Wild-type ATTR Research Articles

TTR gene silencing therapy in post liver transplant hereditary ATTR amyloidosis patients

Objective Patients with hereditary transthyretin (TTR) amyloidosis (hATTR) often experience disease progression after orthotopic liver transplant (POLT) due in part to wild type ATTR amyloid deposition. The management strategy is not defined. We propose that TTR gene silencing with an antisense oligonucleotide or a small interfering ribonucleic acid may be a treatment for these patients. Methods We reviewed the charts of hATTR patients POLT treated with a TTR gene silencing agent at 7 different Amyloid Clinics between 2018–2020. Results Nine hATTR patients with POLT were treated with TTR gene silencing therapy (Inotersen). The median age was 61 years. The median time from OLT to initiation of TTR gene silencing therapy was 7.5 years. The median duration of therapy was 12 months. Neuropathy impairment score remained stable or improved in all patients. Five patients stopped treatment: 3 because of thrombocytopenia, 2 because of reversible liver rejection. Three patients who discontinued treatment subsequently experienced worsening of their neuropathy. Conclusion TTR gene silencing therapy in hATTR patients with POLT could be a treatment option. Vigilant monitoring of renal, liver and bone marrow functions is necessary because of frequent complications. Further studies are needed to determine efficacy.

Cardiac sympathetic denervation in wild-type transthyretin amyloidosis

Background Tissue accumulation of misfolded transthyretin (TTR) may occur because of TTR gene mutations (variant amyloid TTR amyloidosis, ATTRv), or as an age-related phenomenon (wild-type ATTR, ATTRwt). Cardiac sympathetic denervation has been reported in ATTRv, but has never been investigated in ATTRwt. Methods Fifteen consecutive patients with ATTRwt cardiomyopathy (81% men, median age 82 years, no one with prior myocardial infarction) underwent Cadmium Zinc Telluride tomographic imaging for amyloid burden (99mTc-hydroxymethylene diphosphonate – 99mTc-HMDP), innervation (123I-metaiodobenzylguanidine – 123I-MIBG), and perfusion (99mTc-tetrofosmin). Results Median summed 99mTc-HMDP score was 60 (58–62), denoting a severe and diffuse amyloid burden. Planar 123I-MIBG examination showed decreased early and late H/M ratios (late H/M ratio: 1.5 [1.3–1.6], range 1.2–1.9, reference value ≥2.0). Summed 123I-MIBG score was 12 (6–22), with the most prominent denervation in the infero-septal, inferior, and infero-lateral regions; summed rest score was 7 (5–11), with lowest degrees of myocardial perfusion in the inferior and infero-septal regions. The correlation between amyloid burden (as relative 99mTc-HMDP uptake) and innervation (as relative 123I-MIBG uptake) did not achieve statistical significance at both segmental (p = .252) and regional level (p = .251). Nevertheless, denervation tended to worsen in parallel with the amyloid burden, and 123I-MIBG scores increased with 99mTc-HMDP scores. Segments and regions with prominent hypoperfusion also showed a higher degree of denervation (r = 0.500 and 0.591, respectively; both p < .001). Conclusions Patients with ATTRwt cardiomyopathy display cardiac sympathetic denervation, particularly in the inferior and septal myocardial wall. Myocardial hypoperfusion has a similar regional pattern, while the amyloid burden is more extensive.

The Bioequivalence of Tafamidis 61‐mg Free Acid Capsules and Tafamidis Meglumine 4 × 20‐mg Capsules in Healthy Volunteers

Tafamidis, a non‐nonsteroidal anti‐inflammatory benzoxazole derivative, acts as a transthyretin (TTR) stabilizer to slow progression of TTR amyloidosis (ATTR). Tafamidis meglumine, available as 20‐mg capsules, is approved in more than 40 countries worldwide for the treatment of adults with early‐stage symptomatic ATTR polyneuropathy. This agent, administered as an 80‐mg, once‐daily dose (4 × 20‐mg capsules), is approved in the United States, Japan, Canada, and Brazil for the treatment of hereditary and wild‐type ATTR cardiomyopathy in adults. An alternative single solid oral dosage formulation (tafamidis 61‐mg free acid capsules) was developed and introduced for patient convenience (approved in the United States, United Arab Emirates, and European Union). In this single‐center, open‐label, randomized, 2‐period, 2‐sequence, crossover, multiple‐dose phase 1 study, the rate and extent of absorption were compared between tafamidis 61‐mg free acid capsules (test) and tafamidis meglumine 80‐mg (4 × 20‐mg) capsules (reference) after 7 days of repeated oral dosing under fasted conditions in 30 healthy volunteers. Ratios of adjusted geometric means (90%CI) for the test/reference formulations were 102.3 (98.0‐106.8) for area under the concentration‐time profile over the dosing interval and 94.1 (89.1‐99.4) for the maximum observed concentration, satisfying prespecified bioequivalence acceptance criteria (90%CI, 80‐125). Both tafamidis regimens had an acceptable safety/tolerability profile in this population.

