Prevalence and clinical phenotype of hereditary transthyretin amyloid cardiomyopathy in patients with increased left ventricular wall thickness

The French hypertrophic cardiomyopathy gene register: A systematic large gene screening for hypertrophic cardiomyopathy

BACKGROUND

Although the optimal approach is debated, systematic genetic screening for hypertrophic cardiomyopathy (HCM) is recommended.

AIMS

The performance of this approach was tested in GEREMY, a HCM prospective observational French register.

METHODS

Screening was based on a 12-gene panel, including the Fabry disease (GLA) and the transthyretin (TTR) genes. In case of a negative result and according to the clinical profile, 17-80 gene panels of were used.

RESULTS

A 748 adult cohort was examined: 68.9 % male, 54.6 ± 18.1 years, 27.5 % with a HCM family history, maximal wall thickness 19.1 ± 4.8 mm. Pathogenic or likely pathogenic variants were identified in 296 (39.6 %) patients, localized 1) in sarcomeric genes in 233, most frequently MYBPC3 (150) and MYH7 (42), with 24 identified only by large panels, with multiple variants in 8 patients and 2) in non-sarcomeric genes in 63, identified only with large panels in 26, predominantly TTR (26) and GLA(9), representing 8.8 % and 3.0 % of positive studies, respectively. Performance was 57.1 % before 40 years and 68.6 % in case of FH (vs otherwise 28.7 % and 26.1 % respectively, p < 0.001). In patients with a negative study, 148 had variants of unknown significance and 95 had senile or AL amyloidosis.

CONCLUSIONS

Systematic genetic screening with a limited panel showed good performance, with diagnosis of Fabry disease (∼1 %) and hereditary TTR amyloidosis (∼3.5 %). Larger targeted panels were conclusive in 35.3 % of patients, of which 12 % had a negative initial approach.

Cardiac amyloidosis and red flags: natural history and its impact in morbimortality

INTRODUCTION AND OBJECTIVES

Red flags (RF) are typical cardiac and extracardiac manifestations that may precede the definitive diagnosis of cardiac amiloidosis (CA) by several years, playing a pivotal role in the early diagnosis of the disease. The principal aim of the research was to determine the chronology of onset of RF throughout the natural history of CA as well as its prognostic influence.

PATIENTS AND METHODS

Observational, retrospective inquiry of consecutive patients with a definitive diagnosis of CA in a terciary hospital centre in Ciudad Real (Spain) between February 2016 and December 2023. We defined 21 RF and 3 adverse clinical events, establishing the date of occurrence of each of them.

RESULTS

102 patients (81.6±7.7 years; 84,3% males) with a diagnosis of CA (89.2% TTR; 10,8% AL) were included. The prevalence of RF was very high (8.4±2.3). In the natural history, the first to appear were integumentary, with the most specific cardiological ones being the closest to diagnosis. The 2-year mortality was 49%, with biomarker RFs and the presence of ≥10 RFs being associated with higher mortality.

CONCLUSIONS

RFs proved highly prevalent among patients with CA and substantially preceded disease diagnosis. RF burden was associated with prognosis in the follow-up of ATTR patients.

Health-related quality of life is an independent predictor of mortality and hospitalisations in transthyretin amyloid cardiomyopathy: a prospective cohort study

PURPOSE

Transthyretin amyloid cardiomyopathy (ATTR-CM) is associated with severely impaired health-related quality of life (HRQL). HRQL is an independent predictor of outcome in heart failure (HF), but data on patients with ATTR-CM is scarce. This study therefore aims to evaluate the association of HRQL with outcome in ATTR-CM.

METHODS

Patients from our prospective ATTR-CM registry were assessed using the Kansas City cardiomyopathy questionnaire (KCCQ), the Minnesota living with HF questionnaire (MLHFQ), and the EuroQol five dimensions questionnaire (EQ-5D). Cox regression analysis was utilised to assess the impact of HRQL on all-cause mortality.

RESULTS

167 patients [80 years; interquartile range (IQR): 76-84; 80.8% male] were followed for a median of 27.6 (IQR: 9.7-41.8) months. The primary endpoint of all-cause mortality was met by 43 (25.7%) patients after a median period of 16.2 (IQR: 9.1-28.1) months. In a univariate Cox regression for mortality, a 10-point change in the KCCQ implied a hazard ratio (HR) of 0.815 [95%-confidence interval (CI): 0.725-0.916; p = 0.001], in the EQ-5D VAS of 0.764 (95%-CI: 0.656-0.889; p < 0.001), and 1.163 (95%-CI: 1.114-1.433; p < 0.001) in the MLHFQ. After adjustment for established biomarkers of HF, all-cause mortality was predicted independently by the EQ-5D VAS (HR: 0.8; 95%-CI: 0.649-0.986; p = 0.037; per 10 points) and the MLHFQ (HR: 1.228; 95%-CI: 1.035-1.458; p = 0.019; per 10 points).

CONCLUSION

HRQL is a predictor of outcome in ATTR-CM. The EQ-5D VAS and the MLHFQ predict survival independent of biomarkers of HF.

Safety assessment of Tafamidis: a real-world pharmacovigilance study of FDA adverse event reporting system (FAERS) events

OBJECTIVE

Tafamidis-associated adverse events (AEs) were investigated retrospectively by data mining the US Food and Drug Administration Adverse Event Reporting System (FAERS) to inform clinical safety.

METHODS

Data were gathered from the FAERS database, which spans the second quarter of 2019 to the fourth quarter of 2023. A total number of 8532 reports of Tafamidis-related adverse events were detected after evaluating 8,432,351 data. Disproportionality analyses were used to quantify the signal and assess the significance of Tafamidis-associated AEs using four algorithms, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the multi-item gamma Poisson shrinker (MGPS) and the Bayesian confidence propagation neural network (BCPNN).

RESULTS

Among the 8532 reports of AEs with Tafamidis as the primary suspected drug, Tafamidis-induced AEs were identified as occurring in 27 system organ classes (SOC). A total of 207 Tafamidis-induced AEs were detected which simultaneously complied with the four algorithms. Our analysis also identified new adverse reactions including Hypoacusis, Deafness, and Essential hypertension. The median onset of adverse reactions associated with Tafamidis was 180 days (interquartile range [IQR] 51-419 days).

CONCLUSION

Tafamidis is a drug that has shown favorable safety and tolerability results in clinical trials. However, a number of adverse reactions associated with Tafamidis have been identified through analysis of the FAERS database. In clinical applications, it is recommended to closely monitor patients' hearing while using Tafamidis. In addition, it is hoped that further experimental and clinical studies will be conducted in the future to understand the mechanism of occurrence between Tafamidis and adverse reactions such as primary hypertension, hyperlipidemia, and height reduction.

Prevalence and characteristics of transthyretin amyloid cardiomyopathy in hypertrophic cardiomyopathy

AIMS

Recognition of transthyretin amyloid cardiomyopathy is increasing due to advances in cardiac imaging and diagnostic strategies, but questions remain regarding disease frequency and characteristics. We examined the prevalence and characteristics of transthyretin amyloid cardiomyopathy in older patients with hypertrophic cardiomyopathy of unascertained aetiology.

