Updates in cardiac amyloidosis: a review

Detection of amyloid deposition in the hip and shoulder joints on CT scans as indicative of ATTR-type cardiac amyloidosis

BackgroundAmyloid deposition manifests as thickening and calcification of the joints on computed tomography (CT) images.PurposeTo investigate the diagnostic potential of thickening and calcification of the shoulder and hip joints for the detection of transthyretin amyloid cardiomyopathy (ATTR-CM).Material and MethodsWe included 19 patients who had been assessed using 99mTc-pyrophosphate scintigraphy between January 2019 and December 2022 and diagnosed with ATTR-CM. The incidence of calcification and synovial thickening in the hip and shoulder joints of the patients and controls was evaluated. Two radiologists determined differences in joint calcification and thickness on CT images using Pearson chi-square tests and unpaired t-tests, respectively.ResultsShoulder and hip joint thickness (both P < 0.01) and calcifications (P < 0.05) significantly differed between the groups. The area under the receiver operating characteristic curve (AUC) was 0.74 for the shoulder joint, and the cut-off Youden index was 16.1 mm, with a sensitivity and specificity of 63.2% and 78.9%, respectively. The AUC was 0.844 for the hip joint, with an optimal cutoff of 11.8 mm, with a sensitivity and specificity of 71.4% and 89.5%, respectively. Inter-observer agreement was substantial between the radiologists for detecting hip and/or shoulder joint calcification (κ = 0.712). The interclass correlation coefficients (2, 1) were 0.65 and 0.71 for measurements of shoulder and hip joint thickness, respectively.ConclusionThickened and calcified shoulder and hip joints are more likely to be found in patients with clinically diagnosed ATTR-CM than those without.

The value of left ventricular T1 mapping and left atrial strain for distinguishing myocardial amyloidosis and hypertrophic cardiomyopathy

PURPOSE

This study aimed to use T1 mapping and left atrial feature tracking techniques to distinguish myocardial amyloidosis (CA) from hypertrophic cardiomyopathy (HCM).

METHODS

A retrospective analysis was conducted on 130 subjects who underwent cardiac magnetic resonance examinations from January 2021 to May 2024 at 1.5 and 3.0 T systems. Measurements of global left ventricular myocardial T1 values were performed, a standardized T1 z-score used as an assessment metric to overcome the effects of various manufacturers and field strengths. Left atrial strain was measured with feature tracking techniques.

RESULTS

42 CA patients、58 HCM patients and 30 healthy subjects were analyzed. For both 1.5T and 3.0T systems, the overall T1 values of LV myocardium was significantly higher in the CA group compared with the HCM and control groups (p < 0.001). T1z-scores in the CA and HCM groups were 4.8 ± 2.2 and 3.4 ± 1.9, respectively (p < 0.001). Myocardial strain analysis showed that atrial strain was significantly lower in the CA group when compared with the HCM and healthy control groups (p < 0.05). The correlation between left atrial strain and function parameters was assessed through Spearman correlation analysis. Multivariate logistic regression analysis showed that a combination model including T1z-score and left atrial reservoir function (Es) had an improved ability to discriminate CA and HCM with a higher AUC (0.937), with a sensitivity of 95.2% and a specificity of 83.3% (P < 0.05).

CONCLUSION

T1 mapping combined with Εs could effectively distinguish CA from HCM, and provide new insights for the diagnosis of the etiology and treatment of cardiac hypertrophic diseases.

Amyloidosis of the heart: pathophysiology, diagnosis, and treatment

INTRODUCTION

Cardiac amyloidosis is characterized by amyloid fibril aggregation due to misfolded circulating proteins and their deposition in the heart, leading to cardiac damage and dysfunction. Given cardiac amyloidosis is associated with a poor prognosis without treatment, early diagnosis and management are critical to increase survival from the disease.

AREAS COVERED

This article provides an overview of the disease process, diagnostic modalities, and therapies for cardiac amyloidosis.

EXPERT OPINION

Recent technological advances have led to the development of reliable and accurate diagnostic modalities for identifying cardiac amyloidosis. Recent introduction of novel disease-modifying therapies for cardiac amyloidosis has resulted in improvements in the management and prognosis of the disease.

Early Amyloid Diagnosis and Treatment: Experience of Single Hand Surgeon With a Series of 182 Carpal Tunnel Biopsies

BACKGROUND

Amyloidosis is a systemic disease characterized by buildup of abnormal amyloid deposits that may lead to multiple organ failure and is associated with early onset musculoskeletal manifestations. Orthopedic surgeons are positioned to aid with early diagnosis in the form of a biopsy which allows for workup for other areas of disease, specifically cardiac manifestations, and intervention prior to irreversible cardiac damage. In this review, we describe the biopsy results of a series of 182 patients and workup and treatment of the 46 amyloid positive patients biopsied by a single surgeon during a 4-year period.

METHODS

We retrospectively reviewed biopsy results from 2019 to 2024 for all patients who met criteria for biopsy at time of open carpal tunnel release (CTR). All surgeries were performed by a single surgeon at a single academic institution. Patient selection was based on a previously published algorithm.

RESULTS

Forty-six (25.3%) of 182 patients who underwent CTR and met criteria for biopsy were found to test positive on Congo red staining and liquid chromatography tandem mass spectrometry. All 46 patients were referred to cardiology for evaluation. Thirty-three patients completed cardiology evaluation and 32 of those patients were started on treatment as a result of testing.

CONCLUSIONS

The incidence of amyloid positive biopsy results was 25.3% in a single surgeon, single institution study using currently accepted screening criteria. All positive patients were referred for cardiac imaging and evaluation to obtain early diagnosis of amyloid cardiomyopathy and initiate treatment if indicated. A significant portion of patients referred to cardiology (58%) were started on pharmacological management as a result.

LEVEL OF EVIDENCE

Retrospective cohort study, II, prognostic.

Integrated specialty care for amyloidosis: a scoping review using the Consolidated Framework for Implementation Research

BACKGROUND

Amyloidosis is a complex and rare disease requiring specialized, multidisciplinary care to effectively manage its diverse manifestations. Existing evidence underscores the benefits of such care, linked to improved patient outcomes and clinician satisfaction. With the rising incidence of amyloidosis diagnoses and rapid advancements in treatment, the need for coordinated, expert-led care is increasing. However, implementing these centers is challenging due to resource allocation and inter-specialty collaboration. While resource allocation is a known hurdle, there has not been a comprehensive review of all the barriers and facilitators to establishing these clinics. This scoping review aims to identify the barriers and facilitators related to the implementation of coordinated, multidisciplinary specialty care clinics in amyloidosis management.

METHODS

An electronic search was conducted in Medline, Embase, and CINAHL for studies published in English from 2013 to 2023, supplemented by a grey literature search. The inclusion criteria focused on studies discussing multidisciplinary clinical environments for amyloidosis care, particularly light-chain (AL) and transthyretin amyloidosis (TTR). Exclusion criteria included books, opinion pieces, dissertations, and conference abstracts. Data were analyzed and synthesized using a narrative synthesis approach, guided by the Consolidated Framework for Implementation Research (CFIR), and reported according to PRISMA-ScR guidelines.

RESULTS

The search resulted in 1547 findings. After screening with Covidence, 7 papers were included in the final review. Independent reviewers screened and extracted the papers. Key facilitators identified include access to experts, adequate staffing, secure funding, partnerships with patient advocacy groups, and robust processes for multidisciplinary communication. Barriers primarily relate to the complexity of care, a lack of standardized protocols, difficulties in communication and coordination between providers, and challenges in training and maintaining knowledgeable care providers. The review also revealed significant gaps in existing research.

CONCLUSIONS

This review enhances understanding of the barriers and facilitators in establishing amyloidosis specialty clinics. Addressing these barriers and leveraging facilitators are crucial for shaping the future of amyloidosis care. These insights support a model for implementing integrated care for this growing patient population and highlight the need for further research to support policy development and effective implementation of these specialized clinics.

