Diagnostic delay in wild type transthyretin cardiac amyloidosis – A clinical challenge

Changes of clinical characteristics, distribution of red flags and prognosis in contemporary patients with wild-type transthyretin amyloidosis cardiomyopathy

AIM

Increased diagnostic awareness and specific disease treatments have changed the landscape of transthyretin cardiac amyloidosis (ATTR). Patients with wild-type ATTR (ATTRwt) are increasingly being diagnosed, potentially changing the clinical profile and prognosis compared with existing retrospective data. We aimed to study the clinical characteristics, distribution of red flags and prognosis of contemporary ATTRwt patients.

METHODS

From January 1st 2017, to December 31st 2022, 213 consecutive patients were diagnosed with ATTRwt and prospectively followed up. Data on clinical characteristics, biomarkers, echocardiography findings, hospitalization due to worsening heart failure (WHF) and all-cause mortality were collected.

RESULTS

A 37% increase in newly diagnosed patients from 2017-2019 (n = 90) vs. 2020-2022 (n = 123) was observed. The majority of patients presented with NAC disease stage I in the latter period (49% in 2017-2019 vs. 58% in 2020-2022, p = .16). Red flags were primarily cardiac-related, including elevated NT-proBNP, impaired left ventricular longitudinal systolic strain with an apical sparing pattern, heart failure with increased left ventricular wall thickness and elevated troponins. NAC disease stage I as well as low NT-proBNP levels (<1000 ng/L) were significantly associated with better survival (both p < .001). When compared with NAC disease stage II + III combined, patients with NAC disease stage I had a significantly lower risk of WHF hospitalization or death (log rank test: p = .0001). Independent predictors of the combined endpoint WHF hospitalization or death were NT-proBNP (HR 1.03 [95% CI 1.00-1.07], p < .049) and prior implantation of permanent pacemaker (HR 2.01 [1.30-3.11], p = .002).

CONCLUSION

Increased diagnostic awareness resulted in a 37% increase in newly diagnosed patients in 2020-2022 vs. 2017-2019. As expected all-cause mortality but also the morbidity in terms of risk of hospitalization with WHF were significantly lower in patients with NAC disease stage I, as well as in those with low NT-proBNP levels <1000 ng/L. These findings underline the importance of continuous attention to diagnostic awareness, as early diagnosis is critical for initiating both general and specific ATTR treatment, thus improving prognosis.

Diagnostic and therapeutic challenges in rapidly progressing cardiac amyloidosis: a literature review based on case report

INTRODUCTION

Cardiac amyloidosis is a rarely reported and potentially fatal variant of the systemic disease. Its early diagnosis could potentially lead to significantly improved clinical outcomes.

CASE PRESENTATION

A 56-year-old female presented with dyspnea and palpitations. Her physical exam and non-invasive evaluation with cardiac magnetic resonance imaging (CMRI) revealed restrictive cardiomyopathy, and the bone marrow biopsy results showed systemic amyloidosis.

DISCUSSION

The diagnosis of cardiac amyloidosis is not always straightforward, and delay can cause the progression of the disease and an increased risk of morbidity and mortality. Electrocardiograms, echocardiograms, cardiac magnetic resonance imaging, and histopathologic evaluation are the main methods for diagnosing cardiac amyloidosis. The treatment consists of controlling heart failure symptoms and disease-modifying interventions, including medical and surgical therapeutic methods.

CLINICAL LEARNING POINT (CONCLUSION)

Cardiac involvement is the main cause of death in systemic amyloidosis. Early suspicion, diagnosis, and treatment are crucial in improving patients' survival. CMRI can play an essential role in the diagnosis of cardiac Amyloidosis. A graphical abstract is provided for visual summary.

Tracking the pre-clinical progression of transthyretin amyloid cardiomyopathy using artificial intelligence-enabled electrocardiography and echocardiography

Background and Aims

Diagnosing transthyretin amyloid cardiomyopathy (ATTR-CM) requires advanced imaging, precluding large-scale testing for pre-clinical disease. We examined the application of artificial intelligence (AI) to echocardiography (TTE) and electrocardiography (ECG) as a scalable strategy to quantify pre-clinical trends in ATTR-CM.

Methods

Across age/sex-matched case-control datasets in the Yale-New Haven Health System (YNHHS) we trained deep learning models to identify ATTR-CM-specific signatures on TTE videos and ECG images (area under the curve of 0.93 and 0.91, respectively). We deployed these across all studies of individuals referred for cardiac nuclear amyloid imaging in an independent population at YNHHS and an external population from the Houston Methodist Hospitals (HMH) to define longitudinal trends in AI-defined probabilities for ATTR-CM using age/sex-adjusted linear mixed models, and describe discrimination metrics during the early pre-clinical stage.

Results

Among 984 participants referred for cardiac nuclear amyloid imaging 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 both cohorts and modalities, AI-defined ATTR-CM probabilities derived from 7,423 TTEs and 32,205 ECGs showed significantly faster progression rates in the years before clinical diagnosis in cases versus controls (p time × group interaction ≤0.004). In the one-to-three-year window before cardiac nuclear amyloid imaging sensitivity/specificity metrics were estimated at 86.2%/44.2% [YNHHS] vs 65.7%/65.5% [HMH] for AI-Echo, and 89.8%/40.6% [YNHHS] vs 88.5%/35.1% [HMH] for AI-ECG.

Conclusions

We demonstrate that AI tools for echocardiographic videos and ECG images can enable scalable identification of pre-clinical ATTR-CM, flagging individuals who may benefit from risk-modifying therapies.

Artificial intelligence-guided detection of under-recognized cardiomyopathies on point-of-care cardiac ultrasound: a multi-center 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 developed and tested artificial intelligence (AI) models to automate the detection of underdiagnosed 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 customized loss function weighted for view quality to derive a POCUS-adapted, multi-label, video-based convolutional neural network (CNN) that discriminates HCM (hypertrophic cardiomyopathy) and ATTR-CM (transthyretin amyloid cardiomyopathy) from controls without known disease. We evaluated the final model across independent, internal and external, retrospective cohorts of individuals who underwent cardiac POCUS across YNHHS and Mount Sinai Health System (MSHS) emergency departments (EDs) (2011-2024) to prioritize key views and validate the diagnostic and prognostic performance of single-view screening protocols.

Findings

We identified 33,127 patients (median age 61 [IQR: 45-75] years, n=17,276 [52·2%] female) at YNHHS and 5,624 (57 [IQR: 39-71] years, n=1,953 [34·7%] female) at MSHS with 78,054 and 13,796 eligible cardiac POCUS videos, respectively. An AI-enabled single-view screening approach successfully discriminated HCM (AUROC of 0·90 [YNHHS] & 0·89 [MSHS]) and ATTR-CM (YNHHS: AUROC of 0·92 [YNHHS] & 0·99 [MSHS]). In YNHHS, 40 (58·0%) HCM and 23 (47·9%) ATTR-CM cases had a positive screen at median of 2·1 [IQR: 0·9-4·5] and 1·9 [IQR: 1·0-3·4] years before clinical diagnosis. Moreover, among 24,448 participants without known cardiomyopathy followed over 2·2 [IQR: 1·1-5·8] years, AI-POCUS probabilities in the highest (vs lowest) quintile for HCM and ATTR-CM conferred a 15% (adj.HR 1·15 [95%CI: 1·02-1·29]) and 39% (adj.HR 1·39 [95%CI: 1·22-1·59]) higher age- and sex-adjusted mortality risk, respectively.