PREVALENCE AND CHARACTERISTICS OF WILD TYPE TRANSTHYRETIN AMYLOID CARDIOMYOPATHY IN HOSPITALIZED PATIENTS REFERRED FOR TC-99M PYROPHOSPHATE (PYP) SCAN

Understanding the characteristics of patients with a final diagnosis of wild type ATTR cardiomyopathy (ATTR-CA wt) may help optimally triage patients for Tc-99m PYP scanning. We evaluated hospitalized patients who had a positive PYP scan with no TTR gene mutation and negative serum AL studies (ATTR

Carpal tunnel syndrome in cardiac amyloidosis: implications for early diagnosis and prognostic role across the spectrum of aetiologies

We aimed to assess carpal tunnel syndrome (CTS) prevalence in transthyretin (TTR)-related and light-chain amyloidosis (AL), comparing it to the general population, adjusted for age and gender. In TTR-related amyloidosis (ATTR) we investigated (i) CTS prevalence in relation to genotype, cardiac amyloidosis (CA), age and gender; (ii) CTS role as an incremental risk factor for CA; (iii) temporal relationship between CTS and CA; and (iv) CTS prognostic role. Data from 538 subjects (166 hereditary ATTR, 107 wild-type ATTR, 196 AL amyloidosis, and 69 TTR mutation carriers; 64% male, median age 62.4 years), evaluated at our centre (Bologna, Italy), were analysed and compared to a published cohort of 14.9 million people, in which incidence rates of CTS had been estimated. CTS prevalence was highest in ATTR patients with CA (20.3% vs. 4.1% in the general population), while it was comparable to the general population when CA was absent and in AL patients. CTS standardized incidence rates were markedly elevated in ATTR males in the eighth decade of life (13.08 in hereditary ATTR, 15.5 in wild-type ATTR). The risk of developing CA was greater in ATTR patients with CTS; the probability of having CTS was highest 5-9 years prior to CA diagnosis. CTS was an independent mortality risk factor in ATTR. Compared to general population the adjusted prevalence of CTS is higher among elderly men with ATTR; CTS is a prognostic marker in ATTR, independently of cardiac involvement, and precedes CA diagnosis by 5-9 years. The awareness of this association and time delay offers the possibility of an early pre-clinical ATTR-CA diagnosis.

P825 Multi-modality imaging for noninvasive diagnosis of transthyretin amyloid cardiomyopathy-single centre experience

Abstract Background Thransthyretin amyloidosis (ATTR) is a rare progressive disease that may present as heart failure with preserved ejection fraction, severe aortic stenosis, hypertrophic cardiomyopathy (HCM) or resctrictive cardiomyopathy. There are two types of ATTR: hereditary ATTR (hATTR) caused by mutations in the TTR gene and wild-type ATTR (wtATTR) resulting from deposition of wild-type TTR protein. Purpose We describe the clinical heterogeneity of ATTR patients from our centre diagnosed noninvasively in 2018-2019. Methods All patients presented intensive cardiac uptake at 99mTc-DPD scintigraphy. Light chain amyloidosis was excluded. Results 8 patients were diagnosed with ATTR (Table 1). Three unrelated male patients were diagnosed with hATTR due to rare mutations: 2 of them had Phe33Leu, 1 patient had Glu89Lys mutation. Five patients (males) were diagnosed with wtATTR. Age of onset differed among the patients. Characteristic clinical features included cardiomyopathy with increased left and right ventricular wall thickness. Only 2 patients had restrictive filling pattern, 3 patients had atrial fibrillation. Laboratory examination showed increased level of troponin T and NT-proBNP. Three patients had bilateral carpal tunnel syndrome. Thanks to DPD-scintygraphy we excluded ATTR in two patients with false-positive results of histological exam for TTR-related amyloid deposits. Conclusions Although ATTR is known for its broad clinical spectrum, patients from our center presented mostly as HCM phenocopies but in different stages of heart failure. Appropriate diagnosis of ATTR is crucial and have direct therapeutic impact. Echocardiography raise the suspicion of amyloid cardiomyopathy, while other imaging technique (DPD-scintigraphy) confirm it or exclude it in noninvasive way. Patient 1 2 3 4 5 6 7 8 Mutation Glu89Lys Phe33Leu Phe33Leu wild type wild type wild type wild type wild type Sex male male male male male male male male Age of onset 57 56 55 77 78 80 77 76 Electrocardiogram AF low QRS voltage low QRS voltage AF, RBBB LVH LVH pseudoinfarct pattern, low QRS voltage AF, LVH Maximal wall thickness [mm] 23 20 18 28 22 23 18 20 LVEF% 45 40 40 60 65 60 45 55 Asymmetric hypertrophy pattern + - - - + + - + NYHA III II II II III II II II NT-proBNP pg/ml 2122 1200 1500 2755 222 2630 2426 hs-Troponin T ng/l 50 98 42 65 35 63 64 Abstract P825 Figure 1

