Efficacy and Safety of Acoramidis in Transthyretin Amyloid Cardiomyopathy

A Multicenter Study of Contemporary Long-Term Tafamidis Outcomes in Transthyretin Amyloid Cardiomyopathy

BACKGROUND

Tafamidis improved survival and decreased cardiovascular hospitalizations in the ATTR-ACT trial. Due to improved recognition and earlier diagnosis, the epidemiology of transthyretin amyloid cardiomyopathy (ATTR-CM) is rapidly evolving.

OBJECTIVES

The authors sought to evaluate the contemporary long-term outcomes of patients with ATTR-CM treated with tafamidis.

METHODS

Patients with ATTR-CM who received at least 1 dose of tafamidis between 2018 and 2021 at 5 amyloidosis centers in the United States were enrolled. Primary outcome was all-cause mortality.

RESULTS

Among 624 patients, mean age was 76.9 ± 8.4 years, 12.5% were female, 17.5% were Black, and 17.5% had variant ATTR-CM. At the time of tafamidis start, 52% had NYHA functional class II, 34% had NYHA functional class III, 40% were in National Amyloidosis Center (NAC) Stage ≥II, 38% were in Columbia Stage ≥II, and the median NT-proBNP level was 1,914 (Q1-Q3: 957-3914) pg/mL. Over a median follow-up of 43.2 months (Q1-Q3: 25.2-52.8 months), 241 patients (38.6%) died. The probability of freedom from death at 65 months was 54.1% (95% CI: 47.4%-60.4%). Similarly, restricting the cohort to patients who received tafamidis within 6 months of their ATTR-CM diagnosis (n = 397, 63.6%) showed similar results, with a survival probability of 49.6% (95% CI: 37.6%-60.5%) at 65 months.

CONCLUSIONS

In a contemporary cohort of tafamidis-treated patients with ATTR-CM, 39% of patients died over a median of 43 months. Further work is needed to improve our understanding of ATTR-CM, its natural history, and how to further improve survival and prevent progression of heart failure.

Sodium-glucose cotransporter 2 inhibitors in transthyretin amyloid cardiomyopathy: navigating potential benefits and uncertainties

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have garnered attention for their potential role in managing transthyretin amyloid cardiomyopathy (ATTR-CM), a progressive condition characterized by significant morbidity and mortality. ATTR-CM remains underdiagnosed despite advances in diagnostic modalities. While tafamidis and acoramidis have emerged as effective therapies, residual cardiovascular risk persists, highlighting the need for adjunctive treatments. SGLT2i, initially developed as antidiabetic agents, have demonstrated cardioprotective effects in various heart failure phenotypes, including preserved and reduced ejection fractions. Emerging evidence suggests their utility in ATTR-CM, potentially addressing unmet needs, such as symptom burden, hospitalizations, and survival. Clinical studies indicate that SGLT2i reduce all-cause mortality, major adverse cardiac events (MACE), and heart failure hospitalizations, with benefits extending to cardiovascular mortality and improved functional status. Moreover, these agents appear to mitigate arrhythmic complications, evidenced by reduced cardioversion procedures and antiarrhythmic therapy requirements. Observational studies also highlight the potential synergy of SGLT2i with tafamidis, suggesting additive benefits in addressing amyloid deposition and heart failure. However, limitations, including the absence of randomized controlled trials, immortal time bias, and population heterogeneity, necessitate further research. Future directions involve elucidating mechanisms of action, exploring personalized treatment strategies, and leveraging big data analytics for real-world insights. SGLT2i's potential to transform ATTR-CM management underscores their promise, though robust trials are imperative to validate findings and optimize clinical applications.

Clinical Phenotype and Prognostic Significance of Frailty in Transthyretin Cardiac Amyloidosis

BACKGROUND

The prevalence and clinical impact of frailty in transthyretin cardiac amyloidosis (ATTR-CA) remains poorly characterized.

OBJECTIVES

This study aimed to evaluate the prevalence, clinical determinants, and prognostic significance of frailty in a large cohort of patients with ATTR-CA.

METHODS

Frailty was assessed in 880 patients with ATTR-CA (median age 80 years [Q1-Q3: 75-84 years], 719 [81.7%] male) using the Clinical Frailty Scale (CFS). Frailty was analyzed as a continuous variable and categorized as CFS 1 to 3, CFS 4 or 5, CFS 6 or 7, and CFS 8 or 9.

RESULTS

Frailty was observed in 502 (57.1%) patients (CFS 4 or 5: 364 [41.4%]; CFS 6 or 7: 129 [14.7%]; CFS 8 or 9: 9 [1.0%]). Independent predictors of worsening frailty included older age, female sex, non-p.(V142I) hereditary ATTR-CA variants, and National Amyloidosis Centre stage 3 disease. Mortality rates increased incrementally with frailty severity (deaths per 100 person-years: 2.9 vs 11.0 vs 21.1 vs 40.9; log-rank P < 0.001). Frailty was independently associated with higher mortality risk across all age groups, genotypes, and disease stages.

CONCLUSIONS

Frailty is common in ATTR-CA and is independently linked to increased mortality risk. Incorporating frailty assessment alongside traditional markers enhances prognostication across genotypes and disease severities, particularly for short-term risk estimation.

Changing Treatment Landscape in Transthyretin Cardiac Amyloidosis

The demographics of patients with transthyretin amyloidosis with cardiomyopathy have evolved over the past decade, mostly driven by improved awareness of the disease among clinicians, noninvasive imaging tools for diagnosis, and new, effective treatments. Patients are now diagnosed earlier in their disease course, and treatment is initiated in those with milder disease, leading to improved outcomes. Earlier treatment of patients with milder disease may lead to accelerated disease stabilization and greater preservation of function. In addition, identification of patients with transthyretin amyloidosis with cardiomyopathy at an earlier disease stage translates to healthier study populations at enrollment in clinical trials, with slower disease progression compared with patients in prior trials. In this context, effect sizes between active treatment and placebo arms will likely be smaller than those seen in historic trials, although it is still possible to observe clinically relevant differences. In this review, we discuss how patient characteristics have changed from the ATTR-ACT trial to the more recent APOLLO-B, ATTRibute-CM, and HELIOS-B studies. In addition, we consider how measures of the minimal clinically important difference for particular end points can assist in clinical decision-making and targeting treatment goals. Treatment goals are evolving over time with the need for evidence-based recommendations in this clinical space. Lastly, we address unmet needs and future expectations for the management of transthyretin amyloidosis with cardiomyopathy.

Advances in the screening, diagnosis, and treatment of transthyretin amyloid cardiomyopathy: New insights and future directions

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive form of heart failure caused by myocardial tissue infiltration with fibrillar amyloid deposits. ATTR-CM has been traditionally underrecognized and regarded by clinicians as a challenging condition to manage, owing to limited availability of effective screening methods, diagnostic testing, and therapeutic options. More recently, multiple clinical trials have emerged evaluating the efficacy of novel pharmacologic therapies which target amyloid generation and pre-existing amyloid deposits. Results reveal robust treatment benefits in function and survival, offering clinicians and patients new therapeutics which alter the clinical trajectory of ATTR-CM. Importantly, the benefits of treatment with these therapies appear to be more pronounced when initiated at an early stage of disease. As a result, a renewed interest in the early detection of ATTR-CM has developed, with efforts currently underway to promote increased disease awareness and enhance diagnosis through standardized screening algorithms and advanced imaging techniques. This review will provide an in-depth description of the advancements in ATTR-CM screening, diagnosis, and treatment that are currently available for implementation in routine care. Furthermore, we highlight several investigational modalities on the horizon for ATTR-CM with a particular focus on their potential roles in future clinical practice.

Cardiac disease monitoring measures in patients with transthyretin amyloid cardiomyopathy treated with tafamidis

BACKGROUND

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) often experience worsening cardiac disease (WCD) despite disease-modifying treatment. However, a strict definition is lacking. Recent studies have shown that N-terminal pro-B-natriuretic peptide (NT-proBNP increase), or intensification of oral diuretics, is associated with increased mortality risk.

AIM

To describe the pattern of WCD at 1 year in patients with ATTR-CM on tafamidis and explore the association with mortality and cardiovascular (CV) hospitalisation.

