Cardiovascular toxicity from therapies for light chain amyloidosis

Amyloid light-chain (AL) amyloidosis is a hematological disorder characterized by abnormal proliferation of a plasma cell clone producing monoclonal free light chains that misfold and aggregate into insoluble fibrils in various tissues. Cardiac involvement is a common feature leading to restrictive cardiomyopathy and poor prognosis. Current first-line treatments aim at achieving hematological response by targeting the plasma cell clones, and these have been adapted from multiple myeloma therapy. Patients with AL amyloidosis often exhibit multiorgan involvement, making them susceptible to cancer therapy-related cardiovascular toxicity. Managing AL amyloidosis is a complex issue that requires enhanced knowledge of the cardio-oncological implications of hematological treatments. Future research should focus on implementing and validating primary and secondary prevention strategies and understanding the biochemical basis of oncological therapy-related damage to mitigate cardiovascular toxicity.

Cardiac "hypertrophy" phenotyping: differentiating aetiologies with increased left ventricular wall thickness on echocardiography

Aims

Differentiating phenotypes of cardiac "hypertrophy" characterised by increased wall thickness on echocardiography is essential for management and prognostication. Transthoracic echocardiography is the most commonly used screening test for this purpose. We sought to identify echocardiographic markers that distinguish infiltrative and storage disorders that present with increased left ventricular (LV) wall thickness, namely, cardiac amyloidosis (CA) and Anderson-Fabry disease (AFD), from hypertensive heart disease (HHT).

Methods

Patients were retrospectively recruited from Westmead Hospital, Sydney, and Princess Alexandra Hospital, Brisbane. LV structural, systolic, and diastolic function parameters, as well as global (LVGLS) and segmental longitudinal strains, were assessed. Previously reported echocardiographic parameters including relative apical sparing ratio (RAS), LV ejection fraction-to-strain ratio (EFSR), mass-to-strain ratio (MSR) and amyloidosis index (AMYLI) score (relative wall thickness × E/e') were evaluated.

Results

A total of 209 patients {120 CA [58 transthyretin amyloidosis (ATTR) and 62 light-chain (AL) amyloidosis], 31 AFD and 58 HHT patients; mean age 64.1 ± 13.7 years, 75% male} comprised the study cohort. Echocardiographic measurements differed across the three groups, The LV mass index was higher in both CA {median 126.6 [interquartile range (IQR) 106.4-157.9 g/m²]} and AFD [median 134 (IQR 108.8-152.2 g/m²)] vs. HHT [median 92.7 (IQR 79.6-102.3 g/m²), p < 0.05]. LVGLS was lowest in CA [median 12.29 (IQR 10.33-15.56%)] followed by AFD [median 16.92 (IQR 14.14-18.78%)] then HHT [median 18.56 (IQR 17.51-19.97%), p < 0.05]. Diastolic function measurements including average e' and E/e' were most impaired in CA and least impaired in AFD. Indexed left atrial volume was highest in CA. EFSR and MSR differentiated secondary (CA + AFD) from HHT [receiver operating curve-area under the curve (ROC-AUC) of 0.80 and 0.91, respectively]. RAS and AMYLI score differentiated CA from AFD (ROC-AUC of 0.79 and 0.80, respectively). A linear discriminant analysis with stepwise variable selection using linear combinations of LV mass index, average e', LVGLS and basal strain correctly classified 79% of all cases.

Conclusion

Simple echocardiographic parameters differentiate between different "hypertrophic" cardiac phenotypes. These have potential utility as a screening tool to guide further confirmatory testing.

Refractory Arrhythmias as a Potential Indicator of Underlying Cardiac Amyloidosis: A Case Report

