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Background Transthyretin amyloid cardiomyopathy (ATTR‐CM) has a specific pathophysiology, with myocardial stiffening and systolic dysfunction only in advanced stages. We aimed to investigate the response to cardiac resynchronization therapy (CRT) in ATTR‐CM compared with heart failure. Methods In this multicenter, observational study, patients with ATTR‐CM receiving CRT (n=101) were matched to patients without amyloid cardiomyopathy by sex, age, and implantation type (CRT with versus without defibrillator versus conduction system pacing, upgrade versus first implant). We evaluated changes in QRS duration and echocardiographic parameters following CRT implantation and at the most recent available assessments. The study end points were all‐cause death alone or combined with heart failure hospitalization. Results Patients with ATTR‐CM (median age, 76 [interquartile range, 72–83] years, 98% men, left ventricular (LV) ejection fraction 30% [26–33]) showed greater QRS shortening after CRT implantation ( P =0.012), but not after a median of around 1 year ( P =0.152). There were no significant differences in the absolute LV ejection fraction changes immediately after implantation (+7 [+2/+10] versus +3 [0/+9] units; P =0.124), or to the last echo ( P =0.796), which was performed after 1.3 years in patients with ATTR‐CM and 2.9 years in patients without amyloid cardiomyopathy. Patients with ATTR‐CM had a shorter survival than controls ( P <0.001 for both end points). Patients with ATTR‐CM experiencing an early improvement in LV ejection fraction had a longer survival (log‐rank, 4.3; P =0.038). Conclusions Following CRT implantation, patients with ATTR‐CM show QRS narrowing and improvement in LV ejection fraction, not different from patients without amyloid cardiomyopathy. Early favorable LV remodeling seems to be associated with a lower risk of all‐cause death.

BACKGROUND: Transthyretin amyloidosis with cardiomyopathy is a progressive disease caused by the deposition of transthyretin (TTR) as amyloid in the myocardium. Current therapies may slow disease progression but do not clear existing deposits. Coramitug is a humanized monoclonal antibody that targets misfolded transthyretin, designed to promote clearance of transthyretin amyloid through antibody-mediated phagocytosis. METHODS: This phase 2, double-blind, placebo-controlled trial randomized participants with transthyretin amyloidosis with cardiomyopathy to receive infusions every 4 weeks of either coramitug at 2 dosages (10 mg/kg or 60 mg/kg) or placebo in a 1:1:1 ratio for 52 weeks. The primary end points were the change from baseline to week 52 in the 6-minute walk test and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels. Safety was assessed for up to 64 weeks by assessing treatment-emergent adverse events, all-cause mortality, and number of cardiovascular events (comprising hospitalization caused by cardiovascular events or urgent heart failure visits). RESULTS: In total, 104 participants (median age, 77 years; 93% men; 84% New York Heart Association class II; 13% with variant transthyretin amyloidosis with cardiomyopathy) were randomized and dosed: 34 to 10 mg/kg of coramitug, 35 to 60 mg/kg of coramitug, and 35 to placebo. Median NT-proBNP was 1985 pg/mL (interquartile range, 1224, 3406). In total, 90% of participants were receiving disease-modifying therapy; 84% were treated with tafamidis and 7 (6.7%) with transthyretin silencers (patisiran, n=4; vutrisiran, n=3). From baseline to week 52, 60 mg/kg of coramitug significantly reduced NT-proBNP levels compared with placebo (–48% [95% CI, –65% to –22%]; P =0.0017). The change in 6-minute walk test from baseline to week 52 was not statistically different from placebo with either dose. Coramitug (60 mg/kg) was associated with improved functional echocardiographic parameters and was well tolerated. CONCLUSIONS: This phase 2 trial showed that coramitug, an antibody targeting misfolded transthyretin in transthyretin amyloidosis with cardiomyopathy, was well tolerated and, at a dose of 60 mg/kg, resulted in a statistically significant reduction in NT-proBNP, a validated marker of disease progression, with no statistically significant effect on 6-minute walk test within 52 weeks. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05442047.