METHODS AND RESULTS

TTRACK was a multicentre, non-interventional, cross-sectional epidemiologic study funded by Pfizer and conducted in 20 hospitals and medical centres in 11 countries (NCT03842163). Eligible patients were aged ≥50 years, had hypertrophic cardiomyopathy (maximal end-diastolic left ventricular wall thickness ≥15 mm on echocardiogram) without an identified genetic or alternative origin at study enrolment, and underwent 99mTechnetium bone scintigraphy, with or without single photon emission computed tomography (SPECT). Cardiac-versus-bone uptake on scans was visually scored from 0 to 3 (Perugini scoring). Patients with grades 1-3 underwent monoclonal protein and laboratory testing and transthyretin (TTR) gene sequencing. Of 766 eligible patients, 691 (90.2%) had scintigraphy alone and 75 (9.8%) scintigraphy plus SPECT. Two hundred and eight patients (27.2%) had grade 2 or 3 cardiac uptake on scintigraphy; 144 (18.8%) had grade 2 or 3 cardiac uptake and no evidence of plasma cell dyscrasia and were diagnosed with transthyretin amyloid cardiomyopathy. Of patients with transthyretin amyloid cardiomyopathy, 11 (7.6%) had a pathogenic TTR gene variant and 34 (23.8%), 74 (51.7%), and 35 (24.5%) had New York Heart Association class I, II, and III/IV heart failure (HF) symptoms, respectively. Clinical and laboratory diagnostic characteristics were observed in ≥90% of patients with transthyretin amyloid cardiomyopathy. The characteristics most strongly associated with transthyretin amyloid cardiomyopathy on multivariable analysis were carpal tunnel syndrome (odds ratio [OR] 54.3; P < 0.0001) and male sex (OR 7.9; P < 0.0001).

CONCLUSIONS

In the TTRACK study, almost one in five patients ≥50 years of age with hypertrophic cardiomyopathy had transthyretin amyloid cardiomyopathy. Greater awareness of the frequency and characteristics of transthyretin amyloid cardiomyopathy in older patients with hypertrophic cardiomyopathy are needed to help improve early detection of this debilitating but treatable disease.

Mechanisms of damage and therapies for cardiac amyloidosis: a role for inflammation?

The term cardiac amyloidosis (CA) refers to the accumulation of extracellular amyloid deposits in the heart because of different conditions often affecting multiple organs including brain, kidney and liver. Notably, cardiac involvement significantly impacts prognosis of amyloidosis, with cardiac biomarkers playing a pivotal role in prognostic stratification. Therapeutic management poses a challenge due to limited response to conventional heart failure therapies, necessitating targeted approaches aimed at preventing, halting or reversing amyloid deposition. Mechanisms underlying organ damage in CA are multifactorial, involving proteotoxicity, oxidative stress, and mechanical interference. While the role of inflammation in CA remains incompletely understood, emerging evidence suggests its potential contribution to disease progression as well as its utility as a therapeutic target. This review reports on the cardiac involvement in systemic amyloidosis, its prognostic role and how to assess it. Current and emerging therapies will be critically discussed underscoring the need for further efforts aiming at elucidating CA pathophysiology. The emerging evidence suggesting the contribution of inflammation to disease progression and its prognostic role will also be reviewed possibly offering insights into novel therapeutic avenues for CA.

Echocardiographic factors associated with thromboembolic events in patients with cardiac amyloidosis without atrial fibrillation

AIMS

Cardiac amyloidosis (CA) is associated with various complications, and one of them are thromboembolic events (TEEs), which can significantly impact patients' quality of life. Predicting and managing the risk of these TEEs in patients without atrial fibrillation (AF) pose significant challenges, as many occur independently of AF presence. Several predictors, particularly echocardiographic ones, have been linked to an increased risk, but there is no consensus on stratification or preventive treatment. The main objective was to determine the prevalence of TEEs in a cohort of CA patients without AF and identify echocardiographic predictors.

METHODS

A retrospective, single-center study including confirmed CA patients. A prespecified list of variables was defined, and only patients with at least 70 % of these variables were included. Risk rates were analyzed through binary logistic regression, with a significance level set at p < 0.05.

RESULTS

75 patients were included. Baseline characteristics are depicted in Fig. 1. Fifteen TEEs (20 %) were described, with 80 % being ischemic strokes. While diastolic dysfunction and pulmonary systolic arterial pressure (PSAP) were predictors in univariate analysis, the multivariate backward LR model identified interventricular septum diameter (IVSD) as the sole predictor, OR 1.280 (1.061-1.543), p = 0.010. It is also interesting to mention that analyzing the increase of every 3 mm in SIV, the chance of developing ETES was: OR = 2.095 (1.195-3.671), p = 0.010.

CONCLUSIONS

An IVSD evaluated by echocardiography demonstrated good performance capacity as a factor associated with TEEs in this cohort of patients with AC without AF. For every 3 mm increase in IVSD, the risk of developing TEEs doubles.

Transthyretin amyloid cardiomyopathy in patients with unexplained increased left ventricular wall thickness

Amyloid cardiomyopathy (CA) was previously considered a rare disease; however, rapid advancements in imaging modalities have led to an increased frequency of its diagnosis. The aim of this prospective study was to assess the prevalence and clinical phenotype of transthyretin amyloidosis (ATTR) cardiomyopathy in patients exhibiting unexplained increased left ventricular (LV) wall thickness. From 2020 to 2022, we enrolled 100 consecutive adults with unexplained increased LV wall thickness in the study. The analysis included clinical data, electrocardiography, transthoracic echocardiography, single-photon emission computed tomography/computed tomography with 3,3-disphono-1,2-propanodicarboxylic acid, genetic testing. Overall, 18% of patients were diagnosed with CA, comprising 5% with light-chain amyloidosis, and 12% with ATTR. To evaluate associations with the ATTR diagnosis, a LOGIT model and multivariate analysis were applied. Notably, age, polyneuropathy, gastropathy, carpal tunnel syndrome, lumbar spine stenosis, low voltage, ventricular arrhythmia, LV mass, LV ejection fraction, global longitudinal strain (GLS), E/A, E/E', right ventricle (RV) thickness, right atrium area, RV VTI, TAPSE, apical sparing, ground glass appearance of myocardium, thickening of interatrial septum, thickening of valves, and the "5-5-5" sign were found to be significantly associated with ATTR (p < 0.05). The best predictive model for ATTR diagnoses exhibited an area under the curve of 0.99, including LV mass, GLS and RV thickness. This study, conducted at a cardiology referral center, revealed that a very considerable proportion of patients with unexplained increased LV wall thickness may suffer from underlying CA. Moreover, the presence of ATTR should be considered in patients with increased LV mass accompanied by reduced GLS and RV thickening.

Cerebrovascular Involvement in Transthyretin Amyloid Cardiomyopathy

Background: Intracardiac thrombosis is common in transthyretin amyloid cardiomyopathy (ATTR-CM), and patients are at risk for thromboembolic events. However, silent cerebral infarcts and the extent of cerebral small vessel disease in patients with cardiac amyloidosis are unknown. Methods: Thirty-two consecutively selected ATTR-CM patients were prospectively studied by cerebral magnetic resonance imaging (cMRI) and compared with 43 CHA2DS2-VASc-matched controls (Co). Structural clinical standard cMRI sequences and features of cerebral vessel involvement were included and quantified by two board certified neuroradiologists in consensus blinded to clinical status. Group differences were estimated using generalized (logistic) linear regression models adjusting for vascular risk factors based on the CHA2DS2-VASc score. Results: The median CHA2DS2-VASc score was 4 for ATTR-CM and Co (p = 0.905). There were no differences between groups in the frequency of current or former smokers (p = 0.755), body-mass-index > 30 (p = 0.106), and hyperlipidemia (p = 0.869). The number of territorial infarcts (4 vs. 0, p = 0.018) was higher in ATTR-CM compared to Co, as was the mean number of cerebral microbleeds (1.4 vs. 0.3, p ≤ 0.001) and the number of Virchow-Robin spaces (43.8 vs. 20.6, p ≤ 0.001). Lacunar lesion presence was higher in ATTR-CM (6 vs. 2, p = 0.054). CHA2DS2-VASc score, atrial fibrillation, anticoagulation, and the interaction term of CHA2DS2-VASc score and atrial fibrillation did not affect the probability of a territorial ischemic lesion or lacunar lesion in logistic regression modeling. Conclusions: In patients with ATTR-CM free from clinically apparent neurological symptoms, cMRI revealed unreported significant small cerebral vessel disease and territorial ischemia. Our findings may support low thresholds for anticoagulation and cMRI in patients with ATTR-CM.