Interpretation

We developed and validated an AI framework that enables scalable, opportunistic screening of treatable cardiomyopathies wherever POCUS is used.

Funding

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

Detection of transthyretin amyloid cardiomyopathy by automated data extraction from electronic health records

AIMS

Transthyretin amyloid cardiomyopathy (ATTR-CM), a progressive and fatal cardiomyopathy, is frequently misdiagnosed or entails diagnostic delays, hindering patients from timely treatment. This study aimed to generate a systematic framework based on data from electronic health records (EHRs) to assess patients with ATTR-CM in a real-world population of heart failure (HF) patients. Predictive factors or combinations of predictive factors related to ATTR-CM in a European population were also assessed.

METHODS AND RESULTS

Retrospective unstructured and semi-structured data from EHRs of patients from OLV Hospital Aalst, Belgium (2012-20), were processed using natural language processing (NLP) to generate an Observational Medical Outcomes Partnership Common Data Model database. NLP model performance was assessed on a random subset of EHRs by comparing algorithm outputs to a physician-generated standard (using precision, recall, and their harmonic mean, or F1-score). Of the 3127 HF patients, 103 potentially had ATTR-CM (age 78 ± 9 years; male 55%; ejection fraction of 48% ± 16). The mean diagnostic delay between HF and ATTR-CM diagnosis was 1.8 years. Besides HF and cardiomyopathy-related phenotypes, the strongest cardiac predictor was atrial fibrillation (AF; 72% in ATTR-CM vs. 60% in non-ATTR-CM, P = 0.02), whereas the strongest non-cardiac predictor was carpal tunnel syndrome (21% in ATTR-CM vs. 3% in non-ATTR-CM, P < 0.001). The strongest combination predictor was AF, joint disorders, and HF with preserved ejection fraction (29% in ATTR-CM vs. 18% in non-ATTR-CM: odds ratio = 2.03, 95% confidence interval = 1.28-3.22).

CONCLUSIONS

Not only well-known variables associated with ATTR-CM but also unique combinations of cardiac and non-cardiac phenotypes are able to predict ATTR-CM in a real-world HF population, aiding in early identification of ATTR-CM patients.

Routine 4D Cardiac CT to Identify Concomitant Transthyretin Amyloid Cardiomyopathy in Older Adults with Severe Aortic Stenosis

Background Transthyretin amyloid cardiomyopathy (ATTR-CM) often coexists with severe aortic stenosis (AS). Although strain analysis from cardiac MRI and echocardiography was demonstrated to predict coexisting ATTR-CM, comparable data from four-dimensional (4D) cardiac CT are lacking despite wide availability. Purpose To evaluate the diagnostic performance of 4D cardiac CT-derived parameters in identifying ATTR-CM in older adults considered for transcatheter aortic valve implantation (TAVI). Materials and Methods This prospective single-center screening study for ATTR-CM included consecutive patients with severe AS considered for TAVI who underwent 4D cardiac CT between August 2019 and August 2021 approximately 1 day before technetium 99m (99mTc) 3,3-diphosphono-1,2-propanodicarboxylic-acid (DPD) scintigraphy. The diagnostic performance of CT-based left ventricular (LV), right ventricular, and left atrial dimensions, ejection fraction (EF), and myocardial strain were evaluated against 99mTc-DPD scintigraphy as the reference standard to identify ATTR-CM. Predictors and an unweighted cardiac CT score were validated with internal bootstrapping. The assignment of variables to the score was based on cutoff values achieving the highest Youden index J. Results Among 263 participants (mean age, 83 years ± 4.6 [SD]; 149 male and 114 female participants), 99mTc-DPD scintigraphy (Perugini grade 2 or 3) confirmed coexisting ATTR-CM in 27 (10.3%). CT-derived LV mass index, LV and LA global longitudinal strain (GLS), and relative apical longitudinal strain each predicted the presence of ATTR-CM with an area under the curve (AUC) of at least 0.70. Implementing these parameters with cutoff values of 81 g/m2 or higher, -14.9% or higher, less than 11.5%, and 1.7 or higher in the CT score, respectively, yielded high diagnostic performance (AUC = 0.89; 95% CI: 0.81, 0.94; P < .001) robust to internal bootstrapping validation (AUC = 0.88; 95% CI: 0.82, 0.94). If two criteria were fulfilled, the sensitivity and specificity in the detection of ATTR-CM were 96.3% (95% CI: 81.0, 99.9) and 58.9% (95% CI: 52.3, 65.2), respectively. Conclusion When compared against 99mTc-DPD scintigraphy as the reference standard, routine 4D cardiac CT in older adults considered for TAVI provided high diagnostic performance in the detection of concomitant ATTR-CM by assessing LV and left atrial GLS, relative apical longitudinal strain, and LV mass index. ClinicalTrials.gov registration no.: NCT04061213 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Tavakoli and Onder in this issue.

Detecting transthyretin amyloid cardiomyopathy (ATTR-CM) using machine learning: an evaluation of the performance of an algorithm in a UK setting

OBJECTIVE

The aim of this study was to evaluate the potential real-world application of a machine learning (ML) algorithm, developed and trained on heart failure (HF) cohorts in the USA, to detect patients with undiagnosed wild type cardiac amyloidosis (ATTRwt) in the UK.

DESIGN

In this retrospective observational study, anonymised, linked primary and secondary care data (Clinical Practice Research Datalink GOLD and Hospital Episode Statistics, respectively, were used to identify patients diagnosed with HF between 2009 and 2018 in the UK. International Classification of Diseases (ICD)-10 clinical modification codes were matched to equivalent Read (primary care) and ICD-10 WHO (secondary care) diagnosis codes used in the UK. In the absence of specific Read or ICD-10 WHO codes for ATTRwt, two proxy case definitions (definitive and possible cases) based on the degree of confidence that the contributing codes defined true ATTRwt cases were created using ML.

PRIMARY OUTCOME MEASURE

Algorithm performance was evaluated primarily using the area under the receiver operating curve (AUROC) by comparing the actual versus algorithm predicted case definitions at varying sensitivities and specificities.

RESULTS

The algorithm demonstrated strongest predictive ability when a combination of primary care and secondary care data were used (AUROC: 0.84 in definitive cohort and 0.86 in possible cohort). For primary care or secondary care data alone, performance ranged from 0.68 to 0.78.

CONCLUSION

The ML algorithm, despite being developed in a US population, was effective at identifying patients that may have ATTRwt in a UK setting. Its potential use in research and clinical care to aid identification of patients with undiagnosed ATTRwt, possibly enabling earlier diagnosis in the disease pathway, should be investigated.

World Heart Federation Consensus on Transthyretin Amyloidosis Cardiomyopathy (ATTR-CM)

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and fatal condition that requires early diagnosis, management, and specific treatment. The availability of new disease-modifying therapies has made successful treatment a reality. Transthyretin amyloid cardiomyopathy can be either age-related (wild-type form) or caused by mutations in the TTR gene (genetic, hereditary forms). It is a systemic disease, and while the genetic forms may exhibit a variety of symptoms, a predominant cardiac phenotype is often present. This document aims to provide an overview of ATTR-CM amyloidosis focusing on cardiac involvement, which is the most critical factor for prognosis. It will discuss the available tools for early diagnosis and patient management, given that specific treatments are more effective in the early stages of the disease, and will highlight the importance of a multidisciplinary approach and of specialized amyloidosis centres. To accomplish these goals, the World Heart Federation assembled a panel of 18 expert clinicians specialized in TTR amyloidosis from 13 countries, along with a representative from the Amyloidosis Alliance, a patient advocacy group. This document is based on a review of published literature, expert opinions, registries data, patients' perspectives, treatment options, and ongoing developments, as well as the progress made possible via the existence of centres of excellence. From the patients' perspective, increasing disease awareness is crucial to achieving an early and accurate diagnosis. Patients also seek to receive care at specialized amyloidosis centres and be fully informed about their treatment and prognosis.