Advances and challenges in echocardiographic diagnosis and management of cardiac amyloidosis

Cardiac amyloidosis is an infiltrative cardiomyopathy characterized by the abnormal accumulation of amyloid proteins within the heart muscle. It is recognized as a rare yet significant cardiac disease that is often overlooked as a potential cause of heart failure and cardiac arrhythmias, particularly in older individuals with rates escalating from 8 to 17 cases per 100,000 individuals. Cardiac amyloidosis primarily manifests as two predominant subtypes: light-chain and transthyretin amyloidosis, collectively accounting for over 95% of clinical cases. Early diagnosis of these conditions is often hindered by overlapping symptoms with other cardiac pathologies, resulting in diagnostic delays and suboptimal patient outcomes. Echocardiography, a non-invasive imaging technique, has become indispensable for diagnosing cardiac amyloidosis, uncovering crucial echocardiographic signs such as thickening of the left ventricular wall, diastolic dysfunction, and a granular appearance of the myocardium. Recent advancements in echocardiography have significantly enhanced the diagnostic accuracy of cardiac amyloidosis and improved patient management. Advanced echocardiographic techniques, including strain imaging, 3D echocardiography, and contrast echocardiography, have significantly enhanced diagnostic accuracy and prognostication. Future directions in echocardiography encompass the integration of artificial intelligence, the development of novel contrast agents, and the refinement of 4D echocardiography to further optimize patient care. This study explores the pivotal role of echocardiography in both diagnosing and managing cardiac amyloidosis, delving into the disease's underlying mechanisms, distinctive imaging characteristics, the significance of regular echocardiographic assessments, and discusses the challenges associated with differentiating between various types of amyloidosis without supplemental imaging or biopsy methods.

Prevalence and outcomes of concomitant cardiac amyloidosis and coronary artery disease

BACKGROUND

Cardiac amyloidosis (CA) and coronary artery disease (CAD) can have similar presentations in the acute care setting which can potentially delay the diagnosis of CA.

METHODS

We conducted a retrospective analysis of patients referred to our institution for evaluation of cardiac amyloidosis. We obtained demographic and clinical characteristics, laboratory data, and echocardiographic measurements of those patients with confirmed cardiac amyloidosis. The population was divided into two groups based on the presence of CAD. Frequency of heart failure hospitalizations, and one-year overall mortality were compared between both groups.

RESULTS

Between 2018 to 2021, 327 patients with suspected cardiac amyloidosis were referred to our institution. Out of 114 confirmed CA patients, 28 patients (25%) had concomitant CAD and CA. The overall mean age of CA diagnosis was 74.7 (±8.4) years for the CAD group and 69.7 (±9.8) for the non-CAD group (P value 0.002). Notably, a higher percentage of males were observed in the CAD group (92/.9% vs. 60%, p-value 0.002), and a higher prevalence of hypertension (92.9% vs 70%, p-value 0.018) and dyslipidemia (89.3% vs 59%, p-value 0.004) were also found in the CAD group. Overall, there were no significant differences in outcomes.

CONCLUSION

Larger studies are needed to identify characteristics that will result in a prompt diagnosis of CA in patients with concomitant CAD. Although our study did not appreciate a significant difference between these two groups, outcomes of our study were likely impacted by a small sample size in the CA with CAD cohort.

Deep learning model to diagnose cardiac amyloidosis from haematoxylin/eosin-stained myocardial tissue

Aims

Amyloid deposition in myocardial tissue is a definitive feature for diagnosing cardiac amyloidosis, though less invasive imaging modalities such as bone tracer cardiac scintigraphy and cardiac magnetic resonance imaging have been established as first steps for its diagnosis. This study aimed to develop a deep learning model to support the diagnosis of cardiac amyloidosis from haematoxylin/eosin (HE)-stained myocardial tissue.

Methods and results

This single-centre retrospective observational study enrolled 166 patients who underwent myocardial biopsies between 2008 and 2022, including 76 patients diagnosed with cardiac amyloidosis and 90 with other diagnoses. A deep learning model was developed to output the probabilities of cardiac amyloidosis for all the small patches cutout from each myocardial specimen. The developed model highlighted the area in the stained images as highly suspicious, corresponding to where Dylon staining marked amyloid deposition, and discriminated the patches in the evaluation dataset with an area under the curve of 0.965. Provided that the diagnostic criterion for cardiac amyloidosis was defined as a median probability of cardiac amyloidosis >50% in all patches, the model achieved perfect performance in discriminating patients with cardiac amyloidosis from those without it, with an area under the curve of 1.0.

Conclusion

A deep learning model was developed to diagnose cardiac amyloidosis from HE-stained myocardial tissue accurately. Although further prospective validation of this model using HE-stained myocardial tissues from multiple centres is needed, it may help minimize the risk of missing cardiac amyloidosis and maximize the utility of histological diagnosis in clinical practice.

Cardiovascular magnetic resonance-derived left atrioventricular coupling index as a novel prognostic marker for light-chain amyloidosis

BACKGROUND

Left atrioventricular coupling index (LACI) is a novel biomarker, and the prognostic value of LACI to predict cardiovascular events has been validated. The present study aimed to explore the prognostic value of LACI in patients with light-chain (AL) amyloidosis.

METHODS

We prospectively enrolled 179 patients with AL amyloidosis who underwent cardiovascular magnetic resonance imaging between December 2011 and January 2020. LACI was defined as the ratio between the left atrial volume and the left ventricular volume at end-diastole. The primary endpoint was all-cause mortality. Receiver operating characteristic curve was used to identify the optimal cut-off of LACI in predicting all-cause mortality. Univariable and multivariable Cox proportional hazard models were used to assess the association of LACI and primary endpoint.

RESULTS

During a median follow-up of 30 months, 118 (65.9 %) patients with all-cause mortality were documented. LACI was significantly higher in patients with primary endpoint compared to those without primary endpoint (55.4 %, interquartile range: 31.6 %-71.5 % vs. 39.4 %, interquartile range: 24.1 %-54.7 %, p = 0.001). The optimal cut-off for LACI to predict mortality was 49.3 %. In multivariate Cox regression analysis, LACI≥49.3 % (HR 1.907, 95 % CI 1.273-2.857, p = 0.002) was an independent predictor of all-cause mortality. On Kaplan-Meier analysis, patients at advanced Mayo stage (IIIa and IIIb) can be further risk stratified using LACI≥49.3 % (log-rank p = 0.035, p = 0.025).

CONCLUSION

The LACI provides powerful independent prognostic value in AL amyloidosis. The LACI has incremental prognostic value to predict all-cause mortality over the Mayo stage in patients at the advanced Mayo stage.

Prevalence of transthyretin cardiac amyloidosis in patients with aortic stenosis

BACKGROUND

Transthyretin cardiac amyloidosis (ATTRCA) is a prevalent disease, and it can be associated with heart failure (HF), left ventricle hypertrophy (LVH), atrial fibrillation (AF), and aortic stenosis (AS).

AIM

The study aims to detect the prevalence of ATTRCA in the symptomatic AS population.

METHOD

A single-center prospective study screening for ATTRCA in patients diagnosed with symptomatic severe AS undergoing aortic valve (AV) intervention.