Early Diagnosis of Amyloidosis and Cardiac Involvement through Carpal Tunnel Surgery and Predictive Factors

Background/Objectives: To determine the prevalence of amyloidosis through the analysis of synovial tissue and transverse carpal ligament (TCL) in patients undergoing surgery for carpal tunnel syndrome (CTS), detect predictive factors for the presence of amyloid, and assess cardiac involvement degree. Methods: A prospective study with longitudinal cohort follow-up at a teaching hospital. Patients undergoing CTS surgery from 1 January 2019 to 31 May 2021 were included. Samples from synovial and TCL tissues were examined for amyloid presence. Multivariate analysis was used to detect predictive factors of the presence of amyloid. Patients with amyloid underwent echocardiography, laboratory analyses, and scintigraphy. Results: Two hundred and forty-six patients were included. The prevalence of amyloid was 11.4% in TCL and 12.6% in synovial tissues. Age (p = 0.035; OR 1.123), bilateral CTS symptoms (p = 0.022; OR 3.647), and trigger finger (p < 0.001; OR 3.537) were predictors of the presence of amyloid. Seventeen patients were diagnosed with transthyretin amyloidosis (ATTR) located in the carpus (no scintigraphic cardiac uptake or grade 0), one with light chain amyloidosis, eight with ATTR with cardiac involvement (grades 2-3), and five with ATTR in the carpus and scintigraphic uptake grade 1 (with normal echocardiogram and blood and urine tests). Conclusions: We detected amyloid in 12.6% of unselected consecutive patients who underwent CTS surgery. Biopsy in patients with CTS for amyloid detection, especially in elderly patients with bilateral symptoms and trigger finger, may be useful for the early diagnosis of amyloidosis, primarily due to transthyretin.

Carpal Tunnel Syndrome and Transthyretin Amyloidosis in the All of Us Research Program

OBJECTIVE

To evaluate the association of carpal tunnel syndrome (CTS) with incident heart failure and incident amyloidosis and to assess the risk of CTS in pathogenic TTR genetic variant carriers.

METHODS

This prospective cohort study included multiethnic US adults 18 years of age and older without prevalent heart failure and amyloidosis with available genotypic data from the All of Us Research Program. The primary outcomes were incident heart failure and incident amyloidosis. The association of incident heart failure and incident amyloidosis with CTS was assessed using multivariable adjusted Cox models accounting for age, sex, race and ethnicity, obesity, hypertension, diabetes, statin use, and smoking status.

RESULTS

Of the 166,987 individuals included, the median age was 54 (38 to 66) years; 105,279 (63.0%) were female, and 92,780 (55.6%) were non-Hispanic White individuals; CTS was identified in 12,407 (7.4%) individuals. Compared with individuals without CTS, the adjusted hazard ratio for incident heart failure was 1.13 (95% CI, 1.02 to 1.26) in individuals with CTS. The risk of amyloidosis was ∼3-fold higher (adjusted hazard ratio, 2.86; 95% CI, 1.71 to 4.77) in individuals with CTS compared with those without CTS. Individuals carrying a pathogenic TTR variant had an approximately 40% higher risk (adjusted hazard ratio, 1.38; 95% CI, 1.16 to 1.65) for development of CTS compared with noncarriers.

CONCLUSION

Cardiac amyloidosis screening programs may use CTS as a sentinel event and use genetic testing to identify individuals at a higher risk of TTR amyloidosis.

The Diagnostic and Therapeutic Implications of Phenocopies and Mimics of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common myocardial disease defined by increased left ventricular wall thickness unexplained by loading conditions. HCM frequently is caused by pathogenic variants in sarcomeric protein genes, but several other syndromic, metabolic, infiltrative, and neuromuscular diseases can result in HCM phenocopies. This review summarizes the current understanding of these HCM mimics, highlighting their importance across the life course. The central role of a comprehensive, multiparametric diagnostic approach and the potential of precision medicine in tailoring treatment strategies are emphasized.

Etiologies and predictors of mortality in an all-comer population of patients with non-ischemic heart failure

BACKGROUND

Despite progress in diagnosis and therapy of heart failure (HF), etiology and risk stratification remain elusive in many patients.

METHODS

The My Biopsy HF Study (German clinical trials register number: DRKS22178) is a retrospective monocentric study investigating an all-comer population of patients with unexplained HF based on a thorough workup including endomyocardial biopsy (EMB).

RESULTS

655 patients (70.9% men, median age 55 [45/66] years) with non-ischemic, non-valvular HF were included in the analyses. 489 patients were diagnosed with HF with reduced ejection fraction (HFrEF), 52 patients with HF with mildly reduced ejection fraction (HFmrEF) and 114 patients with HF with preserved ejection fraction (HFpEF). After a median follow-up of 4.6 (2.5/6.6) years, 94 deaths were enumerated (HFrEF: 68; HFmrEF: 8; HFpEF: 18), equating to mortality rates of 3.3% and 11.6% for patients with HFrEF, 7.7% and 15.4% for patients with HFmrEF and 5.3% and 11.4% for patients with HFpEF after 1 and 5 years, respectively. In EMB, we detected a variety of putative etiologies of HF, including incidental cardiac amyloidosis (CA, 5.8%). In multivariate logistic regression analysis adjusting for age, sex and comorbidities only CA, age and NYHA functional class III + IV remained independently associated with all-cause mortality (CA: HRperui 3.13, 95% CI 1.5-6.51; p = 0.002).

CONCLUSIONS

In an all-comer population of patients presenting with HF of unknown etiology, incidental finding of CA stands out to be independently associated with all-cause mortality. Our findings suggest that prospective trials would be helpful to test the added value of a systematic and holistic work-up of HF of unknown etiology.

Sex differences in transthyretin cardiac amyloidosis

Transthyretin cardiac amyloidosis (ATTR-CA) is a progressive disease characterized by the deposition of abnormal transthyretin protein fibrils in the heart, leading to cardiac dysfunction. Recent evidence suggests that sex differences may play a significant role in various steps of ATTR-CA, including clinical presentation, diagnostic challenges, disease progression, and treatment outcomes. ATTR-CA predominantly affects men, whereas women are older at presentation. Women generally present with a history of heart failure with preserved ejection fraction and/or carpal tunnel syndrome. When indexed, left ventricular (LV) wall thickness is equal, or even increased, than men. Women also have smaller LV cavities, more preserved ejection fractions, and apparently a slightly worse right ventricular and diastolic function. Given the under-representation on women in clinical trials, no data regarding sex influence on the treatment response are currently available. Finally, it seems there are no differences in overall prognosis, even if premenopausal women may have a certain level of myocardial protection. Genetic variations, environmental factors, and hormonal changes are considered as potential contributors to observed disparities. Understanding sex differences in ATTR-CA is vital for accurate diagnosis and management. By considering these differences, clinicians can improve diagnostic accuracy, tailor treatments, and optimize outcomes for both sexes with ATTR-CA.

