Frequency and distribution of senile cardiovascular amyloid. A clinicopathologic correlation

Hereditary transthyretin amyloidosis: a myriad of factors that influence phenotypic variability

Hereditary transthyretin-related amyloidosis (ATTRv amyloidosis) is a rare and progressively debilitating disease characterized by the deposition of transthyretin (TTR) amyloid fibrils in various organs and tissues, most commonly in the heart and peripheral nerves. This pathological deposition can lead to significant organ dysfunction and, ultimately, organ failure. ATTRv amyloidosis exhibits a broad range of clinical presentations, from purely neurological symptoms to purely cardiac manifestations, as well as mixed phenotypes which result from both neurological and cardiac implications. This wide phenotypical spectrum realistically challenges disease diagnosis and prognosis, especially in individuals without or with an unknown family history. Multiple factors are thought to contribute to this variability, including genetic, epigenetic, and even environmental influences. Understanding these factors is crucial, as they can significantly affect disease expression and progression. This review aims to summarize each of these contributing factors, to help elucidate the current knowledge on the phenotypical variability of ATTRv amyloidosis.

Prevalence, Characteristics, and Impact on Prognosis of Aortic Stenosis in Patients With Cardiac Amyloidosis

BACKGROUND

Cardiac amyloidosis (CA) is frequently found in older patients with aortic stenosis (AS). However, the prevalence of AS among patients with CA is unknown. The objective was to study the prevalence and prognostic impact of AS among patients with CA.

METHODS AND RESULTS

We conducted a retrospective analysis of a prospective registry comprising 976 patients with native aortic valves who were confirmed with wild type transthyretin amyloid (ATTRwt), hereditary variant transthyretin amyloid (ATTRv), or immunoglobulin light-chain (AL) CA. CA patients' echocardiograms were re-analyzed focusing on the aortic valve. Multivariable Cox regression analysis was performed to assess the mortality risk associated with moderate or greater AS in ATTRwt CA. The crude prevalence of AS among patients with CA was 26% in ATTRwt, 8% in ATTRv, and 5% in AL. Compared with population-based controls, all types of CA had higher age- and sex-standardized rate ratios (SRRs) of having any degree of AS (AL: SRR, 2.62; 95% Confidence Interval (CI) [1.09-3.64]; ATTRv: SRR, 3.41; 95%CI [1.64-4.60]; ATTRwt: SRR, 10.8; 95%CI [5.25-14.53]). Compared with hospital controls, only ATTRwt had a higher SRR of having any degree of AS (AL: SRR, 0.97, 95%CI [0.56-1.14]; ATTRv: SRR, 1.27; 95%CI [0.85-1.44]; ATTRwt: SRR, 4.01; 95%CI [2.71-4.54]). Among patients with ATTRwt, moderate or greater AS was not associated with increased all-cause death after multivariable adjustment (hazard ratio, 0.71; 95%CI [0.42-1.19]; P=0.19).

CONCLUSIONS

Among patients with CA, ATTRwt but not ATTRv or AL is associated with a higher prevalence of patients with AS compared with hospital controls without CA, even after adjusting for age and sex. In our population, having moderate or greater AS was not associated with a worse outcome in patients with ATTRwt.

2024 Australia-New Zealand Expert Consensus Statement on Cardiac Amyloidosis

Over the past 5 years, early diagnosis of and new treatments for cardiac amyloidosis (CA) have emerged that hold promise for early intervention. These include non-invasive diagnostic tests and disease modifying therapies. Recently, CA has been one of the first types of cardiomyopathy to be treated with gene editing techniques. Although these therapies are not yet widely available to patients in Australia and New Zealand, this may change in the near future. Given the rapid pace with which this field is evolving, it is important to view these advances within the Australian and New Zealand context. This Consensus Statement aims to update the Australian and New Zealand general physician and cardiologist with regards to the diagnosis, investigations, and management of CA.

Clinical Outcomes of Aortic Stenosis in Amyloidosis: A United States National Cohort Study

BACKGROUND

Literature regarding outcomes associated with surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR) among amyloidosis (AM) with aortic stenosis (AS) is limited.

OBJECTIVES

We aim to study the mortality and in-hospital clinical outcomes among AM with AS associated with SAVR or TAVR.

METHODS

We performed a retrospective study of all hospitalisation encounters associated with a diagnosis of AM with AS, using the Nationwide Readmissions Database for the years 2012-2019. Primary outcomes were in-hospital mortality, and 30-day readmissions.

RESULTS

A total of 4,820 index hospitalisations of AS (mean age 78.35±10.11 years; female 37.76%) among AM were reported. Total 464 patients had mechanical intervention, 251 patients (54.1%) TAVR and 213 patients (45.9%) SAVR. A total of 317 patients (6.77%) with AS died; TAVR 4.4%, SAVR 11.9% (p=0.01) and 6.66% died among the subgroup who did not have any mechanical intervention. Higher complication rates were observed among patients who had SAVR than those who had TAVR including acute kidney injury (39.8% vs 22.4%; p=0.01), septic shock (12.1% vs 4.4%; p=0.05) and cardiogenic shock (22% vs 4.4%; p<0.001). Acute heart failure was higher among patients who had TAVR (40.2% vs 27.5%; p=0.04) than those who had SAVR. All conduction block and ischaemic stroke were similar between the two groups (p=0.09 and p=0.1). The overall 30-day readmission rate among AM with AS encounters was 16.82%, higher among TAVR compared to SAVR subgroups (21.25% vs 11.17%; p=0.001).

CONCLUSIONS

Among AM with AS hospitalisations, TAVR had mortality benefits compared to SAVR and non-mechanical intervention subgroups. Moreover, higher 30-day mortality rate were observed among SAVR subgroup, which may suggest that TAVR should be strongly considered in AM patients complicated by AS.

Molecular mechanisms and emerging therapies in wild-type transthyretin amyloid cardiomyopathy

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is an underrecognized cause of heart failure due to misfolded wild-type transthyretin (TTRwt) myocardial deposition. The development of wild-type TTR amyloid fibrils is a complex pathological process linked to the deterioration of homeostatic mechanisms owing to aging, plausibly implicating multiple molecular mechanisms. The components of amyloid transthyretin often include serum amyloid P, proteoglycans, and clusterin, which may play essential roles in the localization and elimination of amyloid fibrils. Oxidative stress, impaired mitochondrial function, and perturbation of intracellular calcium dynamics induced by TTR contribute to cardiac impairment. Recently, tafamidis has been the only drug approved by the U.S. Food and Drug Administration (FDA) for the treatment of ATTRwt-CM. In addition, small interfering RNAs and antisense oligonucleotides for ATTR-CM are promising therapeutic approaches and are currently in phase III clinical trials. Newly emerging therapies, such as antibodies targeting amyloid, inhibitors of seed formation, and CRISPR‒Cas9 technology, are currently in the early stages of research. The development of novel therapies is based on progress in comprehending the molecular events behind amyloid cardiomyopathy. There is still a need to further advance innovative treatments, providing patients with access to alternative and effective therapies, especially for patients diagnosed at a late stage.