METHODS

Patients diagnosed with ATTR-CM at Columbia University after 2018 who were treated with tafamidis were enrolled in the study. WCD was defined as: increase in NT-proBNP >700 pg/mL and >30% from baseline or oral diuretic intensification (ODI) or both. Survival and CV hospitalisation risk analysis was performed using Kaplan-Meier curves, Cox regression and competing risk regression adjusted for age, genotype and disease severity by the National Amyloidosis Centre (NAC) stage.

RESULTS

A total of 238 patients were enrolled, 100 (42%) of whom showed WCD at 1 year. WCD was associated with increased mortality risk (log rank, p<0.0001, HR=1.91 (1.10-3.32), p=0.023, after adjustment for age, genotype and baseline NAC stage). In competing risk analysis, WCD was associated with increased risk for CV-related hospitalisation (HR=1.8 (1.17-2.99, p=0.009)) after adjustment for age, genotype and baseline NAC stage.

CONCLUSIONS

NT-proBNP increase and ODI can serve as markers of WCD and predict mortality and CV hospitalisations in a cohort of patients taking tafamidis.

Rationale and Design of ANTHOLOGY: An ATTR Amyloidosis Real-World Evidence Program Aiming to Address Gaps in Amyloidosis Care

INTRODUCTION

Patients with amyloid transthyretin (ATTR) amyloidosis typically experience rapid disease progression, poor treatment outcomes, irreversible loss of health-related quality of life (HRQoL), and premature mortality. Early diagnosis is vital. However, diagnostic delays and misdiagnosis are common due to under-recognition of early signs and symptoms.

METHODS

ANTHOLOGY is an ATTR amyloidosis program, evidence generation, and quality improvement opportunity comprised of two multi-country, longitudinal, observational, real-world evidence studies: OverTTuRe (ClinicalTrials.gov identifier, NCT06355934) and MaesTTRo (NCT06465810). OverTTuRe will retrospectively extract and analyze secondary data from a broad spectrum of sources, and MaesTTRo will prospectively collect and analyze data from patient-reported outcome questionnaires, electronic health records, and insurance claims.

PLANNED OUTCOMES

The primary objectives of OverTTuRe are to describe contemporary patient characteristics, treatment patterns and disease outcomes, and to characterize healthcare resource utilization (HCRU) and HRQoL in patients diagnosed with ATTR amyloidosis. Describing patient characteristics and HCRU before diagnosis is a secondary objective. The primary objectives of MaesTTRo are to describe patient characteristics, disease history and treatment patterns from diagnosis, and to prospectively define and assess the real-world effectiveness of current therapies. Secondary objectives are to compare the characteristics of patients according to the therapy received and compare the real-world effectiveness of current therapies. Exploratory objectives are to identify risk factors for disease progression and to describe healthcare costs.

CONCLUSIONS

ANTHOLOGY aims to broaden understanding of the contemporary epidemiology of ATTR amyloidosis, identify opportunities to accelerate diagnosis, and assess real-world comparative effectiveness of treatments. This knowledge will be used to define world-class patient care, improve treatment outcomes and HRQoL, inform updates to clinical practice guidelines and treatment pathways, and transform ATTR amyloidosis management through evidence aimed at improving the quality of the current standard of care TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT06355934 (OverTTuRe) and NCT06465810 (MaesTTRo).

Efficacy of Acoramidis on All-Cause Mortality and Cardiovascular Hospitalization in Transthyretin Amyloid Cardiomyopathy

BACKGROUND

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed chronic disease associated with progressive heart failure that results in impaired quality of life, repeated hospitalizations, and premature death. Acoramidis is a selective, oral transthyretin stabilizer recently approved by the U.S. Food and Drug Administration for the treatment of ATTR-CM. In a phase 3, randomized, double-blind study (ATTRibute-CM [Efficacy and Safety of AG10 in Subjects With Transthyretin Amyloid Cardiomyopathy]), acoramidis was well tolerated and showed clinical efficacy in improving the primary endpoint, a hierarchical combination of all-cause mortality (ACM), cardiovascular-related hospitalization (CVH), N-terminal pro-B-type natriuretic peptide level, and 6-minute walk distance.

OBJECTIVES

The goal of this study was to characterize the efficacy of acoramidis on ACM and CVH.

METHODS

In ATTRibute-CM, participants with ATTR-CM were randomized 2:1 to receive acoramidis hydrochloride (800 mg twice daily) or placebo for 30 months. Efficacy analyses were conducted in the modified intention-to-treat population (participants with a baseline estimated glomerular filtration rate ≥30 mL/min/1.73 m2). CVH and the composite of ACM or first CVH were plotted by using Kaplan-Meier curves and summarized with a stratified Cox proportional hazards model. The annualized frequency of CVH was analyzed by using a negative binomial regression model. Subgroup analyses were conducted for the composite of ACM or first CVH.

RESULTS

Of the 632 participants randomized to treatment, 611 (97%) were included in efficacy analyses (acoramidis, n = 409; placebo, n = 202). Compared with placebo, acoramidis reduced the occurrence of the composite of ACM or first CVH (acoramidis, 35.9%; placebo, 50.5%; HR: 0.64; 95% CI: 0.50-0.83; P = 0.0008) and of first CVH (acoramidis, 26.7%; placebo, 42.6%; HR: 0.60; 95% CI: 0.45-0.80; P = 0.0005), with Kaplan-Meier curves separating at month 3 and continuing to diverge through month 30. Annualized frequency of CVH was reduced with acoramidis compared with placebo (acoramidis, 0.22; placebo, 0.45; relative risk ratio: 50%; 95% CI: 0.36-0.70; P < 0.0001). The efficacy of acoramidis on the composite of ACM or first CVH was consistent across subgroups. Acoramidis was well tolerated, with no safety signals of potential clinical concern identified.

CONCLUSIONS

In participants with ATTR-CM, acoramidis reduced the composite of ACM or first CVH vs placebo, with an early effect driven by a reduction in CVH. (Efficacy and Safety of AG10 in Subjects With Transthyretin Amyloid Cardiomyopathy [ATTRibute-CM]; NCT03860935).

Tafamidis in octogenarians with wild-type transthyretin cardiac amyloidosis: an international cohort study

BACKGROUND AND AIMS

In real-world, wild-type transthyretin cardiomyopathy is increasingly diagnosed in patients ≥ 80 years old (octogenarians), although being underrepresented in randomized clinical trials. Specific data on natural course and outcome under tafamidis treatment in octogenarians are therefore scarce. The impact of tafamidis treatment on mortality in real-world wild-type transthyretin cardiomyopathy octogenarians was studied.

METHODS

An international, multicentre cohort study of 710 consecutive wild-type transthyretin cardiomyopathy patients with mean follow-up of 2.2 ± 1.8 years for all-cause mortality endpoint was performed.

RESULTS

The cohort consisted of 58.5% (415/710) octogenarians (85 ± 4 years, 74.2% male). Before tafamidis availability, natural course in octogenarians (148/257) vs. non-octogenarians (109/257) was poor, with 16% 1-year and 71% 5-year mortality vs. 8% and 47%, respectively (P < .001). Since tafamidis availability, 70.1% (253/361) octogenarians were initiated on tafamidis vs. 83.7% (231/276) non-octogenarians (P < .001). Tafamidis discontinuation was similar (octogenarians 10.3% and non-octogenarians 7.4%; P = .260). Overall tafamidis treated vs. untreated octogenarians had better unadjusted survival (P < .001), with 5% 1-year and 24% 3-year mortality. Tafamidis treatment associated with lower mortality after propensity score matching on baseline variables, including age, National Amyloidosis Centre stage, and New York Heart Association class in on average 394 subjects [hazard ratio (HR) = 0.53, 95% confidence interval (CI) 0.34-0.84, P = .007], also in octogenarians (HR = 0.57, 95% CI 0.33-1.01, P = .053). Neither age at diagnosis (P = .217) nor at treatment initiation (P = .154) interacted with tafamidis mortality benefit. Octogenarians had poorer survival despite tafamidis, when initiated at ≥90 years (HR = 3.3, 95% CI 1.10-9.53, P = .033) and National Amyloidosis Centre Stage ≥3 (HR = 2.4, 95% CI 0.87-6.46, P = .090).

