common first symptoms were sensory (49.5%) and autonomic (37.3%) neuropathy in Val30Met patients, and sensory neuropathy (45.8%) and cardiac disorder (22.9%) in non-Val30Met patients. Most patients first presented with a predominantly neurologic phenotype (Val30Met, 77.8%; non-Val30Met, 70.8%).

CONCLUSIONS

More than one-third of asymptomatic TTR gene carriers in THAOS developed ATTRv amyloidosis within a median 2 years of enrolment. Val30Met versus non-Val30Met patients had a lower transition rate. Given the importance of early treatment, these findings underscore the need for identification and careful monitoring of at-risk TTR gene carriers to enable prompt treatment.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00628745.

Redefining the epidemiology of cardiac amyloidosis. A systematic review and meta-analysis of screening studies

AIMS

An algorithm for non-invasive diagnosis of amyloid transthyretin cardiac amyloidosis (ATTR-CA) and novel disease-modifying therapies have prompted an active search for CA. We examined the prevalence of CA in different settings based on literature data.

METHODS AND RESULTS

We performed a systematic search for screening studies on CA, focusing on the prevalence, sex and age distribution in different clinical settings. The prevalence of CA in different settings was as follows: bone scintigraphy for non-cardiac reasons (n = 5 studies), 1% (95% confidence interval [CI] 0%-1%); heart failure with preserved ejection fraction (n = 6), 12% (95% CI 6%-20%); heart failure with reduced or mildly reduced ejection fraction (n = 2), 10% (95% CI 6%-15%); conduction disorders warranting pacemaker implantation (n = 1), 2% (95% CI 0%-4%); surgery for carpal tunnel syndrome (n = 3), 7% (95% CI 5%-10%); hypertrophic cardiomyopathy phenotype (n = 2), 7% (95% CI 5%-9%); severe aortic stenosis (n = 7), 8% (95% CI 5%-13%); autopsy series of 'unselected' elderly individuals (n = 4), 21% (95% CI 7%-39%). The average age of CA patients in the different settings ranged from 74 to 90 years, and the percentage of men from 50% to 100%. Many patients had ATTR-CA, but the average percentage of patients with amyloid light-chain (AL) CA was up to 18%.

CONCLUSIONS

Searching for CA in specific settings allows to identify a relatively high number of cases who may be eligible for treatment if the diagnosis is unequivocal. ATTR-CA accounts for many cases of CA across the different settings, but AL-CA is not infrequent. Median age at diagnosis falls in the eighth or ninth decades, and many patients diagnosed with CA are women.

Unravelling the role of sex in the pathophysiology, phenotypic expression and diagnosis of cardiac amyloidosis

Sex-related differences in amyloid transthyretin (ATTR) amyloidosis.

Clinical and genetic profile of patients enrolled in the Transthyretin Amyloidosis Outcomes Survey (THAOS): 14-year update

BACKGROUND

Transthyretin amyloidosis (ATTR amyloidosis) is a rare, life-threatening disease caused by the accumulation of variant or wild-type (ATTRwt amyloidosis) transthyretin amyloid fibrils in the heart, peripheral nerves, and other tissues and organs.

METHODS

Established in 2007, the Transthyretin Amyloidosis Outcomes Survey (THAOS) is the largest ongoing, global, longitudinal observational study of patients with ATTR amyloidosis, including both inherited and wild-type disease, and asymptomatic carriers of pathogenic TTR mutations. This descriptive analysis examines baseline characteristics of symptomatic patients and asymptomatic gene carriers enrolled in THAOS since its inception in 2007 (data cutoff: August 1, 2021).