Outcomes of Octogenarian Patients Treated with Tafamidis for Transthyretin Amyloid Cardiomyopathy

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) benefit from disease-modifying agents such as tafamidis. However, the survival benefit of tafamidis in elderly patients (age ≥80 years) is not reported. This study aimed to assess the survival of patients with ATTR-CM aged 80 years and older who were treated with tafamidis compared with patients aged <80 years. We conducted a retrospective analysis of patients with ATTR-CM who underwent tafamidis treatment, aged 45 to 97 years at the time of diagnosis between January 1, 2008, and May 31, 2021. A total of 484 patients were included, with 208 in the ≥80 years group and 276 in the <80 years group. The cohort was followed up for mortality outcomes, and hazard ratios with 95% confidence intervals were calculated. After a median follow-up of 18.5 months, 72 deaths were recorded in the entire cohort. Kaplan-Meier curves showed no differences in survival probability between the 2 groups at 30 months (p for log-rank test = 0.76). The survival rates for patients aged ≥80 years who underwent treatment at 1, 2, 3, 4, and 5 years were 94.7%, 86.0%, 77.0%, 77.0%, and 38.5%, respectively. The corresponding rates for patients aged <80 years who underwent treatment were 93.2, 84.8, 74.4, 68.2, and 64.6%, respectively. In the multivariable analysis, the hazard ratio (95% confidence interval) of the mortality comparing treatment patients aged ≥80 years with those aged <80 years was 0.81 (0.41 to 1.61). In conclusion, tafamidis treatment is associated with similar reductions in mortality in older and younger patients with ATTR-CM.

Amyloidosis and Considerations for the Hand Surgeon

Amyloidosis can lead to cardiac, renal, and other multiorgan failure. New treatments have become available that can prolong survival but rely on early diagnosis. Manifestations of amyloidosis in hand surgery include carpal tunnel syndrome, trigger finger, peripheral neuropathy, and spontaneous distal biceps rupture. Often, these can predate systemic amyloidosis, offering hand surgeons an opportunity to diagnose patients with amyloidosis before systemic disease, refer them for treatment, and potentially alter disease course and prolong survival. In this review, we describe the pathophysiology and two most common subtypes of amyloidosis seen by hand surgeons. We provide guidance on biopsy practices and referral for patients with amyloidosis. Lastly, we provide a brief overview of the treatments for amyloidosis and their effect on disease course.

Current and Evolving Multimodality Cardiac Imaging in Managing Transthyretin Amyloid Cardiomyopathy

Amyloid transthyretin (ATTR) amyloidosis is a protein-misfolding disease characterized by fibril accumulation in the extracellular space that can result in local tissue disruption and organ dysfunction. Cardiac involvement drives morbidity and mortality, and the heart is the major organ affected by ATTR amyloidosis. Multimodality cardiac imaging (ie, echocardiography, scintigraphy, and cardiac magnetic resonance) allows accurate diagnosis of ATTR cardiomyopathy (ATTR-CM), and this is of particular importance because ATTR-targeting therapies have become available and probably exert their greatest benefit at earlier disease stages. Apart from establishing the diagnosis, multimodality cardiac imaging may help to better understand pathogenesis, predict prognosis, and monitor treatment response. The aim of this review is to give an update on contemporary and evolving cardiac imaging methods and their role in diagnosing and managing ATTR-CM. Further, an outlook is presented on how artificial intelligence in cardiac imaging may improve future clinical decision making and patient management in the setting of ATTR-CM.

Exploring Transthyretin Amyloid Cardiomyopathy: A Comprehensive Review of the Disease and Upcoming Treatments

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a mutation-based genetic disorder due to the accumulation of unstable transthyretin protein and presents with symptoms of congestive heart failure (CHF) and numerous extracardiac symptoms like carpal tunnel syndrome and neuropathy. Two subtypes of ATTR-CM are hereditary and wild-type, both of which have different risk factors, gender prevalence and major clinical symptoms. Timely usage of imaging modalities like echocardiography, cardiac magnetic imaging resonance, and cardiac scintigraphy has made it possible to suspect ATTR-CM in patients presenting with CHF. Management of ATTR-CM includes appropriate treatment for heart failure for symptomatic relief, prevention of arrhythmias and heart transplantation for nonresponders. With the recent approval of tafamidis in the successful management of ATTR-CM, numerous potential therapeutic points have been identified to stop or delay the progression of ATTR-CM. This article aims to provide a comprehensive review of ATTR-CM and insights into its novel therapeutics and upcoming treatments.

Frailty in Older Patients with Transthyretin Cardiac Amyloidosis

Background-Transthyretin cardiac amyloidosis (ATTR-CA) prevalence increases with age. The interplay between frailty and heart failure has been increasingly recognized. The objective of this study is to compare clinical, biological, and transthoracic echocardiography (TTE) characteristics of older ATTR-CA patients according to the G8 frailty screening tool. Methods-Patients over 75 years old with a confirmed diagnosis of ATTR-CA were included between January 2020 and April 2021. All patients underwent a routine blood test, TTE, and a functional assessment with a six-minute walking distance test (6MWD) or cardiopulmonary exercise testing (CPET), and the G8 score was calculated. Results-Fifty-two patients were included. Thirty-nine (75%) patients were frail and their mean NYHA stage was more severe (2.2 vs. 1.7; p = 0.004); 62% of them had a Gilmore stage of 2 or 3 (p = 0.05). Global left ventricular strain (GLS) was lower (-11.7% vs. -14.9%; p = 0.014) and the interventricular septum was thicker (18 ± 2 mm vs. 17 ± 2 mm; p = 0.033) in frail patients. There were no significant differences according to functional tests. Conclusion-The majority of older patients with ATTR-CA are frail according to the G8 score. They are more symptomatic and have an increased cardiac involvement and a poorer prognosis, requiring more personalized cardiac management.