RESULTS

A total of 27 patients were enrolled, of which 15 (56%) were men. The mean age was 72.8 ± 10.5 years. HF symptoms were present in 11 (40.7%) patients at New York Heart Association (NYHA) class II, while 15 (55.6%) patients had NYHA class III symptoms. AF was present in 6 (22.2%) patients. The mean left ventricle ejection fraction (LVEF) was 49.4 ± 9.75%, and the mean stroke volume (SV) was 37.4 ± 8.7 ml/m2. The interventricular septal thickness (IVS) was 1.2 ± 0.18 cm. The AS mean gradient was 46 ± 12 mmHg, and the aortic valve area (AVA) was 0.69 ± 0.16 cm2. The ATTRCA was diagnosed by bone scintigraphy in 5 (18.5%) AS patients. Perugini scores of 2 and 3 were considered positive for ATTRCA with the heart/contralateral lung (H/CL) ratio of 1.48 ± 0.35. There was no difference in LVEF between patients with ATTRCA and those without ATTRCA 50 ± 9.8% vs 47 ± 9.3%; p-value 0.55. The ATTRCA had a lower SV of 33.9 ± 6.9 ml/m2 compared to patients without ATTRCA 37.5 ± 8.8 ml/m2; p-value of 0.34. There was no significant difference in LVH or IVS thickness between the patients with ATTRCA and those without ATTRCA. The left ventricle (LV) mass index in ATTRCA was 87 ± 21 g/m2 compared to patients without ATTRCA 98.7 ± 26 g/m2, with a p-value 0.38, and the IVS thickness was 1.1 ± 0.22 cm compared to patients without ATTRCA 1.2 ± 0.18 cm; p-value 0.17. The left atrial (LA) volumes were significantly higher in the ATTRCA group 55.5 ± 25.6 ml/m2 compared to patients without ATTRCA 37.5 ± 10.9 ml/m2 with a significant p-value 0.028. The mean AV gradient was lower in ATTRCA patients at 40.8 ± 8.4 mmHg, compared to patients without ATTRCA at 46.1 ± 12.1 mmHg; it did not reach a statistical significance p-value 0.3. There was a significant difference in LV relative longitudinal strain (LS) between patients with ATTRCA 11.8 ± 3.2 and those without ATTRCA 63.3 ± 22.6 with a significant p-value 0.001.

CONCLUSION

ATTRCA is prevalent in AS patients; bone scintigraphy is recommended for screening AS patients for ATTRCA.

Assessing microvascular dysfunction and predicting long-term prognosis in patients with cardiac amyloidosis by cardiovascular magnetic resonance quantitative stress perfusion

BACKGROUND

Cardiac involvement in light chain amyloidosis (AL) is the main determinant of prognosis. Amyloid can be deposited in the extracellular space and cause an increase in extracellular volume fraction (ECV). At the same time, amyloid can also be deposited in the wall of small vessels and cause microvascular dysfunction. This study sought to investigate the extent of microvascular dysfunction and its incremental prognostic value in cardiac light-chain amyloidosis (AL-CA) by quantitative stress perfusion.

METHODS

A total of 126 AL amyloidosis patients (61.13 ± 8.46 years, 81 male) confirmed by pathology were prospectively recruited. All subjects underwent cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE), T1 mapping, and stress perfusion on a 3T scanner. ECV and myocardial perfusion reserve (MPR) were measured semi-automatically using a dedicated CMR software. Clinical, laboratory, and CMR parameters were analyzed for their prognostic value in the assessment of AL-CA patients. Mortality-associated markers were analyzed by univariate and multivariable Cox regression.

RESULTS

The median follow-up time was 37 (33.6-40.4) months, and 62 patients died. The ECV of survivors was significantly reduced, but the stress myocardial blood flow and MPR were higher (P < 0.001). The MPR of the transmural LGE group was significantly lower than that of the no LGE and subendocardial LGE groups (P < 0.001). In multivariable analysis, ECV, MPR, and LGE were independently predictive. MPR of >1.5 and ECV of ≤53.6% were associated with improved overall survival, both of which provided predictive incremental value in patients with advanced disease. With equal Mayo staging and degree of ECV, MPR improves assessment of patient survival.

CONCLUSION

ECV and MPR showed additive incremental values and further discriminated prognosis of patients in advanced stages. CMR phenotypes with higher ECV and lower MPR had a worse prognosis.

Myocardial Transit Time Mapping by CMR: A Novel Indicator of Microcirculatory Dysfunction in Cardiac Amyloidosis

Cardiac amyloidosis (CA) is characterized by the deposition of amyloid fibrils within the myocardium, resulting in a restrictive physiology. Although microvascular dysfunction is a common feature, it is difficult to assess. This study aimed to explore myocardial transit time (MyoTT) by cardiovascular magnetic resonance (CMR) as a potential novel parameter of microcirculatory dysfunction in CA. This prospective study enrolled 20 CA patients and 20 control subjects. CMR acquisition included cine imaging, pre- and post-contrast T1 mapping, and MyoTT assessment, which was calculated from the time delay in contrast agent arrival between the aortic root and coronary sinus (CS). Compared to the control group, patients with CA exhibited significantly reduced left ventricular (LV) ejection fraction and myocardial strain, an increase in LV global peak wall thickness (LVGPWT), extracellular volume fraction (ECV), and prolonged MyoTT (14.4 ± 3.8 s vs. 7.7 ± 1.5 s, p < 0.001). Moreover, patients at Mayo stage III had a significantly longer MyoTT compared to those at stage I/II. MyoTT showed a positive correlation with the ECV, LVGPWT, and LV global longitudinal strain (LV-GLS) (p < 0.05). The area under the curve (AUC) for MyoTT was 0.962, demonstrating diagnostic performance comparable to that of the ECV (AUC 0.995) and LV-GLS (AUC 0.950) in identifying CA. MyoTT is significantly prolonged in patients with CA, correlating with fibrosis markers, remodeling, and dysfunction. As a novel parameter of coronary microvascular dysfunction (CMD), MyoTT has the potential to be an integral biomarker in multiparametric CMR assessment of CA.

Using machine learning approaches to develop a fast and easy-to-perform diagnostic tool for patients with light chain amyloidosis: a retrospective real-world study

Immunoglobulin light chain (AL) amyloidosis is a severe disorder caused by the accumulation of amyloid fibrils, leading to organ failure. Early diagnosis is crucial to prevent irreversible damage, yet it remains a challenge due to nonspecific symptoms that often appear later in the disease progression. A retrospective study analyzed data collected from 133 AL amyloidosis patients and 271 non-AL patients with similar symptoms but different diagnoses between January 1st, 2017, and September 30th, 2022. Demographic data and laboratory test results were collected. Subsequently, significant features were identified by both logistic regression and independent expert clinical ability. Eventually, logistic regression and four machine learning (ML) algorithms were employed to construct a diagnostic model, utilizing fivefold cross-validation and blind set testing to identify the optimal model. The study successfully identified nine independent predictors of AL amyloidosis patients with kidney or cardiac involvement, respectively. Two models were developed to identify key features that distinguish AL amyloidosis from nephrotic syndrome and hypertrophic cardiomyopathy, respectively. The light gradient boosting machine (LightGBM) model emerged as the most effective, demonstrating superior performance with the area under curve (AUC) of 0.90 in both models, alongside high sensitivity, specificity, and F1-score. This research highlights the potential of using a machine learning-based LightGBM model to facilitate early and accurate diagnosis of AL amyloidosis. The model's effectiveness suggests it could be a valuable tool in clinical settings, aiding in the timely identification of AL amyloidosis among patients with non-specific symptoms. Further validation in diverse populations is recommended to establish its universal applicability.

A Quantitative Diagnostic Method Using 99mTc-pyrophosphate Lateral Planar Images to Distinguish Between Transthyretin Amyloid Cardiomyopathy and False-Positive Images Due to Blood Pools

Background: This study investigated the feasibility of using a quantitative diagnostic method based on 99mTc-pyrophosphate scintigraphy (PYP) lateral planar images to differentiate between PYP-positive (myocardial uptake) and false-positive (blood pool uptake) scans. Methods: The study included 93 consecutive patients with suspected transthyretin amyloid cardiomyopathy (ATTR-CM) who underwent PYP between April 2022 and December 2023. Patients were categorized using planar anterior PYP images according to the Perugini visual grading system; patients with grades ≥ 2 were analyzed. Whether the uptake of the ventricle was in the blood pool or the myocardium was confirmed by transaxial single-photon emission tomography (SPECT). The heart-to-mediastinum ratios (H/M ratio) of the left lateral planar images at 1- and 3-h were calculated by placing a circular region of interest in the heart and cephalodorsal side of the heart to determine optimal cut-off values. Results: Among the PYP images, the study analyzed 15 positives diagnosed as ATTR-CM and 10 false positives. Significant differences were observed in the H/M ratio at 1- and 3-h (both p<0.01), with 100% sensitivity and specificity using cut-off values of 1.22 and 1.21 at 1- and 3-h, respectively. The interclass correlation coefficients (2, 1) between the two readers were 0.919 and 0.958 for the 1- and 3-h H/M ratios, respectively. Conclusions: Lateral planar PYP imaging can exclude PYP false-positive cases caused by blood pools in a simple and quantitative manner using only a 1-h planar image, possibly obviating the need for SPECT imaging.