Primary (AL) amyloidosis is a rare multisystemic disorder that occurs approximately in 9.7-14.0 cases per million per year in the United States. A late diagnosis of amyloidosis can decrease the chance of survival to less than three years. With the intention to diagnose future cases of AL amyloidosis early in clinical presentation, we describe a case of a 64-year-old female who had presented to the hospital for a pre-liver transplant workup for presumed end-stage liver disease secondary to nonalcoholic steatohepatitis (NASH). Pre-transplant electrocardiogram (ECG) findings were significant for atrial fibrillation that was unable to resolve with synchronized cardioversion. Two previous cardioversions attempted in the preceding three years with amiodarone proved unsuccessful. Following her ECG, an endoscopy and colonoscopy were completed that demonstrated a lesion within the gastric mucosa along with two polyps in the transverse colon and ascending colon. Pathology for these lesions revealed amyloidosis in all biopsy sites, which was followed by a bone marrow biopsy also confirming AL amyloidosis and proliferative monoclonal B lymphocytes. A cardiac magnetic resonance imaging (MRI) proceeded to gather more information on the systemic extent of the patient's amyloidosis, which showed signs consistent with cardiac infiltration of amyloid. The patient was discharged with at-home hospice care and later decided to pursue chemotherapy, ultimately expiring from end organ failure. We conclude that failed cardioversion in a patient with persistent atrial fibrillation can be a clinical and diagnostic marker in suspecting a diagnosis of amyloidosis. Thus, we encourage clinicians to consider systemic amyloidosis in the assessment of unsuccessful cardioversion in these patient presentations for the initiation of treatment early on in the disease course.

The emerging significance of amyloid deposits in the ligamentum flavum of spinal stenosis patients: A review

Spinal stenosis is one of the most common neurosurgical diseases and a leading cause of pain and disability. Wild-type transthyretin amyloid (ATTRwt) has been found in the ligamentum flavum (LF) of a significant subset of spinal stenosis patients who undergo decompression surgery. Histologic and biochemical analyses of ligamentum flavum specimens from spinal stenosis patients, normally discarded as waste, have the potential to help elucidate the underlying pathophysiology of spinal stenosis and possibly allow for medical treatment of stenosis as well screen for other systemic diseases. This review article discusses the utility of analyzing LF specimens following spinal stenosis surgery for wild-type transthyretin amyloid (ATTRwt) deposits. Screening of cardiac ATTRwt amyloidosis (ATTRwt-CM) through LF specimens have led to the early diagnosis and treatment of cardiac amyloidosis in several patients, with more expected to benefit from this process. Emerging evidence in the literature also point to ATTRwt as a contributor to a previously unrecognized subtype of spinal stenosis in patients who may in the future benefit from medical therapy. In this article, we review the current literature with regards to the early detection of ATTRwt-CM via LF screening as well the possible contribution of ATTRwt deposits in the LF to spinal stenosis development.

A robust radiomic-based machine learning approach to detect cardiac amyloidosis using cardiac computed tomography

Introduction

Cardiac amyloidosis (CA) shares similar clinical and imaging characteristics (e.g., hypertrophic phenotype) with aortic stenosis (AS), but its prognosis is generally worse than severe AS alone. Recent studies suggest that the presence of CA is frequent (1 out of 8 patients) in patients with severe AS. The coexistence of the two diseases complicates the prognosis and therapeutic management of both conditions. Thus, there is an urgent need to standardize and optimize the diagnostic process of CA and AS. The aim of this study is to develop a robust and reliable radiomics-based pipeline to differentiate the two pathologies.

Methods

Thirty patients were included in the study, equally divided between CA and AS. For each patient, a cardiac computed tomography (CCT) was analyzed by extracting 107 radiomics features from the LV wall. Feature robustness was evaluated by means of geometrical transformations to the ROIs and intra-class correlation coefficient (ICC) computation. Various correlation thresholds (0.80, 0.85, 0.90, 0.95, 1), feature selection methods [p-value, least absolute shrinkage and selection operator (LASSO), semi-supervised LASSO, principal component analysis (PCA), semi-supervised PCA, sequential forwards selection] and machine learning classifiers (k-nearest neighbors, support vector machine, decision tree, logistic regression and gradient boosting) were assessed using a leave-one-out cross-validation. Data augmentation was performed using the synthetic minority oversampling technique. Finally, explainability analysis was performed by using the SHapley Additive exPlanations (SHAP) method.

Results

Ninety-two radiomic features were selected as robust and used in the further steps. Best performances of classification were obtained using a correlation threshold of 0.95, PCA (keeping 95% of the variance, corresponding to 9 PCs) and support vector machine classifier reaching an accuracy, sensitivity and specificity of 0.93. Four PCs were found to be mainly dependent on textural features, two on first-order statistics and three on shape and size features.

Conclusion

These preliminary results show that radiomics might be used as non-invasive tool able to differentiate CA from AS using clinical routine available images.