CONCLUSIONS

Real-world tafamidis treatment improves survival without age affecting treatment efficacy, although mortality remains considerable in octogenarians.

Transthyretin amyloid cardiomyopathy: a paradigm for advancing precision medicine

Development of specific therapies addressing the underlying diseases' mechanisms constitutes the basis of precision medicine. Transthyretin cardiac amyloidosis (ATTR-CM) is an exemplar of precise therapeutic approach in the field of heart failure and cardiomyopathies. A better understanding of the underlying pathophysiology, more precise data of its epidemiology, and advances in imaging techniques that allow non-invasive diagnosis have fostered the development of new and very effective specific therapies for ATTR-CM. Therapeutic advances have revolutionized the field, transforming a rare, devastating, and untreatable disease into a more common disease with several therapeutic alternatives available. Three main types of therapies (stabilizers, suppressors, and degraders) that act at different points of the amyloidogenic cascade have been developed or are currently under investigation. In this review, the key advances in pathophysiology and epidemiology that have occurred in the last decades along with the different therapeutic alternatives available or under development for ATTR-CM are described, illustrating the role of precision medicine applied to cardiovascular disorders. Pending questions that would need to be answered in upcoming years are also reviewed.

Allele-specific electrical genotyping for diagnosis of transthyretin amyloidosis

Clinical genetic testing often takes days to weeks, but rapid, affordable tests during outpatient visits could significantly benefit patients. This is crucial for detecting common, actionable point mutations, such as those linked to hereditary transthyretin (TTR) amyloidosis, which is often underdiagnosed in individuals of West African ancestry with congestive heart failure. Here we developed a method for detecting known DNA variants using allele-specific polymerase chain reaction (ASPCR) and electrical impedance. Oligonucleotide primers were designed to selectively amplify the ancestral and variant allele of TTR c.424G>A (p.Val142Ile). PCR products were detected in solution using passive-flow microfluidic impedance cytometry across multiple excitation frequencies. Impedance responses correlated with DNA concentration, allowing for the calculation of a robust DNA quantification score. TTR V142I genotypes from six patients (four heterozygous, two wildtype) matched results from gel electrophoresis and sequencing. Future improvements will focus on reducing DNA input requirements and enabling multiplex variant detection.

Race, Genetics, and Social Determinants of Health in Transthyretin Cardiac Amyloidosis: A Literature Review and Call to Action

PURPOSE OF REVIEW

Recent evidence suggests that transthyretin cardiac amyloidosis (ATTR-CM) is significantly more common than once believed, yet it remains frequently under- and mis-diagnosed. With effective treatments now available, early and accurate diagnosis has become critical for better patient outcomes. Understanding the interplay between genetics, race, and social determinants of health (SDOH) in influencing both ATTR-CM diagnosis and management is essential for bridging the current gaps.

RECENT FINDINGS

Our analysis reveals multiple barriers affecting ATTR-CM care. Specifically, we discuss how clinician awareness, regional differences in clinical practice, and limited access to health care and specialty centers contribute to diagnostic delays. Additionally, we identify several management obstacles, such as inadequate diversity in clinical trials, high cost of available treatments, and limited ancillary resources. We examine these challenges in detail and provide practical solutions to address them. While disparities in heart failure outcomes have been well-documented, those specific to ATTR-CM remain underrepresented in the literature. This review establishes a structured approach to understanding how biological, structural and SDOH-related disparities impact ATTR-CM diagnosis and management while offering concrete strategies to overcome these challenges. We emphasize the need for enhanced SDOH identification and advocate for coordinated, multidisciplinary efforts to improve ATTR-CM patient outcomes.

New FDA drug approvals for 2024: Synthesis and clinical application

In 2024, the U.S. Food and Drug Administration (FDA) has approved a range of new drugs, including both 32 new chemical entities (NCEs) and 18 biological entities (NBEs). Among the approved new drugs, small-molecule chemical drugs remained the main force for innovation, taking a commanding lead with a proportion of 64 %, covering targets like LACTB, PBP, THR-β, Raf, PDE3/4, and HIF. Monoclonal antibodies followed with 13 drugs (26 %), along with 2 protein-based drugs (4 %), 2 small nucleic acid drugs (4 %), and 1 parathyroid hormone analogue (2 %). The diseases treated by these approved new drugs were diverse, with the total number of new drugs for treating rare diseases and cancers ranking high. Additionally, multiple new drugs were also approved in the fields of anti-infective and central nervous system diseases. Similar to previous years, many of these drugs are likely to undergo accelerated approval processes to address urgent medical needs, particularly for rare diseases. This review provides an overview of the synthesis and clinical applications of NCEs approved by the FDA in 2024. The increasing importance of clinical applications has also been discussed. This review aims to provide valuable insights for the design of future drugs, particularly in the context of rare and complex diseases.

Long-Term Efficacy and Safety of Acoramidis in ATTR-CM: Initial Report From the Open-Label Extension of the ATTRibute-CM Trial

BACKGROUND

In the phase 3 randomized controlled study ATTRibute-CM (Efficacy and Safety of AG10 in Subjects With Transthyretin Amyloid Cardiomyopathy), acoramidis, a transthyretin stabilizer, demonstrated significant efficacy on the primary end point. Participants with transthyretin amyloid cardiomyopathy who completed ATTRibute-CM were invited to enroll in an open-label extension study (OLE). We report the efficacy and safety data of acoramidis in participants who completed ATTRibute-CM and enrolled in the ongoing OLE.

METHODS

Participants who previously received acoramidis through month 30 in ATTRibute-CM continued to receive it (continuous acoramidis), and those who received placebo through month 30 were switched to acoramidis (placebo to acoramidis). Participants who received concomitant tafamidis in ATTRibute-CM were required to discontinue it to be eligible to enroll in the OLE. Clinical efficacy outcomes analyzed through month 42 included time to event for all-cause mortality (ACM) or first cardiovascular-related hospitalization (CVH), ACM alone, first CVH alone, ACM or recurrent CVH, change from baseline in NT-proBNP (N-terminal pro-B-type natriuretic peptide), 6-minute walk distance, serum transthyretin, and Kansas City Cardiomyopathy Questionnaire Overall Summary score. Safety outcomes were analyzed through month 42.

RESULTS

Overall, 438 of 632 participants in ATTRibute-CM completed treatment, and 389 enrolled in the ongoing OLE (263 continuous acoramidis and 126 placebo to acoramidis). The hazard ratio for ACM or first CVH was 0.57 (95% CI, 0.46-0.72) at month 42 based on a stratified Cox proportional hazards model (P<0.0001) favoring continuous acoramidis. Similar analyses were performed on ACM alone and first CVH alone, with hazard ratios of 0.64 (95% CI, 0.47-0.88) and 0.53 (95% CI, 0.41-0.69), respectively, at month 42. Treatment effects for NT-proBNP and 6-minute walk distance also favored continuous acoramidis. On initiation of open-label acoramidis in the placebo-to-acoramidis arm, there was a prompt increase in serum transthyretin. Quality of life assessed by Kansas City Cardiomyopathy Questionnaire Overall Summary score was well preserved in continuous-acoramidis participants compared with the placebo-to-acoramidis participants. No new clinically important safety issues were identified in this long-term evaluation.

CONCLUSIONS

Early initiation and continuous use of acoramidis in the ATTRibute-CM study through month 42 of the ongoing OLE study were associated with sustained clinical benefits in a contemporary transthyretin amyloid cardiomyopathy cohort, with no clinically important safety issues newly identified.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04988386.

CT-derived extracellular volume fraction in aortic stenosis, cardiac amyloidosis, and dual pathology

AIMS

To investigate CT-derived extracellular volume fraction (CT-ECV) in patients with lone aortic stenosis (AS), dual pathology of AS and transthyretin cardiac amyloidosis (AS-ATTR), and lone ATTR, and to examine the diagnostic performance and optimal cut-off values of CT-ECV for differentiating between patients with lone AS and AS-ATTR and between patients with lone AS and lone ATTR.