PITB: A high affinity transthyretin aggregation inhibitor with optimal pharmacokinetic properties

The aggregation of wild-type transthyretin (TTR) and over 130 genetic TTR variants underlies a group of lethal disorders named TTR amyloidosis (ATTR). TTR chemical chaperones are molecules that hold great promise to modify the course of ATTR progression. In previous studies, we combined rational design and molecular dynamics simulations to generate a series of TTR selective kinetic stabilizers displaying exceptionally high affinities. In an effort to endorse the previously developed molecules with optimal pharmacokinetic properties, we conducted structural design optimization, leading to the development of PITB. PITB binds with high affinity to TTR, effectively inhibiting tetramer dissociation and aggregation of both the wild-type protein and the two most prevalent disease-associated TTR variants. Importantly, PITB selectively binds and stabilizes TTR in plasma, outperforming tolcapone, a drug currently undergoing clinical trials for ATTR. Pharmacokinetic studies conducted on mice confirmed that PITB exhibits encouraging pharmacokinetic properties, as originally intended. Furthermore, PITB demonstrates excellent oral bioavailability and lack of toxicity. These combined attributes position PITB as a lead compound for future clinical trials as a disease-modifying therapy for ATTR.

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.

Risk stratification in transthyretin-related cardiac amyloidosis

Transthyretin related cardiac amyloidosis (TTR-CA) is an infiltrative cardiomyopathy that cause heart failure with preserved ejection fraction, mainly in aging people. Due to the introduction of a non invasive diagnostic algorithm, this disease, previously considered to be rare, is increasingly recognized. The natural history of TTR-CA includes two different stages: a presymptomatic and a symptomatic stage. Due to the availability of new disease-modifying therapies, the need to reach a diagnosis in the first stage has become impelling. While in variant TTR-CA an early identification of the disease may be obtained with a genetic screening in proband's relatives, in the wild-type form it represents a challenging issue. Once the diagnosis has been made, in order to identifying patients with a higher risk of cardiovascular events and death it is necessary to focus on risk stratification. Two prognostic scores have been proposed both based on biomarkers and laboratory findings. However, a multiparametric approach combining information from electrocardiogram, echocardiogram, cardiopulmonary exercise test and cardiac magnetic resonance may be warranted for a more comprehensive risk prediction. In this review, we aim at evaluating a step by step risk stratification, providing a clinical diagnostic and prognostic approach for the management of patients with TTR-CA.

Multimodality imaging in the diagnostic management of concomitant aortic stenosis and transthyretin-related wild-type cardiac amyloidosis

Severe aortic stenosis (AS) is the most common valvular heart disease with a prevalence rate of more than 4% in 75-year-old people or older. Similarly, cardiac amyloidosis (CA), especially "wild-type transthyretin" (wTTR), has shown a prevalence rate ranging from 22% to 25% in people older than 80 years. The detection of the concomitant presence of CA and AS is challenging primarily because of the similar type of changes in the left ventricle caused by AS and CA, which share some morphological characteristics. The aim of this review is to identify the imaging triggers in order to recognize occult wtATTR-CA in patients with AS, clarifying the crucial step of the diagnostic process. Multimodality imaging methods such as echocardiography, cardiac magnetic resonance, cardiac computed tomography, and DPD scintigraphy will be analyzed as part of the available diagnostic workup to identify wtATTR-CA early in patients with AS.

Amyloidosis of the Heart: A Comprehensive Review

Cardiac amyloidosis is a progressive, infiltrative cardiomyopathy, whose types are based on various infiltrating amyloids, namely, light chains in primary amyloidosis, mutated transthyretin proteins in hereditary amyloidosis, and wild-type transthyretin proteins in senile amyloidosis. While cardiac amyloidosis has a non-specific presentation, the type-specific presentations may provide some clues to the diagnosis. While tissue biopsy remains the gold standard, other newer non-invasive methods can aid in the diagnostic approach for suspected cardiac amyloidosis. Various medications used to treat heart failure may lead to adverse outcomes in patients with cardiac amyloidosis. More research is needed to understand the adequate management and treatment of cardiac amyloidosis.

Atrial Fibrillation, Thromboembolic Risk, and Anticoagulation in Cardiac Amyloidosis: A Review

Cardiac amyloidosis (CA) is caused by extracellular myocardial deposition of amyloid fibrils that are primary derived either from misfolding of transthyretin (ATTR) or light-chain (AL) proteins. CA is associated with atrial fibrillation, potentiated by electromechanical changes as a result of amyloid infiltration in the myocardium. CA also predisposes to thromboembolism and could potentially simultaneously elevate bleeding risk. In this review, we aim to explore and compare the prevalence and pathophysiological mechanisms of atrial fibrillation and thromboembolism in ATTR and AL, examine bleeding risk and factors that promote bleeding, and compare anticoagulation strategies in CA. Finally, we highlight knowledge gaps in the field of thromboembolism in CA to guide future research.

Oral Therapy for the Treatment of Transthyretin-Related Amyloid Cardiomyopathy

The care of systemic amyloidosis has improved dramatically due to improved awareness, accurate diagnostic tools, the development of powerful prognostic and companion biomarkers, and a continuous flow of innovative drugs, which translated into the blooming of phase 2/3 interventional studies for light chain (AL) and transthyretin (ATTR) amyloidosis. The unprecedented availability of effective drugs ignited great interest across various medical specialties, particularly among cardiologists who are now recognizing cardiac amyloidosis at an extraordinary pace. In all amyloidosis referral centers, we are observing a substantial increase in the prevalence of wild-type transthyretin (ATTRwt) cardiomyopathy, which is now becoming the most common form of cardiac amyloidosis. This review focuses on the oral drugs that have been recently introduced for the treatment of ATTR cardiac amyloidosis, for their ease of use in the clinic. They include both old repurposed drugs or fit-for-purpose designed compounds which bind and stabilize the TTR tetramer, thus reducing the formation of new amyloid fibrils, such as tafamidis, diflunisal, and acoramidis, as well as fibril disruptors which have the potential to promote the clearance of amyloid deposits, such as doxycycline. The development of novel therapies is based on the advances in the understanding of the molecular events underlying amyloid cardiomyopathy.

A novel TTR mutation (p.Ala65Val) underlying late-onset hereditary transthyretin (ATTRv) amyloidosis with mixed cardiac and neuropathic phenotype: a case report

BACKGROUND

Hereditary transthyretin (ATTRv) amyloidosis is a rare, genetically heterogeneous and phenotypically variable systemic disease characterized by deposition of misfolded transthyretin fibrils in various tissues. ATTRv cardiomyopathy and progressive axonal polyneuropathy are the most common manifestations, leading to severe disability and ultimately death within approximately ten years. As disease-modifying treatment options evolve, timely diagnosis and treatment initiation are crucial to prevent rapid disease progression.

CASE PRESENTATION

Here, we report on a 73-year old patient initially diagnosed with cardiac wild-type ATTR (ATTRwt) amyloidosis by endomyocardial biopsy. Molecular genetic analysis revealed a novel TTR sequence variant (p.Ala65Val) that is highly likely to be amyloidogenic in light of previously reported TTR mutations and the patient's clinical presentation and family history.

CONCLUSIONS

Our findings expand the spectrum of known pathogenic TTR mutations and underline the importance of a thorough diagnostic workup in amyloidosis patients including careful genetic testing to avoid misdiagnosis and missing of treatment opportunities and to enable cascade testing and tracking of carriers.