Invasive and Non-Invasive Diagnostic Pathways in the Diagnosis of Cardiac Amyloidosis

The appropriate diagnosis and subtyping of cardiac amyloidosis (CA) is frequently missed or delayed due to its vague presentation, clinical overlapping, and diagnostic pitfalls. Recent developments in both invasive and non-invasive diagnostic techniques have significantly changed the diagnostic approach of CA. With the present review, we aim to summarize the current diagnostic approach of CA and to underline the indications of tissue biopsy, either surrogate site or myocardial. The most important factor for timely diagnosis is increased clinical suspicion, especially in certain clinical scenarios. Appropriate imaging with echocardiography or cardiac magnetic resonance (CMR) can provide significant evidence for the diagnosis of CA. Importantly, all patients should undergo monoclonal proteins assessment, with these results significantly determining the steps to follow. A negative monoclonal protein assessment will lead to a non-invasive algorithm which, in combination with positive cardiac scintigraphy, can establish the diagnosis of ATTR-CA. The latter is the only clinical scenario in which the diagnosis can be established without the need of biopsy. However, if the imaging results are negative but the clinical suspicion remains high, a myocardial biopsy should be performed. In the case of the presence of monoclonal protein, an invasive algorithm follows, first by surrogate site sampling and then by myocardial biopsy if the results are inconclusive or prompt diagnosis is needed. The role of endomyocardial biopsy, even though limited by current advances in other techniques, is highly valuable in selected patients and is the only method to reliably establish a diagnosis in challenging cases.

Cardiac Amyloidosis Imaging, Part 2: Quantification and Technical Considerations

^99mTc-pyrophosphate imaging has been around for a long time. In the 1970s, it was used to image recent myocardial infarction. However, it has recently been recognized for its value in detecting cardiac amyloidosis, leading to widespread use across the United States. Increased use led to considerable procedure variability. As the evidence base to support formal guidelines was being developed, experts from several professional medical societies issued imaging and interpretation recommendations titled "ASNC/AHA/ASE/EANM/HFSA/ISA/SCMR/SNMMI Expert Consensus Recommendations for Multimodality Imaging in Cardiac Amyloidosis: part 1 of 2-Evidence Base and Standardized Methods of Imaging." To reach a consensus on a protocol that would benefit the bulk of laboratories, the experts considered several parameters and radiotracer kinetics. The most critical parameters concerned injection-to-imaging delay and planar imaging versus SPECT. Accordingly, the standardized protocol recommends the injection of 370-740 MBq (10-20 mCi) of ^99mTc-pyrophosphate with imaging 3 h later. Planar images of the chest are acquired in the anterior and lateral views accompanied by SPECT images. Both the planar and the SPECT images are used to semiquantitatively grade the degree of myocardial uptake compared with the amount of uptake in the ribs using a 0-3 scale. A grade of 2 or 3 on the SPECT images is considered positive for cardiac amyloidosis. The planar images are used to calculate a heart-to-contralateral-lung ratio. A ratio greater than 1.3 at 3 h helps to confirm the diagnosis of cardiac amyloid if the SPECT images have positive findings. This article is part of a 3-part series in this issue of the Journal of Nuclear Medicine Technology Part 1 details the etiology of cardiac amyloidosis and ^99mTc-pyrophosphate imaging acquisition parameters. Part 2, this article, describes the procedure evolution over 50 y, image processing, and quantification. It further discusses radiotracer kinetics and 2 important technical considerations: injection-to-imaging delay and planar imaging versus SPECT. Part 3 covers study interpretation along with cardiac amyloidosis diagnosis and treatment.

Cardiac Amyloidosis Imaging, Part 1: Amyloidosis Etiology and Image Acquisition

Cardiac amyloidosis is a systemic form of amyloidosis in which protein-based infiltrates are deposited in myocardial extracellular space. The accumulation of amyloid fibrils causes the myocardium to thicken and stiffen, leading to diastolic dysfunction and, eventually, heart failure. Until recently, cardiac amyloidosis was considered rare. However, the recent adoption of noninvasive diagnostic testing, including ^99mTc-pyrophosphate imaging, has revealed a previously undiagnosed sizable disease prevalence. Light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR), the 2 primary types, account for 95% of cardiac amyloidosis diagnoses. AL results from plasma cell dyscrasia and has a very poor prognosis. The usual treatment for cardiac AL is chemotherapy and immunotherapy. Cardiac ATTR is more chronic, usually resulting from age-related instability and misfolding of the transthyretin protein. ATTR is treated by managing heart failure and using new pharmacotherapeutic drugs. ^99mTc-pyrophosphate imaging can efficiently and effectively distinguish between ATTR and cardiac AL. Although the exact mechanism of myocardial ^99mTc-pyrophosphate uptake is unknown, it is believed to bind to amyloid plaque microcalcifications. ^99mTc-pyrophosphate imaging has a 97% sensitivity and nearly 100% sensitivity for identifying cardiac ATTR when the AL form of the disease is ruled out through serum free light-chain and serum and urine protein electrophoresis with immunofixation testing. Although there are no published ^99mTc-pyrophosphate cardiac amyloidosis imaging guidelines, the American Society of Nuclear Cardiology, Society of Nuclear Medicine and Molecular Imaging, and others have published consensus recommendations to standardize test performance and interpretation. This article, part 1 of a 3-part series in this issue of the Journal of Nuclear Medicine Technology, describes amyloidosis etiology and cardiac amyloidosis characteristics, including the types, prevalence, signs and symptoms, and disease course. It further explains the scan acquisition protocol. Part 2 of the series focuses on image/data quantification and technical considerations. Finally, part 3 describes scan interpretation, along with the diagnosis and treatment of cardiac amyloidosis.