METHODS AND RESULTS

This retrospective study included consecutive patients with severe AS (including lone AS and AS-ATTR) and lone ATTR who underwent CT-ECV analysis and technetium 99 m pyrophosphate (99mTc-PYP) scintigraphy. The diagnostic performance of CT-ECV for detecting cardiac amyloidosis was evaluated using the area under the receiver operating characteristic curve (AUC). Of 138 patients (mean age, 80 ± 8; 96 men), 55 had lone AS, 19 had AS-ATTR, and 64 had lone ATTR. CT-derived extracellular volume fraction of patients with lone AS was 31 ± 5%. CT-derived extracellular volume fraction was significantly lower in patients with AS-ATTR than lone ATTR (45 ± 12% vs. 53 ± 13%, P = 0.04). The AUC for differentiating patients with AS-ATTR from lone AS was lower than for lone ATTR from lone AS [0.90 (95% CI: 0.81, 0.96) vs. 0.95 (95% CI: 0.90, 0.98)]. The cut-off values of CT-ECV for differentiation between patients with lone AS and AS-ATTR were lower than those between patients with lone AS and lone ATTR [36.6% vs. 38.5% (Youden index)]. There was no significant difference in the proportion of 99mTc-PYP scintigraphy grade between patients with AS-ATTR and lone ATTR (P = 0.20).

CONCLUSION

Despite no significant difference in degree of ATTR between patients with AS-ATTR and lone ATTR, CT-ECV of patients with dual AS-ATTR pathology was significantly lower than that of patients with lone ATTR. The diagnostic performance and optimal cut-off values of CT-ECV for differentiating between patients with lone AS and AS-ATTR were lower than those between patients with lone AS and lone ATTR.

"The unbearable lightness" of the primary end point in clinical trials

In this Perspective, I discuss the limitations of a soft primary endpoint that is used in some of the recent randomized phase II/III clinical trials. Unfortunately, many clinicians and investigators do not interpret the data critically to recognize the limitations of such findings. I advise against over-interpreting the effects of an intervention on a soft primary endpoint.

Involvement of bile acid in diarrhoea and therapeutic effect of colestimide in hereditary ATTR amyloidosis

BACKGROUND

Diarrhoea is one of the most serious complications in hereditary ATTR (ATTRv) amyloidosis. However, its precise pathomechanism remains unknown. The present study investigated the involvement of bile acid in diarrhoea along with the therapeutic effect of colestimide, a bile acid sequestrant, in ATTRv amyloidosis.

METHODS

We prospectively enrolled 19 ATTRv amyloidosis patients (9 with refractory diarrhoea and 10 without diarrhoea) and 20 healthy individuals for measurements of serum 7a-hydroxy-4-cholesten-3-one (C4) levels. The patients with diarrhoea were then treated with oral colestimide (1.5 g twice daily) for 28 days. The frequency of diarrhoea and C4 level were evaluated before and after colestimide treatment.

RESULTS

Mean serum C4 level was significantly higher in ATTRv patients with diarrhoea (62.3 ng/mL) than in ATTRv patients without diarrhoea (24.0 ng/mL, p = 0.03). Colestimide treatment significantly decreased mean diarrhoea frequency (pre-treatment period: 9.1 times/week, colestimide treatment period, 6.6 times/week, p = 0.04) and increased mean C4 level (before treatment: 66.2 ng/mL, after treatment: 187.1 ng/mL, p = 0.02).

CONCLUSIONS

Bile acid status was significantly associated with diarrhoea in ATTRv amyloidosis. Colestimide and other bile acid sequestrants may reduce diarrhoea frequency in afflicted patients.

Right ventricular coupling predicts cardiopulmonary fitness in cardiac transthyretin amyloidosis

BACKGROUND

Wild-type transthyretin cardiac amyloidosis (ATTRwt) is an infiltrative disease leading to restrictive cardiomyopathy. We aimed to characterise exercise capacity in ATTRwt and to identify predictors of cardiopulmonary fitness, focusing on echocardiographic and clinical parameters.

METHODS

We studied 110 ATTRwt patients from a prospective single-centre registry (2020-2024) by cardiopulmonary exercise testing (CPET). Besides CPET, all patients underwent comprehensive clinical assessment including follow-up for mortality. In 32 patients follow-up CPET after 1 year was available.

RESULTS

In ATTRwt, reduced aerobic capacity (pVO2 16 [13-18] ml/kg/min), and ventilatory inefficiency (VE/VCO2 slope 35 [30-43]) were common. In the multivariable regression analysis, we identified TAPSE/sPAP ratio as predictive for pVO2 (p = 0.019) and ventilatory efficiency (p = 0.004), while left ventricular ejection fraction or measures of left ventricular hypertrophy were not predictive. Concordantly, TAPSE/sPAP ratio assessed at baseline predicted pVO2 at 1-year follow-up (p = 0.009). Furthermore, patients with a TAPSE/sPAP ratio below the median of 0.38 mm/mmHg presented a higher risk of all-cause death (p = 0.009).

CONCLUSION

In ATTRwt the TAPSE/sPAP ratio, a marker of right ventricular coupling, was an independent predictor of aerobic capacity assessed by CPET, at baseline and after 1 year, highlighting the importance of right ventricular assessment for risk stratification.

New therapies to treat cardiac amyloidosis

PURPOSE OF REVIEW

Review advancements in therapies for transthyretin (ATTR-CM) and immunoglobulin light chain (AL-CM) cardiac amyloidosis.

RECENT FINDINGS

In ATTR-CM, tafamidis remains the cornerstone therapy, with Food and Drug Administration (FDA) approval for over 5 years. Acoramidis, another transthyretin stabilizer, has very recently been FDA-approved following positive results in the ATTRibute-CM trial. Vutrisiran, a transthyretin gene silencer, demonstrated efficacy in the HELIOS-B trial and awaits FDA review. Eplontersen's CARDIO-TTRansform trial, the largest ATTR-CM study to date, is expected to report by late 2025. Innovative approaches such as NTLA-2001 (a CRISPR-Cas9 therapy) and fibril depleters like ALXN2220 and coramitug are advancing in clinical trials. In AL-CM, daratumumab, cyclophosphamide, bortezomib, and dexamethasone (Dara-CyBorD) has established itself as the standard of care. Novel antiplasma cell therapies include CAR-T cells and bispecific antibodies (teclistimab) and fibril depleters. Birtamimab improved survival in advanced AL-CM during the VITAL trial and is under investigation in AFFIRM-AL. Anselamimab is in phase III CARES trials, whereas AT-02 undergoes early-phase testing for ATTR-CM and AL-CM.

SUMMARY

The therapeutic landscape for ATTR-CM and AL-CM is rapidly evolving, driven by novel therapies targeting diverse mechanisms. Ongoing clinical trials promise to further refine the standard of care and improve outcomes for patients with cardiac amyloidosis.

Advances in Studying the Pathologic Mechanisms and Treatment Strategies of Transthyretin Amyloidosis

ABSTRACT

Transthyretin amyloidosis (ATTR) is characterized by the deposition of unstable transthyretin protein (TTR) in the heart or peripheral nerves. Therapeutic strategies for ATTR include inhibition of the secretion of abnormal TTR by the liver, reducing the concentration of aberrant TTR in the circulation, and eliminating amyloid deposits of TTR in tissues. This article delves into the pathogenesis of TTR secretion from the liver into the bloodstream, its deposition in tissues, and the subsequent development of ATTR. In addition, we delineated the advancements in treatment strategies and discussed future research directions to provide novel insights for the identification of diagnostic and preventive targets.

Survival in a Real-World Cohort of Patients With Transthyretin Amyloid Cardiomyopathy Treated With Tafamidis: An Analysis From the Transthyretin Amyloidosis Outcomes Survey (THAOS)

BACKGROUND

In the pivotal Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT), tafamidis significantly reduced mortality rates, leading to its approval in many countries for the treatment of transthyretin amyloid cardiomyopathy (ATTR-CM). Real-world evidence on survival in patients with ATTR-CM following tafamidis treatment has not been extensively reported.