Strain-derived myocardial work in wild-type transthyretin cardiac amyloidosis with aortic stenosis-diagnosis and prognosis

BACKGROUND

Several echocardiographic parameters have been suggested to differentiate wild-type transthyretin cardiac amyloidosis (ATTRwt) from other causes of hypertrophy. These studies have all been performed in small samples of mixed cardiac amyloidosis. The purpose of this study was to investigate the role of echocardiographic parameters in patients with ATTRwt and aortic stenosis (AS) versus patients with AS. The secondary aim was to investigate the role of myocardial work in the prognosis of patients with ATTRwt.

METHODS

The sensitivity and specificity of the relative apical sparing ratio (RAS), the apical-to-basal ratio (AB), the ejection-fraction-to-global-longitudinal-strain ratio (EF/GLS), and the global myocardial work index (GWI) were calculated using receiver-operated characteristics curves and area under the curve (AUC) in patients with ATTRwt and AS (n = 50) versus patients with AS (n = 354). Multivariable regression was used to assess the prognostic value of GWI in patients with ATTRwt (n = 212).

RESULTS

When used to identify AS from ATTRwt + AS, GWI had a sensitivity of 80% and specificity of 70%. The AUC of GWI was larger than that of AB (p = .01) and EF/GLS (p > .01) but not RAS (p = .15). In patients with ATTRwt multivariable regression found age predicted mortality with an estimate of HR = 1.086 (CI: 1.034-1.141) while GWI predicted survival with an estimate of HR = .837 (CI: .733-.956) per 100 mmHg*% increase.

CONCLUSION

GWI was demonstrated to be a viable classifier in ATTRwt and AS versus AS. GWI was demonstrated to independently predict survival in patients with ATTRwt. Further studies examining the role of myocardial work in ATTRwt are warranted.

The patient pathway in ATTR-CM in Greece and how to improve it: A multidisciplinary perspective

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed disease associated with high mortality rates and the patient journey is characterized by increased complexities. Accurate and timely diagnosis and prompt initiation of disease-modifying treatment constitute the contemporary unmet need in ATTR-CM. ATTR-CM diagnosis is characterized by considerable delays and high rates of misdiagnosis. The majority of patients present themselves to primary care physicians, internists, and cardiologists, and many have undergone repeated medical evaluations before an accurate diagnosis has been made. The disease is diagnosed mainly after the development of heart failure symptoms, reflecting a long course of missed opportunities before diagnosis and disease-modifying treatment initiation. Early referral to experienced centers ensures prompt diagnosis and therapy. Early diagnosis, better care coordination, acceleration of digital transformation and reference networks, encouragement of patient engagement, and implementation of rare disease registries are the key pillars to improve the ATTR-CM patient pathway and achieve important benefits in ATTR-CM outcomes.

Clinical characteristics and health care resource use of patients at risk for wild-type transthyretin amyloid cardiomyopathy identified by machine learning model

BACKGROUND: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive, life-threatening systemic disorder that is an underrecognized cause of heart failure (HF). When the diagnosis of wild-type ATTR-CM (ATTRwt-CM) is delayed, patients often undergo additional assessments, deferring appropriate management as symptoms potentially worsen. Prompt recognition of patients at risk for ATTRwt-CM is essential to facilitate earlier diagnosis and disease-modifying treatment. A previously developed machine learning model performed well in identifying ATTRwt-CM in patients with HF vs controls with nonamyloid HF using medical claims/electronic health records, providing a systematic framework to raise disease suspicion. OBJECTIVE: To further evaluate this model's performance in identifying ATTRwt-CM using a large claims database of older adults with HF and confirmed ATTRwt-CM or nonamyloid HF; and to explore the characteristics and health care resource utilization (HCRU) of patients with confirmed and suspected ATTRwt-CM. METHODS: In this retrospective study, the prior model was applied using Humana administrative claims for patients diagnosed with ATTRwt-CM (cases) and nonamyloid HF (controls [1:1]). Patients were aged 65-89 years, had at least 2 claims for HF diagnosis (2015-2020), and were continuously enrolled in a Medicare Advantage prescription drug plan for at least 12 months before and at least 6 months after HF diagnosis. For the assessment of characteristics and HCRU, the suspected risk level was categorized based on the predicted probability (PP) from model output (high, moderate, and low risk: PP≥0.70; ≥0.50 and < 0.70; and < 0.50, respectively). RESULTS: Of 267,025 eligible patients, 119 (0.04%) had confirmed ATTRwt-CM; of 266,906 patients with nonamyloid HF, 10,997 (4.1%), 68,174 (25.5%), and 187,735 (70.3%) were categorized as high, moderate, and low risk for ATTRwt-CM, respectively. The model demonstrated sensitivity/specificity/accuracy/receiver operating characteristic area under the concentration-time curve of 88%/65%/77%/0.89, respectively, in differentiating ATTRwt-CM from nonamyloid HF. In patients with confirmed ATTRwt-CM, the mean (SD) time between HF and ATTRwt-CM diagnoses was 751 (528) days; 65% and 48% were hospitalized before and after ATTRwt-CM diagnosis, respectively. Atrial fibrillation was more common in patients with confirmed ATTRwt-CM and high risk (39% and 55%) vs low risk (27%). Hospitalization and emergency department visits after HF diagnosis were reported in 57% and 46% of patients with high ATTRwt-CM risk, respectively. CONCLUSIONS: The ATTRwt-CM predictive model performed well in identifying disease risk in the Humana Research Database. Patients at high risk for ATTRwt-CM had high HCRU and may benefit from the earlier suspicion of ATTRwt-CM. The model may be used as a tool to identify patients with a suspected high risk for the disease to facilitate earlier detection and treatment. DISCLOSURES: This study was sponsored by Pfizer. Medical writing support was provided by Donna McGuire of Engage Scientific Solutions and funded by Pfizer. Drs Bruno and Schepart and Mr Casey are currently employees of Pfizer and equity holders in this publicly traded company. Dr Reed was an employee of Pfizer at the time that this analysis was planned and conducted. Mr Sheer and Dr Simmons are currently employees of Humana, which received research funding from Pfizer. Dr Nair was an employee of Humana at the time that this analysis was planned and conducted.

Health-related quality of life among transthyretin amyloid cardiomyopathy patients

AIMS

Transthyretin amyloid cardiomyopathy (ATTR CM) is a progressive and severe heart disease with physical and psychological implications. The Nordic PROACT study was conducted to investigate the health-related quality of life (HRQoL) in ATTR CM patients.

