Diagnosing cardiac amyloidosis in every-day practice: A practical guide for the cardiologist

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.

Advances in the Diagnosis and Management of Cardiac Amyloidosis: A Literature Review

Cardiac amyloidosis, increasingly recognized for its significant impact on global heart health and patient survival, demands a thorough review to understand its complexity and the urgency of improved management strategies. As a cause of cardiomyopathy and heart failure, particularly in patients with aortic stenosis and atrial fibrillation, this condition also relates to higher incidences of dementia in the affected populations. The objective of this review was to integrate and discuss the latest advancements in diagnostics and therapeutics for cardiac amyloidosis, emphasizing the implications for patient prognosis. We evaluated the latest literature from major medical databases such as PubMed and Scopus, focusing on research from 2020 to 2024, to gather comprehensive insights into the current landscape of this condition. Insights from our review highlight the complex pathophysiology of cardiac amyloidosis and the diagnostic challenges it presents. We detail the effectiveness of emerging treatments, notably gene silencing therapies like patisiran and vutrisiran, which offer transformative potential by targeting the production of amyloidogenic proteins. Additionally, the stabilization therapy acoramidis shows promise in modifying disease progression and improving clinical outcomes. This review underscores the critical need for updated clinical guidelines and further research to expand access to groundbreaking therapies and enhance disease management. Advocating for continued research and policy support, we emphasize the importance of advancing diagnostic precision and treatment effectiveness, which are vital for improving patient outcomes and addressing this debilitating disease globally.

Anticoagulation in Atrial Fibrillation Associated With Cardiac Amyloidosis: A Narrative Review

Cardiac amyloidosis (CA) involves the abnormal deposition and accumulation of amyloid proteins in the heart muscle. A hallmark of disease progression is declining heart function, which can lead to structural irregularities, arrhythmias, and ultimately heart failure. Atrial fibrillation (AF) is the most common arrhythmia that presents in CA patients, and this arrhythmia is significant because it can moderately increase the risk of patients developing intracardiac thrombi, thereby putting them at risk for thromboembolic events. The management of this complication entails the use of anticoagulants like vitamin K antagonists and direct oral anticoagulants to reduce the risk of thrombus formation. This article seeks to review AF in CA and the use of anticoagulation therapy for the management and reduction of thromboembolic risk. The major conclusions of this review are centered around the need for safe administration of anticoagulant therapy to CA patients, regardless of their CHA2DS2-VASc risk score. This review highlights the importance of taking a multidisciplinary or collaborative approach to CA treatment to ensure that all aspects of this multifaceted disease can be properly managed while minimizing adverse events like bleeding risk and drug-drug interactions.

Recent Progress in the Development and Clinical Application of New Drugs for Transthyretin Cardiac Amyloidosis

ABSTRACT

Transthyretincardiac amyloidosis is a rare disease that has gained significant attention in recent years because of misfolding of transthyretin fibrils produced by the liver, leading to their deposition in the myocardium. The disease has an insidious onset, nonspecific clinical manifestations, and historically lacked effective drugs, making early diagnosis and treatment challenging. The survival time of patients largely depends on the extent of heart involvement at the time of diagnosis, and conventional treatments for cardiovascular disease do not provide significant benefits. Effective management of the disease requires treatment of its underlying cause. Orthotopic liver transplantation and combined hepato-heart transplantation have been clinically effective means of treating transthyretin cardiac amyloidosis mutants for many years. However, transplantation has many limitations in clinical practice. In recent years, the development of new drugs has brought new hope to patients. This review presents the latest advances in drug development and clinical application to provide a reference for clinicians managing transthyretin cardiac amyloidosis.

[2022 ESC guidelines on cardio-oncology : Understanding and treating cardiovascular side effects from cancer therapy]

The continuous improvement in cancer treatment leads to a growing number of long-term survivors. Arguably, the treatment of cardiovascular side effects from cancer therapy is therefore of major importance for the morbidity and mortality affected patients. The 2022 ESC guidelines on cardio-oncology of the European Society of Cardiology (ESC) aim to improve the treatment of affected patients across the entire continuum of therapy and in the long term by establishing standardized procedures for prevention, diagnostics, and treatment of cardiovascular side effects. Suitable diagnostic and therapeutic measures for specific substance classes are defined on the basis of fundamental recommendations for cardio-oncological care in individual therapy phases. Furthermore, the guidelines provide a comprehensive focus on individual risk assessment before the start of therapy as the basis for determining the type and intensity of cardio-oncological care in the further course. In addition, the risk assessment serves as a basis for the initiation of suitable preventive measures to avoid or minimize the development of cardiovascular side effects during therapy. The present article provides an overview of the most important innovations of the 2022 ESC guidelines on cardio-oncology with respect to general definitions and recommendations as well as a summary of the most important recommendations for some specific forms of therapy with relevance for cardio-oncology in the future.