Importance Transthyretin amyloid cardiomyopathy (ATTR-CM), a progressive disease caused by misfolded transthyretin (TTR), occurs as wild-type (ATTRwt-CM) or variant (ATTRv-CM) forms. p.Val142Ile is the most common variant in the US, linked to rapid progression and increased mortality. Acoramidis achieves near-complete (≥90%) TTR stabilization and showed clinical benefit in the 30-month ATTRibute-CM trial and through month 42 in the ongoing open-label extension (OLE). Objective To evaluate the efficacy of acoramidis in ATTRwt-CM, ATTRv-CM, and variant subgroups (p.Val142Ile and non-p.Val142Ile). Design, Setting, and Participants This international, multicenter, phase 3, randomized placebo-controlled study took place from April 2019 to May 2023 with ongoing OLE (month 42). ATTRibute-CM enrolled 632 participants with ATTR-CM; 611 of 632 were included in the modified intention-to-treat (mITT) population. There were 380 participants who continued into the OLE. These data were analyzed from January 2025 to July 2025. Interventions Oral acoramidis, 712 mg, or placebo twice daily for 30 months, followed by 12 months of open-label treatment. Main Outcomes and Measures All-cause mortality (ACM), cardiovascular-related hospitalizations (CVH), serum TTR, 6-minute walk distance, Kansas City Cardiomyopathy Questionnaire Overall Summary score, and N-terminal pro B-type natriuretic peptide in participants with ATTRwt-CM and ATTRv-CM. Post-hoc analyses were conducted in variant subgroups, including p.Val142Ile. Results Overall, 552 participants with wild-type ATTR-CM (mean [SD] age, 78 [6.3] years; 92.0% male and 8.0% female) and 59 participants with variant ATTR-CM (mean [SD] age, 73 [7.7] years; 77.3% male and 22.7% female) were randomized (mITT population), including 35 with p.Val142Ile. Consistent efficacy was observed in wild-type and variant subgroups for ACM/CVH through month 30 and ACM through month 42. At month 30, acoramidis reduced the risk of ACM/first CVH vs placebo by 31% in ATTRwt-CM (hazard ratio [HR], 0.69; 95% CI, 0.52-0.90; P = .007) and by 59% in ATTRv-CM (HR, 0.41; 95% CI, 0.21-0.81; P = .01). ACM was reduced through month 42 with HRs of 0.70 (95% CI, 0.50-0.98; P = .04) and 0.41 (95% CI, 0.19-0.93; P = .03) in the ATTRwt-CM and ATTRv-CM groups, respectively. Consistent treatment benefit was observed in participants with ATTRwt-CM and ATTRv-CM for secondary end points. Within variant subgroups (p.Val142Ile vs non-p.Val142Ile), consistent treatment benefits were observed for ACM/CVH through month 30 and ACM through month 42. Conclusions and Relevance The beneficial effect of acoramidis was observed consistently in ATTRwt-CM and ATTRv-CM groups. These hypothesis-generating results indicate that further studies are warranted to better characterize the therapeutic benefit of acoramidis in variant subgroups. Trial Registration ClinicalTrials.gov Identifiers: NCT03860935 ; NCT04988386

Background: Atrial fibrillation (AF) significantly impacts quality of life (QoL) and is often observed in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). Acoramidis achieves near-complete (≥90%) transthyretin (TTR) stabilization and is approved in the USA, the UK, Europe and Japan for the treatment of ATTR-CM in adults. In the phase 3 ATTRibute-CM study (NCT03860935), acoramidis treatment significantly reduced the time to all-cause mortality (ACM) or first cardiovascular-related hospitalization (CVH) at Month 30, and resulted in improved 6-minute walk distance (6MWD), Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS) scores and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels relative to placebo. The clinical efficacy of acoramidis has not yet been reported in patients with ATTR-CM and with an AF or atrial flutter (AFL) diagnosis at baseline. Research Question: How does acoramidis treatment affect ACM or first CVH, 6MWD, KCCQ-OS scores, and NT-proBNP levels at Month 30 in participants with ATTR-CM with or without AF/AFL diagnosis at baseline? Methods: The ATTRibute-CM study design has been previously published. This post hoc analysis included participants in the modified intention-to-treat population (N=611) grouped by AF/AFL diagnosis at baseline (defined as recorded AF medical history or the presence of AF or AFL on an ECG at enrollment). The rate of ACM or first CVH at Month 30 was compared between groups using a stratified Cox proportional hazards model. Changes from baseline to Month 30 in 6MWD, KCCQ-OS scores and NT-proBNP levels were summarized descriptively. Results: Overall, 62.8% (384/611) of participants had an AF/AFL diagnosis at baseline (acoramidis: 255/409, placebo: 129/202). These participants had lower mean 6MWD and KCCQ-OS scores and higher median NT-proBNP levels than those without AF/AFL diagnosis at baseline. Treatment with acoramidis reduced ACM or first CVH, slowed the decline in 6MWD and KCCQ-OS scores and blunted the rise in NT-proBNP compared with placebo, regardless of AF/AFL diagnosis at baseline ( Table ). Conclusions: Acoramidis improved clinical outcomes (ACM, CVH), functional status, QoL and NT-proBNP levels relative to placebo in participants with ATTR-CM, regardless of AF/AFL diagnosis at baseline.