METHODS AND RESULTS

The Nordic PROACT study was a cross-sectional non-interventional study conducted in 12 cardiology hospital clinics across Norway, Sweden, Finland and Denmark. Men and women aged ≥18 years diagnosed with symptomatic ATTR CM were included. The investigator provided information on medical history, biomarkers, current treatment, co-morbidities and disease severity according to the New York Heart Association (NYHA) class and the National Amyloidosis Centre (NAC) staging. Patients completed the HRQoL questionnaires in the form of the Kansas City Cardiomyopathy Questionnaire (KCCQ), the EQ-5D-5L index with Visual Analog Scale (VAS), and the Major Depression Inventory (MDI). A total of 169 patients (mean ± SD age 77.7 ± 6.2 years) were included. Ninety-two per cent were men. Seventy-six per cent had wildtype ATTR CM (ATTRwt CM) and 15% had a hereditary form of ATTR CM (ATTRv CM) while 9% were genetically unclassified. Most patients were in NYHA class II (54%) and NAC stage 1 (53%). Participation in randomized clinical trials (RCT) was noted in 58% of the patients. The 169 ATTR CM patients had a mean ± SD KCCQ score of 64.3 ± 23.1 for total symptom score, 64.8 ± 20.9 for overall summary score (OSS) and 65.1 ± 21.5 for clinical summary score. The EQ-5D-5L total utility score was 0.8 ± 0.2 and the EQ-5D-5L VAS score was 62.9 ± 20.6. The vast majority (89%) did not report any signs of depression. Patients with ATTRv CM had a higher KCCQ OSS as compared with ATTRwt CM, while EQ-5D-5L utility score, EQ-5D-5L VAS and MDI were similar. Non-RCT participants had a poorer HRQoL as compared with RCT participants as reflected in lower KCCQ OSS and EQ-5D-5L VAS scores and a higher MDI score. Patients with higher NYHA classes and NAC disease stages had a poorer HRQoL as demonstrated by lower KCCQ and EQ-5D-5L scores and higher MDI scores. Correlation between KCCQ, EQ-5D-5L and MDI and the covariate NYHA class remained significant (P < 0.05) after adjusting for multiple testing.

CONCLUSIONS

KCCQ scores were lower than previously reported for patients with other heart diseases of non-ATTR CM origin. The HRQoL measures correlated well to NYHA class and NAC disease stage. The prevalence of depression appeared to be low.

Machine Learning Approaches in Diagnosis, Prognosis and Treatment Selection of Cardiac Amyloidosis

Cardiac amyloidosis is an uncommon restrictive cardiomyopathy featuring an unregulated amyloid protein deposition that impairs organic function. Early cardiac amyloidosis diagnosis is generally delayed by indistinguishable clinical findings of more frequent hypertrophic diseases. Furthermore, amyloidosis is divided into various groups, according to a generally accepted taxonomy, based on the proteins that make up the amyloid deposits; a careful differentiation between the various forms of amyloidosis is necessary to undertake an adequate therapeutic treatment. Thus, cardiac amyloidosis is thought to be underdiagnosed, which delays necessary therapeutic procedures, diminishing quality of life and impairing clinical prognosis. The diagnostic work-up for cardiac amyloidosis begins with the identification of clinical features, electrocardiographic and imaging findings suggestive or compatible with cardiac amyloidosis, and often requires the histological demonstration of amyloid deposition. One approach to overcome the difficulty of an early diagnosis is the use of automated diagnostic algorithms. Machine learning enables the automatic extraction of salient information from “raw data” without the need for pre-processing methods based on the a priori knowledge of the human operator. This review attempts to assess the various diagnostic approaches and artificial intelligence computational techniques in the detection of cardiac amyloidosis.

Prompt diagnosis of a wild-type transthyretin cardiac amyloidosis: Role of multimodality imaging

Amyloidosis cardiomyopathy is a rare and underdiagnosed disease characterized by amyloid fibril deposition in the myocardium. The diagnosis of cardiac amyloidosis is often delayed due to a lack of awareness and the necessity of biopsy to confirm the diagnosis. Recent advances in cardiovascular imaging modalities have enhanced earlier recognition of this disease. A 66-year-old man experiences progressive shortness of breath for two weeks. Laboratory testing was significant for an elevation of cardiac biomarkers (creatine kinase: 522 U/L, troponin I: 0.10 ng/mL) and NT-pro-BNP (5074 pg/mL). He was diagnosed with acute coronary syndrome and received stent deployment. Nonetheless, progressive shortness of breath recurred in 2 months. Transthoracic echocardiography (TTE) demonstrated an increased left ventricular (LV) wall thickness with apical sparing. Cardiac magnetic resonance (CMR) imaging demonstrated high native T1 value, increased extracellular volume fraction as well as diffused subendocardial late gadolinium enhancement. Technetium-99m pyrophosphate (99mTc-PYP) scintigraphy, endomyocardial biopsy (EMB), and the genetic study confirmed the diagnosis of wild-type transthyretin amyloidosis (ATTRwt). The nonspecific clinical manifestations, lack of diagnostic biomarkers, and the rarity of systemic amyloidosis usually lead to delayed diagnosis and treatment. Our objective is to emphasize the role of multimodalities imaging in reducing delays to the diagnosis of cardiac amyloidosis.

Summation of Precordial R Wave Amplitudes, a Clinical Parameter for Detecting Early TTR Amyloidosis Cardiac Involvement

There have been several reports on the identification of the stage of transthyretin amyloid cardiomyopathy (ATTR-CM); however, a staging system for ATTR-CM has not yet been established. An 83-year-old woman was referred to our department about ten years ago. Recently, she was diagnosed with ATTR-CM. The electrocardiogram showed characteristic changes that take place over the duration of ATTR-CM progression. Among these, the precordial R amplitudes abruptly decreased before the development of increased ventricular thickness. This case suggested that the decrease in the precordial R wave amplitudes may represent a new diagnostic clue reflecting early myocardial damage due to ATTR-CM.

Amyloidosis from the patient perspective: the French daily impact of amyloidosis study

BACKGROUND

Amyloidosis is a complex group of rare conditions. For patients, amyloidosis is severely debilitating: physically and psychologically. Currently, data are lacking to evaluate the medical, economic, and social burden of systemic amyloidosis.

OBJECTIVE

To analyse the patient burden according to the main types of systemic amyloidosis.

METHODS

The French Daily Impact of Amyloidosis study was an observational, cross-sectional and non-interventional study. Adults diagnosed with light chain (AL), transthyretin (ATTR), amyloid A (AA) and other rare forms of amyloidosis were eligible. Data regarding amyloidosis prevalence, diagnosis, management, and impact on everyday life were collected using a study-specific survey built by the Association Française Contre l'Amylose (AFCA) and the four French National Referral Centres for Amyloidosis.

RESULTS

A total of 603 patients, predominantly male (65%) with an average age of 66.8 years, including 170 AL, 224 ATTRv, 109 ATTRwt and 25 AA amyloidosis patients, completed the study-specific survey. The median delay from presentation to confirmed diagnosis was 27.4 months but varied according to amyloidosis type. Patients before diagnosis had breathlessness (49%), tingling sensation (33%), pain (28%), difficulty in walking (28%) and weight loss (22%). Amyloidosis was most frequently suspected (49%) and confirmed (57%) in local hospitals but managed in French amyloidosis referral centres (58%). Patients often reported problems with mobility, usual activities, pain/discomfort and anxiety/depression, but not with self-care.

CONCLUSIONS

Systemic amyloidosis severely impacts daily life. The delay to confirmed amyloidosis diagnosis needs to be reduced. Early, effective treatment is required to optimise patient benefits.

Incidence and predictors of worsening heart failure in patients with wild-type transthyretin cardiac amyloidosis

BACKGROUND

Prognostic markers of survival have been identified in wild-type transthyretin amyloidosis (ATTRwt), but limited data exist with respect to hospitalizations with worsening heart failure (WHF). Predictive markers of WHF have yet to be identified.

METHODS

From April 2017 to February 2021, 104 patients with ATTRwt were diagnosed and prospectively followed from the time of diagnosis to the time of death or the censoring date of 1 February 2021. Baseline patient characteristics, biomarkers, and advanced echocardiography were used to predict hospitalization with WHF.