New quantitative indices of cardiac amyloidosis with 99mTc-pyrophosphate scintigraphy

PURPOSE

Amyloid light chain (AL) and transthyretin (ATTR) are the major subtypes of cardiac amyloidosis (CA). ^99mTc-pyrophosphate (PYP) scintigraphy is used to differentiate ATTR from other CA subtypes. We adapted the standardized uptake value (SUV) for ^99mTc-PYP and proposed two quantitative indices, amyloid deposition volume (AmyDV) and total amyloid uptake (TAU). This study aimed to evaluate the utility of these quantitative indices in differentiating ATTR from non-ATTRs.

MATERIALS AND METHODS

Before the SUV measurement, the Becquerel calibration factor (BCF) of ^99mTc was obtained by a phantom experiment. Thirty-two patients who had undergone hybrid SPECT/CT imaging 3 h after injection of ^99mTc-PYP (370 MBq) were studied. CT attenuation correction for image reconstruction was applied in all. We calculated SUV, AmyDV, and TAU using a quantitative analysis software program for bone SPECT (GI-BONE) and analyzed AmyDV using two methods: threshold method (set 40%); and constant value method (average SUV_max of ribs). We assessed the diagnostic ability of heart-to-contralateral lung (H/CL) ratio, SUV, AmyDV, and TAU to differentiate ATTR from non-ATTR using receiver operating characteristic (ROC) analysis.

RESULTS

Statistically significant differences in all quantitative indices were observed between ATTR and non-ATTR. The area under the curve of each quantitative index for discriminating between ATTR and non-ATTR were as follows: H/CL, 0.997; SUV_max, 0.953; SUV_mean (M1), 0.964; SUV_mean (M2), 0.969; AmyDV (M1), 0.875; AmyDV (M2), 0.974; and TAU, 0.974. The AmyDV (M2) had higher diagnostic ability than AmyDV (M1). Thus, TAU was calculated as AmyDV (M2) × SUV_mean (M2). In the ROC curve, SUV, AmyDV, and TAU had almost the same diagnostic ability as H/CL in distinguishing ATTR from non-ATTRs.

CONCLUSIONS

We propose two novel 3D-based quantitative parameters (AmyDV and TAU) that have almost equal ability to discriminate ATTR from non-ATTR.

Red flags for the diagnosis of cardiac amyloidosis: simple suggestions to raise suspicion and achieve earlier diagnosis

Cardiac amyloidosis is an infiltrative disease characterized by extracellular deposition of insoluble amyloid fibrils in the heart leading to organ dysfunction. Despite recent diagnostic advances, the diagnosis of cardiac amyloidosis is often delayed or even missed. Furthermore, a long diagnostic delay is associated with adverse outcomes, with the early diagnosed patients showing the longest survival. In this narrative review we aimed to summarize the 'red flags' that may facilitate the correct diagnosis. The red flags may be classified as clinical, biohumoral, electrocardiographic, echocardiographic, and cardiac magnetic resonance features and should promptly raise the suspicion of cardiac amyloidosis in order to start a correct diagnostic pathway and targeted treatment strategies that may improve patients' outcomes.

[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.

Clinical relevance of amyloid in prostate samples: a report on 40 patients

OBJECTIVE

To describe the clinical findings in patients with incidental prostatic amyloidosis.

PATIENTS AND METHODS

Retrospective search in the database of the Department of Pathology, Hospital de Bellvitge, for prostate specimens with amyloid. Congo red and immunohistochemical staining of the sections. Review of the patients' clinical charts for symptoms attributable to systemic amyloidosis.

RESULTS

Amyloid deposition in the prostate was identified and reported in 40 patients between 2001 and 2022. Median age was 76.5 years (range 62-90). Prostate cancer was diagnosed in 25 patients. Only 4 patients had a previous diagnosis of amyloidosis. In the remaining 36 the prostate sample (31 needle biopsies, two transurethral resections (TUR), two simple prostatectomies, one radical cystectomy for bladder cancer) provided the initial diagnosis. Amyloid deposits were mainly located in the wall of small vessels and rarely in the prostatic stroma. Immunohistochemistry was available in 32 cases, 26 of which were positive for TTR. All patients showed at least one symptom indicative of systemic amyloidosis, the most frequent being hearing loss (55%), carpal tunnel syndrome (42,5%) or other osteoarticular symptoms (tendinopathies, osteoarthritis), cataracts (37.5%), and cardiac symptoms (32.5%), among others.

CONCLUSION

The prostate is a target tissue for amyloid deposition. The incidental finding of amyloid in prostate corresponds, in the majority of cases, to previously undiagnosed systemic TTR amyloidosis in patients lacking signs of heart involvement but having mainly osteoarticular symptoms, hearing and visual impairment.

Baseline characteristics and secondary medication adherence among Medicare patients diagnosed with transthyretin amyloid cardiomyopathy and/or receiving tafamidis prescriptions: A retrospective analysis of a Medicare cohort

BACKGROUND: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed, life-threatening condition that mostly affects older persons. In May 2019, regulatory approval of tafamidis provided the first pharmacologic treatment of ATTR-CM. In the pivotal phase 3 Transthyretin Amyloidosis Cardiomyopathy Clinical Trial (ATTR-ACT), 97.2% of patients were classified as adherent (defined as taking ≥ 80% of scheduled doses). Given its recent approval, there is limited real-world evidence examining patient adherence to tafamidis. OBJECTIVE: To evaluate adherence patterns, demographics, and clinical characteristics of patients in the United States receiving tafamidis prescriptions through Medicare. Secondarily, we aimed to evaluate concomitant medications filled by this patient population. METHODS: We conducted a retrospective cohort study of US Medicare claims data, limited by the Health Insurance Portability and Accountability Act of 1996, in adult patients with an adjudicated pharmacy claim for tafamidis (tafamidis free acid 61-mg capsule once daily or tafamidis meglumine four 20-mg capsules once daily) between May 1, 2019, and June 30, 2021. Gaps in therapy were measured using day gaps between prescription refills and continuous measure of medication gaps. Implementation adherence was assessed through modified medication possession ratio (MPRm), medication refill adherence (MRA), and proportion of days covered (PDC). Patients were grouped based on Medicare coverage. Patients were analyzed by subgroups based on age and at the zip code level, via distressed communities index quartiles and rural-urban tiers. RESULTS: A total of 3,558 patients who received a prescription fill of a tafamidis formulation were identified using Medicare Fee-for-Service (FFS) and Medicare Advantage (MA) claims data from May 1, 2019, to June 30, 2021. The characteristics of this patient population were consistent with published literature, as 98.6% were older than 65 years, 53.4% were between 75 years and 84 years, and 81.5% were male. In the patient population receiving tafamidis refills, adherence was high across all 3 measures, with mean MPRm greater than 90% and mean MRA greater than 80%, across all age groups. Mean PDC adherence rates were 79% or more across all age groups. Concomitant medications were generally indicated for heart failure and thrombosis. Among monotherapy groups with similar demographic makeup, adherence was significantly higher among users of tafamidis free acid vs tafamidis meglumine (P < 0.0001 across all mean adherence measures). CONCLUSIONS: Our results demonstrate that real-world adherence to tafamidis in the Medicare population is high, regardless of age, zip code-level socioeconomic quartile, or geography. Adherence was higher among patients receiving tafamidis free acid, suggesting that the enhanced convenience of a single capsule once daily may positively contribute to adherence among patients with ATTR-CM. DISCLOSURES: Darrin Benjumea is an employee of Genesis Research who has been contracted by Pfizer, Inc., for involvement in this study. Andrew Peterson is an employee of University of the Sciences who has been contracted by Pfizer, Inc., for involvement in this study. Zach Bredl is an employee of Care Journey who has been contracted by Pfizer, Inc., for involvement in this study. Anuja Roy, Nick Marchant, Jose Alvir, Rahul Bhambri, Jason Kemner, and Bhash Parasuraman are employees of Pfizer, Inc., and own stock and/or stock options. This study was supported by Pfizer, Inc.