Emerging therapies in transthyretin amyloidosis-a new wave of hope after years of stagnancy?

Transthyretin amyloidosis (ATTR) is a rare, yet underdiagnosed disease characterized by progressive impairment of neurologic and cardiac function due to deposition of misfolded transthyretin. Despite great efforts, such as the introduction of orthotopic liver transplant, the devastating prognosis for both variant and wild-type ATTR patients remained unchanged over the last decades, mainly due to a lack of specific therapies. Fortunately, recent years saw the introduction of promising targeted therapies, which aim to interfere with the deposition of misfolded transthyretin (TTR) at various stages of the cascade underlying ATTR progression. These include TTR tetramer stabilizers (tafamidis, diflunisal, epigallocatechin-3-gallate), TTR silencers (inotersen, patisiran) and fibril disruptors (monoclonal antibodies, doxycycline and tauroursodeoxycholic acid). In the context of this review we explain their mechanisms of action, analyse their efficacy on neurologic and cardiac function based on all clinical trials conducted to date and discuss their clinical applicability. Eventually suggestions for future clinical research into the field are provided.

397a Quantitative 99mTc-DPD Scintigraphy Correlation with Structural and Functional Changes on Echocardiography in Transthyretin Amyloidosis

Cardiac involvement portends poor prognosis in transthyretin amyloidosis (ATTR); increase in LV wall thickness and altered LV function are common manifestations. Our aim was to determine the correlation of LV structural (LVH and wall thickness) and functional changes (LVEF and global longitudinal strain (GLS)) on TTE with Technetium-3-3 Diphosono-1-2 propanodicarboxylic acid (99mTc-DPD) scintigraphy uptake. Hereditary and wild-type ATTR patients with TTE and 99mTc-DPD were selected. Offline measurements performed included LV average wall thickness (AWT = IVS+ PW/2), LV mass indexed (LVMI), LVEF and LV GLS. 99mTc-DPD LV uptake intensity was quantified with reference to aortic arch blood pool with custom software in Interactive Data Language (using a cut-off value of >1.1 for positive findings). Spearman rank correlation, Fisher’s Exact test and ROC curves were performed. The study cohort included 40 patients (male 75%, median age 69±22 years) with a median time difference between imaging of 7 days (IQR=100 days). 99mTc-DPD LV uptake >1.1 was evident in 75% of ATTR patients. Increased AWT (r=0.84), LVMI (r=0.80), reduction in GLS (r=0.71) (p<0.001 for all) were great predictors for increased 99mTc-DPD uptake, while reduction in LVEF (r=-0.55, p<0.001) had moderate prediction of increased uptake (Figure 1). Alterations in LV structure (increased LV AWT and LVMI) with reduced LV function in cardiac ATTR were associated with increased 99mTc-DPD uptake. Therefore, TTE could assess for LVH progression or reduction in LV function for longitudinal follow up of ATTR patients.

A novel monoclonal antibody targeting aggregated transthyretin facilitates its removal and functional recovery in an experimental model.