RESULTS

During the median follow-up period of 23 months, 51% of patients were hospitalized due to WHF. Seventy-three per cent of patients with WHF were admitted at least twice. Patients with WHF during the first year had significantly poorer survival (P < 0.001). Independent predictors of WHF during follow-up were pacemaker implantation prior to diagnosis (PMI, P = 0.037) and right atrial volume index (RAVi, P = 0.008). Patients with PMI had a higher left ventricular mass index and poorer left ventricular and right ventricular systolic function indicating a more advanced stage of amyloid disease.

CONCLUSIONS

A high incidence and recurrence of hospital admissions with WHF were demonstrated in contemporary patients with ATTRwt, which was associated with reduced survival. Patients with pacemaker devices prior to ATTRwt diagnosis experienced more frequent hospitalizations with WHF. PMI and right atrial enlargement were identified as independent predictors of WHF during follow-up.

Sex Differences in Wild-Type Transthyretin Amyloidosis: An Analysis from the Transthyretin Amyloidosis Outcomes Survey (THAOS)

Introduction

Wild-type transthyretin amyloidosis (ATTRwt amyloidosis) is a progressive disease resulting from the accumulation of wild-type transthyretin (TTR) amyloid fibrils, and is diagnosed primarily in males. This analysis examined sex differences in patients with ATTRwt amyloidosis from the Transthyretin Amyloidosis Outcomes Survey (THAOS).

Methods

THAOS is an ongoing, global, longitudinal, observational survey of patients with transthyretin amyloidosis, including both inherited and wild-type disease, and asymptomatic carriers of TTR mutations. THAOS data were analyzed to identify potential differences in demographic and clinical characteristics between males and females with ATTRwt amyloidosis (data cutoff: August 1, 2021).

Results

Of 1386 patients with ATTRwt amyloidosis, 84 (6%) were female and 1302 (94%) were male. Females had a higher median age at enrollment (80 vs. 78 years; p = 0.002) and symptom onset (75 vs. 73 years; p = 0.045) than males. Mean left ventricular (LV) ejection fraction was higher (53% vs. 48%; p = 0.001) and mean LV diastolic diameter lower (42 vs. 46 mm; p < 0.001) in females versus males, but sex was not identified as a predictor of LV mean wall thickness adjusted for height (beta coefficient − 0.22; p = 0.460) or a predominantly cardiac phenotype (odds ratio 1.60; p = 0.191). Modified polyneuropathy disability scores differed between groups (p < 0.001), with a larger proportion of scores ≥ IIIa among females (23% vs. 7%).

Conclusions

Females with ATTRwt amyloidosis in THAOS tended to present at a later age and showed signs of less severe cardiac impairment and more severe walking impairment.

Trial Registration

ClinicalTrials.gov: NCT00628745.

When to Suspect and How to Approach a Diagnosis of Amyloidosis

Diagnoses of amyloidosis, particularly transthyretin amyloid cardiomyopathy (ATTR-CM), are steadily increasing throughout the world, but the condition remains underdiagnosed. Patients with amyloidosis may present to a range of medical and surgical specialties, often with multisystemic disease, and a high index of clinical suspicion is required for diagnosis. Bone scintigraphy and cardiovascular magnetic resonance (CMR) imaging offer highly sensitive and specific imaging modalities for cardiac amyloidosis. Histological confirmation of amyloid deposition and amyloid type remains the cornerstone of diagnosis for most amyloid types, with transthyretin amyloid cardiomyopathy the exception, which may be diagnosed by validated nonbiopsy diagnostic criteria in the majority. Histological diagnosis of amyloid has been enhanced by laser capture microdissection and tandem mass spectrometry. Early diagnosis and treatment prior to the development of end-organ damage remains essential to improving morbidity and mortality for patients with amyloidosis.

Annual Cardiovascular-Related Hospitalization Days Avoided with Tafamidis in Patients with Transthyretin Amyloid Cardiomyopathy

BACKGROUND

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) experience infiltrative cardiomyopathy and heart failure symptoms requiring costly hospitalizations. The Transthyretin Amyloidosis Cardiomyopathy Clinical Trial (ATTR-ACT) demonstrated the efficacy of tafamidis on the frequency of cardiovascular (CV)-related hospitalizations in patients with ATTR-CM.

PURPOSE

As length of stay can affect the total hospitalization burden, our study aimed to better understand the impact of tafamidis on the number of CV-related hospital days avoided in the management of ATTR-CM patients.

METHODS

Data from ATTR-ACT were used to calculate the total burden of CV-related hospitalization (days) by treatment arm in this post hoc analysis.

RESULTS

In the total trial population, patients receiving tafamidis had significantly fewer CV-related hospitalizations per year (relative risk reduction [RRR] 0.68; 0.4750 vs. 0.7025, p < 0.0001) and a shorter mean length of stay per CV-related hospitalization event (8.6250 vs. 9.5625 days) than patients receiving placebo. Taken together, tafamidis prevented 2.62 CV-related hospitalization days per patient per year. A subgroup analysis showed that with earlier treatment initiation of tafamidis, the annual number of CV-related hospitalizations was significantly lowered by 52% compared with placebo (RRR 0.48; 0.3378 vs. 0.7091, p < 0.0001). With 1.14 fewer days per hospitalization, tafamidis reduced the annual number of CV-related hospitalization days by 3.96 days per New York Heart Association class I/II patient.

CONCLUSIONS

In patients with ATTR-CM, tafamidis was associated with a lower rate of CV-related hospitalizations and shorter length of hospital stay. Timely diagnosis and treatment with tafamidis could further decrease the total number of CV-related hospitalization days per year.

CLINICALTRIALS

GOV IDENTIFIER

NCT01994889.

Evaluation of the cardiac amyloidosis clinical pathway implementation: a real-world experience

Aims

The aim of this study is to evaluate the implementation of the cardiac amyloidosis (CA) clinical pathway on awareness among referring cardiologists, diagnostic delay, and severity of CA at diagnosis.

Methods and results

Patients with CA were retrospectively included in this study and divided into two periods: pre-implementation of the CA clinical pathway (2007-18; T1) and post-implementation (2019-20; T2). Patients' and disease characteristics were extracted from electronic health records and compared. In total, 113 patients (mean age 67.8 ± 8.5 years, 26% female) were diagnosed with CA [T1 (2007-18): 56; T2 (2019-20): 57]. The number of CA diagnoses per year has increased over time. Reasons for referral changed over time, with increased awareness of right ventricular hypertrophy (9% in T1 vs. 36% in T2) and unexplained heart failure with preserved ejection fraction (22% in T1 vs. 38% in T2). Comparing T1 with T2, the diagnostic delay also improved (14 vs. 8 months, P < 0.01), New York Heart Association Class III (45% vs. 23%, P = 0.03), and advanced CA stage (MAYO/Gillmore Stage III/IV; 61% vs. 33%, P ≤ 0.01) at time of diagnosis decreased.

Conclusion

After implementation of the CA clinical pathway, the awareness among referring cardiologists improved, diagnostic delay was decreased, and patients had less severe CA at diagnosis. Further studies are warranted to assess the prognostic impact of CA clinical pathway implementation.