Deep Learning to Classify AL versus ATTR Cardiac Amyloidosis MR Images

The aim of this work was to compare the classification of cardiac MR-images of AL versus ATTR amyloidosis by neural networks and by experienced human readers. Cine-MR images and late gadolinium enhancement (LGE) images of 120 patients were studied (70 AL and 50 TTR). A VGG16 convolutional neural network (CNN) was trained with a 5-fold cross validation process, taking care to strictly distribute images of a given patient in either the training group or the test group. The analysis was performed at the patient level by averaging the predictions obtained for each image. The classification accuracy obtained between AL and ATTR amyloidosis was 0.750 for cine-CNN, 0.611 for Gado-CNN and between 0.617 and 0.675 for human readers. The corresponding AUC of the ROC curve was 0.839 for cine-CNN, 0.679 for gado-CNN (p < 0.004 vs. cine) and 0.714 for the best human reader (p < 0.007 vs. cine). Logistic regression with cine-CNN and gado-CNN, as well as analysis focused on the specific orientation plane, did not change the overall results. We conclude that cine-CNN leads to significantly better discrimination between AL and ATTR amyloidosis as compared to gado-CNN or human readers, but with lower performance than reported in studies where visual diagnosis is easy, and is currently suboptimal for clinical practice.

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.

Deep Learning Supplants Visual Analysis by Experienced Operators for the Diagnosis of Cardiac Amyloidosis by Cine-CMR

Background: Diagnosing cardiac amyloidosis (CA) from cine-CMR (cardiac magnetic resonance) alone is not reliable. In this study, we tested if a convolutional neural network (CNN) could outperform the visual diagnosis of experienced operators. Method: 119 patients with cardiac amyloidosis and 122 patients with left ventricular hypertrophy (LVH) of other origins were retrospectively selected. Diastolic and systolic cine-CMR images were preprocessed and labeled. A dual-input visual geometry group (VGG ) model was used for binary image classification. All images belonging to the same patient were distributed in the same set. Accuracy and area under the curve (AUC) were calculated per frame and per patient from a 40% held-out test set. Results were compared to a visual analysis assessed by three experienced operators. Results: frame-based comparisons between humans and a CNN provided an accuracy of 0.605 vs. 0.746 (p < 0.0008) and an AUC of 0.630 vs. 0.824 (p < 0.0001). Patient-based comparisons provided an accuracy of 0.660 vs. 0.825 (p < 0.008) and an AUC of 0.727 vs. 0.895 (p < 0.002). Conclusion: based on cine-CMR images alone, a CNN is able to discriminate cardiac amyloidosis from LVH of other origins better than experienced human operators (15 to 20 points more in absolute value for accuracy and AUC), demonstrating a unique capability to identify what the eyes cannot see through classical radiological analysis.

Transthyretin cardiac amyloidosis: a review of the nuclear imaging findings with emphasis on the radiotracers mechanisms

Cardiac amyloidosis is a protein deposition disease characterized by the infiltration of the myocardium and coronary arteries resulting in a progressive thickening of both ventricles, interatrial septum and atrioventricular valves, eventually leading to organ failure. It is a disease hard to diagnose, due to the lack of diagnostic investigations. However, development of new and more accurate examinations is undergoing. Endomyocardial biopsy is the gold standard investigation for this disease, but it has its limitations (invasive and not widely available). Other investigations may be able to detect the presence of cardiac amyloidosis but cannot specify the type involved. To that end, nuclear medicine through bone scanning offers a simple, non-invasive solution to detect, differentiate and diagnose transthyretin cardiac amyloidosis (ATTR) from other types of cardiac amyloidosis. In order to demonstrate the importance of bone scanning we will present a few methods of image processing based on literature and a personalized method, followed by a few important examples of positive cases. The aim of this review was to present the current methods of ATTR detection with emphasis on nuclear medicine bone scanning and its important place in the decision algorithm of the cardiologist for a personalized approach to this pathology.