Reduction in 99mTc-DPD myocardial uptake with therapy of ATTR cardiomyopathy

Aims: Novel ribonucleic acid interference (RNAi) therapeutics such as patisiran and inotersen have been shown to benefit neurologic disease course and quality of life in patients with hereditary transthyretin amyloidosis (ATTRv). We aimed to determine the impact of RNAi therapeutics on myocardial amyloid load using quantitative single photon emission computed tomography/computed tomography (SPECT/CT) imaging in patients with ATTRv-related cardiomyopathy (ATTRv-CM). We furthermore compared them with wild-type ATTR-CM (ATTRwt-CM) patients treated with tafamidis.Methods and results: ATTRv-CM patients underwent [99mTc]-radiolabeled diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy and quantitative SPECT/CT imaging before and after 12 months (IQR: 11.0-12.0) of treatment with RNAi therapeutics (patisiran: n = 5, inotersen: n = 4). RNAi treatment significantly reduced quantitative myocardial uptake as measured by standardised uptake value (SUV) retention index (baseline: 5.09 g/mL vs. follow-up: 3.19 g/mL, p = .028) in ATTRv-CM patients without significant improvement in cardiac function. Tafamidis treatment resulted in a significant reduction in SUV retention index (4.96 g/mL vs. 3.27 g/mL, p < .001) in ATTRwt-CM patients (historical control cohort: n = 40) at follow-up [9.0 months (IQR: 7.0-10.0)] without beneficial impact on cardiac function.Conclusions: RNAi therapeutics significantly reduce quantitative myocardial uptake in ATTRv-CM patients, comparable to tafamidis treatment in ATTRwt-CM patients, without impact on cardiac function. Serial 99mTc-DPD SPECT/CT imaging may be a valuable tool to quantify and monitor response to disease-specific therapies in both ATTRv-CM and ATTRwt-CM.

Utility of Genetic Testing in Patients with Transthyretin Amyloid Cardiomyopathy: A Brief Review

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an increasingly diagnosed condition. Although wild-type transthyretin amyloidosis (ATTRwt) is the most common ATTR-CM, hereditary transthyretin amyloidosis (ATTRv) may also occur. Currently, genetic testing for transthyretin pathogenic variants is recommended for patients with a confirmed clinical diagnosis of ATTR-CM. In fact, confirmation of this autosomal dominant pathogenic variant prompts genetic counselling and allows early identification of affected relatives. Additionally, in the presence of an ATTR-CM-associated polyneuropathy, specific drugs targeting transthyretin can be used. In this paper, we review the utility of genetic testing for the detection of pathogenic variants among patients harboring ATTR-CM and its impact on the natural history of the disease.

Diagnostic accuracy of bone scintigraphy imaging for transthyretin cardiac amyloidosis: systematic review and meta-analysis

BACKGROUND

Bone scintigraphy imaging is frequently used to investigate patients with suspected transthyretin cardiac amyloidosis (ATTR-CM). However, the reported accuracy for interpretation approaches has changed over time. We performed a systematic review and meta-analysis to determine the diagnostic accuracy of visual planar grading, heart-to-contralateral (HCL) ratio, and quantitative analysis of SPECT imaging and evaluate reasons for shifts in reported accuracy.

METHODS

We performed a systematic review to identify studies of the diagnostic accuracy of bone scintigraphy for ATTR-CM from 1990 until February 2023 using PUBMED and EMBASE. Studies were reviewed separately by two authors for inclusion and for risk of bias assessment. Summary receiver operating characteristic curves and operating points were determined with hierarchical modeling.

RESULTS

Out of a total of 428 identified studies, 119 were reviewed in detail and 23 were included in the final analysis. The studies included a total of 3954 patients, with ATTR-CM diagnosed in 1337 (39.6%) patients and prevalence ranging from 21 to 73%. Visual planar grading and quantitative analysis had higher diagnostic accuracy (.99) than HCL ratio (.96). Quantitative analysis of SPECT imaging had the highest specificity (97%) followed by planar visual grade (96%) and HCL ratio (93%). ATTR-CM prevalence accounted for some of the observed between study heterogeneity.

CONCLUSIONS

Bone scintigraphy imaging is highly accurate for identifying patients with ATTR-CM, with between study heterogeneity in part explained by differences in disease prevalence. We identified small differences in specificity, which may have important clinical implications when applied to low-risk screening populations.

Incidence and survival of transthyretin amyloid cardiomyopathy from a French nationwide study of in- and out-patient databases

BACKGROUND

Precise data about ATTR-CM incidence rates at national level are scarce. Consequently, this study aimed to estimate the annual incidence and survival of transthyretin amyloid cardiomyopathy (ATTR-CM) in France between 2011 and 2019 using real world data. We used the French nationwide exhaustive data (SNDS database) gathering in- and out-patient claims. As there is no specific ICD-10 marker code for ATTR-CM, diagnosis required both amyloidosis (identified by E85. ICD-10 code or a tafamidis meglumine delivery) and a cardiovascular condition (identified by ICD-10 or medical procedure codes related to either heart failure, arrhythmias, conduction disorders or cardiomyopathies), not necessarily reported at the same visit. Patients with probable AL-form of amyloidosis or probable AA-form of amyloidosis were excluded.

RESULTS

Between 2011 and 2019, 8,950 patients with incident ATTR-CM were identified. Incidence rates increased from 0.6 / 100,000 person-years in 2011 to 3.6 / 100,000 person-years in 2019 (p < 0.001), reaching 2377 new cases in 2019. Sex ratios (M/F) increased from 1.52 in 2011 to 2.23 in 2019. In 2019, median age at diagnosis was 84.0 years (85.5 for women and 83.5 for men). Median survival after diagnosis was 41.9 months (95% CI [39.6, 44.1]).

CONCLUSIONS

This is the first estimate of nationwide ATTR-CM incidence in France using comprehensive real-world databases. We observed an increased incidence over the study period, consistent with an improvement in ATTR-CM diagnosis in recent years.

Advance of echocardiography in cardiac amyloidosis

Cardiac amyloidosis (CA) occurs when the insoluble fibrils formed by misfolded precursor proteins deposit in cardiac tissues. The early clinical manifestations of CA are not evident, but it is easy to progress to refractory heart failure with an inferior prognosis. Echocardiography is the most commonly adopted non-invasive modality of imaging to visualize cardiac structures and functions, and the preferred modality in the evaluation of patients with cardiac symptoms and suspected CA, which plays a vital role in the diagnosis, prognosis, and long-term management of CA. The present review summarizes the echocardiographic manifestations of CA, new echocardiographic techniques, and the application of multi-parametric echocardiographic models in CA diagnosis.

Molecular Imaging of Systemic and Cardiac Amyloidosis: Recent Advances and Focus on the Future

Myocardial infiltration by amyloid fibrils causes a severe and progressive form of heart failure. Until recently, this was not treatable. Several novel therapies have recently become available, increasing the urgency to make an accurate diagnosis, evaluate risk, and determine treatment response. Molecular imaging with positron-emitting amyloid tracers has a key emerging role in the evaluation and management of cardiac amyloidosis. In this review, we discuss molecular imaging of cardiac amyloidosis using amyloid PET tracers, including recent advances with a focus on the future.

A simple ATTR-CM score to identify transthyretin amyloid cardiomyopathy burden in HFpEF patients

BACKGROUND

Transthyretin amyloid cardiomyopathy (ATTR-CM) is often found in patients with heart failure with preserved ejection fraction (HFpEF). However, the evidence regarding ATTR-CM and prognosis in HFpEF remains scarce. This study sought to determine whether the ATTR-CM burden was associated with clinical outcomes in HFpEF patients.

METHODS

We evaluated the associations of baseline ATTR-CM score with adverse outcomes in HFpEF patients from the TOPCAT trial using the Cox proportional hazards model or the competing risk regression model. The discriminatory ability of the ATTR-CM score was assessed using the area under the time-dependent receiver operating characteristic curve (AUC).