Cardiac amyloidosis typically manifests as heart failure with preserved left ventricular function due to extracellular plaques comprising aggregated TTR. Despite recent success in halting disease progression with a TTR stabilizer and encouraging preliminary findings with TTR silencers, these agents are not targeting preexisting plaques. Herein, we report the development of a novel monoclonal antibody capable of attenuating experimental cardiac amyloidosis. We generated an IgG1 monoclonal antibody against aggregated TTR that immunoprecipitated the protein in the sera of patients with wild-type ATTR (wtATTR) and robustly stained cardiac plaques from patients. The antibody was shown to facilitate aggregated-TTR uptake by various myeloid cells and to protect cardiomyocytes from TTR-inducible toxicity. In a novel in vivo model of wtATTR amyloidosis, the antibody enhanced the disappearance of the pyrophosphate signals attesting for a rapid amyloid deposit removal and degradation and also exhibited improved echocardiographic measures of cardiac performance. Importantly, a capture ELISA developed based on the antibody exhibited higher levels of aggregated TTR in the sera of wtATTR amyloidosis patients as compared to control patients with heart failure suggesting a potential applicability in diagnosis and pharmacodynamic guidance of dosing. We developed a proprietary antibody targeting aggregated TTR that exhibits beneficial effects in a novel experimental wtATTR model and also possesses a potential diagnostic utility. The antibody could potentially be tested as a disease modifying agent in ATTR amyloidosis.

Stabilization of Cardiac Function With Diflunisal in Transthyretin (ATTR) Cardiac Amyloidosis

Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an underappreciated cause of heart failure that results from misfolded TTR (prealbumin) protein. Diflunisal is an approved non-steroidal anti-inflammatory drug that stabilizes TTR, with limited data available regarding effects on cardiac structure and function. ATTR-CM patients (n=81, 41% treated with 250 mg twice-daily diflunisal by clinical practice) were retrospectively identified with baselineand follow-up (median interval 1 year) serum biomarker andechocardiographic data compared, including global longitudinal strain (GLS). Chi-squared and Wilcoxon tests assessed differences between subjects, divided by treatmentgroup, and univariable and multivariable linear regression was performed. At baseline, patients treated with diflunisal were younger (68 vs 77 years, P = .0001), with lower B-type natriuretic peptide (BNP; 249 vs 545 pg/mL, P = .009) and serum creatinine (1.1 vs 1.2 mg/dL, P = .04), but similar TTR concentration (P = .31), cardiac troponin I (P = .06), and GLS (P = .67). At follow-up, diflunisal untreated versus treated patients showed differences in TTR concentration (19 vs 33 mg/dL, P = .01) and favorable differences in left atrial volume index (+4.6 vs -1.4 mL/m2, P = .002) and cardiac troponin I (+0.03 vs -0.01 ng/mL, P = .01) for the entire cohort. Among the subset with wild-type ATTR (n=53), diflunisal treatment was associated with differences in GLS (+1.2% untreated vs +0.1% treated, P = .03). Changes in wall thickness (P = .2), left ventricular ejection fraction (P = .71), and BNP (P = .42) were similar between groups. In ATTR-CM, diflunisal treatment resulted in measurable differences in some parameters of cardiac structure and function after only 1 year of administration. Further longer-term analysis is warranted.

Wild-type ATTR amyloidosis may be associated with unexpected death among the elderly.

Wild-type ATTR amyloidosis (ATTR-wt) is characterized by the accumulation of amyloid in the heart, leading to fatal heart failure and arrhythmia. In this study, we investigated the amyloid deposits in the heart from 556 forensic autopsy cases over 60 years of age. The prevalence of ATTR-wt was 5.8% (32 of the 556), with the prevalence increasing as a function of age. We identified an ATTR-wt-specific morbidity rate of 12.3% for patients over 80 years of age, while the prevalence among individuals over 90 years of age was 34.9%. In none of these 32 cases had a clinical diagnosis of ATTR-wt been made. In 29 of the 32 cases found to be ATTR-wt positive, an obvious extraneous cause of death was identified and included burning, drowning, hypothermia, suicide, and traffic accident. On the other hand, heart failure due to ATTR-wt was confirmed as the cause of death in 3 of the 32 cases. It is suggested that ATTR-wt may be associated with unexpected death among the elderly.