METHODS AND RESULTS

The Transthyretin Amyloidosis Outcomes Survey (THAOS) was a longitudinal, observational, phase 4 study of patients with transthyretin amyloidosis and asymptomatic participants carrying pathogenic transthyretin variants. Patients from THAOS with a predominantly cardiac phenotype at enrollment were included, and survival was analyzed according to tafamidis treatment status (treated or untreated). Results are based on the completed THAOS dataset. In tafamidis-treated (n = 587) and tafamidis-untreated (n = 854) patients, respectively, median age at enrollment was 77.7 and 76.4 years, 91.8% and 90.0% were male, and 91.8% and 83.8% had wild-type disease. Survival rates (95% CI) at 30 and 42 months, respectively, were 84.4% (80.5-87.7) and 76.8% (70.9-81.7) in tafamidis-treated patients, and 70.0% (66.4-73.2) and 59.3% (55.2-63.0) in tafamidis-untreated patients. Survival rates in genotype subgroups (wild-type and variant) were similar to those of the overall cohort. Survival rates were better in a contemporary cohort, as reflected by a sensitivity analysis performed in patients enrolled after vs before 2019. No new safety signals were identified.

CONCLUSIONS

In this real-world cohort of patients with ATTR-CM, survival rates were higher than in ATTR-ACT and consistent with more recent reports, suggesting early diagnosis and treatment with tafamidis has improved life expectancy in ATTR-CM. These results provide further evidence supporting tafamidis' safety and effectiveness.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00628745.

Enhanced diagnostic and prognostic assessment of cardiac amyloidosis using combined 11C-PiB PET/CT and 99mTc-DPD scintigraphy

BACKGROUND

Cardiac amyloidosis (CA) is a severe condition characterized by amyloid fibril deposition in the myocardium, leading to restrictive cardiomyopathy and heart failure. Differentiating between amyloidosis subtypes is crucial due to distinct treatment strategies. The individual conventional diagnostic methods lack the accuracy needed for effective subtype identification. This study aimed to evaluate the efficacy of combining 11C-PiB PET/CT and 99mTc-DPD scintigraphy in detecting CA and distinguishing between its main subtypes, light chain (AL) and transthyretin (ATTR) amyloidosis while assessing the association of imaging findings with patient prognosis.

METHODS

We retrospectively evaluated the diagnostic efficacy of combining 11C-PiB PET/CT and 99mTc-DPD scintigraphy in a cohort of 50 patients with clinical suspicion of CA. Semi-quantitative imaging markers were extracted from the images. Diagnostic performance was calculated against biopsy results or genetic testing. Both machine learning models and a rationale-based model were developed to detect CA and classify subtypes. Survival prediction over five years was assessed using a random survival forest model. Prognostic value was assessed using Kaplan-Meier estimators and Cox proportional hazards models.

RESULTS

The combined imaging approach significantly improved diagnostic accuracy, with 11C-PiB PET and 99mTc-DPD scintigraphy showing complementary strengths in detecting AL and ATTR, respectively. The machine learning model achieved an AUC of 0.94 (95% CI 0.93-0.95) for CA subtype differentiation, while the rationale-based model demonstrated strong diagnostic ability with AUCs of 0.95 (95% CI 0.88-1.00) for ATTR and 0.88 (95% CI 0.770-0.961) for AL. Survival prediction models identified key prognostic markers, with significant stratification of overall mortality based on predicted survival (p value = 0.006; adj HR 2.43 [95% CI 1.03-5.71]).

CONCLUSION

The integration of 11C-PiB PET/CT and 99mTc-DPD scintigraphy, supported by both machine learning and rationale-based models, enhances the diagnostic accuracy and prognostic assessment of cardiac amyloidosis, with significant implications for clinical practice.

Tracking the Preclinical Progression of Transthyretin Amyloid Cardiomyopathy Using Artificial Intelligence-Enabled Electrocardiography and Echocardiography

Background and Aims

The diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) requires advanced imaging, precluding large-scale pre-clinical testing. Artificial intelligence (AI)-enabled transthoracic echocardiography (TTE) and electrocardiography (ECG) may provide a scalable strategy for pre-clinical monitoring.

Methods

This was a retrospective analysis of individuals referred for nuclear cardiac amyloid testing at Yale-New Haven Health System (YNHHS, internal cohort) and Houston Methodist Hospitals (HMH, external cohort). Deep learning models trained to discriminate ATTR-CM from age/sex-matched controls on TTE videos (AI-Echo) and ECG images (AI-ECG) were deployed to generate study-level ATTR-CM probabilities (0-100%). Longitudinal trends in AI-derived probabilities were examined using age/sex-adjusted linear mixed models, and their discrimination of future disease was evaluated across preclinical stages.

Results

Among 984 participants at YNHHS (median age 74 years, 44.3% female) and 806 at HMH (69 years, 34.5% female), 112 (11.4%) and 174 (21.6%) tested positive for ATTR-CM, respectively. Across cohorts and modalities, AI-derived ATTR-CM probabilities from 7,352 TTEs and 32,205 ECGs diverged as early as 3 years before diagnosis in cases versus controls (p time(x)group interaction≤0.004). Among those with both AI-Echo and AI-ECG available one-to-three years before nuclear testing (n=433 [YNHHS] and 174 [HMH]), a double-negative screen at a 0.05 threshold (164 [37.9%] and 66 [37.9%], vs all else) had 90.9% and 85.7% sensitivity (specificity of 40.3% and 41.2%), whereas a double-positive screen (78 [18.0%] and 26 [14.9%], vs all else) had 85.5% and 88.9% specificity (sensitivity of 60.6% and 42.9%).

Conclusions

AI-enabled echocardiography and electrocardiography may enable scalable risk stratification of ATTR-CM during its pre-clinical course.

Diagnostic value of bone scintigraphy versus cardiovascular magnetic resonance in cardiac amyloidosis

BACKGROUND

Accurate diagnosis of transthyretin amyloidosis cardiomyopathy (ATTR-CM) and its differentiation from light-chain (AL) cardiac amyloidosis (CA) cases (AL-CM) are of paramount importance. Surprisingly, comparative imaging data based on concurrent cardiovascular magnetic resonance (CMR) and bone scintigraphy in the same patients with biopsy-proven diagnosis of CA are still rare.

METHODS

This was a real-world retrospective single-center study based on a local clinical care pipeline and we carefully analyzed clinical, laboratory, CMR, and bone scintigraphy data (and if necessary additional endomyocardial biopsy [EMB] data) in patients with suspected CA. As a major inclusion criterion, we only looked at those patients who underwent both a CMR study and a bone scintigraphy-with a clear-cut imaging finding detected by at least one imaging method.

RESULTS

One hundred twenty three patients in whom the final diagnosis was obtained either non-invasively based on combined findings from bone scintigraphy and monoclonal protein studies or invasively based on additional EMB findings were included. A positive CMR result indicating the presence of CA was found in 121 patients-suggesting a CMR sensitivity of 98.4% for the diagnosis of any CA. Bone scintigraphy identified 18 patients with low to moderate uptake (Perugini score = 0-1) and 105 patients with high uptake (Perugini score ≥2)-resulting in a sensitivity for bone scintigraphy of 85.4% for the diagnosis of any CA. There was an agreement ("diagnostic match") between CMR and bone scintigraphy results in 103 patients (84%) of the total study cohort, while a discrepancy ("diagnostic mismatch") was observed in 20 patients (16%). In 18 out of these 20 diagnostic mismatch cases, CMR correctly diagnosed the presence of CA despite a negative or inconclusive result on bone scintigraphy (8 with AL-CM, 8 with ATTR-CM, and 2 with EMB-proven but unspecified CA).

CONCLUSION

CMR shows a substantially higher diagnostic yield for the diagnosis of CA compared to bone scintigraphy, if a real-world cohort of patients comprising different subtypes of CA is looked at, since CMR does not only detect ATTR-CM but also depicts other CA subtypes such as AL. In case of a clear-cut positive CMR result unequivocally indicative of CA, there is no incremental diagnostic value of an additionally performed bone scintigraphy.