Cardiac Amyloidosis in the Setting of a Sarcomatous Pericardial Mass

Cardiac amyloidosis is a significantly underdiagnosed disease but should be suspected in anyone with restrictive heart physiology. Here, we present a case of a sarcomatous pericardial mass confounding the patient's progressive diastolic heart failure. Amyloidosis was eventually discovered by piecing together serial transthoracic echocardiogram, functional MRI, and technetium-99m (99mTc) pyrophosphate scintigraphy findings along with a negative lab workup. The presence of the sarcomatous pericardial mass raised the question of whether it played a role in the onset and progression of amyloidosis, but nonetheless, the presence of both diseases rendered multifaceted challenges regarding our patient's care. Anyone suspected to have amyloidosis should receive appropriate testing for a definitive diagnosis to catch the disease process and offer early treatment, as exciting research is emerging showing transthyretin stabilizers to have a reduction in all-cause mortality.

Cardiac Amyloidosis Imaging, Part 3: Interpretation, Diagnosis, and Treatment

Cardiac amyloidosis was thought to be rare, undiagnosable, and incurable. However, recently it has been discovered to be common, diagnosable, and treatable. This knowledge has led to a resurgence in nuclear imaging with ^99mTc-pyrophosphate-a scan once believed to be extinct-to identify cardiac amyloidosis, particularly in patients with heart failure but preserved ejection fraction. The renewed interest in ^99mTc-pyrophosphate imaging has compelled technologists and physicians to reacquaint themselves with the procedure. Although ^99mTc-pyrophosphate imaging is relatively simple, interpretation and diagnostic accuracy require an in-depth knowledge of amyloidosis etiology, clinical manifestations, disease progression, and treatment. Diagnosing cardiac amyloidosis is complicated because typical signs and symptoms are nonspecific and usually attributed to other cardiac disorders. In addition, physicians must be able to differentiate between monoclonal immunoglobulin light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). Several clinical and noninvasive diagnostic imaging (echocardiography and cardiac MRI) red flags have been identified that suggest a patient may have cardiac amyloidosis. The intent of these red flags is to raise physician suspicion of cardiac amyloidosis and guide a series of steps (a diagnostic algorithm) for narrowing down and diagnosing the specific amyloid type. One element in the diagnostic algorithm is to identify monoclonal proteins indicative of AL. Monoclonal proteins are detected by serum or urine immunofixation electrophoresis and serum free light-chain assay. Another element is identifying and grading cardiac amyloid deposition using ^99mTc-pyrophosphate imaging. When monoclonal proteins are present and the ^99mTc-pyrophosphate scan is positive, the patient should be further evaluated for cardiac AL. The absence of monoclonal proteins and a positive ^99mTc-pyrophosphate scan is diagnostic for cardiac ATTR. Patients with cardiac ATTR need to undergo genetic testing to differentiate between wild-type ATTR and variant ATTR. This article is the third in a 3-part series in this issue of the Journal of Nuclear Medicine Technology Part 1 reviewed amyloidosis etiology and outlined ^99mTc-pyrophosphate study acquisition. Part 2 described ^99mTc-pyrophosphate image quantification and protocol technical considerations. This article discusses scan interpretation along with cardiac amyloidosis diagnosis and treatment.