RESULTS

This analysis included 3779 symptomatic patients and 1830 asymptomatic gene carriers. Symptomatic patients were predominantly male (71.4%) and had a mean (standard deviation [SD]) age of symptom onset of 56.3 (17.8) years. Val30Met was the most common genotype in symptomatic patients in South America (80.9%), Europe (55.4%), and Asia (50.5%), and more patients had early- versus late-onset disease in these regions. The majority of symptomatic patients in North America (58.8%) had ATTRwt amyloidosis. The overall distribution of phenotypes in symptomatic patients was predominantly cardiac (40.7%), predominantly neurologic (40.1%), mixed (16.6%), and no phenotype (2.5%). In asymptomatic gene carriers, mean (SD) age at enrollment was 42.4 (15.7) years, 42.4% were male, and 73.2% carried the Val30Met mutation.

CONCLUSIONS

This 14-year global overview of THAOS in over 5000 patients represents the largest analysis of ATTR amyloidosis to date and highlights the genotypic and phenotypic heterogeneity of the disease.

CLINICALTRIALS

gov Identifier: NCT00628745.

The revolution of ATTR amyloidosis in cardiology: certainties, gray zones and perspectives

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. Amyloid transthyretin cardiac amyloidosis (ATTR-CA) manifests typically as left ventricular pseudohypertrophy and/or heart failure with preserved ejection fraction and is an underdiagnosed disorder affecting quality of life and prognosis. This justifies the current search for novel tools for early diagnosis and accurate risk prediction, as well as for safe and effective therapies. In this review we will provide an overview of the main unsolved issues and the most promising research lines on ATTR-CA, ranging from the mechanisms of amyloid formation to therapies.

Heart Failure Subtypes and Cardiomyopathies in Women

Heart failure affects over 2.6 million women and 3.4 million men in the United States with known sex differences in epidemiology, management, response to treatment, and outcomes across a wide spectrum of cardiomyopathies that include peripartum cardiomyopathy, hypertrophic cardiomyopathy, stress cardiomyopathy, cardiac amyloidosis, and sarcoidosis. Some of these sex-specific considerations are driven by the cellular effects of sex hormones on the renin-angiotensin-aldosterone system, endothelial response to injury, vascular aging, and left ventricular remodeling. Other sex differences are perpetuated by implicit bias leading to undertreatment and underrepresentation in clinical trials. The goal of this narrative review is to comprehensively examine the existing literature over the last decade regarding sex differences in various heart failure syndromes from pathophysiological insights to clinical practice.

TTR Gly83Arg Mutation: Beyond Familial Vitreous Amyloidosis

BACKGROUND

Gly83Arg variation is a type of TTR mutation specific to the Chinese population. Patients of hereditary transthyretin amyloidosis (ATTR) with Gly83Arg variation predominantly present with blurred vision and most of these cases are reported by ophthalmologists. There is currently no systematic assessment of extraocular features of ATTR with Gly83Arg variation.

METHODS

Six patients and two asymptomatic carriers with molecularly confirmed Gly83Arg variation of ATTR from three unrelated families were identified by sequencing the TTR gene. The clinical, electrophysiological, ultrasonic, and pathological data were collected and analyzed.

RESULTS

This study included six patients and two carriers with TTR Gly83Arg mutation, all of whom came from the Han nationality of China. The average age of onset for the six patients was 39 years, and the course of disease ranged from 5 to 19 years. All the patients started with blurred vision, which was diagnosed as vitreous opacity (VO). Most of the patients developed sensory-motor polyneuropathies over years or even more than a decade (4-15 years) after VO. However, the heterogeneity of peripheral neuropathies among these patients remained large between families. Autonomic impairment also occurred after VO, with varying degrees of abnormalities seen in the associated autonomic assessments. None of the patients had any symptoms of cardiac impairment, but abnormal results were found in examinations. A combined biopsy of the sural nerve and muscle was also performed. Nerve pathology revealed the moderately reduced myelinated nerve fiber density and muscle pathology showed predominant neurogenic impairment accompanied by possible myogenic impairment.

CONCLUSIONS

This is a detailed account of Gly83Arg mutation-related ATTR, focusing on the extraocular presentations of this special variant in Chinese. Clinical features of this variant are early-onset, ocular involvement predominance, neurological, and cardiac involvement along with the disease, and relatively long survival.