A review of recent clinical trials to evaluate disease-modifying therapies in the treatment of cardiac amyloidosis

Cardiac amyloidosis (CA) is a serious condition that results in infiltrative cardiomyopathy and heart failure with preserved ejection fraction (HFpEF) that is caused by the extracellular deposition of amyloid fibrils within heart tissue. While many important features of CA have been known for years, its prevalence in elderly patients with HF is increasingly being recognized. Plasma cells produce monoclonal immunoglobulin light chains which results in the formation and aggregation of amyloid fibrils that are responsible for AL amyloidosis. CA is classified as originating from either transthyretin (ATTR) or light chain (AL) amyloidosis. ATTR CA may result from a genetic mutation in the TTR gene, which is inherited (ATTRv), or from age-related deposition from wild-type ATTR (ATTRwt). Cardiac involvement in AL amyloidosis is attributed to either of two mechanisms: the extracellular deposition of amyloid fibril in the myocardium, or direct cardiotoxicity from the fibril aggregates. Typing of amyloid fibrils, a critical determinant of therapy, has also improved with wider availability of laser capture and mass spectrometry of histologic specimens. Specific and accurate evaluation of CA is now possible using cardiac magnetic resonance imaging and bone scintigraphy tracers. Survival in CA has improved markedly as novel chemotherapy agents have become available, but challenges remain in advanced disease. Broadening the amyloid-specific therapeutic landscape to include RNA inhibitors, fibril formation stabilizers and inhibitors, and immunotherapeutic targeting of amyloid deposits holds promise and may improve outcomes in systemic and cardiac amyloidoses. Treatment strategies for CA has recently undergone transformative changes, leading to some progress in outcomes for certain patients. Here, we discuss the basic features of CA as well as the emergence of novel, disease-modifying strategies that have been recently evaluated in clinical trials for the treatment of CA.

Challenges associated with managing treatment complications in an older patient with cardiac amyloidosis

BACKGROUND

Amyloidosis, particularly wild-type transthyretin amyloidosis (ATTRwt), is an increasingly recognized cause of heart failure with preserved ejection fraction in the aging population. The complexity of managing ATTRwt in older patients underscores the necessity for individualized treatment approaches, yet clinical guidelines are lacking. This case report contributes to the understanding of ATTRwt management in the elderly, emphasizing the intricacies of medication tolerance and therapeutic decision-making.

CASE PRESENTATION

An 83-year-old Korean man with a history of hypertension presented with dyspnea and peripheral edema. Investigations including electrocardiography, transthoracic echocardiography, cardiac magnetic resonance, and Technetium pyrophosphate scintigraphy led to a diagnosis of ATTRwt cardiac amyloidosis. Initial management with heart failure medications, including an angiotensin-converting enzyme inhibitor, diuretic, and mineralocorticoid receptor antagonist, was modified due to evolving clinical presentations, such as hypotension and onset of atrial fibrillation. Challenges included intolerance to beta-blockers and bleeding complications from direct oral anticoagulant therapy. The patient's treatment journey highlighted the need for personalized management strategies in older ATTRwt patients.

CONCLUSIONS

This case illustrates the challenges in diagnosing and managing ATTRwt amyloidosis in the elderly, particularly the complexities in medication management due to the patient's age, comorbid conditions, and side effects. It underscores the importance of a tailored approach in managing ATTRwt in older populations and highlights the need for ongoing research and development of treatment strategies tailored to this demographic.

A rare clinical case of systemic AA amyloidosis with cardiac involvement complicating ankylosing spondylitis: a case report

BACKGROUND

Ankylosing spondylitis (AS) is a type of chronic inflammation that is most prevalent in young adults and is characterized by an inflammatory enthesiopathy that gradually develops toward ossification and ankylosis. If inflammation is left unchecked, it can potentially lead to complications such as secondary amyloidosis, also known as AA amyloidosis, involving the deposition of amyloid serum A protein. Our case presents with a thyroid localization of AA amyloidosis which is secondary to this AS. Such a case has been described in only four cases in the literature. Cardiac localization of AA amyloidosis has been exceptionally described in the literature.

CASE PRESENTATION

We report the case of a young patient with severe AS complicated by secondary amyloidosis with thyroid, cardiac, and probably renal localization. He was treated with anti-TNF therapy, and his condition improved significantly.

CONCLUSIONS

Our case presents several localizations of AA amyloidosis secondary to this AS. Although cardiac involvement is rare in secondary AA amyloidosis, it should always be screened for, even in a cardiacly asymptomatic patient.

An interesting case of AL amyloidosis and MM: a complex scenario with cardiac involvement

Our patient presented with complaints of progressive shortness of breath for 1 month. She was diagnosed with a case of infiltrative type of restrictive cardiomyopathy (RCM) based on echocardiography and cardiac MRI findings. Her fat pad biopsy was suggestive of AL type of amyloidosis (AL). She was diagnosed with a case of multiple myeloma (MM) based on bone marrow biopsy findings with 48% plasma cells and a skeletal survey with lytic bone lesions on the skull, thus meeting the Crab criteria. We want to highlight the complex nature of this case and the difficulties associated with making a diagnosis. This case report presents an excellent opportunity to touch on the interesting topics of RCM, amyloidosis and MM.

Coronary artery bypass grafting for triple vessel disease in cardiac amyloidosis

Cardiac amyloidosis is a rare condition with an estimated incidence of 18-55 per 100 000 person-years. It is associated with either immunoglobulin light chain (AL) or transthyretin amyloid (ATTR), both of which result in a restrictive cardiomyopathy complicated initially by diastolic dysfunction and subsequently followed by biventricular systolic heart failure. Untreated cardiac amyloidosis carries an extremely poor prognosis with an estimated median survival time of less than 1 year in AL and 4 years in ATTR amyloidosis. This is the sixth described report of coronary artery bypass grafting in patients with underlying cardiac amyloidosis.

Absolute quantification of myocardial uptake of 99mTc-DPD in patients with cardiac amyloidosis due to transthyretin deposits (ATTR)

PURPOSE

To determine the diagnostic contribution of the absolute quantification of the myocardial deposit of 99mTc-DPD in patients with cardiac amyloidosis due to transthyretin deposits (ATTR).

MATERIALS AND METHODS

SPECT/CT was performed in 41 patients with positive scintigraphic results for ATTR cardiac amyloidosis. The patients were divided into two groups (Perugini grades 2 and 3) and the SUVmax at the level of the bone and both ventricles and the percentage of dose calculated in these areas were calculated. The Student's t-test was used to compare results and the area under the curve (AUC) was calculated to assess differential efficacy and establish discriminatory cut-off points between both groups of patients.

RESULTS

Statistically significant differences were observed in all the study variables, with the exception of bone SUVmax. The differences with the greatest statistical power were observed in the variables SUVmaxRV and the percentage of dose in both ventricles (p < 0.001). The cut-off point obtained for the variable SUVmaxLV was 8.620 (sensitivity 87.9% and specificity 100%; AUC 0.966), while that of the variable SUVmaxRV was 6.195 (sensitivity 81.8% and specificity 100%; AUC 0.955).

CONCLUSIONS

The absolute quantification of myocardial uptake of 99mTc-DPD in the SPECT/CT images of patients with suspected cardiac amyloidosis due to transthyretin deposits represents a new diagnostic tool that allows adequate classification of patients according to the Perugini visual grading scale.

