Late-onset familial amyloidosis polyneuropathy associated with c.186G>C in transthyretin.

INTRODUCTION: The most common form of hereditary amyloidosis is associated with variants of transthyretin (TTR). Familial amyloidosis polyneuropathy associated with variants of TTR (FAP-TTR) is an infrequent, multisystemic disease, with predominant involvement of the peripheral nervous system. More than 130 pathogenic variants have been identified so far and most of them are amyloidogenic, being Val30Met the most frequently described. CASE REPORT: A 74 year-old male was evaluated for progressive decreased sensitivity and associated loss of strength in four limbs in the previous two years, needing assistance for walking. Areflexia, bilateral tibialis anterior and gastrocnemius atrophy, bilateral anesthesia and apalesthesia were found in lower limbs. Bilateral hypoesthesia was reported in upper limbs. No painful dysesthesia, hyperalgesia or allodynia were found. DNA sequencing of the TTR gene led to the detection of the variant c.186G>C in heterozygous state. The resulting variant (Glu62Asp), located in the critical functional domain, has not been published before. CONCLUSION: The importance of considering late onset, sporadic FAP-TTR as a differential diagnosis of cryptogenic polyneuropathy is highlighted.

Introducción: La forma más común de amiloidosis hereditaria está asociada con variantes de la transtiretina. La polineuropatía amiloidótica familiar asociada con variantes de la TTR (FAP-TTR) es una enfermedad multisistémica poco frecuente, con afectación predominante del sistema nervioso periférico. Hasta ahora se han identificado más de 130 variantes patogénicas y la mayoría de ellas son amiloidogénicas, siendo Val30Met la más frecuentemente descrita. Caso clínico: Un paciente de 74 años fue evaluado por disminución progresiva de la sensibilidad y pérdida asociada de fuerza en las cuatro extremidades de dos años de evolución, necesitando ayuda para caminar. En las extremidades inferiores se observó arreflexia, atrofia bilateral del tibial anterior y del gastrocnemio, anestesia bilateral y apalestesia. Los miembros superiores presentaban hipoestesia bilateral. No se observaron disestesias dolorosas, hiperalgesia ni alodinia. La secuenciación del ADN del gen TTR permitió detectar la variante c.186G>C en estado heterocigoto. La variante resultante (Glu62Asp), localizada en el dominio funcional crítico de la proteína, no ha sido informada con anterioridad. Conclusión: Se destaca la importancia de considerar la FAP-TTR esporádica de aparición tardía como un diagnóstico diferencial de la polineuropatía criptogénica.

Prevalence of moderate-severe aortic stenosis in patients with cardiac amyloidosis in a referral center.

BACKGROUND: Aortic stenosis (AS) is currently the most common valvular disease, with an estimated prevalence of over 4% in octogenarians. OBJECTIVE: To describe the prevalence of moderate-severe aortic stenosis (AS) in patients with wild type transthyretin amyloidosis (ATTRwt). Also, describe the clinical features, echocardiographic characteristics and clinical evolution. METHOD: Retrospective cohort of patients with diagnosis of ATTRwt, belonging to Hospital Italiano de Buenos Aires Institutional Amyloidosis Registry, from 30/11/2007 to 31/05/2021. Patients follow up was carried out through the institution clinical history. The prevalence of moderate-severe AE was estimated and presented as a percentage with its 95% confidence interval (95% CI). The characteristics were compared by groups according to whether or not they had moderate-severe AS. RESULTS: 104 patients with ATTRwt were included. Median follow up was 476 days [interquartile range: 192-749]. Moderate-severe AS prevalence at the ATTRwt time of diagnosis was 10.5% (n = 11; 95% CI: 5-18%). The median age of patients with AS moderate-severe at the time of diagnosis of ATTRwt was 86 years [78-91] and the male sex predominated (82%). Most of the patients had a history of heart failure (n = 8) and atrial fibrillation (n = 8) prior to the diagnosis of ATTRwt. Most of the patients were subclassified as low flow low gradient severe AS group (n = 7). Four patients underwent some intervention on the aortic valve. During follow-up, 5 patients (46%) were hospitalized for decompensated heart failure and 4 (36%) died. CONCLUSIONS: In our cohort, the coexistence of both pathologies had a similar prevalence as reported in the international literature. It was an elderly population with a high percentage of atrial fibrillation and history of heart failure. Most of the patients presented with severe AS with low flow low gradient.