Quantitative SPECT/CT Parameters in the Assessment of Transthyretin Cardiac Amyloidosis-A New Dimension of Molecular Imaging

AIMS

Cardiac transthyretin amyloidosis (ATTR) represents the accumulation of misfolded transthyretin in the heart interstitium. Planar scintigraphy with bone-seeking tracers has long been established as one of the three main steps in the non-invasive diagnosis of ATTR, but lately, single-photon emission computed tomography (SPECT) has gained wide recognition for its abilities to exclude false positive results and offer a possibility for amyloid burden quantitation. We performed a systematic review of the existing literature to provide an overview of the available SPECT-based parameters and their diagnostic performances in the assessment of cardiac ATTR. Methods and Methods: Among the 43 papers initially identified, 27 articles were screened for eligibility and 10 met the inclusion criteria. We summarised the available literature based on radiotracer, SPECT acquisition protocol, analysed parameters and their correlation to planar semi-quantitative indices.

RESULTS

Ten articles provided accurate details about SPECT-derived parameters in cardiac ATTR and their diagnostic potential. Five studies performed phantom studies for accurate calibration of the gamma cameras. All papers described good correlation of quantitative parameters to the Perugini grading system.

CONCLUSIONS

Despite little published literature on quantitative SPECT in the assessment of cardiac ATTR, this method offers good prospects in the appraisal of cardiac amyloid burden and treatment monitoring.

Alternative Isotope Options for Amyloidosis Imaging: A Technologist's Perspective

The recent pyrophosphate shortages can limit the availability of ^99mTc-pyrophosphate scans for cardiac amyloidosis. However, another radiotracer is available: ^99mTc-hydroxymethylene diphosphonate (HMDP). ^99mTc-HMDP, widely available in the United States for bone scanning, has effectively been used in Europe to diagnose transthyretin amyloidosis. ^99mTc-HMDP and ^99mTc-pyrophosphate have comparable blood clearance and sensitivity. The imaging protocols for ^99mTc-HMDP and ^99mTc-pyrophosphate are similar, except ^99mTc-HMDP is imaged 2-3 h after injection and whole-body imaging is optional. The interpretation is also essentially the same; however, caution is needed because of the high soft-tissue uptake with ^99mTc-HMDP, which can affect heart-to-contralateral-lung ratios.

Novel Tracers for the Imaging of Cardiac Amyloidosis

Radionuclide scintigraphy with technetium-labeled bisphosphonates has brought a paradigm shift in diagnosing cardiac amyloidosis (CA), with transthyretin CA now being effectively diagnosed without the need for tissue biopsy. Yet, deficits remain, such as methods for the noninvasive diagnosis of light-chain CA, means to detect CA early, prognostication, monitoring, and therapy response assessment. To address these issues, there has been growing interest in the development and implementation of amyloid-specific radiotracers for PET. The aim of this review is to educate the reader on these novel imaging tracers. Though still investigational, these novel tracers-given their many advantages-are clearly the future of nuclear imaging in CA.

A strange case of Transthyretin Cardiac Amyloidosis in the Elderly: a diagnostic challenge

Abstract

Transthyretin (TTR)-related cardiac amyloidosis is a progressive infiltrative cardiomyopathy that mimics hypertensive, hypertrophic heart disease and may go undiagnosed. We here report the case of a 83-year-old woman, which has rapresented an unique case of transthyretin-related cardiac amyloidosis, as a patient with an initial diagnosis of hypertensive heart disease later develops an infiltrative cardiomyopathy due to amyloid deposits.

Paradoxical Left Ventricular Hypertrophy by Echocardiogram and Low Voltage ECG: A Key Clue in the Diagnostic Workup of Two Distinct Presentations of Cardiac AL Amyloidosis

Cardiac amyloidosis remains a rare disease caused by the extracellular deposition of abnormal proteins-amyloids in the myocardium. These protein structures in the myocardium are associated with high morbidity and mortality, with prognosis hinging on early detection and treatment. Three main types of cardiac amyloidosis have been identified: light chain (AL), familial or senile (ATTR), and secondary amyloidosis which is associated with chronic inflammation. Cardiac amyloidosis classically presents as diastolic heart failure with symptoms of volume overload low voltage on electrocardiogram (ECG) and echocardiographic features of diastolic dysfunction and paradoxical left ventricular hypertrophy (paradoxical with respect to low voltage on ECG). Early suspicion should trigger additional laboratory and imaging workup to facilitate early detection. Early detection remains critical to prognosis. Herein, we present two patients admitted to a safety-net hospital within one month of each other with distinct presentations yet important, overlapping characteristics that led to the diagnosis of AL amyloidosis in both patients.