P336A descriptive analysis of patients with wild-type ATTR cardiomyopathy from the transthyretin amyloidosis outcomes survey

Abstract Introduction Transthyretin amyloidosis (ATTR amyloidosis) is a rare, life-threatening disorder caused by the deposition of amyloid fibrils composed of misfolded transthyretin (TTR). ATTR amyloidosis may arise from mutations in TTR or from aggregation of wild-type TTR (ATTRwt). ATTR amyloidosis with predominantly symptoms of cardiomyopathy (ATTR-CM) includes both hereditary and wild-type forms of the disease. Purpose To describe clinical history and disease presentation in a large population of patients with wild-type ATTR-CM from the Transthyretin Amyloidosis Outcomes Survey (THAOS). THAOS is an ongoing, global, longitudinal, observational survey of patients with ATTR amyloidosis, including both inherited and wild-type disease, and asymptomatic patients with TTR mutations. Methods Data from ATTRwt patients were extracted from THAOS (cut-off date: January 16, 2019) and demographic and clinical characteristics reported using descriptive statistics. Results There were 758 ATTRwt patients in THAOS (95% male). The majority of patients (69.3%) were in the United States, with the remainder in Italy (11.1%), Germany (7.3%), Spain (5.3%), and other countries (7.1%). Most patients (86.3%) were Caucasian, with 3.3% being of African Descent and 3.1% being of other races/ethnicities (7.4% missing data). The median (10–90th percentile) age at symptom onset was 69.7 (54.0–81.3) years and the median (10–90th percentile) time from symptom onset to diagnosis was 3.9 (0.1–17.8) years. Median (10–90th percentile) age at enrollment in THAOS was 76.4 (67.2–85.2) years. Nearly all subjects had either a cardiac (59.6%) or mixed cardiac and neurologic (36.5%) phenotype. At enrollment, 97.1% (577 of 594 patients assessed) had an abnormal ECG, with the prevalence of low voltage being 20.8% (115 of 552) and prevalence of left-ventricular hypertrophy being 2.1% (16 of 758). Atrial fibrillation was documented in 55% of patients (208 of 378). The mean (standard deviation [SD]) left-ventricular septum thickness was 17.5 (3.5) mm (n=505; 94.9% with thickness &gt;12 mm) and mean (SD) left-ventricular ejection fraction (LVEF) was 48.3% (13.2) (n=511; 48.0% with LVEF &lt;50.0%). Other signs and symptoms at enrollment were compatible with a sensory neuropathy in 54.2% of patients, autonomic neuropathy in 33.5% of patients, and motor neuropathy in 29.1% of patients. Gastrointestinal symptoms related to ATTR amyloidosis were present in 10.4% of patients. Conclusions Although patients with wild-type ATTR-CM tend to be older Caucasian men with a mostly cardiac disease phenotype, the clinical spectrum of ATTRwt is heterogeneous and differs from the classic phenotype. Our findings show that ATTRwt should not be considered an exclusively cardiac disease and there is a need for both cardiologic and neurologic assessment of these patients. Further study is needed to determine if the non-cardiac manifestations are due to amyloidosis or more common causes in this older population. Acknowledgement/Funding This study was sponsored by Pfizer.

Phase 1 Investigation of a Ligand-Conjugated Antisense Oligonucleotide with Increased Potency for the Treatment of Transthyretin Amyloidosis

Introduction Hereditary transthyretin amyloidosis (hATTR) is a rare, progressive fatal disease caused by pathogenic variants in the transthyretin (TTR) gene that destabilize the normal tetrameric structure of the TTR oligomers leading to formation of insoluble, extracellular amyloid deposits in multiple organ systems. hATTR patients predominantly develop neuropathy and/or cardiomyopathy. Wild-type TTR can also form amyloid deposits, leading to congestive heart failure. Inotersen is an antisense oligonucleotide (ASO) that inhibits production of both variant and wild-type TTR protein by degradation of the TTR messenger RNA. Inotersen is approved for the treatment of hATTR patients with polyneuropathy. AKCEA-TTR-LRx (ION-682884), an ASO of similar design and sequence, is conjugated to a ligand for selective, receptor-mediated delivery to hepatocytes, the principal source of systemically circulating TTR. This delivery approach has yielded a 20 to 30-fold increase in potency and improved the safety and tolerability profiles of ASOs in human clinical trials. In preclinical studies, AKCEA-TTR-LRx produced significant dose-dependent reductions of TTR messenger RNA and protein levels, with a marked increase in potency compared to inotersen. AKCEA-TTR-LRx is currently in early phase development for the treatment of both hereditary and wild-type ATTR. Hypothesis Based on prior clinical experience with ligand-conjugated ASOs and supporting preclinical results, AKCEA-TTR-LRx is expected to have an increased potency and improved tolerability and safety profile compared to inotersen. Methods A phase 1/2 study was designed to evaluate AKCEA-TTR-LRx in healthy volunteers and patients with transthyretin-mediated amyloidosis (NCT03728634). In phase 1, eligible subjects were assigned to one of two multiple-dose cohorts (45 and 90 mg, n=12 per cohort) and randomized 10:2 (active:placebo) to receive 4, once monthly, SC doses of study drug. A higher, single-dose cohort of healthy volunteers was also evaluated. Results This study is ongoing. Assessment of the safety, tolerability, pharmacokinetics and pharmacodynamics of AKCEA-TTR-LRx in the phase 1 healthy volunteer cohorts will be presented. Conclusions These phase 1 results will guide selection of the dose and treatment schedule for near-term studies to be initiated in patients with ATTR, including phase 3 studies.