ANTECEDENTES: La estenosis aórtica (EA) es actualmente la enfermedad valvular más frecuente, con una prevalencia estimada de más del 4 % en octogenarios. OBJETIVO: Describir la prevalencia de estenosis aórtica (EA) moderada-grave en pacientes con amiloidosis por transtiretina wild type (ATTRwt). Además, describir las características clínicas, ecocardiográficas y la evolución en este grupo de pacientes. MÉTODO: Estudio de cohorte retrospectiva de pacientes con diagnóstico de ATTRwt, pertenecientes al Registro Institucional de Amiloidosis del Hospital Italiano de Buenos Aires, en el periodo del 30/11/2007 al 31/05/2021. El seguimiento de los pacientes se realizó a través de la historia clínica electrónica de la institución. Se estimó la prevalencia de EA moderada-grave, que se presenta como porcentaje con su intervalo de confianza del 95% (IC 95%). Se compararon las características por grupos según tuvieran o no EA moderada-grave. RESULTADOS: Se incluyeron 104 pacientes con diagnóstico de ATTRwt. La mediana de seguimiento fue de 476 días [rango intercuartílico: 192-749]. La prevalencia de EA moderada-grave al momento del diagnóstico de ATTRwt fue del 10.5% (n = 11; IC95%: 5-18%). La mediana de edad de los pacientes con EA fue de 86 años [78-91] y predominó el sexo masculino (81.8%). La mayoría de los pacientes tenían el antecedente de insuficiencia cardiaca (n = 8) y fibrilación auricular (n = 8). Predominaron los pacientes con EA grave de bajo flujo y bajo gradiente (n = 7). Cuatro pacientes fueron sometidos a alguna intervención en la válvula aórtica. Durante el seguimiento, 5 pacientes (46%) tuvieron internaciones por insuficiencia cardiaca descompensada y 4 (36%) fallecieron. CONCLUSIONES: En nuestra cohorte, la coexistencia de ambas patologías tuvo una prevalencia similar a la reportada en la literatura internacional. Se trató de una población añosa con alto porcentaje de fibrilación auricular y antecedente de insuficiencia cardiaca. La mayoría presentaron EA grave de bajo flujo y bajo gradiente.

Real life experience of tafamidis for the treatment of Spanish patients with Val30Met transthyretin amyloidosis with polyneuropathy.

INTRODUCTION: Tafamidis is the only approved transthyretin stabiliser approved for the treatment of variant transthyretin amyloidosis (A-ATTRv) related polyneuropathy (PNP). The aim of this study is to analyse the effectiveness of tafamidis in a real-world setting in Spain. METHODS: This is a national multicenter study in which patients with V30M A-ATTR related PN treated with tafamidis for at least 1 year were included. Clinical, demographic, analytical and neurophysiological variables were analysed. RESULTS: 100 patients were recruited. Overall, 47 patients (47%) were classified as complete responders, 32 (32%) as partial responders and 21 (21%) as non-responders. The median duration of treatment with tafamidis was 35 months. Better treatment response was shown in patients with in polyneuropathy disability score (PND) I, lower neuropathy impairment score (NIS), compound muscle action potential (CMAP) and Norfolk QoL questionnaire. Higher albumin levels and lower NTproBNP levels were also associated with better treatment response. A basal NIS≥15 predicts that the patient could be a non-responder with a 60% probability. CONCLUSIONS: Our results reinforce the tafamidis efficacy to treat A-ATTRv-PNP if started early in the disease course. Patients with the V30M variant, NIS<15 and PND I are the most appropriate subjects for this treatment.

In adults with ATTR cardiac amyloidosis, patisiran reduced decline in functional capacity at 12 mo.

SOURCE CITATION: Maurer MS, Kale P, Fontana M, et al; APOLLO-B Trial Investigators. Patisiran treatment in patients with transthyretin cardiac amyloidosis. N Engl J Med. 2023;389:1553-1565. 37888916.

Impact of vutrisiran on exploratory cardiac parameters in hereditary transthyretin-mediated amyloidosis with polyneuropathy.