Improving cardiovascular outcomes for patients with heart failure in sub-Saharan Africa: conference proceedings of the 2022 Nigerian Cardiovascular Symposium

The Nigerian Cardiovascular Symposium is an annual conference held in partnership with cardiologists in Nigeria and the diaspora to provide updates in cardiovascular medicine and cardiothoracic surgery with the aim of optimising cardiovascular care for the Nigerian population. This virtual conference (due to the COVID-19 pandemic) has created an opportunity for effective capacity building of the Nigerian cardiology workforce. The objective of the conference was for experts to provide updates on current trends, clinical trials and innovations in heart failure, selected cardiomyopathies such as hypertrophic cardiomyopathy and cardiac amyloidosis, pulmonary hypertension, cardiogenic shock, left ventricular assist devices and heart transplantation. Furthermore, the conference aimed to equip the Nigerian cardiovascular workforce with skills and knowledge to optimise the delivery of effective cardiovascular care, with the hope of curbing 'medical tourism' and the current 'brain drain' in Nigeria. Challenges to optimal cardiovascular care in Nigeria include workforce shortage, limited capacity of intensive care units, and availability of medications. This partnership represents a key first step in addressing these challenges. Future action items include enhanced collaboration between cardiologists in Nigeria and the diaspora, advancing participation and enrollment of African patients in global heart failure clinical trials, and the urgent need to develop heart failure clinical practice guidelines for Nigerian patients.

Hypertensive Heart Disease-The Imaging Perspective

Hypertensive heart disease (HHD) develops in response to the chronic exposure of the left ventricle and left atrium to elevated systemic blood pressure. Left ventricular structural changes include hypertrophy and interstitial fibrosis that in turn lead to functional changes including diastolic dysfunction and impaired left atrial and LV mechanical function. Ultimately, these changes can lead to heart failure with a preserved (HFpEF) or reduced (HFrEF) ejection fraction. This review will outline the clinical evaluation of a patient with hypertension and/or suspected HHD, with a particular emphasis on the role and recent advances of multimodality imaging in both diagnosis and differential diagnosis.

Semi-Quantification of Myocardial Uptake of Bone-Seeking Agents in Suspected Cardiac Amyloidosis

INTRODUCTION

Bone scintigraphy has emerged as a key tool for non-invasive etiologic diagnosis of transthyretin (ATTR) cardiac amyloidosis (CA). We focused on a new semi-quantification method (on planar imaging) that could complement the qualitative/visual Perugini scoring system, especially when SPET/CT is not available.

MATERIAL AND METHODS

We retrospectively/qualitatively evaluated 8674 consecutive, planar 99mTc-biphosphonate scintigraphies (performed for non-cardiac reasons), identifying 68 (0.78%) individuals (mean age 79 ± 7 years, range 62-100 years; female/male ratio 16/52) presenting myocardial uptake. Due to the retrospective nature of the study, no SPET/CT, pathologic or genetic confirmation was obtained. The Perugini scoring system was determined (in patients presenting cardiac uptake) and compared with three newly proposed semi-quantitative indices. We took 349 consecutive bone scintigraphies, qualitatively absent of any cardiac/pulmonary uptake, as "healthy controls" (HC).

RESULTS

The heart-to-thigh ratio (RHT) and lung-to-thigh ratio (RLT) indices were significantly higher in patients than in HCs (p ≤ 0.0001). There were statistically significant differences for RHT in HCs vs. patients with qualitative Perugini scores of 1 or >1 (with p ranging from ≤0.001 to ≤0.0001). ROC curves showed that RHT outperformed the other indices and was more accurate in both male and female groups. Furthermore, in the male population, RHT accurately distinguished HCs and patients with scores of 1 (less likely affected by ATTR) from patients with qualitative scores >1 (more likely affected by ATTR) with an AUC of 99% (sensitivity: 95%; specificity: 97%).

CONCLUSION

The proposed semi-quantitative RHT index can accurately/semi-quantitatively distinguish between HCs and subjects probably affected by CA (Perugini scores from 1 to 3), and could be particularly useful when no SPET/CT data are available (such as in retrospective studies and data mining). Furthermore, RHT can semi-quantitatively predict, with very high accuracy, subjects in the male population more likely to be affected by ATTR. The present study, although using a very large sample, is however retrospective, monocentric, and therefore the generalizability of the results should be proved by an accurate external validation.