Clinically approved representative small-molecule drugs for cardiopathy therapy

The application of therapeutic agents for cardiopathy has brought about significant advancements in the treatment of cardiovascular diseases. The intervention of small-molecule drugs has led to substantial reductions in morbidity and mortality rates, along with decreased utilization of healthcare resources. However, current treatment modalities do not exhibit uniform efficacy across all patients, and the emergence of drug resistance poses a significant challenge to further therapeutic efforts. Additionally, chronic administration of these drugs can result in toxicities, adding complexity to long-term management. This review focuses on the application of clinically approved small-molecule drugs for the treatment of cardiopathy, covering major classes such as angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, β-blockers, and sodium-glucose co-transporter 2 inhibitors. The review provides an in-depth analysis of their synthetic routes, mechanisms of action, and roles in cardiopathy treatment. It also offers perspectives on future directions in the development of next-generation cardioprotective agents, aiming to optimize therapeutic strategies for cardiovascular disease management.

Comparison of in-clinic assessment of 6MWT by conventional method and using wearable sensors for patients with ATTR-CM

INTRODUCTION

The 6-minute walk test (6MWT) is used to assess submaximal exercise capacity in clinical trials. Conducting the 6MWT can be challenging when patients cannot visit the clinic due to physical/travel limitations. This pilot study assessed the feasibility of conducting the 6MWT using wearable sensors for patients with transthyretin amyloid cardiomyopathy.

METHODS

Participants were enrolled in the phase 3 ATTRibute-CM trial. Sensors were positioned on patients' feet and lower back during the 6MWT. The 6-minute walk distance (6MWD) was compared with the distance measured by a trained observer during a concurrent conventional test. Pearson and concordance correlation coefficients were estimated.

RESULTS

Twelve participants from five centers participated; 11 had evaluable data. Mean 6MWD was 330.3 m (conventional method) and 335.1 m (wearable sensors); mean difference (SD) was 4.7 m (10.95). Pearson and concordance correlation coefficients for 6MWD were 0.998 (95% CI: 0.992-0.999) and 0.997 (95% CI: 0.991-0.999), respectively.

CONCLUSIONS

The 6MWD measured using wearable sensors and by the conventional method were closely correlated. Conducting the 6MWT with wearable sensors may be feasible and as reliable as the conventional method in a monitored clinic setting. Whether at-home 6MWD measured by wearable sensors correlates with in-clinic monitoring deserves further study.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier is NCT03860935.

Disease-modifying therapies for amyloid transthyretin cardiomyopathy: Current and emerging medications

Transthyretin amyloidosis (ATTR) is a rare disease that results in amyloid fibril misfolding and deposition in multiple organs, including the heart, leading to the development of ATTR cardiomyopathy (ATTR-CM), which is associated with poor outcomes. In the last decade, several disease-modifying medications are in advanced stages of clinical development or have been approved to treat ATTR-CM. The purpose of this review is to critically evaluate clinical trial data investigating the use of approved and investigational medications for the treatment of ATTR-CM. We performed a comprehensive literature search via PubMed and EMBASE to identify randomized controlled trials evaluating medications for the treatment of ATTR-CM published through August 2024. This narrative review describes the pathophysiology of ATTR-CM, highlights important screening and diagnostic work-up, and summarizes the existing clinical evidence resulting from our literature search. Several classes of disease-modifying medications are in development for ATTR-CM. The tetramer stabilizers and transthyretin silencers have proven to be the most effective therapies to date. Tafamidis and acoramidis are currently approved for ATTR-CM while vutrisiran approval for ATTR-CM may be forthcoming. Other disease-modifying medication classes in development include antisense oligonucleotides, gene editing therapies, and monoclonal antibodies. However, several unmet needs exist including the lack of cost-effectiveness due to the extremely high acquisition costs of these medications. Disease-modifying medications approved and in development to treat ATTR-CM offer hope for patients with this disease, but their lack of affordability is the biggest barrier to their use.

Early diagnosis, disease stage and prognosis in wild-type transthyretin amyloid cardiomyopathy: The DIAMOND study

AIMS

Disease staging and prognostic scoring in wild-type transthyretin-related cardiac amyloidosis (ATTRwt-CA) can be captured by two systems (NAC and Columbia scores). However, uncertainty remains as epidemiology of the disease is evolving rapidly. We evaluated features associated with staging systems across ATTRwt-CA patients from different diagnostic pathways, and their association with prognosis.

METHODS

We performed an analysis on DIAMOND patients with available data to evaluate NAC and Columbia score. DIAMOND was a retrospective study from 17 Italian referral centres for CA, enrolling 1281 patients diagnosed between 2016 and 2021, and aimed at describing characteristics of pathways leading to ATTRwt-CA diagnosis. Of the original cohort, 811 patients were included in this analysis. Each patient had NAC and Columbia score calculated. Patients were grouped according to NAC and Columbia scoring classes. We described characteristics of patients according to staging classes and diagnostic pathways at diagnosis. Prevalence of early diagnoses, defined as NAC Ia, NYHA class I, no use of diuretics, no history of heart failure (HF) hospitalizations nor of atrial fibrillation prior to diagnosis, was investigated. Finally, prognostic variables were tested alone and grouped as NAC or Columbia scores in Cox univariate and multivariate regression analyses. Prognosis was investigated as all-cause mortality, in the whole population and dividing patients in HF versus other diagnostic pathways.

RESULTS

Only 1% of the study population had an early ATTRwt-CA diagnosis. Distribution of prognostic variables and of NAC and Columbia classes was heterogeneous across diagnostic pathways. The prevalence of NAC III and Columbia III was higher in the HF diagnostic pathway, but all NAC and Columbia classes were present in all pathways. Both NAC and Columbia scores were associated with all-cause mortality at univariate Cox regression analysis in the whole population, in patients from the HF diagnostic pathway and in those from other pathways. At multivariate analysis, Columbia score remained significantly associated with the outcome, together with age at diagnosis, left ventricular ejection fraction and maximal wall thickness.

CONCLUSIONS

In this contemporary nationwide cohort, an ATTRwt-CA early diagnosis was very rare. Disease staging with NAC and Columbia scoring systems determined classes of patients with heterogeneous features. Both scores were significantly associated with mortality, but other variables also had prognostic significance.

Cardiac amyloidosis: Innovations in diagnosis and treatment

Cardiac amyloidosis (CA) is a progressive, underdiagnosed condition caused by the deposition of misfolded proteins in the myocardium, forming amyloid fibrils that impair cardiac structure and function. This review highlights recent advances in the diagnosis and treatment of amyloid light-chain (AL) and transthyretin (ATTR) CA, which globally account for most cases of CA. Novel diagnostic tools, including artificial intelligence-enhanced analysis and advanced imaging modalities like positron emission tomography with amyloid-specific tracers, might improve detection rates and diagnostic accuracy to enable non-invasive subtype differentiation. Furthermore, many innovative treatments are being investigated. For AL-CA, anti-fibril therapies are showing promising results, complementing traditional chemotherapy and autologous stem cell transplantation. In ATTR-CA, gene silencing and anti-fibril therapies are being tested in clinical trials and hold promise of halting disease progression and reducing amyloid deposits, respectively.

Artificial intelligence-guided detection of under-recognised cardiomyopathies on point-of-care cardiac ultrasonography: a multicentre study

BACKGROUND

Point-of-care ultrasonography (POCUS) enables cardiac imaging at the bedside and in communities but is limited by abbreviated protocols and variation in quality. We aimed to develop and test artificial intelligence (AI) models to screen for under-diagnosed cardiomyopathies from cardiac POCUS.

METHODS

In a development set of 290 245 transthoracic echocardiographic videos across the Yale-New Haven Health System (YNHHS), we used augmentation approaches, and a customised loss function weighted for view quality to derive a POCUS-adapted, multi-label, video-based convolutional neural network that discriminates hypertrophic cardiomyopathy and transthyretin amyloid cardiomyopathy from controls without known disease. We evaluated the model across independent, internal, and external, retrospective cohorts of individuals undergoing cardiac POCUS across YNHHS and the Mount Sinai Health System (MSHS) emergency departments (between 2012 and 2024) to prioritise key views and validate the diagnostic and prognostic performance of single-view screening protocols.