RESULTS

We included 870 HFpEF patients, 18.9% of which had an ATTR-CM score ≥6. Per 1 increment in the ATTR-CM score was significantly associated with an increased risk of the primary outcome (adjusted hazard ratio [HR] 1.19, 95% confidence interval [CI] 1.12-1.27) with an AUC of 0.652 (0.594-0.711), whereas patients with ATTR-CM score ≥6 presented higher risks of the primary outcome (adjusted HR 2.20, 95% CI 1.65-2.95). Similar results were observed toward the secondary outcomes.

CONCLUSIONS

The simple ATTR-CM score identified an 18.9% ATTR-CM burden in HFpEF patients, and a higher ATTR-CM burden might predict adverse outcomes with moderate discriminatory abilities in HFpEF.

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.

Optimal practices for the management of hereditary transthyretin amyloidosis: real-world experience from Japan, Brazil, and Portugal

Hereditary transthyretin (ATTRv) amyloidosis is a rare and autosomal dominant disorder associated with mutations in the transthyretin gene. Patients present with diverse symptoms related to sensory, motor, and autonomic neuropathy, as well as gastrointestinal, ocular, cardiac, renal and orthopedic symptoms, resulting from the deposition of transthyretin amyloid fibrils in multiple organs. The progressive nature of ATTRv amyloidosis necessitates pre- and post-onset monitoring of the disease. This review article is primarily based on a collation of discussions from a medical advisory board meeting in August 2021. In this article, we summarize the best practices in amyloidosis centers in three major endemic countries for ATTRv amyloidosis (Japan, Brazil, and Portugal), where most patients carry the Val30Met mutation in the transthyretin gene and the patients' genetic background was proven to be the same. The discussions highlighted the similarities and differences in the management of asymptomatic gene mutation carriers among the three countries in terms of the use of noninvasive tests and tissue biopsies and timing of starting the investigations. In addition, this article discusses a set of practical tests and examinations for monitoring disease progression applicable to neurologists working in diverse medical settings and generalizable in non-endemic countries and areas. This set of assessments consists of periodic (every 6 to 12 months) evaluations of patients' nutritional status and autonomic, renal, cardiac, ophthalmologic, and neurological functions. Physical examinations and patient-reported outcome assessments should be also scheduled every 6 to 12 months. Programs for monitoring gene mutation carriers and robust referral networks can aid in appropriate patient management in pre- to post-onset stages. For pre- and post-symptom onset testing for ATTRv amyloidosis, various noninvasive techniques are available; however, their applicability differs depending on the medical setting in each country and region, and the optimal option should be selected in view of the clinical settings, medical environment, and available healthcare resources in each region.

Changes in amyloidosis phenotype over 11 years in a cardiac amyloidosis referral centre cohort in France

BACKGROUND

Early cardiac amyloidosis (CA) diagnosis enables patients to access effective treatments for better long-term outcomes, yet it remains under-recognised, misdiagnosed and inadequately managed.

AIM

To reduce diagnostic delays, we aimed to describe the epidemiological and clinical characteristics and changes over an 11-year period.

METHODS

This was a retrospective, observational cohort study of all patients referred to the Henri-Mondor Hospital for suspected CA.

RESULTS

Overall, 3194 patients were identified and 3022 were included and analysed. Our patients came from varied ethnic backgrounds, and more than half (55.2%) had confirmed CA. Over 11 years, referrals increased 4.4-fold, mostly from cardiologists. Notably, wild-type transthyretin amyloidosis (ATTRwt) became the predominant diagnosis, with referrals increasing 15-fold from 20 in 2010-2012 to 308 in 2019-2020. The number of amyloid light chain (AL) diagnoses increased, whilst variant transthyretin amyloidosis (ATTRv) numbers remained relatively stable. Concerning disease severity, AL patients presented more frequently with severe cardiac involvement whereas an increasing number of ATTRwt patients presented with National Amyloid Centre stage I (22.0% in 2013-2014 to 45.9% in 2019-2020). Lastly, among patients diagnosed with ATTRv in 2019-2020, 83.9% had ATTR Val122Ile cardiac phenotype.

CONCLUSIONS

This study shows that increasing cardiologist awareness and referrals have increased CA diagnoses. With improved awareness and non-invasive diagnostic techniques, more patients with ATTRwt with milder disease and more ATTRv Val122Ile mutations are being referred and diagnosed. Although more AL cases are being recognised, patients are diagnosed with severe cardiac involvement.

[Transthyretin amyloid cardiomyopathy]

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed cause of heart failure and arrhythmia. This differential diagnosis should particularly be considered in older patients with left ventricular hypertrophy (LVH) who are also suffering from heart failure with preserved ejection fraction (HFpEF) or aortic valve stenosis. ATTR-CM is caused either by a genetic variation or by aging processes. The extracellular accumulation of amyloid fibrils in the heart causes a restrictive cardiomyopathy, which leads to typical heart failure symptoms as well as cardiac conduction and repolarization disturbances. Extracardiac problems such as a carpal tunnel syndrome can also be indicative for ATTR-CM. The disease can be diagnosed either by a myocardial biopsy or alternatively by a positive bone scintigraphy with the simultaneous exclusion of monoclonal proteins in blood and urine. Besides a symptomatic treatment, the transthyretin (TTR) stabilizer tafamidis is now available, which can significantly delay the disease progress. In the coming years, the approval of further drugs for the treatment of ATTR-CM is to be expected.

British Society of Echocardiography guideline for the transthoracic echocardiographic assessment of cardiac amyloidosis

These guidelines form an update of the BSE guideline protocol for the assessment of restrictive cardiomyopathy (Knight et al. in Echo Res Prac, 2013). Since the original recommendations were conceived in 2013, there has been an exponential rise in the diagnosis of cardiac amyloidosis fuelled by increased clinician awareness, improvements in cardiovascular imaging as well as the availability of new and effective disease modifying therapies. The initial diagnosis of cardiac amyloidosis can be challenging and is often not clear-cut on the basis of echocardiography, which for most patients presenting with heart failure symptoms remains the first-line imaging test. The role of a specialist echocardiographer will be to raise the suspicion of cardiac amyloidosis when appropriate, but the formal diagnosis of amyloid sub-type invariably requires further downstream testing. This document seeks to provide a focused review of the literature on echocardiography in cardiac amyloidosis highlighting its important role in the diagnosis, prognosis and screening of at risk individuals, before concluding with a suggested minimum data set, for use as an aide memoire when reporting.

Status and Future Directions of Therapeutics and Prognosis of Cardiac Amyloidosis

Accumulation of aberrant proteins in the heart causes cardiac amyloidosis, an uncommon and complicated illness. It can be classified into two main types: light chain (AL) and transthyretin (ATTR). The diagnosis of cardiac amyloidosis is challenging due to its non-specific clinical presentation and lack of definitive diagnostic tests. Diagnostic accuracy has increased with the advent of modern imaging methods, including cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET) scans. Depending on the severity of cardiac amyloidosis, a number of treatments may be attempted and specified according to the subtype of amyloidosis and the presence of complications. However, there are still significant challenges in treating this condition due to its complexity and lack of effective treatments. The prognosis for patients with cardiac amyloidosis is poor. Despite recent advances in diagnosis and treatment, there is still a need for more effective treatments to improve outcomes for patients with this condition. Therefore, we aim to review the current and future therapeutics reported in the literature and among ongoing clinical trials recruiting patients with CA.