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

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

Changes in Exercise Tolerance over Time in Patients with Transthyretin Amyloidosis Cardiomyopathy Treated with Tafamidis

Tafamidis improves the prognosis of patients with transthyretin amyloidosis cardiomyopathy (ATTR-CM). Additionally, it delays the decline in exercise tolerance, as observed in the six-minute walking test. However, the changes in cardiopulmonary function over time based on cardiopulmonary exercise tests are unclear. Thus, this preliminary study investigated the changes in exercise tolerance after one year of tafamidis treatment using cardiopulmonary exercise testing. Eight patients with ATTR-CM (average age: 77 years; male: n = 7) underwent cardiopulmonary exercise testing at baseline and after one year of tafamidis treatment. All eight patients completed a one-year follow-up. At baseline, the anaerobic threshold oxygen uptake (AT VO_2: 10.9 ± 1.5) and peak VO₂ (14.3 ± 3.0 mL/kg/minute) indicated relatively favorable exercise capacity; however, the minute ventilation/carbon dioxide production (VE/VCO₂ slope), which indicates effective ventilation, showed poor performance (33.7 ± 12.8). One year after tafamidis treatment, frailty, as assessed by the Clinical Frailty Scale, had progressed in seven of eight patients (88%) (P < 0.01), and AT VO₂ and peak VO₂ were significantly reduced (19.2% and 22.3%, respectively; P < 0.05). The VE/VCO₂ slope and peak O₂ pulse decreased nonsignificantly by approximately 20% (P = 0.47, and P = 0.16, respectively). Further, the structure of the ventricles and atrium and the left ventricle ejection fraction on echocardiography did not change. Thus, exercise tolerance in patients with ATTR-CM was reduced after one year despite tafamidis administration. Not only ATTR-CM progression, but also frailty progression may influence this decrease in exercise tolerance. A comprehensive approach, including tafamidis administration and cardiac rehabilitation, is required for further improvement in the exercise capacity of patients with ATTR-CM.

Prognosis of light chain amyloidosis: a multivariable analysis for survival prediction in patients with cardiac involvement proven by endomyocardial biopsy

BACKGROUND

Cardiac involvement is a main determinant of mortality in light chain (AL) amyloidosis but data on survival of patients with cardiac AL amyloidosis proven by endomyocardial biopsy (EMB) are sparse.

METHODS

This study analysed clinical, laboratory, electrocardiography and echocardiographic parameters for their prognostic value in the assessment of patients with AL amyloidosis and cardiac involvement. Patients with AL amyloidosis who had their first visit to the amyloidosis centre at the University Hospital Heidelberg between 2006 and 2017 (n=1628) were filtered for cardiac involvement proven by EMB. In the final cohort, mortality-associated markers were analysed by univariate and multivariable Cox regression. Cut-off values for each parameter were calculated using the survival time.

RESULTS

One-hundred and seventy-four patients could be identified. Median overall survival time was 1.5 years and median follow-up time was 5.2 years. At the end of the investigation period, 115 patients had died. In multivariable analysis, New York Heart Association-functional class >II (HR 1.65; 95% CI 1.09 to 2.50; p=0.019), left ventricular global longitudinal strain (HR 1.12; 95% CI 1.03 to 1.22; p=0.007), left ventricular end-systolic volume (HR 1.02; 95% CI 1.01 to 1.03; p=0.001), systolic pulmonary artery pressure (HR 0.98; 95% CI 0.96 to 0.99; p=0.027), N-terminal pro-B-type natriuretic peptide (HR 1.57; 95% CI 1.17 to 2.11; p=0.003) and difference in free light chains (HR 1.30; 95% CI 1.05 to 1.62; p=0.017) were independently predictive.

CONCLUSION

Among all patients with AL amyloidosis those with cardiac involvement represent a high-risk population with limited therapy options. Therefore, accurate risk stratification is necessary to identify cardiac amyloidosis patients with favourable prognosis. Incorporation of modern imaging techniques into existing or newly developed scoring systems is a promising option that might enable the implementation of risk-adapted therapeutic strategies.

Feature tracking cardiac magnetic resonance imaging to assess cardiac manifestations of systemic diseases

Feature-tracking cardiac magnetic resonance (FT-CMR), with the ability to quantify myocardial deformation, has a unique role in the evaluation of subclinical myocardial abnormalities. This review aimed to evaluate the clinical use of cardiac FT-CMR-based myocardial strain in patients with various systemic diseases with cardiac involvement, such as hypertension, diabetes, cancer-therapy-related toxicities, amyloidosis, systemic scleroderma, myopathies, rheumatoid arthritis, thalassemia major, and coronavirus disease 2019 (COVID-19). We concluded that FT-CMR-derived strain can improve the accuracy of risk stratification and predict cardiac outcomes in patients with systemic diseases prior to symptomatic cardiac dysfunction. Furthermore, FT-CMR is particularly useful for patients with diseases or conditions which are associated with subtle myocardial dysfunction that may not be accurately detected with traditional methods. Compared to patients with cardiovascular diseases, patients with systemic diseases are less likely to undergo regular cardiovascular imaging to detect cardiac defects, whereas cardiac involvement in these patients can lead to major adverse outcomes; hence, the importance of cardiac imaging modalities might be underestimated in this group of patients. In this review, we gathered currently available data on the newly introduced role of FT-CMR in the diagnosis and prognosis of various systemic conditions. Further research is needed to define reference values and establish the role of this sensitive imaging modality, as a robust marker in predicting outcomes across a wide spectrum of patients.

Functional and Metabolic Imaging in Heart Failure with Preserved Ejection Fraction: Promises, Challenges, and Clinical Utility

Heart failure with preserved ejection fraction (HFpEF) is recognised as an increasingly prevalent, morbid and burdensome condition with a poor outlook. Recent advances in both the understanding of HFpEF and the technological ability to image cardiac function and metabolism in humans have simultaneously shone a light on the molecular basis of this complex condition of diastolic dysfunction, and the inflammatory and metabolic changes that are associated with it, typically in the context of a complex patient. This review both makes the case for an integrated assessment of the condition, and highlights that metabolic alteration may be a measurable outcome for novel targeted forms of medical therapy. It furthermore highlights how recent technological advancements and advanced medical imaging techniques have enabled the characterisation of the metabolism and function of HFpEF within patients, at rest and during exercise.

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.

Systemic amyloidosis with amyloid goiter: An autopsy report

Systemic amyloidosis is a rare but potentially lethal disease characterized by amyloid accumulation in all organs. Amyloid goiter is an extremely rare pathological lesion characterized by thyroid gland enlargement with fat deposition due to local or systemic amyloidosis. A 60 s woman with rheumatoid arthritis was found unconscious on her bed and declared dead after failed cardiopulmonary resuscitation. Postmortem computed tomography showed severe enlargement of the heart and thyroid glands, suggestive of cardiac hypertrophy and thyroidism. Histological examination revealed amorphous eosinophilic deposits with parenchymal cell destruction in all organs, including the heart and thyroid gland. Abnormal amorphous deposits in the tissues were positive for amyloid A as noted upon Congo red immunohistochemical staining and birefringence microscopy, confirming systemic amyloidosis with amyloid goiter. Serum biochemical analysis revealed increased levels of C-reactive protein; anti-cyclic citrullinated peptide antibody; creatinine kinase-myoglobin binding and N-terminal pro-brain natriuretic peptide; and thyroglobulin, free triiodothyronine, and free thyroxine, indicating systemic inflammation, active rheumatoid arthritis, heart failure, and destructive hyperthyroidism, respectively. These findings suggested that the cause of death was undiagnosed heart failure due to secondary systemic amyloid A (AA) amyloidosis related to rheumatoid arthritis. In addition, destructive hyperthyroidism caused by systemic AA amyloidosis may have also been one of the causes of death as indicated by cardiac overload. To the best of our knowledge, this is the first forensic autopsy report of cardiac amyloidosis with amyloid goiter. In conclusion, this autopsy report highlights the importance of increased awareness and early intervention for severe but treatable complications of systemic amyloidosis.

Amyloidoses in Onco-Nephrology Practice: A Multidisciplinary Case-Based Conference Report

Introduction and Objective

Amyloidoses are a heterogeneous group of disorders resulting from deposition of amyloid fibrils into extracellular tissues. While the kidneys are one of the most frequent sites of amyloid deposition, amyloid deposits can also affect a wide range of organ systems, including the heart, liver, gastrointestinal tract, and peripheral nerves. The prognosis of amyloidosis, especially with cardiac involvement, remains poor; however, a collaborative approach applying new tools for diagnosis and management may improve outcomes. In September 2021, the Canadian Onco-Nephrology Interest Group hosted a symposium to discuss diagnostic challenges and recent advances in the management of amyloidosis from the perspectives of the nephrologist, cardiologist, and onco-hematologist.