AIMS: HELIOS-A was a Phase 3, open-label study of vutrisiran, an RNA interference therapeutic, in patients with hereditary transthyretin (ATTRv) amyloidosis with polyneuropathy. This analysis evaluated vutrisiran's impact on exploratory cardiac endpoints in HELIOS-A patients. METHODS AND RESULTS: Patients were randomized 3:1 to subcutaneous vutrisiran 25 mg every 3 months or intravenous patisiran 0.3 mg/kg every 3 weeks (reference group) for 18 months. Exploratory cardiac endpoints included change from baseline in N-terminal prohormone of brain-type natriuretic peptide (NT-proBNP) and echocardiographic parameters versus external placebo (APOLLO study). The modified intent-to-treat (mITT) population comprised randomized patients receiving any study drug (n = 122). A cardiac subpopulation with evidence of cardiac amyloid involvement (n = 40) was prespecified. 99mTc scintigraphy exploratory assessments in a planned vutrisiran-treated cohort at select sites were compared with baseline. At Month 18, vutrisiran demonstrated beneficial effects on NT-proBNP versus external placebo in the mITT and cardiac subpopulations (adjusted geometric mean fold change ratio [95% confidence interval] 0.480 [0.383-0.600], p = 9.606 × 10-10 and 0.491 [0.337-0.716], p = 0.0004, respectively). Benefits or trends towards benefit in echocardiographic parameters versus external placebo were observed for both populations. In 99mTc scintigraphy assessments, 32/47 (68.1%) and 31/48 (64.6%) patients exhibited reduced normalized left ventricular total uptake and heart-to-contralateral lung ratio, respectively. Perugini grade was reduced or unchanged versus baseline in 55/57 (96.5%) evaluable patients. No increase in cardiac adverse events was observed with vutrisiran versus external placebo. CONCLUSIONS: Vutrisiran demonstrated evidence of potential benefit on cardiac manifestations in patients with ATTRv amyloidosis with polyneuropathy, with an acceptable safety profile.

Transthyretin-derived amyloid (ATTR) and sarcoidosis: Does ATTR deposition cause a granulomatous inflammatory response in older adults with sarcoidosis?

This study aimed to assess the frequency and association between transthyretin-derived (ATTR) amyloidosis and sarcoidosis in a large autopsy cohort including many cases of sudden cardiac death (SCD). We identified 73 sporadic ATTR amyloidosis cases and 11 sarcoidosis cases, among which we found two cases with concomitant ATTR amyloidosis and sarcoidosis (2.4% of all cases; 2.7% within the sporadic ATTR group). The first case involved a 92-year-old man who experienced SCD. In this patient's heart, we observed ATTR deposition and noncaseating epithelioid granulomas consistent with sarcoidosis. Focally, ATTR deposits and granulomas co-localized, with histiocyte phagocytosis of transthyretin-immunoreactive fragments. However, in most lesions, they were distributed independently. The second case was that of an 86-year-old woman who also experienced SCD. In this patient, we detected ATTR deposition in the heart and lung, while noncaseating epithelioid granulomas were only observed in the lung, liver, kidney, and thyroid. Furthermore, no co-localization of the two lesions was observed. Based on these findings, we concluded that the coexistence of ATTR amyloidosis and sarcoidosis was likely coincidental. Nevertheless, despite the rarity of the combination of these two diseases, it should be recognized as a potential cause of SCD, especially among elderly people.

Multiorgan Dysfunction and Associated Prognosis in Transthyretin Cardiac Amyloidosis.