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.

Transthyretin amyloid cardiomyopathy. Features of histological diagnosis: study design

Aim. To compare efficiency and specific features of transthyretin amyloid staining by different histological dyes and thus to assess their suitability for diagnostic purposes. Materials and methods. Samples of left and right heart ventricles were taken from patients over 70 years-old of both genders (n=10) with immunohistochemically verified transthyretin amyloidosis (ATTR). All samples were stained with Congo red, Alcian blue, toluidine blue and methylene violet. Results. Specificity and sensitivity of Congo red staining was comparable to those of immunohistochemical staining. For verification of amyloid presence after Congo red staining one could use fluorescent microscopy instead of polarization microscopy. It allows a more accurate diagnosis of amyloidosis. Confocal microscopy with spectral unmixing improves detection sensitivity of amyloid by elimination of background fluorescence of muscle tissue and autofluorescence of lipofuscin. Alcian blue staining gives the same result as Congo red. In addition, its less labor-intensive and free of false-positive and false-negative results caused by final processing of slide preparation. Toluidine blue and methylene violet develop metachromatic staining upon binding to transthyretin fibrils, likely due to specific biochemical features of these fibrils. Conclusion. The most reliable method for histochemical diagnosis of ATTR is the Congo red staining with subsequent analysis using fluorescence or confocal microscopy. For diagnostic screening, the use of Sodium sulphate-Alcian blue staining method is highly promising. Metachromatic stains are less effective for ATTR diagnosis.

Unmasking the Prevalence of Amyloid Cardiomyopathy in the Real World: Results from Phase 2 of AC-TIVE Study, an Italian Nationwide Survey

AIM

To investigate the prevalence of amyloid cardiomyopathy (AC) and the diagnostic accuracy of echocardiographic red flags of AC among consecutive adult patients undergoing transthoracic echocardiogram for reason other than AC in 13 Italian institutions.

METHODS AND RESULTS

This is an Italian prospective multicentric study, involving a clinical and instrumental work-up to assess AC prevalence among patients ≥ 55 years old with an "AC suggestive" echocardiogram (i.e. at least one echocardiographic red flag of AC in hypertrophic, non-dilated left ventricles with preserved ejection fraction). The study was registered at ClinicalTrials.gov (#NCT04738266). 381 patients with an "AC suggestive" echocardiogram were identified among a cohort of 5315 screened subjects. 217 patients completed the investigations. A final diagnosis of AC was made in 62 patients with an estimated prevalence of 29% (95% CI: 23%-35%). Transthyretin-related AC (ATTR-AC) was diagnosed in 51 and light chain related AC (AL-AC) in 11 patients. Either apical sparing or a combination of ≥ 2 other echocardiographic red flags, excluding interatrial septum thickness, provided a diagnostic accuracy > 70%.

CONCLUSION

In a cohort of consecutive adults with echocardiographic findings suggestive of AC and preserved LVEF, the prevalence of AC (either ATTR or AL) was 29%. Easily available echocardiographic red flags, when combined together, demonstrated good diagnostic accuracy.

Renal Involvement in Transthyretin Amyloidosis: The Double Presentation of Transthyretin Amyloidosis Deposition Disease

Transthyretin (TTR) amyloidosis (ATTR) is either an inherited condition or a non hereditary disease due to misfolding of wild-type (WT) TTR. Amyloid deposits can be mainly detected in nerves in the inherited form and in myocardium in the acquired variant. Renal involvement has been described only in the Val30Met mutation of the familial form and is thought to be extremely rare in the WT TTR. However, ATTR is multi-organ disease, and even in the WT forms, apparently limited to the heart, carpal tunnel syndrome and lumbar or cervical spine amyloid deposition have been described. A series of 4 cases of biopsy-proven renal TTR amyloid deposition is reported in the present paper. We describe 2 WT ATTR patients, 1 patient with c.424G&#x3e;A (p.(Val142Ile)) mutation of the TTR gene, and 1 patient with Val30Met mutation of the TTR gene. In all patients, the biopsy showed the presence of amyloid deposits with different distribution (#1 pericapsular, #2–3 vessels, #4 vessels, interstitium of medulla and cortex, and tubular basement membrane). The use of immunohistochemistry has enabled the identification of TTR, and identify the precursor protein. The possibility of kidney involvement in TTR amyloidosis should be taken into account in patients with renal impairment and unexplained cardiomyopathy and/or neuropathy. This is even of greater interest to the elderly for the possible confounding co-existence of plasma cell dyscrasia that could lead the clinician, in the presence of renal amyloid deposits, to misdiagnose AL amyloidosis and undertake inappropriate treatments.

The Transthyretin/Oleuropein Aglycone Complex: A New Tool against TTR Amyloidosis

The release of monomers from the homotetrameric protein transthyretin (TTR) is the first event of a cascade, eventually leading to sporadic or familial TTR amyloidoses. Thus, ligands able to stabilize TTR and inhibit monomer release are subject of intense scrutiny as potential treatments against these pathologies. Here, we investigated the interaction between TTR and a non-glycated derivative of the main olive polyphenol, oleuropein (OleA), known to interfere with TTR aggregation. We coupled fluorescence studies with molecular docking to investigate the OleA/TTR interaction using wild-type TTR, a monomeric variant, and the L55P cardiotoxic mutant. We characterized a fluorescence band emitted by OleA upon formation of the OleA/TTR complex. Exploiting this signal, we found that a poorly specific non-stoichiometric interaction occurs on the surface of the protein and a more specific stabilizing interaction takes place in the ligand binding pocket of TTR, exhibiting a K_D of 3.23 ± 0.32 µM, with two distinct binding sites. OleA interacts with TTR in different modes, stabilizing it and preventing its dissociation into monomers, with subsequent misfolding. This result paves the way to the possible use of OleA to prevent degenerative diseases associated with TTR misfolding.