Methods and Sources of Information

Through structured presentations, the group discussed a series of cases highlighting the varied clinical presentations of amyloidoses affecting the kidney and heart. Expert opinions, clinical trial findings, and publication summaries were used to illustrate patient-related and treatment-related considerations in the diagnosis and management of amyloidoses.

Key findings

(1) Overview of the clinical presentation of amyloidoses and the role of specialists in performing timely and accurate diagnostic workup; (2) review of best practices for multidisciplinary management of amyloidosis, including prognostic variables and determinants of treatment response; and (3) update on new and emerging treatments in the management of light chain and amyloid transthyretin amyloidoses.

Limitations

This conference featured multidisciplinary discussion of cases, and learning points reflect the assessments by the involved experts/authors.

Implications

Identification and management of amyloidoses can be facilitated with a multidisciplinary approach and higher index of suspicion from cardiologists, nephrologists, and hemato-oncologists. Increased awareness of clinical presentations and diagnostic algorithms for amyloidosis subtyping will lead to more timely interventions and improved clinical outcomes.

Non-LGE Cardiac Magnetic Resonance Imaging in Patients with Cardiac Amyloidosis

Cardiac involvement is the leading cause of death in patients with cardiac amyloidosis. Early recognition is crucial as it can significantly change the course of the disease. Until now, the imaging modality of choice for diagnosing cardiac amyloidosis has been cardiac magnetic resonance imaging (CMR) with late gadolinium enhancement (LGE). LGE-CMR in patients with cardiac amyloidosis reveals characteristic LGE patterns that lead to a diagnosis while also correlating well with disease prognosis. However, LGE-CMR has numerous drawbacks that the newer CMR modality, T1 mapping, aims to improve. T1 mapping can be further subdivided into native T1 mapping, which does not require the use of contrast, and ECV measurement, which requires the use of contrast. Numerous T1 mapping techniques have been developed, each one with its own advantages and disadvantages when it comes to procedure difficulty and image quality. A literature review to identify relevant published articles was performed by two authors. This review aimed to present the value of T1 mapping in diagnosing cardiac amyloidosis, quantifying the amyloid burden, and evaluating the prognosis of patients with amyloidosis with cardiac involvement.

Amyloidosis: What does pathology offer? The evolving field of tissue biopsy

Since the mid-nineteenth century pathology has followed the convoluted story of amyloidosis, recognized its morphology in tissues and made identification possible using specific staining. Since then, pathology studies have made a significant contribution and advanced knowledge of the disease, so providing valuable information on the pathophysiology of amyloid aggregation and opening the way to clinical studies and non-invasive diagnostic techniques. As amyloidosis is a heterogeneous disease with various organ and tissue deposition patterns, histology evaluation, far from offering a simple yes/no indication of amyloid presence, can provide a wide spectrum of qualitative and quantitative information related to and changing with the etiology of the disease, the comorbidities and the clinical characteristics of patients. With the exception of cardiac transthyretin related amyloidosis cases, which today can be diagnosed using non-biopsy algorithms when stringent clinical criteria are met, tissue biopsy is still an essential tool for a definitive diagnosis in doubtful cases and also to define etiology by typing amyloid fibrils. This review describes the histologic approach to amyloidosis today and the current role of tissue screening biopsy or targeted organ biopsy protocols in the light of present diagnostic algorithms and various clinical situations, with particular focus on endomyocardial and renal biopsies. Special attention is given to techniques for typing amyloid fibril proteins, necessary for the new therapies available today for cardiac transthyretin related amyloidosis and to avoid patients receiving inappropriate chemotherapy in presence of plasma cell dyscrasia unrelated to amyloidosis. As the disease is still burdened with high mortality, the role of tissue biopsy in early diagnosis to assure prompt treatment is also mentioned.

Cardiovascular Magnetic Resonance Imaging-Based Right Atrial Strain Analysis of Cardiac Amyloidosis

Background: Cardiac amyloidosis (CA) manifests in a hypertrophic phenotype with a poor prognosis, making differentiation from hypertrophic cardiomyopathy (HCM) challenging and delaying early treatment. The extent to which magnetic resonance imaging (MRI) quantifies the right atrial strain (RAS) and strain rate (RASR), providing valuable diagnostic information, is not yet clinically established. Aims: This study assesses diagnostic differences in the longitudinal RAS and RASR between CA and HCM patients, control subjects (CTRL) and CA subtypes in addition to the impact of atrial fibrillation (AF) on the right atrial function in CA patients. The RAS and RASR of tricuspid regurgitation (TR) patients are used to assess the potential for diagnostic overlap. Methods: RAS and RASR quantification was conducted via MRI feature-tracking for biopsy-confirmed CA patients with subtypes identified. Strain parameters were compared for CTRL, HCM and TR patients. Post hoc testing identified intergroup differences. Results: In total, 41 CA patients were compared to 47 CTRL, 20 HCM and 31 TR patients. Reservoir (R), conduit and booster RAS and RASRs allow for significant differentiation (p < 0.001) between CA and HCM patients (R: 10.6 ± 14.3% vs. R: 33.5 ± 16.3%) and CTRL (R: 44.6 ± 15.7%). Booster and reservoir RAS and RASRs qualified as reliable diagnostic tests (AUC > 0.8). CA patients with AF, in contrast to sinus rhythm, demonstrated a significantly impaired reservoir RAS and RASR and booster RASR. The discriminative power of RAS for CA vs. TR was insufficient (R: 10.6% ± 14.3% vs. 7.0% ± 6.0%, p = 0.069). Differentiation between 21 transthyretin and 20 light-chain amyloidosis subtypes was not achievable (R: 0.7% ± 1.0% vs. 0.7% ± 1.0%, p = 0.827). Conclusion: The MRI-derived RAS and RASR are impaired in CA patients and may support noninvasive differentiation between CA, HCM and CTRL.

Idiopathic membranous nephropathy with renal amyloidosis: A case report

Background

Immunoglobulin light chain amyloidosis is a clonal, non-proliferative plasma cell disorder, in which fragments of immunoglobulin light chain are deposited in tissues. Clinical features depend on organs involved but can include restrictive cardiomyopathy, nephrotic syndrome, hepatic failure, peripheral/autonomic neuropathy, and atypical multiple myeloma. Membranous nephropathy (MN) is a group of diseases characterized by deposition of immune complexes under the epithelial cells of glomerular basement and diffuse thickening of the basement membrane. Most patients with idiopathic MN (IMN) have been exposed to phospholipase A2 receptor (PLA2R) antigen, and anti-PLA2R antibodies that attack podocytes can be detected in their blood. IMN combined with amyloidosis nephropathy without secondary factors is rare. The present study describes a patient with IMN combined with immunoglobulin light chain amyloidosis nephropathy.

Case report

A 39-year-old man was admitted to our hospital because of weight loss and edema. His clinical manifestation was nephrotic syndrome. Renal pathology revealed MN. A positive Congo red staining and the pathognomonic apple-green birefringence under cross-polarized light were considered to be associated with amyloid nephropathy. Immunofluorescence showed that λ light chain was positive. Heavy chain deposition disease and amyloid-associated protein amyloidosis were excluded by immunofluorescence and immunohistochemistry, respectively. Subsequent examinations showed that his serum was negative for antibodies against the PLA2R, but PLA2R was present in renal tissue. The final diagnosis was IMN with light chain amyloid nephropathy.

Conclusion

Renal amyloidosis accompanied by IMN is uncommon. Attention should be paid to the subtype of the disease and the exclusion of secondary factors. Perfect clinical and pathological examination are helpful for the classification and staging of the disease. Congo red staining, light microscopy, immunofluorescence, immunohistochemistry, electron microscopic examination, pathological tissue staining for PLA2R antigen and testing for anti-PLA2R antibody in serum are helpful.