Treating amyloid transthyretin cardiomyopathy: lessons learned from clinical trials

An increasing awareness of the disease, new diagnostic tools and novel therapeutic opportunities have dramatically changed the management of patients with amyloid transthyretin cardiomyopathy (ATTR-CM). Supportive therapies have shown limited benefits, mostly related to diuretics for the relief from signs and symptoms of congestion in patients presenting heart failure (HF). On the other hand, huge advances in specific (disease-modifying) treatments occurred in the last years. Therapies targeting the amyloidogenic cascade include several pharmacological agents that inhibit hepatic synthesis of TTR, stabilize the tetramer, or disrupt fibrils. Tafamidis, a TTR stabilizer that demonstrated to prolong survival and improve quality of life in the ATTR-ACT trial, is currently the only approved drug for patients with ATTR-CM. The small interfering RNA (siRNA) patisiran and the antisense oligonucleotide (ASO) inotersen have been approved for the treatment of patients with hereditary ATTR polyneuropathy regardless of the presence of cardiac involvement, with patisiran also showing preliminary benefits on the cardiac phenotype. Ongoing phase III clinical trials are investigating another siRNA, vutrisiran, and a novel ASO formulation, eplontersen, in patients with ATTR-CM. CRISPR-Cas9 represents a promising strategy of genome editing to obtain a highly effective blockade of TTR gene expression.

Investigation on the high recurrence of the ATTRv-causing transthyretin variant Val142Ile in central Italy

The p.Val142Ile variant in transthyretin (encoded by the TTR gene) is the most common genetic cause of transthyretin-related amyloidosis. This allele is particularly prevalent in communities ofAfrican descent compared with populations of different ancestries, where its frequency is two orders of magnitude lower. For this reason, p.Val142Ile has always been considered an "African" variant, with limited studies performed on individuals of European descent. However, recent reports of higher-than-expected prevalence in European-ancestry populations question the African specificity of this allele. Here we show that the high recurrence of p.Val142Ile in central Italy is due to a founder effect and not to recent admixture from African populations, highlighting how this may be the case in other communities. This suggests a probable underestimate of the global prevalence of p.Val142Ile, and further emphasizes the importance of routine inclusion of TTR in gene panels used for clinical genetic testing in hypertrophic cardiomyopathy (independently of the patient's geographical origin), that transthyretin-related amyloidosis can mimic.

Trends in diagnosis of cardiac transthyretin amyloidosis: 3-year analysis of scintigraphic studies: Prevalence of myocardial uptake and its predictor factors

To determine the prevalence of myocardial uptake (MU) and to identify predictors of MU in patients undergoing scintigraphy. Retrospective single-center series of technetium-99 m-labelled 3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scans performed from March 2017 to March 2020. All patients undergoing scintigraphy were included, except those with preexisting amyloidosis. The features of MU, patients' characteristics and comorbidities were documented. Multivariate analysis was used to find items predicting MU. A total of 3,629 99mTc-DPD scans (total 11,444) were performed in patients aged > 70. The overall prevalence of MU was 2.7% (82/3,629); 1.2% in 2017-2018, to 2% in 2018-2019, and to 3.7% in 2019-2020. The prevalence of MU in patients without suspected cardiomyopathy was 1.2%; 1.1% in 2017-2018, 1.5% in 2018-2019 and 1% in 2019-2020. There is an increase in the number of requests due to suspected cardiomyopathy from 0.2% in 2017-2018 to 1.4% in 2018-2019 and to 4.8% in 2019-2020. Age, male sex, hypertension, heart failure, atrial fibrillation, atrioventricular block, aortic stenosis, and carpal tunnel syndrome were found to be predictors of MU. In patients without heart failure, only age, atrial fibrillation, and carpal tunnel syndrome were predicted MU. The prevalence of MU in scintigraphic studies surged over time due to the incremental referrals under the indication of cardiomyopathy workup. Atrial fibrillation and carpal tunnel syndrome were predictors for MU in patients without heart failure. Identifying patients with MU and no heart failure for extended screening for ATTR can lead to an earlier diagnosis and application of novel treatments.

State of the Art of Cardiac Amyloidosis

Cardiac amyloidosis is defined by extracellular deposition of misfolded proteins in the heart. The most frequent cases of cardiac amyloidosis are caused by transthyretin and light chain amyloidosis. This condition is underdiagnosed, and its incidence has been continuously rising in recent studies because of the aging of the population and the development of noninvasive multimodal diagnostic tools. Amyloid infiltration affects all cardiac tunics and causes heart failure with preserved ejection fraction, aortic stenosis, arrythmia, and conductive disorder. Innovative, specific therapeutic approaches have demonstrated an improvement in affected organs and the global survival of patients. This condition is no longer considered rare and incurable. Thus, better knowledge of the disease is mandatory. This review will provide a digest of the clinical signs and symptoms of cardiac amyloidosis, the diagnostic tools used to confirm the diagnosis, and current symptomatic and etiopathogenic management considerations according to guidelines and recommendations.

Quantitative 99mTc-DPD-SPECT/CT assessment of cardiac amyloidosis

INTRODUCTION

Transthyretin (ATTR) amyloidosis is responsible for the majority of cardiac amyloidosis (CA) cases and can be reliably diagnosed with bone scintigraphy and the visual Perugini score. We aimed to implement a quantification method of cardiac amyloid deposits in patients with suspected cardiac amyloidosis and to compare performance to visual scoring.

METHODS AND MATERIALS

136 patients received 99mTc-DPD-bone scintigraphy including SPECT/CT of the thorax in case of suspicion of cardiac amyloidosis. Imaging phantom studies were performed to determine the scaling factor for standardized uptake value (SUV) quantification from SPECT/CT. Myocardial tracer uptake was quantified in a whole heart volume of interest.

RESULTS

Forty-five patients were diagnosed with CA. A strong relationship between cardiac SUVmax and Perugini score was found (Spearman r 0.75, p < 0.0001). Additionally, tracer uptake in bone decreased with increasing cardiac SUVmax and Perugini score (p < 0.0001). ROC analysis revealed good performance of the SUVmax for the detection of ATTR-CA with AUC of 0.96 ± 0.02 (p < 0.0001) with sensitivity 98.7% and specificity 87.2%.

CONCLUSION

We demonstrate an accessible and accurate quantitative SPECT approach in CA. Quantitative assessment of the cardiac tracer uptake may improve diagnostic accuracy and risk classification. This method may enable monitoring and assessment of therapy response in patients with ATTR amyloidosis.

Redefining the epidemiology of cardiac amyloidosis. A systematic review and meta-analysis of screening studies

AIMS

An algorithm for non-invasive diagnosis of amyloid transthyretin cardiac amyloidosis (ATTR-CA) and novel disease-modifying therapies have prompted an active search for CA. We examined the prevalence of CA in different settings based on literature data.

METHODS AND RESULTS

We performed a systematic search for screening studies on CA, focusing on the prevalence, sex and age distribution in different clinical settings. The prevalence of CA in different settings was as follows: bone scintigraphy for non-cardiac reasons (n = 5 studies), 1% (95% confidence interval [CI] 0%-1%); heart failure with preserved ejection fraction (n = 6), 12% (95% CI 6%-20%); heart failure with reduced or mildly reduced ejection fraction (n = 2), 10% (95% CI 6%-15%); conduction disorders warranting pacemaker implantation (n = 1), 2% (95% CI 0%-4%); surgery for carpal tunnel syndrome (n = 3), 7% (95% CI 5%-10%); hypertrophic cardiomyopathy phenotype (n = 2), 7% (95% CI 5%-9%); severe aortic stenosis (n = 7), 8% (95% CI 5%-13%); autopsy series of 'unselected' elderly individuals (n = 4), 21% (95% CI 7%-39%). The average age of CA patients in the different settings ranged from 74 to 90 years, and the percentage of men from 50% to 100%. Many patients had ATTR-CA, but the average percentage of patients with amyloid light-chain (AL) CA was up to 18%.

CONCLUSIONS

Searching for CA in specific settings allows to identify a relatively high number of cases who may be eligible for treatment if the diagnosis is unequivocal. ATTR-CA accounts for many cases of CA across the different settings, but AL-CA is not infrequent. Median age at diagnosis falls in the eighth or ninth decades, and many patients diagnosed with CA are women.