Inhibiting mTTR Aggregation/Fibrillation by a Chaperone-like Hydrophobic Amino Acid-Conjugated SPION

Transthyretin (TTR) aggregation via misfolding of a mutant or wild-type protein leads to systemic or partial amyloidosis (ATTR). Here, we utilized variable biophysical assays to characterize two distinct aggregation pathways for mTTR (a synthesized monomer TTR incapable of association into a tetramer) at pH 4.3 and also pH 7.4 with agitation, referred to as mTTR aggregation and fibrillation, respectively. The findings suggest that early-stage conformational changes termed monomer activation here determine the aggregation pathway, resulting in developing either amorphous aggregates or well-organized fibrils. Less packed partially unfolded monomers consisting of more non-regular secondary structures that were rapidly produced via a mildly acidic condition form amorphous aggregates. Meanwhile, more hydrophobic and packed monomers consisting of rearranged β sheets and increased helical content developed well-organized fibrils. Conjugating superparamagnetic iron oxide nanoparticles (SPIONs) with leucine and glutamine (L-SPIONs and G-SPIONs in order) via a trimethoxysilane linker provided the chance to study the effect of hydrophobic/hydrophilic surfaces on mTTR aggregation. The results indicated a powerful inhibitory effect of hydrophobic L-SPIONs on both mTTR aggregation and fibrillation. Monomer depletion was introduced as the governing mechanism for inhibiting mTTR aggregation, while a chaperone-like property of L-SPIONs by maintaining an mTTR native structure and adsorbing oligomers suppressed the progression of further fibril formation.

Plasmin activity promotes amyloid deposition in a transgenic model of human transthyretin amyloidosis

Cardiac ATTR amyloidosis, a serious but much under-diagnosed form of cardiomyopathy, is caused by deposition of amyloid fibrils derived from the plasma protein transthyretin (TTR), but its pathogenesis is poorly understood and informative in vivo models have proved elusive. Here we report the generation of a mouse model of cardiac ATTR amyloidosis with transgenic expression of human TTR^S52P. The model is characterised by substantial ATTR amyloid deposits in the heart and tongue. The amyloid fibrils contain both full-length human TTR protomers and the residue 49-127 cleavage fragment which are present in ATTR amyloidosis patients. Urokinase-type plasminogen activator (uPA) and plasmin are abundant within the cardiac and lingual amyloid deposits, which contain marked serine protease activity; knockout of α₂-antiplasmin, the physiological inhibitor of plasmin, enhances amyloid formation. Together, these findings indicate that cardiac ATTR amyloid deposition involves local uPA-mediated generation of plasmin and cleavage of TTR, consistent with the previously described mechano-enzymatic hypothesis for cardiac ATTR amyloid formation. This experimental model of ATTR cardiomyopathy has potential to allow further investigations of the factors that influence human ATTR amyloid deposition and the development of new treatments.

ATTR amyloidosis causes heart failure through the accumulation of misfolded transthyretin in cardiac muscle. Here the authors report a mouse model of ATTR amyloidosis and demonstrate the involvement of protease activity in ATTR amyloid deposition.

Association between spinal stenosis and wild-type ATTR amyloidosis

Age-related cardiac amyloidosis results from deposits of wild-type tranthyretin amyloid (ATTRwt) in cardiac tissue. ATTR may play a role in carpal tunnel syndrome (CTS) and in spinal stenosis (SS), indicating or presaging systemic amyloidosis. We investigated consecutive patients undergoing surgery for SS for ATTR deposition in the resected ligamentum flavum (LF) and concomitant risk of cardiac amyloidosis. Each surgical specimen (LF) was stained with Congo red, and if positive, the amyloid deposits were typed by mass spectrometry. Patients with positive specimens underwent standard of care evaluation with fat pad aspirates, serum and urine protein electrophoresis with immunofixation, free light-chain assay, TTR gene sequencing and technetium 99 m-pyrophosphate-scintigraphy. In 2018-2019, 324 patients underwent surgery for SS and 43 patients (13%) had ATTR in the LF with wild-type TTR gene sequences. Two cases of ATTRwt cardiac amyloidosis were diagnosed and received treatment. In this large series, ATTRwt was identified in 13% of the patients undergoing laminectomy for SS. Patients with amyloid in the ligamentum flavum were older and had a higher prevalence of CTS, suggesting a systemic form of ATTR amyloidosis involving connective tissue. Further prospective study of patients with SS at risk for systemic amyloidosis is warranted.

Incidence and Characterization of Concealed Cardiac Amyloidosis Among Unselected Elderly Patients Undergoing Post-mortem Examination

Background: The prevalence of cardiac amyloidosis (CA) is unknown. Aims and Methods: We sought to (a) determine the prevalence of CA in unselected patients ≥75 years undergoing autopsy, (b) characterize cardiological profiles of CA and non-CA patients by providing clinical-histological correlations, and (c) compare their cardiological profiles. After dedicated staining, the localization (interstitial or vascular) and the distribution (non-diffuse or diffuse) of amyloid deposition were analyzed. Cardiological data at last evaluation were retrospectively assessed for the presence of CA red-flags. Results: CA (50% light chains, 50% transthyretin) was found in 43% (n = 24/56) of the autopsied hearts. Atria were involved in 96% of cases. Amyloid localized both at the perivascular and interstitial levels (95.5 and 85%, respectively) with a slightly predominant non-diffuse distribution (58% of cases). Compared to the other patients, CA patients had a more frequent history of heart failure (HF) (79 vs. 47%, p = 0.014), advanced NYHA functional class (III-IV 25 vs. 6%, p = 0.047), atrial fibrillation (68 vs. 36%, p = 0.019), discrepancy between QRS voltage and left ventricular (LV) thickness (70 vs. 12%, p < 0.001), thicker LV walls (15 vs. 11 mm, p < 0.001), enlarged left atrium (49 vs. 42 mm, p = 0.019) and restrictive filling pattern (56 vs. 19%, p = 0.020). The presence of right ventricular amyloidosis seemed to identify hearts with a higher amyloid burden. Among the CA patients, >30% had ≥3 echocardiographic red-flags of disease. Conclusion: CA can be found in 43% of autopsied hearts from patients ≥75 years old, especially in patients with HF, LV hypertrophy and atrial fibrillation.