ADVANCES IN KNOWLEDGE

The proposed heart-to-thigh ratio (RHT) can distinguish healthy controls and subjects that are probably affected by cardiac amyloidosis in a simple and more reproducible way, as compared to standard qualitative/visual evaluation.

[Cardiac magnetic resonance-feature tracking technique can assess cardiac function and prognosis in patients with myocardial amyloidosis]

OBJECTIVE

To quantitatively assess cardiac functions in patients with cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) using cardiac magnetic resonance-feature tracking (CMR-FT) technique and evaluate the prognostic value of CMR-FT in patients with CA.

METHODS

We retrospectively collected the data from 31 CA patients with systemic amyloidosis confirmed by Congo red staining and serum immunohistochemistry after extracardiac tissue biopsy undergoing CMR at our hospital from March, 2013 to June, 2021.Thirty-one age and gender matched patients with asymmetric left ventricular wall hypertrophy and 31 healthy individuals without organic or functional heart disease served as the controls.Radial, circumferential and longitudinal strains and strain rates of the left ventricle at the global level and in each myocardial segment (basal, middle and apical) were obtained with CMR-FT technique and compared among the 3 groups.The predictive value of myocardial strains and strain rates for all-cause mortality in CA patients was analyzed using a stepwise COX regression model.

RESULTS

The left ventricular volume, myocardial mass, ejection fraction and cardiac output differed significantly among the groups (P < 0.05).Except for apical longitudinal strain, the global and segmental strains were all significantly lower in CA group than in HCM group (P < 0.05).The global and segmental strains were all significantly lower in CA group than in the healthy individuals (P < 0.05).The basal strain rates in the 3 directions were significantly lower in CA group than in the healthy individuals (P < 0.05), but the difference in apical strain rates was not statistically significant between the two groups.Multivariate stepwise COX analysis showed that troponin T (HR=1.05, 95%CI: 1.01-1.10, P=0.017) and middle peak diastolic circumferential strain rate (HR=6.87, 95%CI: 1.52-31.06, P=0.012) were strong predictors of death in CA patients.

CONCLUSION

Strain and strain rate parameters derived from CMR-FT based on cine sequences are new noninvasive imaging markers for assessing cardiac impairment in CA and cardiac function changes in HCM, and provide independent predictive information for all-cause mortality in CA patients.

Cardiac amyloidosis: A survey of current awareness, diagnostic modalities, treatment practices, and clinical challenges among cardiologists in selected Middle Eastern countries

BACKGROUND

Cardiac amyloidosis (CA) is a chronic progressive disease caused by the deposition of amyloid fibrils in cardiac tissues. Diagnosis and management of CA are complicated and have developed over the years.

HYPOTHESIS

Middle Eastern countries have significant knowledge disparities in diagnosing, managing, and treating different subtypes of CA.

METHODS

An online survey was sent to cardiologists in four countries (Saudi Arabia, Lebanon, Egypt, and Iraq) interested in heart failure and practicing for more than a year. The survey questioned the characteristics of the participants and their institutions. It addressed their knowledge and practices in CA specifically diagnostic modalities, treatment options, and interest in education and knowledge exchange.

RESULTS

A total of 85 physicians participated in the survey. There was a variation in the participating cardiologists' knowledge, experience level, and readiness of their institutes to manage patients with ATTR-CM. Most participants believed that a high rate of ATTR-CM misdiagnosis existed. Participants' knowledge of the diagnostic modalities and "red flags" raising suspicion about ATTR-CM varied. Another challenge was the availability of essential diagnostic modalities among various cardiology centers. A knowledge gap was also observed regarding updates in ATTR-CM management. However, there was a high endorsement of the need for more education, physician networking, and knowledge exchange.

CONCLUSIONS

This survey highlighted the need for increasing awareness levels among cardiologists in the four selected Middle Eastern countries. Cardiologists are most likely to benefit from additional training and knowledge exchange on the latest management advances of this disease. Thus, measures must be taken to focus on the physician's awareness of ATTR-CM patient journey to achieve a better quality of care and outcome.

Association of Left Atrial Hemodynamics by Magnetic Resonance Imaging With Long-Term Outcomes in Patients With Cardiac Amyloidosis

BACKGROUND

Left atrial (LA) function and strain patterns by magnetic resonance imaging (MRI) have been investigated as markers of several cardiovascular pathologies, including cardiac amyloidosis (CA). However, associations with clinical outcomes have not been investigated.