Applying diagnosis support systems in electronic health records to identify wild-type transthyretin amyloid cardiomyopathy risk

Aim: Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is frequently misdiagnosed, and delayed diagnosis is associated with substantial morbidity and mortality. At three large academic medical centers, combinations of phenotypic features were implemented in electronic health record (EHR) systems to identify patients with heart failure at risk for ATTRwt-CM. Methods: Phenotypes/phenotype combinations were selected based on strength of correlation with ATTRwt-CM versus non-amyloid heart failure; different clinical decision support and reporting approaches and data sources were evaluated on Cerner and Epic EHR platforms. Results: Multiple approaches/sources showed potential usefulness for incorporating predictive analytics into the EHR to identify at-risk patients. Conclusion: These preliminary findings may guide other medical centers in building and implementing similar systems to improve recognition of ATTRwt-CM in patients with heart failure.

Sex-related differences in clinical presentation and all-cause mortality in patients with cardiac transthyretin amyloidosis and light chain amyloidosis

We aimed to ascertain whether sex-related differences are relevant to clinical presentation, cardiac phenotype and all-cause mortality in different types of cardiac amyloidosis, a field still poorly investigated. Medical files from consecutive patients diagnosed with cardiac amyloidosis between 2000 and 2020, at Careggi University Hospital, were retrospectively evaluated. Over this period, 259 patients (12% females) were diagnosed with wild type transthyretin amyloidosis (wtATTR), 52 (25% females) with hereditary transthyretin amyloidosis (hATTR) and 143 (47% females) with light chain amyloidosis (AL). Women with wtATTR, compared to men, were significantly older at the time of diagnosis and showed higher National Amyloidosis Centre score, thicker normalized interventricular septum, higher diastolic dysfunction and worse right ventricular function. Females with hATTR and AL had lower normalized cardiac mass compared to men, otherwise, bio-humoral parameters, NYHA class, and ECG characteristics were similar. Comparing females and male with wtATTR, hATTR and AL, no differences in Kaplan-Meier curves for all-cause mortality were observed with regard to sex, p-value >0.05. In conclusion, we did not observe major differences in clinical expression related to sex in different types of cardiac amyloidosis: specifically, all-cause mortality was not affected. Nevertheless, women with wtATTR had echocardiographic signs of more advanced disease and higher NAC score at diagnosis suggesting a possible later recognition of disease compared to men.

Suspecting and diagnosing transthyretin amyloid cardiomyopathy (ATTR-CM) in India: An Indian expert consensus

Transthyretin cardiac amyloidosis (ATTR-CM) is a rare and under-recognized disorder characterized by the aggregation of transthyretin-derived insoluble amyloid fibrils in the myocardium. Heterogeneity of symptoms at presentation, makes its diagnosis often delayed. An expert panel gathered on a virtual platform across India to conduct a meeting for developing a guiding tool for ATTR-CM diagnosis. The panel recommended younger age (≥40 years) for suspecting ATTR-CM and thick-walled non-dilated hypokinetic ventricle was considered as one of the important red flags. Electrocardiogram (ECG) and echocardiography (ECHO) findings were recommended as primary tests to raise the suspicion while nuclear scintigraphy and hematological tests were recommended to confirm the diagnosis and rule out amyloid light-chain (AL) amyloidosis. Cardiac magnetic resonance (CMR) and biopsy were recommended in case of ambiguity in the presence of red flags. Considering the lack of expert guidelines in the Indian scenario, a standardized diagnostic algorithm was also proposed.

Two Decades of Cardiac Amyloidosis: A Danish Nationwide Study

Background

Cardiac amyloidosis (CA) has been associated with poor outcomes. Screening studies suggest that CA is overlooked-especially in the elderly. Recent advances in treatment have brought attention to the disease, but data on temporal changes in CA epidemiology are sparse.

Objectives

The aim of this work was to describe all patients with CA in Denmark, examining changes in patient characteristics from 1998 to 2017.

Methods

All patients with any form of amyloidosis diagnosed from 1998 to 2017, as well as their comorbidities and pharmacotherapy, were identified in Danish nationwide registries. CA was defined as any diagnosis code for amyloidosis combined with a diagnosis code for heart failure, cardiomyopathy, or atrial fibrillation or a procedural code for pacemaker implantation, regardless of the order. The index date was defined as the date of meeting those criteria. Patients were divided into 5-year periods by index date. For comparison, we also included control subjects (1:4 ratio) from the general population.

Results

CA criteria were met by 619 patients. Comparing 1998-2002 vs 2013-2017, the median age at baseline increased from 67.4 years (interquartile range [IQR]: 53.9-75.2 years) to 72.3 years (IQR: 66.0-79.3 years). The frequency of male patients increased from 62.1% to 66.2%. The incidence of CA rose from 0.88 to 3.56 per 100,000 person-years in the Danish population aged ≥65 years, and the 2-year mortality decreased from 82.6% (IQR: 69.9%-90.5%) to 50.2% (IQR: 43.1%-56.9%). Compared with control subjects, the mortality among CA patients was significantly higher (log-rank test: P < 0.0001).

Conclusions

CA, as defined in this study, was increasingly diagnosed on a national scale. The increasing frequency of male patients and median age suggest that wild-type transthyretin amyloidosis is driving this increase. Greater recognition of earlier, less advanced cases might explain decreasing mortality.

History of extracardiac/cardiac events in cardiac amyloidosis: prevalence and time from initial onset to diagnosis

Aims

Cardiac amyloidosis (CA) has a poor prognosis which is aggravated by diagnostic delay. Amyloidosis extracardiac and cardiac events (AECE and ACE) may help improve CA diagnosis and typing. The aim of this study was to compare AECE and ACE between different CA types and assess their relationship with survival.

Methods and results

This retrospective cohort study conducted in France from June 2008 to May 2019, at the Henry Mondor Hospital. This cohort included 983 patients with CA. Mean age at inclusion was 73.1 ± 11.4 years, 726 (75.1%) were male and the mean body mass index was 24.5 ± 4.1 kg/m². Among them, 321 had immunoglobulin light chain (AL) amyloidosis, 434 had wild‐type transthyretin (ATTRwt), and 212 had hereditary transthyretin (ATTRv). The first AECE and/or ACE occurred at a mean age of 63 ± 11 years for AL and ATTRv, and 70 ± 12 years for ATTRwt (P < 0.01). The median (Q1–Q3) delay between declaration of the first events and diagnosis varied from 11.1 (5.9; 34.8) months for AL to 92.2 (39.0; 174.7) months for ATTRwt (P < 0.01). The nature of the onset of AECE or ACE varied based on amyloidosis type, heart failure symptoms for AL (26%) and integumentary symptoms for ATTRv with cardiologic or mixed phenotype (39%) and ATTRwt (42%). In AL and ATTRwt, a short delay between the onset of the first AECE or ACE and diagnosis was associated with reduced survival rate (log‐rank test P‐value <0.01).

Conclusions

This study highlights the impact of amyloidosis type and evolution on diagnostic delay and on prognosis. Physicians must be aware and vigilant in front of extracardiac and cardiac events to considerably improve early diagnosis of amyloidosis.

Echocardiographic assessment of cardiac amyloidosis

Cardiac amyloidosis, a form of infiltrative cardiomyopathy, is associated with poor prognosis in untreated patients. Early diagnosis is important for timely initiation of effective therapies. Despite advances in diagnostic modalities, it remains a challenging diagnosis, requiring high index of clinical suspicion. Echocardiography represents the first-line cardiac imaging modality for evaluation of heart failure and suspected cardiac amyloidosis. In this review, we discuss echocardiographic findings in cardiac amyloidosis.