Advances in the treatment of hereditary transthyretin amyloidosis: A review.

IntroductionAmyloid transthyretin amyloidosis (ATTR) is a progressive and often fatal disease caused by the buildup of mutated (hereditary ATTR [hATTR]; also known as ATTR variant [ATTRv]) or normal transthyretin (wild‐type ATTR) throughout the body. Two new therapies—inotersen, an antisense oligonucleotide therapy, and patisiran, an RNA interference therapy—received marketing authorization and represent a significant advance in the treatment of amyloidosis. Herein, we describe the clinical presentation of ATTR, commonly used procedures in its diagnosis, and current treatment landscape for ATTR, with a focus on hATTR.MethodsA PubMed search from 2008 to September 2018 was conducted to review the literature on ATTR.ResultsUntil recently, there have been few treatment options for polyneuropathy of hATTR. Inotersen and patisiran substantially reduce the amyloidogenic precursor protein transthyretin and have demonstrated efficacy in patients with early‐ and late‐stage disease and in slowing or improving neuropathy progression. In contrast, established therapies, such as liver transplantation, typically reserved for patients with early‐stage disease, and tafamidis, indicated for the treatment of early‐stage disease in Europe, or diflunisal, a nonsteroidal anti‐inflammatory drug that is used off‐label, are associated with side effects and/or unclear efficacy in certain patient populations. Thus, inotersen and patisiran are positioned to be the preferred therapeutic modalities.ConclusionsImportant differences between inotersen and patisiran, including formulation, dosing, requirements for premedications, and safety monitoring, require an understanding and knowledge of each treatment for informed decision making.

Prevalence of Cardiac Amyloidosis in Patients with Carpal Tunnel Syndrome.

Carpal tunnel syndrome (CTS) is a common finding among patients with cardiac amyloidosis. We sought to determine the prevalence of cardiac amyloidosis in patients who had undergone CTS surgery. From 2005 to 2014, 308 patients ≥ 60years underwent CTS surgery. Of these, 233 (76%) agreed to participate in the study and 101 (73 ± 8years; 68% females) showed left ventricular hypertrophy (LVH) ≥ 12mm and underwent additional studies to diagnose AL and ATTR amyloidosis. Based on complementary studies, three patients were diagnosed with cardiac amyloidosis (two wild-type ATTR and one AL). The three patients showed bilateral CTS with no occupational risk factors. Prevalence of cardiac amyloidosis in the overall cohort was only 1.2% (3/233), but among patients with LVH and bilateral CTS, the prevalence was 5.5% (3/55) and 13.6% (3/22) if cases with an occupational risk factor were excluded. Cardiac amyloidosis should be excluded in the presence of bilateral CTS and particularly if an occupational risk factor is absent.

Prevalence of cardiac amyloidosis among elderly patients with systolic heart failure or conduction disorders

Objective: Cardiac amyloid infiltration can lead to systolic heart failure (HF) or to conduction disorders (CD). Patients with transthyretin (ATTR) amyloidosis are particularly exposed. We sought to determine the prevalence of ATTR and AL among patients >60 years admitted with CD or unexplained systolic HF and increased wall thickness.Materials and Methods: We studied 143 patients (57% males, 79 ± 9 years) with HF (N = 28) or CD requiring pacemaker implantation (N = 115). In total, 139 (97%) patients (28 with HF and 111 with CD) underwent 99mTc-DPD scintigraphy to detect ATTR, and 105 (73%; 19 HF and 86 CD) underwent AL screening.Results: Five patients (4%; 95%CI:0–7%) exhibited wild-type ATTR (ATTRwt) amyloidosis, 2 (2%; 95%CI:0–4%) had CD and 3 (11%; 95%CI:0–23%) HF. No patient showed AL. The 2 ATTRwt patients with CD were previously asymptomatic, did not show classical ECG signs and exhibited mild LV hypertrophy with preserved LVEF. By contrast, all ATTRwt patients with HF had ECG and echocardiographic signs of amyloid. During a mean follow-up of 18 ± 11 months, 3(60%) patients with ATTRwt amyloidosis (1 CD and 2 HF) and 14(10.4%) without died.Conclusion: Prevalence of ATTRwt amyloidosis in patients with CD requiring pacemaker is low. Although, additional studies are needed, prevalence seems to be higher in elderly patients with systolic HF.