Introduction: Transthyretin (TTR) amyloid cardiomyopathy (ATTR-CM) arises from amyloidogenic aggregates of destabilized TTR protein in variant (ATTRv-CM) or acquired wild-type TTR (ATTRwt-CM). The p.V142I (V122I) variant is the most common pathogenic TTR allele in the USA and has higher mortality vs wild type. Acoramidis, an oral TTR stabilizer achieving ≥90% stabilization, is approved in USA, UK, Europe, and Japan for treating ATTR-CM in adults. In ATTRibute-CM (NCT03860935), acoramidis showed a reduction in all-cause mortality (ACM) or first cardiovascular-related hospitalization (CVH) vs placebo (PBO), with consistent benefit in ATTRwt-CM and ATTRv-CM (all variants). We report clinical outcomes in participants with p.V142I ATTRv-CM. Research Question: What was the efficacy of acoramidis for clinical outcomes (ACM, CVH) in participants with p.V142I ATTRv-CM in ATTRibute-CM? Methods: In ATTRibute-CM, 632 participants were randomized 2:1 to receive acoramidis HCl 800 mg or PBO twice daily for 30 months. All participants enrolled in open-label extension (OLE) received acoramidis only. Exploratory post hoc analyses were done in the p.V142I ATTRv-CM subgroup. Time-to-event analyses used a stratified Cox proportional hazards model using treatment group as an explanatory factor and baseline 6MWD as a covariate, stratified by randomization factors: serum NT-proBNP and eGFR. ACM was analyzed at Month 42 (ATTRibute-CM 30 months + 12 months OLE). Results: Of the 59 patients with ATTRv-CM reported at randomization, 35 (59.3%) had p.V142I (23 acoramidis, 12 PBO) with comparable baseline characteristics; 4 were homozygous for p.V142I (1 acoramidis, 3 PBO). Through Month 30, ACM/first CVH occurred in 43.5% (10/23) of acoramidis vs 83.3% (10/12) in PBO (HR 0.311; 95% CI 0.120–0.805; Figure 1 ). Through Month 42, ACM occurred in 26.1% (6/23) of continuous acoramidis vs 66.7% (8/12) in PBO to acoramidis (HR 0.307; 95% CI 0.097–0.973; Figure 2 ). Conclusions: In participants with p.V142I ATTRv-CM, acoramidis use was associated with 69% risk reduction in ACM/first CVH through Month 30 and ACM through Month 42 vs PBO. This is the first report of clinical benefit of this magnitude observed in this high-risk population. These findings have biologic plausibility and may reflect the near-complete stabilization observed experimentally with acoramidis in p.V142I ATTR fibrils. These observations require confirmation in larger cohort studies.