Advances in Diagnosis and Treatment of Cardiac and Renal Amyloidosis

Diagnoses of amyloidosis are increasing annually, and advances in bone scintigraphy and cardiac MRI accompanied by development of nonbiopsy diagnostic criteria have specifically led to a huge increase in transthyretin amyloidosis cardiomyopathy (ATTR-CM) diagnoses worldwide. Tafamidis use is increasing, and there are several ongoing phase III clinical trials of novel agents that promise to transform the treatment landscape for patients with ATTR-CM. In systemic light chain (AL) amyloidosis, more effective chemotherapeutic agents continue to improve patient outcomes. Accelerating the removal of amyloid deposits to accompany these therapies remains the holy grail. However, in the meantime, early diagnosis is undoubtedly key in improving patient outcomes.

Early Diagnosis and Outcome in Patients With Wild-Type Transthyretin Cardiac Amyloidosis

Whether diagnostic timing in transthyretin (TTR) cardiac amyloidosis (CA) predisposes patients to worse outcomes is unresolved. We aimed to describe the long-term association of diagnostic timing (time from first onset of symptoms consistent with CA leading to medical contact to definitive diagnosis) with mortality in patients with wild-type TTR-CA (ATTRwt-CA). Overall, we reviewed the medical records of 160 patients seen at a tertiary care amyloidosis unit from January 1, 2016, to January 1, 2020 (median [interquartile range] follow-up, 21 [10 to 34] months), and compared them by survival. Median diagnostic timing was 4 (2 to 12) months and was longer in nonsurvivors (9 [3 to 15] vs 3 [1 to 7] months; P<.001). Patients diagnosed 6 or more months after symptom onset had higher mortality, with a median survival of 30 months (95% CI, 22 to 37 months). On Cox multivariable analysis, timing was independently associated with all-cause mortality (hazard ratio per month increase, 1.049 [95% CI, 1.017 to 1.083]) together with age at diagnosis, disease stage, New York Heart Association class, and coronary artery disease. In conclusion, diagnostic timing of ATTRwt-CA is associated with mortality. Timely diagnosis is warranted whenever "red flags" are present.

A Descriptive Analysis of ATTR Amyloidosis in Spain from the Transthyretin Amyloidosis Outcomes Survey

Introduction

Transthyretin amyloidosis (ATTR amyloidosis) is a clinically heterogeneous disease caused by mutations in the transthyretin (TTR) gene or aggregation of wild-type transthyretin (ATTRwt). In Spain, there are two large endemic foci of ATTR amyloidosis caused by the Val30Met variant, with additional cases across the country; however, these data may be incomplete, as there is no centralized patient registry. The Transthyretin Amyloidosis Outcomes Survey (THAOS) is an ongoing, global, longitudinal, observational survey of patients with ATTR amyloidosis, including both inherited and wild-type disease, and asymptomatic patients with TTR mutations. This analysis aimed to gain a deeper understanding of the clinical profile of patients with ATTR amyloidosis in Spain.

Methods

This was a descriptive analysis of the demographic and clinical characteristics of symptomatic patients enrolled at six sites geographically dispersed throughout Spain (data cutoff: January 6, 2020). Patient data at enrollment, including genotype, demographics, and clinical presentation for symptomatic patients, were recorded. Patients were grouped by predominant phenotype based on clinical measures at enrollment: predominantly cardiac, predominantly neurologic, or mixed (cardiac and neurologic).

Results

There were 379 patients (58.0% male; 63.3% symptomatic) enrolled in the six THAOS sites in Spain. Predominant genotypes were the Val30Met mutation (69.1%) or ATTRwt (15.6%). Predominant phenotype distribution was neurologic (50.4%), mixed (35.8%), and cardiac (13.8%) for all symptomatic patients (n = 240); neurologic (67.8%), mixed (21.2%), and cardiac (11.0%) for symptomatic Val30Met (n = 146); and mixed (64.9%), cardiac (22.8%), and neurologic (12.3%) for symptomatic ATTRwt (n = 57). Symptomatic patients reported a range of ATTR amyloidosis signs and symptoms at enrollment, with autonomic neuropathy and sensory neuropathy common in all phenotypes.

Conclusions

These results from THAOS highlight the phenotypic heterogeneity associated with ATTR amyloidosis in Spain and the importance of comprehensive neurologic and cardiac evaluations in all patients with ATTR amyloidosis.

Trial registration

ClinicalTrials.gov: NCT00628745.

Estimating the health benefits of timely diagnosis and treatment of transthyretin amyloid cardiomyopathy

Aim: Delayed diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) represents a missed opportunity for intervention. This study estimates the health benefits of timely diagnosis and treatment with tafamidis. Methods: A disease simulation model was developed to predict health outcomes under scenarios of timely and delayed diagnosis and treatment. Efficacy and quality of life (QoL) profiles were derived from the pivotal tafamidis trial and diagnostic delay durations from the literature. Results: Timely diagnosis and treatment were predicted to extend mean life expectancy by 5.46 and 7.76 years, relative to delayed diagnosis, for wild-type and hereditary ATTR-CM, respectively. Corresponding QALY gains were 4.50 and 6.22. Conclusion: Timely diagnosis and treatment with tafamidis are predicted to significantly improve survival and QoL for ATTR-CM patients.

Health impact of tafamidis in transthyretin amyloid cardiomyopathy patients: an analysis from the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT) and the open-label long-term extension studies

AIM

The Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT) showed that tafamidis reduced all-cause mortality and cardiovascular-related hospitalizations in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). This study aimed to estimate the impact of tafamidis on survival and quality-adjusted life-years (QALYs).

METHODS AND RESULTS

A multi-state, cohort, Markov model was developed to simulate the disease course of ATTR-CM throughout a lifetime. For survival extrapolation, survival curves were fitted by treatment arm and New York Heart Association (NYHA) Class I/II (68% of patients) and NYHA Class III (32% of patients) cohorts using the individual patient-level data from both the ATTR-ACT and the corresponding long-term extension study. Univariate and multivariate sensitivity analyses were conducted. The predicted mean survival for the total population (NYHA Class I/II + III) was 6.73 years for tafamidis and 2.85 years for the standard of care (SoC), resulting in an incremental mean survival of 3.88 years [95% confidence interval (CI) 1.32-5.66]. Of the 6.73 life-years, patients on tafamidis spend, on average, 4.82 years in NYHA Class I/II, while patients on SoC spend an average of 1.60 life-years in these classes. The combination of longer survival in lower NYHA classes produced a QALY gain of 5.39 for tafamidis and 2.11 for SoC, resulting in 3.29 incremental QALYs (95% CI 1.21-4.74) in favour of tafamidis.

CONCLUSION

Based on the disease simulation model results, tafamidis is expected to more than double the life expectancy and QALYs of ATTR-CM patients compared to SoC. Longer-term follow-up data from the ATTR-ACT extension study will further inform these findings.

CLINICAL TRIALS.GOV IDENTIFIER

NCT01994889 (date of registration: 26 November 2013).

Impact of Delayed Diagnosis and Misdiagnosis for Patients with Transthyretin Amyloid Cardiomyopathy (ATTR-CM): A Targeted Literature Review

INTRODUCTION

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive, fatal and under-recognized disease. This targeted literature review assessed the extent and consequences of diagnostic delay and misdiagnosis in ATTR-CM.

METHODS

The Embase database was searched together with proceedings of eight cardiology conferences to identify publications or abstracts on ATTR-CM. Outcomes of interest were time from symptom onset to diagnosis, rates of delayed diagnosis and misdiagnosis, and costs, healthcare resource use or clinical outcomes whilst undiagnosed/misdiagnosed.