A descriptive study of transthyretin amyloidosis in a tertiary hospital without a referral unit

BACKGROUND AND OBJECTIVE

Transthyretin amyloidosis (ATTR) is a rare disease that is part of systemic amyloidosis and is life-threatening. It can affect all organs and systems, the most frequent being neurological and cardiac involvement. This study aims to detect possible ATTR cases and carry out a descriptive study of them.

MATERIAL AND METHODS

Descriptive single-centre study carried out in a tertiary hospital, which included patients with suspected ATTR between September 2016 and January 2020.

RESULTS

A total of 190 suspected ATTR patients were detected. The study includes 100 of these patients, as well as 10 relatives of patients in whom ATTR was detected in its genetic variant (ATTRv). In total, ATTRv was detected in 7 individuals (3 with a presymptomatic mutation of the disease), 16 patients with age-related ATTR and 31 individuals with unknown cardiac amyloidosis with the tests performed, which confirms the presence of this disease in non-endemic areas.

CONCLUSIONS

ATTR is a disease that must be taken into account in the differential diagnosis of patients with heart failure with preserved LVEF, especially if associated with neurological symptoms.

Aortic Valve Stenosis and Cardiac Amyloidosis: A Misleading Association

The association between aortic stenosis (AS) and cardiac amyloidosis (CA) is more frequent than expected. Albeit rare, CA, particularly the transthyretin (ATTR) form, is commonly found in elderly people. ATTR-CA is also the most prevalent form in patients with AS. These conditions share pathophysiological, clinical and imaging findings, making the diagnostic process very challenging. To date, a multiparametric evaluation is suggested in order to detect patients with both AS and CA and choose the best therapeutic option. Given the accuracy of modern non-invasive techniques (i.e., bone scintigraphy), early diagnosis of CA is possible. Flow-charts with the main CA findings which may help clinicians in the diagnostic process have been proposed. The prognostic impact of the combination of AS and CA is not fully known; however, new available specific treatments of ATTR-CA have changed the natural history of the disease and have some impact on the decision-making process for the management of AS. Hence the relevance of detecting these two conditions when simultaneously present. The specific features helping the detection of AS-CA association are discussed in this review, focusing on the shared pathophysiological characteristics and the common clinical and imaging hallmarks.

Age-related amyloidosis outside the brain: A state-of-the-art review

Inside and outside the brain, accumulation of amyloid fibrils plays key roles in the pathogenesis of fatal age-related diseases such as Alzheimer's and Parkinson's diseases and wild-type transthyretin amyloidosis. Although the incidence of all amyloidoses increases with age, for some types of amyloidosis aging is known as the main direct risk factor, and these types are typically diseases of elderly people. More than 10 different precursor proteins are known to cause age-associated amyloidosis; these proteins include amyloid β protein, α-synuclein, transthyretin, islet amyloid polypeptide, atrial natriuretic factor, and the newly discovered epidermal growth factor-containing fibulin-like extracellular matrix protein 1. Except for intracerebral amyloidoses, most age-related amyloidoses have been little studied. Indeed, in view of the increasing life expectancy in our societies, understanding how aging is involved in the process of amyloid fibril accumulation and the effects of amyloid deposits on the aging body is extremely important. In this review, we summarize current knowledge about the nature of amyloid precursor proteins, the prevalence, clinical manifestations, and pathogenesis of amyloidosis, and recent advances in our understanding of age-related amyloidoses outside the brain.

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.

Frailty in Wild-Type Transthyretin Cardiac Amyloidosis: The Tip of the Iceberg

ATTRwt-CA occurs in elderly patients and leads to severe heart failure. The disease mechanism involves cardiac and extracardiac infiltration by amyloid fibrils. The objectives of this study are to describe the frailty phenotype in patients with ATTRwt-CA and to assess the associations between frailty parameters, the severity of cardiac involvement, and the course of amyloid disease. We used multidimensional geriatric tools to prospectively assess frailty in patients with ATTRwt-CA consulting (in 2018-2019) in the French National Reference Center for Cardiac Amyloidosis. We included 36 patients (35 males; median age: 82 years (76-86). A third of the patients were categorized as NYHA class III or IV, and 39% had an LVEF below 45%. The median serum NTproBNP was 3188 (1341-8883) pg/mL. The median duration of amyloidosis was 146 months (73-216). The frequency of frailty was 50% and 33% according to the physical frailty phenotype and the Short Emergency Geriatric Assessment questionnaire, respectively. Frailty affected a large number of domains, namely autonomy (69%), balance (58%), muscle weakness (74%), malnutrition (39%), dysexecutive syndrome (72%), and depression (49%). The severity of CA was significantly associated with many frailty parameters independently of age. Balance disorders and poor mobility were also significantly associated with a longer course of amyloid disease. Frailty is frequent in patients with ATTRwt-CA. Some frailty parameters were significantly associated with a longer course of amyloid disease and CA severity. Taking into account frailty in the assessment and management of ATTRwt should improve patients' quality of life.

The Ultrastructure of Tissue Damage by Amyloid Fibrils

Amyloidosis is a group of diseases that includes Alzheimer’s disease, prion diseases, transthyretin (ATTR) amyloidosis, and immunoglobulin light chain (AL) amyloidosis. The mechanism of organ dysfunction resulting from amyloidosis has been a topic of debate. This review focuses on the ultrastructure of tissue damage resulting from amyloid deposition and therapeutic insights based on the pathophysiology of amyloidosis. Studies of nerve biopsy or cardiac autopsy specimens from patients with ATTR and AL amyloidoses show atrophy of cells near amyloid fibril aggregates. In addition to the stress or toxicity attributable to amyloid fibrils themselves, the toxicity of non-fibrillar states of amyloidogenic proteins, particularly oligomers, may also participate in the mechanisms of tissue damage. The obscuration of the basement and cytoplasmic membranes of cells near amyloid fibrils attributable to an affinity of components constituting these membranes to those of amyloid fibrils may also play an important role in tissue damage. Possible major therapeutic strategies based on pathophysiology of amyloidosis consist of the following: (1) reducing or preventing the production of causative proteins; (2) preventing the causative proteins from participating in the process of amyloid fibril formation; and/or (3) eliminating already-deposited amyloid fibrils. As the development of novel disease-modifying therapies such as short interfering RNA, antisense oligonucleotide, and monoclonal antibodies is remarkable, early diagnosis and appropriate selection of treatment is becoming more and more important for patients with amyloidosis.