BACKGROUND: Transthyretin cardiac amyloidosis (ATTR-CA) is a progressive and ultimately fatal cardiomyopathy. Biomarkers reflecting multiorgan dysfunction are of increasing importance in patients with heart failure; however, their significance in ATTR-CA remains largely unknown. The aims of this study were to characterize the multifaceted nature of ATTR-CA using blood biomarkers and assess the association between blood biomarkers and prognosis. METHODS AND RESULTS: This is a retrospective cohort study of 2566 consecutive patients diagnosed with ATTR-CA between 2007 and 2023. Anemia (39%), high urea (52%), hyperbilirubinemia (18%), increased alkaline phosphatase (16%), increased CRP (C-reactive protein; 27%), and increased troponin (98.2%) were common findings in the overall population, whereas hyponatremia (6%) and hypoalbuminemia (2%) were less common. These abnormalities were most common in patients with p.(V142I) hereditary ATTR-CA, and became more prevalent as the severity of cardiac disease increased. Multivariable Cox regression analysis demonstrated that anemia (hazard ratio [HR], 1.19 [95% CI, 1.04-1.37]; P=0.01), high urea (HR, 1.23 [95% CI, 1.04-1.45]; P=0.01), hyperbilirubinemia (HR, 1.32 [95% CI, 1.13-1.57; P=0.001), increased alkaline phosphatase (HR, 1.20 [95% CI, 1.01-1.42; P=0.04), hyponatremia (HR, 1.65 [95% CI, 1.28-2.11]; P<0.001), and troponin-T >56 ng/L (HR, 1.72 [95% CI, 1.46-2.03]; P<0.001) were all independently associated with mortality in the overall population. The association between biomarkers and mortality varied across the spectrum of genotypes and left ventricular ejection fraction, with anemia remining independently associated with mortality in p.(V142I) hereditary ATTR-CA (HR, 1.58 [95% CI, 1.17-2.12]; P=0.003) and in a subgroup of the overall population with a left ventricular ejection fraction ≤40% (HR, 1.39 [95% CI, 1.08-1.81]; P=0.01). CONCLUSIONS: Cardiac and noncardiac biomarker abnormalities were common and reflect the complex and multifaceted nature of ATTR-CA, with a wide range of biomarkers remaining independently associated with mortality. Clinical trials are needed to investigate whether biomarker abnormalities represent modifiable risk factors that if specifically targeted could improve outcomes.

Outcomes of Octogenarian Patients Treated with Tafamidis for Transthyretin Amyloid Cardiomyopathy.

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) benefit from disease-modifying agents such as tafamidis. However, the survival benefit of tafamidis in elderly patients (age ≥80 years) is not reported. This study aimed to assess the survival of patients with ATTR-CM aged 80 years and older who were treated with tafamidis compared with patients aged <80 years. We conducted a retrospective analysis of patients with ATTR-CM who underwent tafamidis treatment, aged 45 to 97 years at the time of diagnosis between January 1, 2008, and May 31, 2021. A total of 484 patients were included, with 208 in the ≥80 years group and 276 in the <80 years group. The cohort was followed up for mortality outcomes, and hazard ratios with 95% confidence intervals were calculated. After a median follow-up of 18.5 months, 72 deaths were recorded in the entire cohort. Kaplan-Meier curves showed no differences in survival probability between the 2 groups at 30 months (p for log-rank test = 0.76). The survival rates for patients aged ≥80 years who underwent treatment at 1, 2, 3, 4, and 5 years were 94.7%, 86.0%, 77.0%, 77.0%, and 38.5%, respectively. The corresponding rates for patients aged <80 years who underwent treatment were 93.2, 84.8, 74.4, 68.2, and 64.6%, respectively. In the multivariable analysis, the hazard ratio (95% confidence interval) of the mortality comparing treatment patients aged ≥80 years with those aged <80 years was 0.81 (0.41 to 1.61). In conclusion, tafamidis treatment is associated with similar reductions in mortality in older and younger patients with ATTR-CM.

Rare c.302C>T TTR Variant Associated with Transthyretin Amyloidosis.

Background and Objectives: Hereditary transthyretin amyloidosis (ATTRv) is a rare disease caused by pathogenic variants in the transthyretin (TTR) gene. More than 140 different disease-causing variants in TTR have been reported. Only a few individuals with a rare TTR variant, c.302C>T, p.(Ala101Val) (historically known as p.(Ala81Val)), primarily associated with cardiac ATTRv, have been described. Therefore, our aim was to analyze the clinical characteristics of individuals with the identified c.302C>T TTR variant at our center. Materials and Methods: We analyzed data from individuals with ATTRv who were diagnosed and treated at Vilnius University Hospital Santaros Klinikos. ATTRv was confirmed by negative hematological analysis for monoclonal protein, positive tissue biopsy or bone scintigraphy and a pathogenic TTR variant. Results: During 2018-2021, the TTR NM_000371.3:c.302C>T, NP_000362.1:p.(Ala101Val) variant was found in one individual in a homozygous state and in three individuals in a heterozygous state. The age of onset of symptoms ranged from 44 to 74 years. The earliest onset of symptoms was in the individual with the homozygous variant. A history of carpal tunnel syndrome was identified in two individuals. On ECG, three individuals had low QRS voltage in limb leads. All individuals had elevated NT-proBNP and hsTroponine I levels on baseline laboratory tests and concentric left ventricular hypertrophy on transthoracic echocardiography. The individual with the homozygous c.302C>T TTR variant had the most pronounced polyneuropathy with tetraparesis. Other patients with the heterozygous variant had more significant amyloid cardiomyopathy. When screening family members, the c.302C>T TTR variant was identified in two phenotypically negative relatives at the ages of 33 and 47 years. Conclusions: c.302C>T is a rare TTR variant associated with ATTRv cardiomyopathy. The homozygous state of this variant was not reported before, and is associated with earlier disease onset and neurological involvement compared to the heterozygote state.