Trends in diagnosis, referral, red flag onset, patient profiles and natural outcome of de novo cardiac amyloidosis and their multidisciplinary implications

BACKGROUND

Cardiac amyloidosis (CA) is often overlooked or misdiagnosed. Effects of growing disease awareness, diagnostic ameliorations and novel treatment options on CA diagnosis and management are scarcely reported.

OBJECTIVE

To report trends in diagnosis, referral routes, clinical presentation, early onset diagnostic red flags and outcome in de novo CA subjects.

METHODS

An unselected cohort of 139 de novo CA patients over an 8-year period in a tertiary referral hospital was recruited.

RESULTS

Transthyretin (ATTR, 82%, n = 114) was the most common CA form; Light-chain (AL, 15%, n = 21) and secondary (AA, 3%, n = 4) are less prevalent. Increased awareness over time led to a marked ATTR diagnostic surge, steep non-invasive diagnostic approach increment and increased nuclear medicine and external cardiologist referrals (all p < 0.001). A total of 41% (n = 57/139) of patients were referred by non-cardiology specialist disciplines. Specific referral to rule out CA (24-36%) and diagnostic time lag from symptom onset (9 ± 12 to 8 ± 14 months), however, did not improve (all p > 0.050). Multiple early red flag events preceded CA diagnose several years in ATTR: Left ventricular hypertrophy (LVH, 60%, 4.9 ± 4.3 y), heart failure (54%, 2.5 ± 3.5 y), atrial fibrillation (47%, 5.9 ± 6.7 y), bilateral carpal tunnel syndrome (43%, 9.5 ± 5.7 y) and spinal stenosis (40%, 7.4 ± 6.5 y). LVH ≥ 12 mm was absent in 11% ATTR (n = 13/114) and 5% AL (n = 1/21) patients. Hypertension was common in both ATTR (n = 70/114, 62%) and AL (n = 10/21, 48%). 56% (n = 78/139) of CA presented with heart failure. Cumulative 1 and 5-year mortality of 10%/66%, 40%/52% and 75%/75% for ATTR, AL, and AA, respectively, remains high.

CONCLUSIONS

Although CA diagnostic uptake and referral improve, specialist-specific disease and diagnostic red flag ignorance result in non-timely diagnosis and unfavourable outcome.

Transthyretin cardiac amyloidosis

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized cause of heart failure (HF) and mortality worldwide. Advances in non-invasive diagnosis, coupled with the development of effective treatments, have shifted ATTR-CA from a rare and untreatable disease to a relatively prevalent condition that clinicians should consider on a daily basis. Amyloid fibril formation results from age-related failure of homoeostatic mechanisms in wild-type ATTR (ATTRwt) amyloidosis (non-hereditary form) or destabilizing mutations in variant ATTR (ATTRv) amyloidosis (hereditary form). Longitudinal large-scale studies in the United States suggest an incidence of cardiac amyloidosis in the contemporary era of 17 per 100 000, which has increased from a previous estimate of 0.5 per 100 000, which was almost certainly due to misdiagnosis and underestimated. The presence and degree of cardiac involvement is the leading cause of mortality both in ATTRwt and ATTRv amyloidosis, and can be identified in up to 15% of patients hospitalized for HF with preserved ejection fraction. Associated features, such as carpal tunnel syndrome, can preceed by several years the development of symptomatic HF and may serve as early disease markers. Echocardiography and cardiac magnetic resonance raise suspicion of disease and might offer markers of treatment response at a myocardial level, such as extracellular volume quantification. Radionuclide scintigraphy with 'bone' tracers coupled with biochemical tests may differentiate ATTR from light chain amyloidosis. Therapies able to slow or halt ATTR-CA progression and increase survival are now available. In this evolving scenario, early disease recognition is paramount to derive the greatest benefit from treatment.

Transthyretin Cardiac Amyloidosis Scintigraphy Using Planar D-SPECT on Dedicated Cardiac CZT Camera

BACKGROUND

Bone scintigraphy is a main diagnostic tool in suspected ATTR patients. Almost all literature is based on conventional whole body gamma cameras, and there is very sparse data evaluating the use of dedicated cardiac CZT cameras. The aim of this study was to evaluate the utility of bone scintigraphy in suspected transthyretin cardiac amyloidosis (ATTR-CA) patients on a dedicated cardiac CZT camera.

METHODS

Seventy-three patients with suspected ATTR-CA underwent planar and SPECT Tc-99 m pyrophosphate scintigraphy using dedicated cardiac CZT camera between May and August 2019.

RESULTS

Planar D-SPECT image quality was mostly good. Six patients were identified as ATTR-CA positive. Inter-observer agreement based on both Perugini score and on planar D-SPECT H/CL ratio was excellent.

CONCLUSIONS

ATTR-CA scintigraphy using dedicated cardiac CZT camera was feasible, and yielded planar D-SPECT images with excellent inter-observer agreement.

[Cardiac amyloidosis: State of art in 2022]

The 3 main types of cardiac amyloidosis are linked to two protein precursors: AL amyloidosis secondary to free light chain deposits in the context of monoclonal gammopathy (mainly of undetermined significance or myeloma) and transthyretin amyloidosis (ATTR), comprising wild-type transthyretin amyloidosis (ATTRwt for wild type) and hereditary transthyretin amyloidosis (ATTRv for variant). These diseases are underdiagnosed and highly prevalent in common cardiac phenotypes in recent studies (heart failure with preserved ejection fraction, severe aortic stenosis, hypertrophic cardiomyopathy). Myocardial amyloid infiltration affects all cardiac structures and clinically promotes predominantly heart failure, conductive disorders and cardioembolic events. The search for extracardiac signs makes it possible to arouse diagnostic suspicion. Electrocardiogram, echocardiography and cardiac MRI can suspect cardiac amyloidosis. The diagnostic confirmation follows a simple algorithm including a systematic search for monoclonal gammapathy and a disphosphonate scintigraphy. Histological proof is necessary in case of AL or ATTR amyloidosis with concomitant monoclonal gammopathy in order to initiate specific treatment. Due to the late disease onset in ATTRv, genetic testing must be routine in all cases of ATTR. These diseases are no longer perceived as incurable since recent therapeutic innovations. A better knowledge of the disease is more than ever necessary.

Re-Definition of the Epidemiology of Cardiac Amyloidosis

The epidemiology of cardiac amyloidosis (CA), traditionally considered a rare and incurable disease, has changed drastically over the last ten years, particularly due to the advances in diagnostic methods and therapeutic options in the field of transthyretin CA (ATTR-CA). On the one hand, the possibility of employing cardiac scintigraphy with bone tracers to diagnose ATTR-CA without a biopsy has unveiled the real prevalence of the disease; on the other, the emergence of effective treatments, such as tafamidis, has rendered an early and accurate diagnosis critical. Interestingly, the following subgroups of patients have been found to have a higher prevalence of CA: elderly subjects > 75 years, patients with cardiac hypertrophy hospitalized for heart failure with preserved ejection fraction, subjects operated on for bilateral carpal tunnel syndrome, patients with cardiac hypertrophy not explained by concomitant factors and individuals with aortic valve stenosis. Many studies investigating the prevalence of CA in these particular populations have contributed to rewriting the epidemiology of the disease, increasing the awareness of the medical community for a previously underappreciated condition. In this review, we summarized the latest evidence on the epidemiology of CA according to the different clinical settings typically associated with the disease.

Clinical and genetic profile of patients enrolled in the Transthyretin Amyloidosis Outcomes Survey (THAOS): 14-year update

BACKGROUND

Transthyretin amyloidosis (ATTR amyloidosis) is a rare, life-threatening disease caused by the accumulation of variant or wild-type (ATTRwt amyloidosis) transthyretin amyloid fibrils in the heart, peripheral nerves, and other tissues and organs.