Heart failure following transcatheter aortic valve replacement

Introduction: Over the past decade, the number of transcatheter aortic valve replacement (TAVR) procedures has increased exponentially. Despite major improvements in both device and successes, the rate of hospital readmission after TAVR remains high, with heart failure (HF) decompensation being one of the most important causes.Areas covered: This review provides an overview of the current status of HF following TAVR, including details about its incidence, clinical impact, contributing factors, and current and future treatment perspectives.Expert opinion: HF decompensation has been identified as the most common cause of rehospitalization following TAVR, and it has been associated with a negative prognosis. Multiple preexisting factors including low flow status, cardiac amyloidosis, myocardial fibrosis, multivalvular disease, pulmonary hypertension, coronary artery disease, and atrial fibrillation have been associated with an increased risk of HF events. Also, multiple post-procedural factors like the occurrence of significant paravalvular leaks, severe prosthesis-patient mismatch, and conduction disturbances have also contributed to increase this risk . Thus, reducing HF events in TAVR recipients would require a multifactorial and multidisciplinary effort including the optimization of the medical treatment and close follow-up and treatment of residual or concomitant valvular disease and conduction disturbance issues. Future studies in this challenging group of patients are warranted.

Wild-type ATTR amyloidosis of the prostate: a case review

The amyloidoses are a rare group of disorders caused by the deposition of amyloid fibrils in organ tissues. Transthyretin-mediated amyloidosis is a subcategory of amyloidosis, which can be further subdivided into hereditary transthyretin-mediated or wild-type (‘senile’) amyloidosis. Involvement of the prostate by any type of amyloidosis is rare, with only a handful of cases reported in the literature. We report here a case of a 64-year-old Caucasian man who was incidentally found to have wild-type transthyretin-mediated amyloidosis of the prostate following a radical prostatectomy for treatment of a localised, Gleason 7 (4 + 3) adenocarcinoma of the prostate. TTR subtyping was confirmed by mass spectrometry. His family history was negative for known amyloidosis, and sequencing of the entire TTR gene was negative for any mutations, so he was therefore considered to have wild-type TTR amyloidosis. He was subsequently found to have additional foci of amyloid deposition in the gastrointestinal tract. Wild-type transthyretin-mediated amyloidosis as an incidental finding in a prostate biopsy is an extremely rare finding. Treatment options for transthyretin-mediated amyloidosis are limited, and further research and treatment options are needed in this rare and difficult to manage disease.

Level of evidence: The level of evidence according to the Oxford Centre of Evidence-based Medicine levels of evidence is not applicable to this case report. Given that this is a rare entity, decisions made in managing this case were based on a level of evidence of 5.

Effects of sporadic transthyretin amyloidosis frequently on the gallbladder and the correlation between amyloid deposition in the gallbladder and heart: A forensic autopsy-based histopathological evaluation

The aim of the study is to evaluate the clinicopathological features of cholecystic ATTR deposition in patients with cardiac involvement, investigate the correlation of amyloid deposition severity in the gallbladder and the heart, and compare its prevalence in the gallbladder and other organs. Fifty patients with sporadic ATTR amyloidosis were identified. Of these, we evaluated 15 patients who underwent gallbladder sampling accurately. Among 10 patients (67%) with cholecystic deposition, six exhibited detectable deposition in the hematoxylin and eosin-stained specimens, and all of them displayed obstructive vascular deposition (VD). The severity of gall bladder VD was statistically correlated with that of cardiac VD and atrial interstitial deposition (ID). Additionally, all patients exhibiting cholecystic ID displayed severe ventricular and atrial IDs. In visceral organs excluding the heart, amyloid deposition was commonly observed in the lungs (93%), followed by the gastrointestinal tract (47%-80%), liver (60%) and periosteal tissues (53%). The involvement of the gallbladder was prevalent and comparable to that of the gastrointestinal tract. Moreover, the severity of cholecystic deposition was correlated with that of cardiac deposition. Therefore, pathologists should be aware that sporadic ATTR amyloidosis is a common condition and should not be overlooked.

Cardiac Amyloidosis: Multimodal Imaging of Disease Activity and Response to Treatment

Cardiac amyloidosis (CA) is a disease characterized by the deposition of misfolded protein deposits in the myocardial interstitium. Although advanced CA confers significant morbidity and mortality, the magnitude of deposition and ensuing clinical manifestations vary greatly. Thus, an improved understanding of disease pathogenesis at both cellular and functional levels would afford critical insights that may improve outcomes. This review will summarize contemporary therapies for the 2 major types of CA, transthyretin and light chain amyloidosis, and outline the capacity of imaging modalities to both diagnose CA, inform prognosis, and follow response to available therapies. We explore the current landscape of echocardiography, cardiac magnetic resonance, and bone scintigraphy in the assessment of functional and cellular parameters of dysfunction in CA throughout disease pathogenesis. Finally, we examine the impact of concurrent advances in both therapeutics and imaging on future research questions that improve our understanding of underlying disease mechanisms. Multimodal imaging in CA affords an indispensable tool to offer individualized treatment plans and improve outcomes in patients with CA.

Multidisciplinary Approaches for Transthyretin Amyloidosis

Amyloidosis caused by systemic deposition of transthyretin (TTR) is called ATTR amyloidosis and mainly includes hereditary ATTR (ATTRv) amyloidosis and wild-type ATTR (ATTRwt) amyloidosis. Until recently, ATTRv amyloidosis had been considered a disease in the field of neurology because neuropathic symptoms predominated in patients described in early reports, whereas advances in diagnostic techniques and increased recognition of this disease revealed the presence of patients with cardiomyopathy as a predominant feature. In contrast, ATTRwt amyloidosis has been considered a disease in the field of cardiology. However, recent studies have suggested that some of the patients with ATTRwt amyloidosis present tenosynovial tissue complications, particularly carpal tunnel syndrome, as an initial manifestation of amyloidosis, necessitating an awareness of this disease among neurologists and orthopedists. Although histopathological confirmation of amyloid deposits has traditionally been considered mandatory for the diagnosis of ATTR amyloidosis, the development of noninvasive imaging techniques in the field of cardiology, such as echocardiography, magnetic resonance imaging, and nuclear imaging, enabled nonbiopsy diagnosis of this disease. The mechanisms underlying characteristic cardiac imaging findings have been deciphered by histopathological studies. Novel disease-modifying therapies for ATTR amyloidosis, such as TTR stabilizers, short interfering RNA, and antisense oligonucleotides, were initially approved for ATTRv amyloidosis patients with polyneuropathy. However, the indications for the use of these disease-modifying therapies gradually widened to include ATTRv and ATTRwt amyloidosis patients with cardiomyopathy. Since the coronavirus disease 2019 (COVID-19) pandemic, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, occurred, the minimization of hospital visits and telemedicine have become increasingly important. As older age and cardiovascular disease are major factors associated with increased disease severity and mortality of COVID-19, many ATTR amyloidosis patients are at increased risk of disease aggravation when they are infected with SARS-CoV-2. From this viewpoint, close interspecialty communication to determine the optimal interval of evaluation is needed for the management of patients with ATTR amyloidosis.