Atrial fibrillation and subtype of atrial fibrillation in cardiac amyloidosis: clinical and echocardiographic features, impact on mortality

Background: Atrial fibrillation (AF) commonly affects patients with cardiac amyloidosis (CA). Amyloid deposition within the left atrium may be responsible for the subtype of AF in either permanent or non-permanent form. The prognostic implications of AF and its clinical subtype according to the type of CA are still controversial in this population. This study sought to investigate the prevalence, incidence and prognostic implications of AF and the clinical subtype of AF (permanent or non-permanent) in patients with CA.Methods: Two hundred and thirty-eight patients with CA and full medical records were retrospectively enrolled in the study: About 115 (48%) with light chain (AL) amyloidosis and 123 (52%) with transthyretin amyloidosis (ATTR). Patient’s medical records were reviewed to establish baseline prevalence, incidence and impact on all-cause and cardiovascular mortality during follow-up of AF.Results: One hundred and four (44%) patients had history of AF at the time of diagnosis: 62 (60%) permanent and 42 (40%) non-permanent. There were 30 (26%) and 74 (60%) patients with history of AF among patients with AL and ATTR (including 5 hereditary and 69 wild-type), respectively (p<.0001). During the follow-up, 48 new patients developed AF (29, 12 and 7 among patients with AL, wild-type ATTR and hereditary ATTR). After adjustment for age, survival was similar in patients with or without history of AF (HR 0.87 (95% CI, 0.60 to 1.27; p = .467). AF had no impact on cardiovascular mortality. Among the 152 patients with history of AF included in the whole study, there were 75 (49%) patients with permanent AF. After adjustment for age, survival was similar in patients with permanent and non-permanent AF: HR 1.29 (95% CI, 0.84 to 1.99; p = .251). The results were the same among patients with AL or wild-type amyloidosis. Subtype of AF had no impact on cardiovascular mortality.Conclusions: AF is common in patients with CA. However, AF and clinical subtype of AF have no impact on all-cause mortality, whatever the type of amyloidosis.

Analysis of NT-proBNP Baseline Levels in APOLLO as a Predictor of Survival in Hereditary Transthyretin-mediated (hATTR) Amyloidosis

Hereditary transthretin amyloidosisis (hATTR) is a multisystemic, fatal disease resulting TTR amyloid deposition. Clinical manifestations include neuropathy as well as cardiomyopathy, a major cause of death. NT-proBNP, cardiac biomarker, has shown prognostic value in cardiac diseases clinically validated. For hATTR and wild-type ATTR, survival in patients with NT-proBNP levels > 3000 ng/L was linked with poorer survival. APOLLO, phase 3, randomized (2:1), double-blind study of patisiran 0.3 mg/kg or placebo IV q3 W in patients with hATTR with polyneuropathy. Fifty-six% of patients had cardiac involvement defined by prespecified criteria: left ventricular (LV) wall thickness ≥ 13 mm and absence of aortic valve disease or hypertension. n = 225: mean age 61 years, 57% non-V30 M mutation, NT-proBNP median 756.4 ng/L. To assess the prognostic significance of baseline factors on survival, a Cox regression analyses were conducted. NT-proBNP was evaluated as a continuous variable following logarithmic transformation as well as a binary variable using a cut off value of 3000 ng/mL. Median survival follow-up duration was 18.7 months. 13 deaths not related to the treatment, 6 (8%) PB0 arm and 7 (5%) in patisiran arm. NT-proBNP was the key significant factor predictive of survival based on univariate and multivariate analyses. The risk of death increased with higher baseline NT-proBNP (hazard ratio = 2.9) [95% CI: 1.8, 4.8, P -value = 8.7 × 10–7] per unit increment in log(NT–proBNP). Patients with NT-proBNP > 3000 ng/L ( n = 29) had a 19.3-fold [95% CI 5.9, 62.8, p -value = 8.7 × 10–7] increased risk for mortality compared with those below 3000 ng/L ( n = 196). Based on the data from APOLLO, baseline NT-proBNP serum levels in hATTR patients are predictive of survival. These data underscore the importance of diagnosing and treating patients early in the course of the disease.