Differential Diagnosis of Thick Myocardium according to Histologic Features Revealed by Multiparametric Cardiac Magnetic Resonance Imaging

Left ventricular (LV) wall thickening, or LV hypertrophy (LVH), is common and occurs in diverse conditions including hypertrophic cardiomyopathy (HCM), hypertensive heart disease, aortic valve stenosis, lysosomal storage disorders, cardiac amyloidosis, mitochondrial cardiomyopathy, sarcoidosis and athlete's heart. Cardiac magnetic resonance (CMR) imaging provides various tissue contrasts and characteristics that reflect histological changes in the myocardium, such as cellular hypertrophy, cardiomyocyte disarray, interstitial fibrosis, extracellular accumulation of insoluble proteins, intracellular accumulation of fat, and intracellular vacuolar changes. Therefore, CMR imaging may be beneficial in establishing a differential diagnosis of LVH. Although various diseases share LV wall thickening as a common feature, the histologic changes that underscore each disease are distinct. This review focuses on CMR multiparametric myocardial analysis, which may provide clues for the differentiation of thickened myocardium based on the histologic features of HCM and its phenocopies.

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.

Multi-parametric speckle tracking analyses to characterize cardiac amyloidosis: a comparative study of systolic left ventricular longitudinal myocardial mechanics

Cardiac amyloidosis (CAM), the most common cardiac storage disease is associated with significant changes in left-ventricular (LV) morphology and function. To gain particular insights into LV systolic longitudinal myocardial mechanics we investigated seven parameters derived by speckle-tracking-echocardiography (STE) in patients with confirmed CAM (n = 59). The results were compared with those of individuals with healthy heart (n = 150) and another primary myocardial disease with also thickened myocardium and severe diastolic and systolic LV-dysfunction (symptomatic LV-non-compaction-cardiomyopathy, LV-NC, n = 30). In addition to standard echocardiographical measures, the STE-derived data were evaluated and documented utilizing polar-diagrams to obtain overviews of longitudinal myocardial mechanics of the entire LV. Compared with healthy individuals, patients with CAM and LV-NC showed significantly reduced LV-ejection-fraction (EF), global longitudinal systolic peak-strain, strain-rate, and displacement. Pre-systolic stretch-index, post-systolic index, and the EF/global peak-longitudinal-strain-ratio (EF/S) were increased. In contrast to healthy-hearts and the LV-NC group only patients with CAM demonstrated significantly reduced time-to-peak systolic longitudinal strain and time-to-peak strain-rate. Although the level of the segmental values in longitudinal mechanics was significantly different between the groups, comparable intraventricular baso-apical parameter-gradients were found for systolic longitudinal peak-strain and strain-rate, pre-systolic-stretch-index, post-systolic-index, and peak systolic displacement. Compared to ATTR-amyloidosis (ATTR-CAM), patients with AL-amyloidosis (AL-CAM) demonstrated significantly lower end-diastolic and end-systolic LV-volumes, LV-mass-indices, relative apical strain, time-to-peak systolic longitudinal strain, and time-to-peak longitudinal strain-rate. CAM and LV-NC demonstrated altered myocardial mechanics with significantly different STE-derived echocardiographical parameters. ATTR-amyloidosis and AL-amyloidosis had at least significantly different time-to-peak strain, time-to-peak strain-rate and relative apical sparing values.

The Emerging Roles of the β-Secretase BACE1 and the Long Non-coding RNA BACE1-AS in Human Diseases: A Focus on Neurodegenerative Diseases and Cancer

The β-Secretase (BACE1) is widely studied to be particularly involved in amyloid deposition, a process known as the pathogenic pathway in neurodegenerative diseases. Therefore, BACE1 expression is frequently reported to be upregulated in brain samples of the patients with Alzheimer’s disease (AD). BACE1 expression is regulated by BACE1-AS, a long non-coding RNA (lncRNA), which is transcribed in the opposite direction to its locus. BACE1-AS positively regulates the BACE1 expression, and their expression levels are regulated in physiological processes, such as brain and vascular homeostasis, although their roles in the regulation of amyloidogenic process have been studied further. BACE1-AS dysregulation is reported consistent with BACE1 in a number of human diseases, such as AD, Parkinson’s disease (PD), heart failure (HF), and mild cognitive impairment. BACE1 or less BACE1-AS inhibition has shown therapeutic potentials particularly in decreasing manifestations of amyloid-linked neurodegenerative diseases. Here, we have reviewed the role of lncRNA BACE1 and BACE1-AS in a number of human diseases focusing on neurodegenerative disorders, particularly, AD.

A Risk Score to Diagnose Cardiac Involvement and Provide Prognosis Information in Patients at Risk of Cardiac Light-Chain Amyloidosis

Background

Cardiac light-chain amyloidosis (AL CA) portends poor prognosis. Contrast cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) imaging is an important tool in recognizing AL CA. But contraindications to contrast CMR would significantly restrict its clinical application value. Our study aims to construct a convenient risk score to help identify cardiac involvement in patients at risk of AL CA. Moreover, we also investigate whether this risk score could provide prognosis information.

Materials and Methods

Sixty-three patients at risk of AL CA were retrospectively included in our study. Basic clinical characters, lab results, 12-lead electrocardiogram data, and cardiac magnetic resonance image data were collected. AL CA was diagnosed according to typical CA LGE pattern. Logistic analysis was used to figure out predictive parameters of AL CA and their β coefficients, further constructing the risk score. Receiver operating characteristics (ROC) curve was used to find the cut-off point best distinguishing AL CA+ from AL CA–patients. Bootstrapping was used for internal validation. All patients were divided into high-risk and low-risk group according to the diagnostic cut-off point, and followed up for survival information. Kaplan-Meier plots and log-rank test were performed to analyze if this score had prognostic value.

Results

The risk score finally consisted of 4 parameters: pericardial effusion (PE) (1 point), low electrocardiographic QRS voltages (LQRSV) (1 point), CMR-derived impaired global radial strain (GRS) (<15.14%) (1 point) and increased left ventricular maximum wall thickness (LVMWT) (>13 mm) (2 points). Total score ranged from 0 to 5 points. A cut-off point of 1.5 showed highest accuracy in diagnosing AL CA with an AUC of 0.961 (95% CI: 0.924–0.997, sensitivity: 90.6%, specificity: 83.9%). Kaplan-Meier plots and log-rank test showed that the high-risk group had significantly poor overall survival rates.

Conclusion

In patients at risk of AL CA, a risk score incorporating the presence of PE, LQRSV, and CMR-derived impaired GRS and increased LVMWT is predictive of a diagnosis of AL CA by LGE criteria. This risk score may be helpful especially when contrast CMR is not available or contraindicated, and further studies should be considered to validate this score.

Magnetic Resonance Imaging in Cardiac Amyloidosis: Unraveling the Stealth Entity

Amyloidosis is a systemic disease involving many organs. Cardiac involvement is a significant cause of morbidity and mortality in these patients. Diagnosis of cardiac amyloidosis is based on endomyocardial biopsy which however is invasive and associated with complications. Noninvasive methods of diagnosis include magnetic resonance imaging (MRI) with various methods and sequences involved. Our study aims at describing MRI features of cardiac amyloidosis including new imaging sequences and to prognosticate the patients based on imaging features. We included 35 patients with suspected cardiac amyloidosis who underwent MRI at our center over 4 years. All images were retrieved from our archive and assessed by an experienced radiologist. Common morphological features in our patients included increased wall thickness of left ventricle (LV) (16. 1 ± 4.1 mm), right ventricle (RV) (6.3 ± 1.1 mm), and interatrial septum (6.2 ± 0.8 mm). Global late gadolinium enhancement (LGE) ( n  = 21 [65%]) including subendocardial or transmural was the most common pattern followed by patchy enhancement. Global transmural LGE was associated with worse prognosis. Four types of myocardial nulling patterns were observed on postcontrast time to invert (TI) scout imaging: normal nulling pattern (myocardium nulls after blood and coincident with spleen) and abnormal nulling pattern (ANP) which is further divided into three types: Type 1-myocardium nulls before blood pool but coincident with spleen, Type 2-myocardium nulling coincident with blood but not coincident with spleen, and Type 3-features of both Type 1 and Type 2. Type 3 ANP was the most common ( n  = 23) nulling pattern in our patients. Cardiac MRI is an essential in noninvasive diagnosis of cardiac amyloidosis. Transmural global LGE serves as a poor prognosticator in these patients. "Three-tier" TI scout imaging is essential to avoid false-negative enhancement results. Type 3 ANP is the most specific nulling pattern in cardiac amyloidosis.