Cardiovascular disease risk assessment in patients with familial Mediterranean fever related renal amyloidosis

Chronic inflammation and proteinuria is a risk factor for cardiovascular disease (CVD) in patients with chronic kidney diseases and rheumatologic disorders. Our aim was to investigate the CVD events (CVDEs) and survival between the patients with FMF-related AA amyloidosis and glomerulonephropathies (GN) to define possible predictors for CVDEs. A prospective follow-up study with FMF-amyloidosis and glomerulonephropathy (GN) was performed and patients were followed for CVDEs. Flow-mediated dilatation (FMD), FGF-23, serum lipid, hsCRP levels, BMI and HOMA were assessed. A Cox regression analysis was performed to evaluate the risk factors for CVDEs. There were 107 patients in the FMF-amyloidosis group and 126 patients with GN group. Forty-seven CVDEs were observed during the 4.2-years follow up; all 28 patients in the FMF-amyloidosis group and 14/19 patients with GN developed CVDEs before the age of 40 (p = 0.002). CVD mortality was 2.8 times higher (95% CI 1.02–7.76) in patients with FMF-amyloidosis. Across both groups, FMD and FGF23 (p < 0.001) levels were independently associated with the risk of CVDEs. Patients with FMF-amyloidosis are at increased risk of early CVDEs with premature mortality age. FGF 23, FMD and hsCRP can stratify the risk of early CVD in patients with FMF-related AA amyloidosis.

Right Heart Changes Impact on Clinical Phenotype of Amyloid Cardiac Involvement: A Single Centre Study

Amyloidosis is due to deposition of an excessive amount of protein in many parenchymal tissues, including myocardium. The onset of cardiac Amyloidosis (CA) is an inauspicious prognostic factor, which can lead to sudden death. We retrospectively analyzed 135 patients with systemic amyloidosis, admitted to our ward between 1981 and 2019. Among them, 54 patients (46.30% F/53.70% M, aged 63.95 ± 12.82) presented CA at baseline. In 53 patients, it was associated with a multiorgan involvement, while in one there was a primary myocardial deposition. As a control group, we enrolled 81 patients (49.30% F/50.70% M, aged 58.33 ± 15.65) who did not meet the criteria for CA. In 44/54 of patients CA was associated with AL, 5/54 with AA and 3/54 of patients with ATTR, and in 1/54 AL was related to hemodialysis and in 1/54 to Gel-Amyloidosis. The most common AL type was IgG (28/44); less frequent forms were either IgA (7/44) or IgD (2/44), while seven patients had a λ free light chain form. The 32 AL with complete Ig were 31 λ-chain and just one k-chain. CA patients presented normal BP (SBP 118.0 ± 8.4 mmHg; DBP 73.8 ± 4.9 mmHg), while those with nCA had an increased proteinuria (p = 0.02). TnI and NT-proBNP were significantly increased compared to nCA (p = 0.031 and p = 0.047, respectively). In CA patients we found an increased LDH compared to nCA (p = 0.0011). CA patients were also found to have an increased interventricular septum thickness compared to nCA (p = 0.002), a decreased Ejection Fraction % (p = 0.0018) and Doppler velocity E/e’ ratio (p = 0.0095). Moreover, CA patients had an enhanced right atrium area (p = 0.0179), right ventricle basal diameter (p = 0.0112) and wall thickness (p = 0.0471) compared to nCA, and an increased inferior cava vein diameter (p = 0.0495) as well. TAPSE was the method chosen to evaluate systolic function of the right heart. In CA subjects very poor TAPSE levels were found compared to nCA patients (p = 0.0495). Additionally, we found a significant positive correlation between TAPSE and lymphocyte count (r = 0.47; p = 0.031) as well as Gamma globulins (r = 0.43, p = 0.033), Monoclonal components (r = 0.72; p = 0.047) and IgG values (r = 0.62, p = 0.018). Conversely, a significant negative correlation with LDH (r = −0.57, p = 0.005), IVS (r = −0.51, p = 0.008) and diastolic function evaluated as E/e’ (r = −0.60, p = 0.003) were verified. CA patients had very poor survival rates compared to controls (30 vs. 66 months in CA vs. nCA, respectively, p = 0.15). Mean survival of CA individuals was worse also when stratified according to NT-proBNP levels, using 2500 pg/mL as class boundary (174 vs. 5.5 months, for patients with lower vs. higher values than the median, respectively p = 0.013). In much the same way, a decreased right heart systolic function was correlated with a worse prognosis (18.0 months median survival, not reached in subjects with lower values than 18 mm, p = 0.0186). Finally, our data highlight the potential prognostic and predictive value of right heart alterations characterizing amyloidosis, as a novel clinical parameter correlated to increased LDH and immunoglobulins levels. Overall, we confirm the clinical relevance of cardiac involvement suggests that right heart evaluation may be considered as a new marker for clinical risk stratification in patients with amyloidosis.