Introduction: Patients with variant transthyretin (TTR) amyloid cardiomyopathy (ATTRv-CM) experience early onset disease, rapid progression, and poor outcomes due to amyloid aggregated from destabilized tetrameric TTR. Acoramidis, a highly selective, oral TTR stabilizer, achieves ≥90% TTR stabilization and is approved in the USA, EU, Japan, and UK for adults with wild-type (ATTRwt-CM) or ATTRv-CM. In the phase 3 ATTRibute-CM study and its open-label extension (OLE), acoramidis reduced both the risk of all-cause mortality (ACM) or first cardiovascular-related hospitalization (CVH) through Month 30 and risk of ACM through Month 42 by 36%. Research Question: Is acoramidis efficacy in ATTRv-CM consistent with that observed in the overall ATTRibute-CM population? Methods: In ATTRibute-CM, participants with ATTR-CM were randomized 2:1 to acoramidis HCl 800 mg or PBO, twice daily (BID) for 30 months. After Month 30, all participants enrolled in the OLE received acoramidis HCl 800 mg BID. Genotype (ATTRwt-CM or ATTRv-CM) was captured at randomization; efficacy was analyzed separately in ATTRv-CM. Time-to-event analyses used a stratified Cox model with terms for treatment, baseline 6MWT, genotype, genotype×treatment interaction, stratified by randomization NT-proBNP and eGFR levels. ACM was analyzed at Month 42 (ATTRibute-CM 30 months + OLE 12 months). Results: The ATTRv-CM group comprised 59 patients (39 acoramidis, 20 PBO). Baseline characteristics were mostly similar in both groups ( Table ). The three most common variants reported were p.V142I (n=35), p.I88L (n=7), and p.T80A (n=5). Compared with PBO, acoramidis reduced the risk of ACM/first CVH through Month 30 by 59% (acoramidis, 46.2%; PBO, 75.0%; HR 0.41; 95% CI 0.21–0.81; P =0.011; Fig 1 ) and ACM through Month 42 by 59% (continuous acoramidis, 30.8%; PBO to acoramidis, 60.0%; HR 0.41; 95% CI 0.19–0.93; P =0.032; Fig 2 ) , with Kaplan–Meier curves separating at Months 5 and 10, respectively. Conclusions: In ATTRibute-CM, acoramidis use was associated with clinical benefit in the ATTRv-CM group as demonstrated by a 59% risk reduction in both ACM/first CVH at Month 30, and ACM at Month 42 compared to PBO. These previously unreported findings support the hypothesis that near complete TTR stabilization observed experimentally with acoramidis across multiple TTR mutations translates into improvement in long-term outcomes. Further validation by individual TTR variant is warranted.

Introduction: Diastolic dysfunction is a hallmark of heart failure with preserved ejection fraction, yet echocardiographic grading is challenging in patients with hypertrophic or amyloid cardiomyopathies due to variable structural and functional remodeling. Consequently, there is a need for additional diagnostic tools to identify patients at increased risk of diastolic dysfunction and enhanced filling pressure. Research Question: What is the accuracy of an artificial intelligence (AI)-enabled electrocardiogram (ECG) model to predict diastolic dysfunction in hypertrophic and amyloid cardiomyopathy? Methods: We included patients with diverse phenotypes of hypertrophic cardiomyopathy (HCM) and cardiac amyloidosis and validated Mayo Clinic's AI-enabled ECG model to grade diastolic function (normal: grade 0/1; abnormal: grade 2/3). Echocardiographic analysis of systolic (LVEF) and diastolic function was performed within 14 days of ECG recording. Diastolic function was graded based on E/e’ (>14), left atrial volume index (>34 mL/m2), pulmonary venous atrial reversal flow duration (≥30 ms), and peak tricuspid regurgitation velocity (>2.8 m/s). Filling pressure was considered increased if ≥3 parameters were abnormal, inconclusive if 2 were abnomal, and normal if ≥3 were normal. Echocardiograms with severe mitral regurgitation were excluded. Results: We identified and matched 840 ECGs from non-obstructive HCM patients (n=125, age 58±19y, 70% male), 145 ECGs from obstructive HCM patients (n=29, age 56±18y, 66% male), 225 ECGs from apical HCM patients (n=33, age 66±14y, 61% male), and 382 ECGs from cardiac amyloidosis patients (n=49, age 70±13y, 57% male). The AI-enabled ECG model predicted diastolic dysfunction with an accuracy of 65% (non-obstructive HCM), 67% (obstructive HCM), 65% (apical HCM), and 75% (cardiac amyloidosis), with sensitivities of 94% and 97% for obstructive HCM and cardiac amyloidosis, respectively, and high positive and negative predictive values for cardiac amyloidosis. Systolic dysfunction (LVEF≤40%) was more common in cardiac amyloidosis (29%) than in all HCM patients (5%). Conclusion: The AI-enabled ECG model demonstrates moderate accuracy but high sensitivity for detecting diastolic dysfunction and increased filling pressure, especially in obstructive HCM and cardiac amyloidosis. The AI-enabled ECG is a useful, widely scalable, and low cost tool to identify patients at increased risk for diastolic dysfunction.