FINDINGS

Between Nov 1, 2023, and March 28, 2024, we identified 33 127 patients (mean age 58·9 [SD 20·5] years, 17 276 [52·2%] were female, 14 923 [45·0%] were male, and for 928 [2·8%] sex was recorded as unknown) at YNHHS and 5624 patients (mean age 56·0 [20·5] years, 1953 [34·7%] were female, 2470 [43·9%] were male, and for 1201 [21·4%] sex was recorded as unknown) at MSHS with 78 054 and 13 796 eligible cardiac POCUS videos, respectively. AI deployed to single-view POCUS videos successfully discriminated hypertrophic cardiomyopathy (eg, area under the receiver operating characteristic curve 0·903 [95% CI 0·795-0·981] in YNHHS; 0·890 [0·839-0·938] in MSHS for apical-4-chamber acquisitions) and transthyretin amyloid cardiomyopathy (0·907 [0·874-0·932] in YNHHS; 0·972 [0·959-0·983] in MSHS for parasternal acquisitions). In YNHHS, 40 (58%) of 69 hypertrophic cardiomyopathy cases and 22 (46%) of 48 transthyretin amyloid cardiomyopathy cases would have had a positive screen by AI-POCUS at a median of 2·1 (IQR 0·9-4·5) years and 1·9 (0·6-3·5) years before diagnosis. Moreover, among 25 261 participants without known cardiomyopathy followed up over a median of 2·8 (1·2-6·4) years, AI-POCUS probabilities in the highest (vs lowest) quintile for hypertrophic cardiomyopathy and transthyretin amyloid cardiomyopathy conferred a 17% (adjusted hazard ratio 1·17, 95% CI 1·06-1·29; p=0·0022) and 32% (1·39, 1·19-1·46; p<0·0001) higher adjusted mortality risk, respectively.

INTERPRETATION

We developed and validated an AI framework that enables scalable, opportunistic screening of under-recognised cardiomyopathies through simple POCUS acquisitions.

FUNDING

National Heart, Lung, and Blood Institute, Doris Duke Charitable Foundation, and BridgeBio.

Suspicion and referral of patients with transthyretin amyloid cardiomyopathy: Recommendations by a Portuguese multidisciplinary expert panel

Early diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) is crucial for better disease management and outcome. To ensure timely diagnosis, a multidisciplinary panel of Portuguese experts, including cardiologists, internal medicine specialists, and general practitioners, have developed a national consensus to aid physicians in enhancing the referral of patients with suspicion of ATTR-CM in Portugal. A structured approach was used to develop the consensus: (1) an online survey aimed at identifying clinical red flags, patient journeys, and diagnostic tools related to ATTR-CM; (2) a face-to-face roundtable meeting where the survey findings were discussed and a consensus was reached on referral and diagnostic algorithms for ATTR-CM in Portugal; and (3) critical review of the proposed algorithms. The referral and diagnostic algorithms for ATTR-CM in Portugal were developed considering current recommendations, but also the existence of a nationwide network of specialized cardiomyopathy clinics and national reference centers for familial amyloid polyneuropathy due to the endemic p.V50M variant. This collaborative effort aims to enhance awareness, facilitate timely referrals and improve early diagnosis, ultimately ensuring better management of ATTR-CM patients in Portugal.

Multifaceted pulmonary manifestations of amyloidosis: state-of-the-art update

INTRODUCTION

Amyloidosis, a polymeric deposition disease classified according to protein subtype, may have varied pulmonary manifestations. Its anatomic-radiologic phenotypes include nodular, cystic, alveolar-septal, and tracheobronchial forms. Clinical presentation may range from asymptomatic parenchymal nodules to respiratory failure from diffuse parenchymal infiltration or diaphragmatic deposition.

AREAS COVERED

In this review, we systematically describe the molecular subtypes of amyloidosis and their clinical and radiologic findings in the lungs as well as key extrapulmonary organ systems. We detail novel treatment approaches to systemic amyloidosis. We also discuss prognostic elements for each subtype. We identify key clinical scenarios where reaching a precise diagnosis can be complicated, and we offer insights on the varied presentations of pulmonary amyloidosis.

EXPERT OPINION

Pulmonary amyloidosis is often difficult to diagnose as it may mimic other conditions, including fibrotic interstitial lung diseases and neoplasms, or can co-exist with certain connective tissue diseases. Despite some early artificial intelligence screening tools, improved familiarity among clinicians can aid in the more accurate and timely diagnosis of this multidimensional clinical entity. We additionally believe that multidisciplinary clinical pathwaysto diagnose and/or treat pulmonary amyloidosis have the potential to improve awareness, decrease diagnostic delay, and further elucidate knowledge on this multifaceted disease.

2024 update in heart failure

In the last years, major progress has occurred in heart failure (HF) management. The 2023 ESC focused update of the 2021 HF guidelines introduced new key recommendations based on the results of the last years of science. First, two drugs, sodium-glucose co-transporter-2 (SGLT2) inhibitors and finerenone, a novel nonsteroidal, selective mineralocorticoid receptor antagonist (MRA), are recommended for the prevention of HF in patients with diabetic chronic kidney disease (CKD). Second, SGLT2 inhibitors are now recommended for the treatment of HF across the entire left ventricular ejection fraction spectrum. The benefits of quadruple therapy in patients with HF with reduced ejection fraction (HFrEF) are well established. Its rapid and early up-titration along with a close follow-up with frequent clinical and laboratory re-assessment after an episode of acute HF (the so-called 'high-intensity care' strategy) was associated with better outcomes in the STRONG-HF trial. Patients experiencing an episode of worsening HF might require a fifth drug, vericiguat. In the STEP-HFpEF-DM and STEP-HFpEF trials, semaglutide 2.4 mg once weekly administered for 1 year decreased body weight and significantly improved quality of life and the 6 min walk distance in obese patients with HF with preserved ejection fraction (HFpEF) with or without a history of diabetes. Further data on safety and efficacy, including also hard endpoints, are needed to support the addition of acetazolamide or hydrochlorothiazide to a standard diuretic regimen in patients hospitalized due to acute HF. In the meantime, PUSH-AHF supported the use of natriuresis-guided diuretic therapy. Further options and most recent evidence for the treatment of HF, including specific drugs for cardiomyopathies (i.e., mavacamten in hypertrophic cardiomyopathy and tafamidis in transthyretin cardiac amyloidosis), device therapies, cardiac contractility modulation and percutaneous treatment of valvulopathies, with the recent finding from the TRILUMINATE Pivotal trial, are also reviewed in this article.

Predictors of mortality by an artificial intelligence enhanced electrocardiogram model for cardiac amyloidosis

AIMS

We aim to determine if our previously validated, diagnostic artificial intelligence (AI) electrocardiogram (ECG) model is prognostic for survival among patients with cardiac amyloidosis (CA).

METHODS

A total of 2533 patients with CA (1834 with light chain amyloidosis (AL), 530 with wild-type transthyretin amyloid protein (ATTRwt) and 169 with hereditary transthyretin amyloid (ATTRv)] were included. An amyloid AI ECG (A2E) score was calculated for each patient reflecting the likelihood of CA. CA stage was calculated using the European modification of the Mayo 2004 criteria for AL and Mayo stage for transthyretin amyloid (ATTR). Risk of death was modelled using Cox proportional hazards, and Kaplan-Meier was used to estimate survival.

RESULTS

Median age of the cohort was 67 [inter-quartile ratio (IQR) 59, 74], and 71.6% were male. The median overall survival for the cohort was 35.6 months [95% confidence interval (CI) 32.3, 39.5]. For AL, ATTRwt and ATTRv, respectively, median survival was 22.9 (95% CI 19.2, 28.2), 47.2 (95% CI 43.4, 52.3) and 61.4 (95% CI 48.7, 75.9) months. On univariate analysis, an increasing A2E score was associated with more than a two-fold risk of all-cause death. On multivariable analysis, the A2E score retained its importance with a risk ratio of 2.0 (95% CI 1.58, 2.55) in the AL group and 2.7 (95% CI 1.81, 4.24) in the ATTR group.

CONCLUSIONS

Among patients with AL and ATTR amyloidosis, the A2E model helps to stratify risk of CA and adds another dimension of prognostication.