METHODS

Established in 2007, the Transthyretin Amyloidosis Outcomes Survey (THAOS) is the largest ongoing, global, longitudinal observational study of patients with ATTR amyloidosis, including both inherited and wild-type disease, and asymptomatic carriers of pathogenic TTR mutations. This descriptive analysis examines baseline characteristics of symptomatic patients and asymptomatic gene carriers enrolled in THAOS since its inception in 2007 (data cutoff: August 1, 2021).

RESULTS

This analysis included 3779 symptomatic patients and 1830 asymptomatic gene carriers. Symptomatic patients were predominantly male (71.4%) and had a mean (standard deviation [SD]) age of symptom onset of 56.3 (17.8) years. Val30Met was the most common genotype in symptomatic patients in South America (80.9%), Europe (55.4%), and Asia (50.5%), and more patients had early- versus late-onset disease in these regions. The majority of symptomatic patients in North America (58.8%) had ATTRwt amyloidosis. The overall distribution of phenotypes in symptomatic patients was predominantly cardiac (40.7%), predominantly neurologic (40.1%), mixed (16.6%), and no phenotype (2.5%). In asymptomatic gene carriers, mean (SD) age at enrollment was 42.4 (15.7) years, 42.4% were male, and 73.2% carried the Val30Met mutation.

CONCLUSIONS

This 14-year global overview of THAOS in over 5000 patients represents the largest analysis of ATTR amyloidosis to date and highlights the genotypic and phenotypic heterogeneity of the disease.

CLINICALTRIALS

gov Identifier: NCT00628745.

Suspicion, screening, and diagnosis of wild-type transthyretin amyloid cardiomyopathy: a systematic literature review

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt CM) is a more common disease than previously thought. Awareness of ATTRwt CM and its diagnosis has been challenged by its unspecific and widely distributed clinical manifestations and traditionally invasive diagnostic tools. Recent advances in echocardiography and cardiac magnetic resonance (CMR), non-invasive diagnosis by bone scintigraphy, and the development of disease-modifying treatments have resulted in an increased interest, reflected in multiple publications especially during the last decade. To get an overview of the scientific knowledge and gaps related to patient entry, suspicion, diagnosis, and systematic screening of ATTRwt CM, we developed a framework to systematically map the available evidence of (i) when to suspect ATTRwt CM in a patient, (ii) how to diagnose the disease, and (iii) which at-risk populations to screen for ATTRwt CM. Articles published between 2010 and August 2021 containing part of or a full diagnostic pathway for ATTRwt CM were included. From these articles, data for patient entry, suspicion, diagnosis, and screening were extracted, as were key study design and results from the original studies referred to. A total of 50 articles met the inclusion criteria. Of these, five were position statements from academic societies, while one was a clinical guideline. Three articles discussed the importance of primary care providers in terms of patient entry, while the remaining articles had the cardiovascular setting as point of departure. The most frequently mentioned suspicion criteria were ventricular wall thickening (44/50), carpal tunnel syndrome (42/50), and late gadolinium enhancement on CMR (43/50). Diagnostic pathways varied slightly, but most included bone scintigraphy, exclusion of light-chain amyloidosis, and the possibility of doing a biopsy. Systematic screening was mentioned in 16 articles, 10 of which suggested specific at-risk populations for screening. The European Society of Cardiology recommends to screen patients with a wall thickness ≥12 mm and heart failure, aortic stenosis, or red flag symptoms, especially if they are >65 years. The underlying evidence was generally good for diagnosis, while significant gaps were identified for the relevance and mutual ranking of the different suspicion criteria and for systematic screening. Conclusively, patient entry was neglected in the reviewed literature. While multiple red flags were described, high-quality prospective studies designed to evaluate their suitability as suspicion criteria were lacking. An upcoming task lies in defining and evaluating at-risk populations for screening. All are steps needed to promote early detection and diagnosis of ATTRwt CM, a prerequisite for timely treatment.

Screening for ATTR amyloidosis in the clinic: overlapping disorders, misdiagnosis, and multiorgan awareness

Amyloid transthyretin (ATTR) amyloidosis is a clinically heterogeneous and fatal disease that results from deposition of insoluble amyloid fibrils in various organs and tissues, causing progressive loss of function. The objective of this review is to increase awareness and diagnosis of ATTR amyloidosis by improving recognition of its overlapping conditions, misdiagnosis, and multiorgan presentation. Cardiac manifestations include heart failure, atrial fibrillation, intolerance to previously prescribed antihypertensives, sinus node dysfunction, and atrioventricular block, resulting in the need for permanent pacing. Neurologic manifestations include progressive sensorimotor neuropathy (e.g., pain, weakness) and autonomic dysfunction (e.g., erectile dysfunction, chronic diarrhea, orthostatic hypotension). Non-cardiac red flags often precede the diagnosis of ATTR amyloidosis and include musculoskeletal manifestations (e.g., carpal tunnel syndrome, lumbar spinal stenosis, spontaneous rupture of the distal tendon biceps, shoulder and knee surgery). Awareness and recognition of the constellation of symptoms, including cardiac, neurologic, and musculoskeletal manifestations, will help with early diagnosis of ATTR amyloidosis and faster access to therapies, thereby slowing the progression of this debilitating disease.

Changing concepts in heart muscle disease: the evolving understanding of hypertrophic cardiomyopathy

Sixty years ago, hypertrophic cardiomyopathy (HCM) was considered a rare lethal disease that affected predominantly young adults and for which there were few treatment options. Today, it is recognised to be a relatively common disorder that presents throughout the life course with a heterogeneous clinical phenotype that can be managed effectively in the majority of individuals. A greater awareness of the condition and less reluctance from healthcare practitioners to make the diagnosis, coupled with improvements in cardiac imaging, including greater use of artificial intelligence and improved yields from screening efforts, have all helped facilitate a more precise and timely diagnosis. This enhanced ability to diagnose HCM early is being paired with innovations in treatment, which means that the majority of patients receiving a contemporary diagnosis of HCM can anticipate a normal life expectancy and expect to maintain a good functional status and quality of life. Indeed, with increasing translation of molecular genetics from bench to bedside associated with a growing number of randomised clinical trials of novel therapies aimed at ameliorating or perhaps even preventing the disease, the next chapter in the story for HCM will provide much excitement and more importantly, offer much anticipated reward for our patients.

New Advanced Imaging Parameters and Biomarkers-A Step Forward in the Diagnosis and Prognosis of TTR Cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative disorder characterized by extracellular myocardial deposits of amyloid fibrils, with poor outcome, leading to heart failure and death, with significant treatment expenditure. In the era of a novel therapeutic arsenal of disease-modifying agents that target a myriad of pathophysiological mechanisms, timely and accurate diagnosis of ATTR-CM is crucial. Recent advances in therapeutic strategies shown to be most beneficial in the early stages of the disease have determined a paradigm shift in the screening, diagnostic algorithm, and risk classification of patients with ATTR-CM. The aim of this review is to explore the utility of novel specific non-invasive imaging parameters and biomarkers from screening to diagnosis, prognosis, risk stratification, and monitoring of the response to therapy. We will summarize the knowledge of the most recent advances in diagnostic, prognostic, and treatment tailoring parameters for early recognition, prediction of outcome, and better selection of therapeutic candidates in ATTR-CM. Moreover, we will provide input from different potential pathways involved in the pathophysiology of ATTR-CM, on top of the amyloid deposition, such as inflammation, endothelial dysfunction, reduced nitric oxide bioavailability, oxidative stress, and myocardial fibrosis, and their diagnostic, prognostic, and therapeutic implications.