Introduction: Acoramidis, an oral transthyretin (TTR) stabilizer achieving near-complete (≥90%) TTR stabilization, is now approved in the USA, EU, Japan, and UK for the treatment of TTR amyloid cardiomyopathy (ATTR-CM). In the 30-month phase 3 ATTRibute-CM study, acoramidis reduced all-cause mortality (ACM) or first cardiovascular-related hospitalization (CVH) vs placebo. Through Month 42 (M42) of the open-label extension (OLE; 30 months ATTRibute-CM + 12 months OLE), the clinical benefit of acoramidis was sustained, resulting in a 36% and 43% risk reduction in ACM and ACM/first CVH, respectively, compared with the placebo to acoramidis group Research Question: Are the long-term clinical benefits of acoramidis on ACM and ACM/first CVH in ATTR-CM over 42 months consistent across patient subgroups? Methods: ATTRibute-CM study design has been previously described. At the end of the 30-month double-blind period, patients enrolled into OLE continued acoramidis or switched from placebo to acoramidis; all patients received open-label acoramidis HCI 800 mg BID. Data cut was performed after 12 months in OLE. Subgroup analysis for ACM and ACM/first CVH through M42 were conducted for randomization stratification factors (genotype, NT-proBNP, and eGFR levels) and other pre-specified subgroups. ACM included death due to any cause, cardiac mechanical assist device placement, and heart transplant. CVH included CV hospitalizations (≥24 h) and urgent visits (<24 h) for decompensated heart failure requiring IV diuretics and was adjudicated by an independent Clinical Events Committee. Results: Overall, 389 patients enrolled in the OLE (263 continuous acoramidis and 126 placebo to acoramidis). The analyses of ACM/first CVH ( Figure 1 ) and ACM ( Figure 2 ) through M42 consistently favored patients initially randomized to acoramidis across all patient subgroups, including those based on sex, age, country, ATTR-CM genotype, baseline NT-proBNP, baseline eGFR, NYHA class, and NAC stage. The largest effect size for the reduction in ACM/first CVH (HR <0.50) was observed in the following subgroups: female, non-Caucasian patients, variant ATTR-CM, or NAC stage 2. Conclusions: The long-term benefit of acoramidis was consistently shown in patients initially randomized to acoramidis treatment compared with placebo to acoramidis switch after 30 months across multiple clinically relevant subgroups, underscoring the importance of early initiation of acoramidis to reduce the long-term risk of ACM or CVH.

Abstract Background and Aims Accurate differentiation of cardiac amyloidosis (CA) from phenotypic mimics remains challenging using current clinical and echocardiographic techniques. The accuracy of a novel artificial intelligence (AI) screening algorithm for echocardiography-based CA detection was assessed. Methods Utilizing a multisite, multiethnic dataset (n = 2612, 52% CA), a convolutional neural network was trained to differentiate CA from phenotypic controls using transthoracic apical four-chamber video clips. External validation was conducted globally across 18 sites including 597 CA cases and 2122 controls. Classification accuracy was assessed on the entire external validation dataset, and subgroup analyses were performed both on technetium pyrophosphate scintigraphy referrals, and individuals matched for age, sex, and wall thickness. Model accuracy was also compared with the transthyretin CA score and the increased wall thickness score within a subset of older heart failure with preserved ejection fraction patients with increased wall thickness. Results Cardiac amyloidosis patients and controls displayed similar age, sex, race, and comorbidities. After the removal of uncertain AI predictions (13%), model discrimination and classification were excellent for the entire external validation dataset [area under the receiver operating characteristic curve (AUROC) 0.93, sensitivity 85%, specificity 93%], irrespective of CA subtype (sensitivity: light-chain = 84%, wild-type transthyretin = 85%, and hereditary transthyretin = 86%). Performance was maintained in subgroup analysis in patients clinically referred for technetium pyrophosphate scintigraphy imaging (AUROC 0.86, sensitivity 77%, specificity 86%) and matched patients (AUROC 0.92, sensitivity 84%, specificity 91%). The AI model (AUROC 0.93) also outperformed transthyretin CA score (AUROC 0.73) and increased wall thickness (AUROC 0.80) scores. Conclusions This AI screening model—using only an apical four-chamber view—effectively differentiated CA from other causes of increased left ventricular wall thickness.