PURPOSE

To compare LA function and strain by MRI in CA patients to a matched cohort of patients without cardiovascular disease (CVD) and evaluate the association with long-term clinical outcomes in CA patients.

STUDY TYPE

Retrospective case control.

POPULATION

A total of 51 patients with CA and 51 age-, gender-, and race-matched controls without CVD who underwent MRI in sinus rhythm.

FIELD STRENGTH/SEQUENCE

ECG-gated balanced steady-state free precession sequence at 1.5 T.

ASSESSMENT

All measurements were completed by one investigator (M.M.B.). LA function and strain parameters were measured including LA indexed minimum and maximum volumes, LA reservoir (R), contractile (CT), and conduit (CD) strain. We compared groups after adjusting for age, hypertension, New York Heart Association class, modified staging system (troponin-I, BNP, estimated GFR) and left ventricular ejection fraction (LVEF) for an endpoint of all-cause mortality and a composite endpoint of heart failure hospitalization (HFH) or death.

STATISTICAL TESTS

Differences between groups were evaluated with t tests for continuous variables or χ² tests for categorical variables. A multivariable regression model was used to assess the associations of the P values-two-sided tests-<0.05 were considered statistically significant.

RESULTS

CA patients with median follow up of 4.9 (8.5) months had significantly lower LA strain and higher LA volumes in comparison to the matched cohort. In the multivariable analysis, only LVEF was significantly associated with death while ƐCT (OR 0.6, CI: 0.41-0.89), indexed minimum LA volume (OR 1.06, CI: 1.02-1.13) and indexed maximum LA volume (OR 1.08, CI: 1.01-1.15) were significantly associated with the composite outcome of death or HFH.

CONCLUSION

In this retrospective study of CA patients, ƐCT and indexed minimum and maximum LA volumes were significantly associated with the composite outcome of death or HFH.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Multimodality Imaging for Diagnosing Transthyretin Cardiac Amyloidosis

Amyloidosis is the result of the extracellular deposition of amyloid in various organs. Common types are light-chain and transthyretin amyloidosis. Cardiac amyloidosis (CA) is a restrictive cardiomyopathy caused by amyloid infiltration in cardiac tissues. The detection of CA is increasing with the advent of easily accessible imaging modalities. Early diagnosis ensures a better prognosis. We present a case of cardiac amyloidosis, diagnosed from specific imaging findings on cardiac magnetic resonance imaging and more precisely as transthyretin type based on findings on nuclear scintigraphy.

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.

Prognostic role of three-dimensional speckle-tracking echocardiography-derived left ventricular global longitudinal strain in cardiac amyloidosis: Insights from the MAGYAR-Path Study

INTRODUCTION

Systemic amyloidosis is an uncommon disorder in which amyloid fibrils deposit extracellularly. Three-dimensional speckle-tracking echocardiography (3DSTE) is a novel method able to assess left ventricular (LV) global longitudinal strain (GLS). Our aim was to evaluate the prognostic impact of 3DSTE-derived LV-GLS in patients with cardiac amyloidosis (CA).

MATERIALS AND METHODS

A total of 35 patients suffering from light-chain (AL) CA or transthyretin (TTR) CA were selected, but 7 patients had to be excluded due to insufficient image quality or were lost for follow-up. With AL-CA 23 cases, while for TTR-CA 5 patients were diagnosed. Complete two-dimensional Doppler and 3DSTE were performed in all subjects.

RESULTS

The median follow-up was 201 days (ranging from 36 to 632 days) during which cardiovascular event was detected in 17 CA patients, including 8 cardiac deaths. Six patients were diagnosed with acute heart failure, two patients needed invasive interventions (percutaneous coronary intervention with stent-implantation, implantable cardioverter defibrillator implantation) and in one patient new higher grade atrioventricular block was registered. Using ROC analysis, 3DSTE-derived LV-GLS ≥11.8% (absolute value) was found to be a significant predictor for cardiovascular event-free survival (sensitivity 65%, specificity 64%, area under the curve 0.71, p = .05). Lower LV ejection fraction was confirmed in patients with LV-GLS <11.8% as compared to cases with LV-GLS ≥11.8%. In case of a cardiovascular event, LV-GLS was lower as compared to that of subjects with no events. Multivariable regression analysis confirmed that LV-GLS and LV end-diastolic diameter were independent predictors of cardiovascular survival.

CONCLUSION

3DSTE-derived LV-GLS is an independent predictor for future cardiovascular events in CA patients.