When and how do patients with cardiac amyloidosis die?

BackgroundCardiac amyloidosis (CA) is an underappreciated cause of morbidity and mortality. Light-chain (AL) and transthyretin (ATTR) amyloidosis have different disease trajectories. No data are available on subtype-specific modes of death (MOD) in patients with CA.Methods and resultsWe retrospectively investigated 66 with AL and 48 with wild-type ATTR amyloidosis (ATTRwt) from 2000 to 2018. ATTRwt differed from AL by age (74.6 ± 5.4 years vs. 63 ± 10.8 years), posterior wall thickness (16.8 ± 3.3 mm vs. 14.3 ± 2.2 mm), left ventricular mass index (180.7 ± 63.2 g/m2 vs. 133.5 ± 42.2 g/m2), and the proportions of male gender (91.7% vs. 59.1%), atrial enlargement (92% vs. 68.2%) and atrial fibrillation (50% vs. 12.1%). In AL NYHA Functional Class and proteinuria (72.7% vs. 39.6%) were greater; mean arterial pressure (84.4 ± 13.5 mmHg vs. 90.0 ± 11.3 mmHg) was lower. Unadjusted 5-year mortality rate was 65% in AL-CA vs. 44% in the ATTRwt group. Individuals with AL-CA were 2.28 times ([95%CI 1.27–4.10]; p = 0.006) more likely to die than were individuals with ATTRwt-CA. Information on MOD was available in 56 (94.9%) of 59 deceased patients. MOD was cardiovascular in 40 (66.8%) and non-cardiovascular in 16 (27.1%) patients. Cardiovascular [28 (68.3%) vs. 13 (80%)] death events were distributed equally between AL and ATTRwt (p = 0.51).ConclusionOur data indicate no differences in MOD between patients with AL and ATTRwt cardiac amyloidosis despite significant differences in clinical presentation and disease progression. Cardiovascular events account for more than two-thirds of fatal casualties in both groups.Graphic abstract

Transthyretin cardiac amyloidosis in continental Western Europe: an insight through the Transthyretin Amyloidosis Outcomes Survey (THAOS).

AimsTransthyretin amyloidosis (ATTR amyloidosis) is a heterogeneous disorder with cardiac, neurologic, and mixed phenotypes. We describe the phenotypic and genotypic profiles of this disease in continental Western Europe as it appears from the Transthyretin Amyloidosis Survey (THAOS).Methods and resultsTHAOS is an ongoing, worldwide, longitudinal, observational survey established to study differences in presentation, diagnosis, and natural history in ATTR amyloidosis subjects. At data cut-off, 1411 symptomatic subjects from nine continental Western European countries were enrolled in THAOS [1286 hereditary (ATTRm) amyloidosis; 125 wild-type ATTR (ATTRwt) amyloidosis]. Genotypes and phenotypes varied notably by country. Four mutations (Val122Ile, Leu111Met, Thr60Ala, and Ile68Leu), and ATTRwt, were associated with a mainly cardiac phenotype showing symmetric left ventricular (LV) hypertrophy, normal diastolic LV dimensions and volume, and mildly depressed LV ejection fraction (LVEF). Morphologic and functional abnormalities on echocardiogram were significantly more severe in subjects with cardiac (n‘= 210), compared with a mixed (n = 298), phenotype: higher median (Q1–Q3) interventricular septal thickness [18 (16–21) vs. 16 (13–20) mm; P = 0.0006]; and more frequent incidence of LVEF <50% (38.1 vs. 17.5%; P = 0.0008). Subjects with cardiac mutations or ATTRwt (or cardiac or mixed phenotype) had a lower survival rate than subjects in other genotype (or the neurologic phenotype) categories (P < 0.0001, for both).ConclusionATTR amyloidosis genotypes and phenotypes are highly heterogeneous in continental Western Europe. A geographic map of the different disease profiles and awareness that a subset of subjects have a dominant cardiac phenotype, mimicking hypertrophic cardiomyopathy, at presentation can facilitate the clinical recognition of this underdiagnosed disease.Trial registrationClinicalTrials.gov: NCT00628745.