Hereditary Transthyretin Amyloidosis Polyneuropathy

In the last decade, we have witnessed dramatic improvements in the diagnosis, workup, management, and monitoring of patients with hereditary transthyretin amyloidosis (ATTRv). Updated imaging techniques (e.g., 99mTc-PYP scan) are increasingly being used in place of tissue biopsies for confirmation of disease. Novel treatments now include antisense oligonucleotide and RNA interference drugs, whereas new applications such as CRISPR and amyloid antibodies are being studied for potential use in the future. These treatments have dramatically improved quality of life and increased survival in patients with ATTRv. Despite these breakthroughs, many challenges remain. Some of these challenges include early recognition and diagnosis of ATTRv, monitoring and initiation of treatment in asymptomatic or paucisymptomatic carriers, adequate treatment in people with mixed phenotype (i.e., cardiac and neurological), and the emergence of new phenotypes in people living longer with the disease (i.e., central nervous system and ocular complications). Research in those areas of deficit is ongoing, and in the future, we may have preventive therapies, better biomarkers, more efficient therapies for organs that we cannot currently target, and enhanced diagnostic techniques with the help of novel imaging techniques and artificial intelligence. In this review, we will summarize the current knowledge about polyneuropathy related to ATTRv and its management, discuss methods to improve early diagnosis and monitoring, and discuss emerging trends.

Chest pain and coronary artery disease in cardiac amyloidosis: Prevalence, mechanisms, and clinical implications

Amyloidosis is a systemic disease affecting multiple organs, and often presents with cardiac involvement, with 2 primary underlying pathologies: amyloid light chain- and transthyretin cardiac amyloidosis. Chest pain can occur in both types with variable clinical presentations. This narrative review describes the relationship between cardiac amyloidosis (CA) and chest pain. A PubMed search (June 03. 2024) identified 393 articles related to chest pain in CA. Twenty-eight studies, in English and with full text, were selected. Articles included were case reports, reviews, perfusion- and autopsy studies. In CA patients 10%-20% report chest pain as the initial symptom preceding the diagnosis, and the overall prevalence of chest pain is 38% of patients with CA and it is related to an increased risk of heart failure hospitalization. The mechanisms leading to chest pain in CA patients include increased left ventricular diastolic pressure, infiltration of amyloid fibrils inside and around coronary arteries, and amyloid compression of the microvasculature. The mechanisms commonly lead to elevations of plasma troponin levels, which are higher in amyloid patients with chest pain compared to amyloid patients without chest pain. Symptomatic treatment of chest pain can be challenging due to the low tolerability of medical therapy and poor outcomes of coronary interventions in alleviating the pain and with a higher rate of complications. Our review underscores the importance of recognizing chest pain as a CA symptom, particularly in the elderly. Persistent troponin elevation without coronary artery disease could indicate CA. Screening-based and longitudinal studies are crucial for understanding the relationship between chest pain and CA. Acknowledging the significance of chest pain in CA may facilitate early intervention and improve patient outcomes.

Evolving Strategies in Cardiac Amyloidosis: From Mechanistic Discoveries to Diagnostic and Therapeutic Advances

Diagnosis and treatment of cardiac amyloidosis have rapidly evolved over the past decade by harnessing mechanisms of disease pathogenesis. Cardiac amyloidosis is caused by myocardial deposition of fibrils formed by misfolded proteins, namely transthyretin (ATTR) and immunoglobulin light chains (AL). Advances in noninvasive imaging have revolutionized diagnosis of ATTR cardiomyopathy (CM). Novel treatments for ATTR-CM utilize a range of therapeutic techniques, including protein stabilizers, interfering RNA, gene editing, and monoclonal antibodies. AL-CM, primarily driven by plasma cell dyscrasias, requires treatment with chemotherapy and consideration for autologous stem cell transplant. These incredible advances aim to improve patient outcomes in cardiac amyloidosis.

Development and preclinical testing of a naloxone prodrug depot for extended protection against opioid overdose

The opioid crisis, driven by synthetic opioids like fentanyl, demands innovative solutions. The opioid antidote naloxone has a short action ( ~ 1 hour), requiring repeated doses. To address this, we present a new and simple naloxone prodrug delivery system repurposing a hydrophilic derivative of acoramidis, a potent transthyretin ligand. When the fully soluble prodrug solution is administered subcutaneously, the prodrug forms a zwitterionic depot at physiological pH, enabling extended naloxone release. This non-polymeric depot-forming approach is rare and employs carboxylesterase 2 for selective bioactivation, ensuring controlled drug release. In male rats and cynomolgus monkeys, a single subcutaneous dose provides steady naloxone release over several days, reducing blood-brain barrier diffusion, withdrawal symptoms, and CNS toxicity. Preclinical studies demonstrated efficacy in rat overdose models and achieved monkey naloxone levels matching effective human therapeutic levels. Although monkey efficacy was not assessed, combined rat efficacy and monkey pharmacokinetics suggest strong potential for successful human translation.

Repurposing of Agrochemicals as ATTRv Amyloidosis Inhibitors

Transthyretin (TTR), a plasma protein, undergoes transformation into amyloid fibers, leading to ATTRv amyloidosis, a disease characterized by organ deposition of TTR amyloid fibrils and subsequent organ failure. Developing compounds that bind and kinetically stabilize TTR is a crucial strategy in the treatment of ATTRv amyloidosis. In this study, we narrowed 651 pesticide-related compounds down to 14 possible TTR binders through in silico screening; subsequent in vitro analysis revealed that 7 of them exhibited amyloid fibril formation inhibition activity. The herbicide components bromoxynil (6) and ioxynil (21) showed especially high ligand efficiency and efficiently inhibited amyloid fibril formation of amyloidogenic V30M-TTR. Additionally, aclonifen (9) exhibited moderate fibril formation inhibition activity, but showed selective binding to TTR comparable to that of tafamidis. While improvement is needed to the selective TTR-binding or fibril formation inhibition activity, the compounds identified herein are promising lead candidates for the development of ATTRv amyloidosis therapeutics.

The Accuracy of Technetium-99 m Pyrophosphate Imaging in Diagnosing Transthyretin Cardiac Amyloidosis and Its Impact on Patient Management

PURPOSE OF REVIEW

This review evaluates recent advancements in Technetium-99 m pyrophosphate (99mTc-PYP) imaging for transthyretin amyloid cardiomyopathy (ATTR-CM). We summarize the advantages of single-photon emission computed tomography (SPECT) over planar imaging, the potential impact of quantitative methods, and emerging data for quantifying response to therapy.

RECENT FINDINGS

The current literature demonstrates the superior diagnostic accuracy of SPECT compared with planar imaging in 99mTc-PYP studies. Emerging quantitative methods, using hybrid SPECT/CT and artificial intelligence, show promise for enhancing diagnostic precision and risk assessment. Recent studies have also highlighted the potential of 99mTc-PYP quantification for monitoring treatment response. 99mTc-PYP SPECT imaging has exceptional diagnostic accuracy for ATTR-CM. Quantitative techniques, which can be facilitated by artificial intelligence, improve risk stratification and may aid in treatment monitoring. Future research should focus on clarifying the clinical role and optimal approach for quantification.

Transthyretin Cardiac Amyloidosis: Current and Emerging Therapies

PURPOSE OF REVIEW

In this article, we describe current and newer TTR stabilizers, TTR silencers which include small interfering RNA agents (siRNA), antisense oligonucleotides (ASO) and CRISPR-Cas9 gene editing, and TTR depleters, which investigates the use of monoclonal antibodies to remove amyloid fibril deposits for patients with advanced disease.

RECENT FINDINGS

Once thought to be a rare and fatal condition, increased recognition, improved non-invasive diagnostic tools, and the explosive development of novel therapies, has transformed the landscape of transthyretin amyloid cardiomyopathy (ATTR-CM). Advances in cardiac imaging with respect to echocardiography, cardiac magnetic resonance imaging (CMR), and radionuclide bone scintigraphy has increased the diagnosis of ATTR-CM over the last twenty years. Ongoing clinical trials are evaluating several novel therapies at several mechanistic targets in the transthyretin (TTR) amyloidogenesis cascade, including the recently published findings from the study of vutrisiran, a siRNA agent. Our review provides a comprehensive summary of current and emerging therapies for ATTR-CM. While these are promising, disease-modifying treatments, reaching vulnerable populations early in the disease course should be a focus for future studies and interventions.