RESULTS

Twenty-three articles were included. Weighted means of reported mean and median diagnostic delays were 6.1 and 3.4 years for wild-type (ATTRwt-CM) and 5.7 and 2.6 years for hereditary (ATTRv-CM). Misdiagnosis occurred in 34-57% of patients when reported. Evaluation and misdiagnosis by multiple healthcare providers before receiving an ATTR-CM diagnosis was common, and there was evidence that patients undergo unnecessary or inappropriate evaluations or treatments while misdiagnosed. Diagnostic "red flags" were reported to be underused. Data on the consequences of delay for patients and health systems were sparse, but given the progressive nature of ATTR-CM, delay is likely to have adverse consequences.

CONCLUSION

ATTR-CM patients commonly experience diagnostic delay and misdiagnosis. Efforts are required to provide timely diagnosis so that patients can benefit from earlier access to new disease-modifying therapies.

Emerging therapy in light-chain and acquired transthyretin-related amyloidosis: an Italian single-centre experience in heart transplantation

AIMS

The prognosis for patients affected by light-chain cardiac amyloidosis and acquired transthyretin-related (TTR) amyloidosis is poor. Heart transplantation (HTx) could improve prognosis also enabling autologous stem cell transplantation (ASCT) in the first group.

METHODS AND RESULTS

A total of 36 patients affected by systemic amyloidosis have been referred to our centre from 2009 to 2019. Of these, nine had cardiac involvement: seven by light-chain amyloidosis and two by acquired TTR amyloidosis. None died while waiting for HTx. A specific internal protocol useful to select candidates and to monitor the organ involvement after HTx was developed. Median age at diagnosis was 54 years and 66% were male. The most common short-term complication after HTx was renal failure (44%), followed by acute cardiac rejection more than 2R (22%). ASCT was performed in six out of seven light-chain cardiac amyloidosis patients, with a median time of 6 months after HTx. Two patients affected by light-chain cardiac amyloidosis died due to amyloidosis relapse: one before undergoing ASCT. After a median follow-up of 31 (7-124) months, 1- and 5-year survival was 88 and 66% in the cardiac light-chain amyloidosis group. Conversely, 1- and 5-year survival was 100% in the acquired TTR amyloidosis group.

CONCLUSION

HTx may represent a valuable option in carefully selected patients. ASCT after HTx is an effective treatment that could decrease amyloidosis relapse in light-chain cardiac amyloidosis patients. A multidisciplinary approach is mandatory to select the best candidates and to obtain the most effective results with a specific surveillance follow-up protocol.

Estimating the Gender Distribution of Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy: A Systematic Review and Meta-Analysis

INTRODUCTION

This study investigates the gender distribution in patients diagnosed with wild-type transthyretin amyloidosis cardiomyopathy (ATTRwt).

METHODS

A systematic review and meta-analysis of the male proportion in diagnosed ATTRwt patients were conducted. To avoid overlapping population, pooled estimates in the primary analysis were based on all unique studies. In secondary analyses, we considered predefined subsets of studies based on study sample size, recruitment years, geography, study design, age at diagnosis, and method of diagnosis. Additional meta-regression analyses were tested for potential determinants of gender distribution.

RESULTS

Twenty-eight unique studies (2542 patients) were included in the meta-analysis. Male proportion in patients with ATTRwt was 86.9% (95% confidence interval 81.5-91.6%). Studies, including patients older than 80 years at diagnosis, had a 29.1% (p value < 0.001) lower male proportion compared to studies, including younger patients. After adjusting for age, studies using autopsy as a method of diagnosis had a 21.1% (p value 0.002) lower male proportion compared to other studies.

CONCLUSIONS

Studies conducted to date suggest ATTRwt disproportionally affects males. The proportion of males was significantly impacted by the age at diagnosis and method diagnosis, which may suggest important gender-based differences in the clinical manifestation and diagnostic challenges of ATTRwt in females that warrant future research.

Diagnostic and lifetime hospital costs of patients suffering from wild-type transthyretin amyloid cardiomyopathy in Denmark

AIMS

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt) is a fast progressing and fatal disease associated with substantial delays in diagnosis. Between the first symptoms and diagnosis, patients are frequently hospitalized, primarily with cardiac symptoms. After diagnosis, patients continue to experience frequent hospital admissions. The objective of this study was to estimate the Danish diagnostic and lifetime hospital costs associated with the treatment of patients with ATTRwt both before and after they are diagnosed.

MATERIALS AND METHODS

We developed a cost model for Danish hospital costs associated with ATTRwt, including the costs of diagnosis, cardiac implants, and hospital admissions covering inpatient hospitalization and outpatient hospital care (ambulatory and emergency services). The number of diagnoses, cardiac implants, inpatient hospitalization and outpatient hospital care were estimated based on published data. Estimates of the unit costs were based on publicly available Danish reference costs. We calculated the total hospital costs covering the median lifespan of patients from onset of symptoms, which is 13 months prior to diagnosis, to 52 months after diagnosis which is the median survival time after diagnosis.

RESULTS

The average cost of diagnosing ATTRwt was USD 3,424 per patient; the average costs of cardiac implants were USD 1,851 per patient. Hospital admissions costs totaled USD 3,345 pre-diagnosis and USD 59,449 post-diagnosis per patient, on average. The total diagnostic and lifetime (65 months) hospital costs associated with ATTRwt were USD 68,069.

CONCLUSIONS

Caring for patients with ATTRwt places a significant economic burden on the healthcare system. The study emphasizes the cost saving potential for medical interventions in this patient population.

Prevalence and Prognostic Implications of Increased Apical-to-Basal Strain Ratio in Patients with Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

The aim of this study was to investigate the preoperative prevalence, relation to symptoms, and prognostic implications of elevated left ventricular (LV) apical-to-basal strain ratio (ABr) in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement.

METHODS

A total of 499 contemporary consecutive patients with AS treated with transcatheter aortic valve replacement were retrospectively included. Patients were included if they underwent preoperative echocardiography with adequate image quality for assessment of LV global longitudinal strain. Baseline clinical and echocardiographic data were collected and analyzed in ABr subgroups. From two-dimensional echocardiographic apical images, ABr was calculated as mean longitudinal strain of the five LV apical segments divided by the mean of the six basal segments.

RESULTS

Median follow-up time was 743 days. Mean age was 79.8 ± 7 years. The prevalence of severely increased ABr ≥4 was 16% (n = 78). Patients with ABr ≥4 had higher preoperative New York Heart Association functional class; 77% of those with ABr ≥4 were in New York Heart Association functional class III or IV compared with 59% of those with ABr of 0 to 1.9 (P < .01). Median preoperative N-terminal pro-brain natriuretic peptide level in patients with ABr ≥4 was 1,781 pmol/L, compared with 876 pmol/L in those with ABr of 0 to 1.9 (P = .003). N-terminal pro-brain natriuretic peptide levels at 3-month follow-up remained considerably elevated in patients with ABr ≥4 (the median in patients with ABr ≥4 was 1,262 pmol/L vs 645 pmol/L in those with ABr of 0 to 1.9, P < .01). AS severity was comparable across ABr subgroup levels. Overall, increased ABr ≥4 was associated with poor survival, as overall 3-year survival was 67% among patients with ABr ≥4 compared with 83% in those with ABr of 2 to 3.9 and 86% in those with ABr of 0 to 1.9 (P = .04).

CONCLUSION

Among patients with increased ABr ≥4, pre- and postoperative New York Heart Association functional class, serum N-terminal pro-brain natriuretic peptide level, and mortality were significantly increased, and ABr may thus serve as a new echocardiographic marker of high mortality risk among patients with AS treated with transcatheter aortic valve replacement.