Breakthrough advances enhancing care in ATTR amyloid cardiomyopathy.

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.

Diagnosis and treatment of hereditary transthyretin amyloidosis with polyneuropathy in the United States: Recommendations from a panel of experts.

Hereditary transthyretin (ATTRv; v for variant) amyloidosis is a rare, multisystem, progressive, and fatal disease in which polyneuropathy is a cardinal manifestation. Due to a lack of United States (US)-specific guidance on ATTRv amyloidosis with polyneuropathy, a panel of US-based expert clinicians convened to address identification, monitoring, and treatment of this disease. ATTRv amyloidosis with polyneuropathy should be suspected in unexplained progressive neuropathy, especially if associated with systemic symptoms or family history. The diagnosis is confirmed through genetic testing, biopsy, or cardiac technetium-based scintigraphy. Treatment should be initiated as soon as possible after diagnosis, with gene-silencing therapeutics recommended as a first-line option. Consensus is lacking on what represents "disease progression" during treatment; however, the aggressive natural history of this disease should be considered when evaluating the effectiveness of any therapy.

Simultaneous onset of acute myocardial infarction, bicuspid aortic stenosis, and cardiac transthyretin amyloidosis-A clinically complex confluence.

The coexistence of bicuspid aortic valve disease and coronary artery disease is well-established, but the identification of cardiac amyloidosis in this population has surged with advancing imaging techniques, introducing complexities in patient management. This case report emphasizes the pivotal role of multimodality imaging in accurately diagnosing three concurrent pathologies.

Phenotypic characteristics of F64L, I68L, I107V, and S77Y ATTRv genotypes from the Transthyretin Amyloidosis Outcomes Survey (THAOS).

Transthyretin amyloidosis (ATTR amyloidosis) is a progressive, multi-systemic disease with wild-type (ATTRwt) and hereditary (ATTRv) forms. Over 130 variants associated with ATTRv amyloidosis have been identified, although little is known about the majority of these genotypes. This analysis examined phenotypic characteristics of symptomatic patients with ATTRv amyloidosis enrolled in the Transthyretin Amyloidosis Outcomes Survey (THAOS) with four less frequently reported pathogenic genotypes: F64L (c.250T>C, p.F84L), I68L (c.262A>T, p.I88L), I107V (c.379A>G; p.I127V), and S77Y (c.290C>A; p.S97Y). THAOS is the largest ongoing, global, longitudinal observational study of patients with ATTR amyloidosis, including both ATTRwt and ATTRv amyloidosis. This analysis describes the baseline demographic and clinical characteristics of untreated symptomatic patients with the F64L, I68L, I107V, or S77Y genotypes at enrollment in THAOS (data cutoff date: January 4, 2022). There were 141 symptomatic patients with F64L (n = 46), I68L (n = 45), I107V (n = 21), or S77Y (n = 29) variants at the data cutoff. Most patients were male and median age at enrollment was in the sixth decade for S77Y patients and the seventh decade for the others. A predominantly neurologic phenotype was associated with F64L, I107V, and S77Y genotypes, whereas patients with the I68L genotype presented with more pronounced cardiac involvement. However, a mixed phenotype was also reported in a considerable proportion of patients in each variant subgroup. This analysis from THAOS represents the largest study of ATTRv symptomatic patients with the F64L, I68L, I107V, and S77Y genotypes. These data add to the limited knowledge on the clinical profile of patients with specific ATTRv variants and emphasize the importance of comprehensive assessment of all patients. Trial registration ClinicalTrials.gov: NCT00628745.