Pharmacodynamic evaluation and safety assessment of treatment with antibodies to serum amyloid P component in patients with cardiac amyloidosis: an open-label Phase 2 study and an adjunctive immuno-PET imaging study

BACKGROUND

In a Phase I study treatment with the serum amyloid P component (SAP) depleter miridesap followed by monoclonal antibody to SAP (dezamizumab) showed removal of amyloid from liver, spleen and kidney in patients with systemic amyloidosis. We report results from a Phase 2 study and concurrent immuno-positron emission tomography (PET) study assessing efficacy, pharmacodynamics, pharmacokinetics, safety and cardiac uptake (of dezamizumab) following the same intervention in patients with cardiac amyloidosis.

METHODS

Both were uncontrolled open-label studies. After SAP depletion with miridesap, patients received ≤ 6 monthly doses of dezamizumab in the Phase 2 trial (n = 7), ≤ 2 doses of non-radiolabelled dezamizumab plus [89Zr]Zr-dezamizumab (total mass dose of 80 mg at session 1 and 500 mg at session 2) in the immuno-PET study (n = 2). Primary endpoints of the Phase 2 study were changed from baseline to follow-up (at 8 weeks) in left ventricular mass (LVM) by cardiac magnetic resonance imaging and safety. Primary endpoint of the immuno-PET study was [89Zr]Zr-dezamizumab cardiac uptake assessed via PET.

RESULTS

Dezamizumab produced no appreciable or consistent reduction in LVM nor improvement in cardiac function in the Phase 2 study. In the immuno-PET study, measurable cardiac uptake of [89Zr]Zr-dezamizumab, although seen in both patients, was moderate to low. Uptake was notably lower in the patient with higher LVM. Treatment-associated rash with cutaneous small-vessel vasculitis was observed in both studies. Abdominal large-vessel vasculitis after initial dezamizumab dosing (300 mg) occurred in the first patient with immunoglobulin light chain amyloidosis enrolled in the Phase 2 study. Symptom resolution was nearly complete within 24 h of intravenous methylprednisolone and dezamizumab discontinuation; abdominal computed tomography imaging showed vasculitis resolution by 8 weeks.

CONCLUSIONS

Unlike previous observations of visceral amyloid reduction, there was no appreciable evidence of amyloid removal in patients with cardiac amyloidosis in this Phase 2 trial, potentially related to limited cardiac uptake of dezamizumab as demonstrated in the immuno-PET study. The benefit-risk assessment for dezamizumab in cardiac amyloidosis was considered unfavourable after the incidence of large-vessel vasculitis and development for this indication was terminated. Trial registration NCT03044353 (2 February 2017) and NCT03417830 (25 January 2018).

Physiology, Diagnosis and Treatment of Cardiac Light Chain Amyloidosis

AL (light-chain) amyloidosis is a systemic disease in which amyloid fibers are formed from kappa or lambda immunoglobulin light chains, or fragments thereof, produced by a neoplastic clone of plasmocytes. The produced protein is deposited in tissues and organs in the form of extracellular deposits, which leads to impairment of their functions and, consequently, to death. Despite the development of research on pathogenesis and therapy, the mortality rate of patients with late diagnosed amyloidosis is 30%. The diagnosis is delayed due to the complex clinical picture and the slow progression of the disease. This is the type of amyloidosis that most often contributes to cardiac lesions and causes cardiac amyloidosis (CA). Early diagnosis and correct identification of the type of amyloid plays a crucial role in the planning and effectiveness of therapy. In addition to standard histological studies based on Congo red staining, diagnostics are enriched by tests to determine the degree of cardiac involvement. In this paper, we discuss current diagnostic methods used in cardiac light chain amyloidosis and the latest therapies that contribute to an improved patient prognosis.

Protein Aggregation and Self Assembly in Health and Disease

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Self-attachment of proteins leading to the formation of highly insoluble protein oligomers and aggregates has become an important focus of research owing to its diverse implications in pathophysiology and diseases. This has become a more frequent phenomenon in most neurological and neurodegenerative diseases as well as in dementia. In recent years such event of protein aggregation has linked to other disease conditions, disorders or adverse health conditions. Interestingly, aggregation of protein also plays role in development, growth or metabolism. Most often physiological proteins are initially bio-synthesised in native or nascent geometrical forms or conformations but later they undergo specific folding pattern and thereby acquire a stable configuration that is biologically relevant and active. It is highly important that these proteins remain in their biologically active configuration in order to exert their functional properties. Any alteration or change to this structural configuration can be detrimental to their specific functions and may cause pathological consequences leading to the onset of diseases or disorders. Several factors such as the action of chaperones, binding partners, physiological metal ions, pH level, temperature, ionic strength, interfacial exposure (solid-liquid, liquid-liquid, gas-liquid), mutation and post translational modification, chemical changes, interaction with small molecules such as lipids, hormones, etc. and solvent environment have been either identified or proposed as important factors in conferring the ultimate status of protein structure and configuration. Among many misfolding protein conformations, self-assembly or aggregation is the most significant. It leads to the formation of highly oligomeric self-aggregates that precipitate and interfere with many biochemical processes with serious pathological consequences. The most common implication of protein aggregation leading to the formation of deposits / plaques of various morphological types is the onset of neurological and neurodegenerative diseases that include Alzheimer’s, Parkinson’s, Huntington, ALS (Amyotrophic Lateral Sclerosis), CJD (Creutzfeldt Jakob Dementia), Prion diseases, Amyloidosis and other forms of dementia. However increasingly studies revealed that protein aggregation may also be associated with other diseases such as cancer, type 2 diabetes, renal, corneal and cardiovascular diseases. Protein aggregation diseases are now considered as part of “Proteinopathy” which refers to conditions where proteins become structurally abnormal or fail to fold into stable normal configurations. In this review, we reflect on various aspects of protein self-aggregation, potential underlying causes, mechanism, role of secondary structures, pathological consequences and possible intervention strategies as reported in published literatures.

Myocardial Injury in Multiple Myeloma Patients With Preserved Left Ventricular Ejection Fraction: Noninvasive Left Ventricular Pressure-Strain Myocardial Work

Introduction

Over one-half of patients with multiple myeloma (MM) die of heart failure or arrhythmia. Left ventricular ejection fraction (LVEF) is used to describe left ventricular systolic function. However, depressed LVEF means advanced stage of left ventricular dysfunction in patients with MM. Left ventricular pressure-strain-derived myocardial work (LVMW) is a novel and noninvasive method for evaluating LV function related to LV dynamic pressure load. MW is assessed by LV MW index (LVMWI), constructive work, wasted work, and LV MW efficiency (LVMWE). In this study, we aimed to investigate the value of LVMW in cardiac function assessment and clinical prognosis of MM patients with preserved LVEF.

Methods

A total of 72 subjects, including 40 untreated MM patients with preserved EF (including the thick wall and normal wall groups) and 32 non-MM patients, were enrolled in this study. Laboratory data and clinical history of all the patients were collected. All the patients underwent comprehensive echocardiographic examinations and then LVMWI and LVMWE were calculated. Moreover, cardiac adverse events (CAEs) were observed in MM patients treated with bortezomib-based therapy after 6 months and the prognostic value of MW was assessed.

Results

(1) LV myocardial global work index (GWI), myocardial global work efficiency (GWE), and global longitudinal strain (GLS) were lower in the thick wall group of patients with MM compared with the normal wall group and controls. Cardiac segmental analysis of LVMWI in patients with MM showed an apical sparing pattern; (2) The area under the curve (AUC) of GWE for judging the disease severity based on the Revised International Staging System (R-ISS) was 0.835 (95% CI: 0.684–0.933, p < 0.05); (3) GWE, Lg_dFLC, and arrhythmia were independent risk factors of CAEs. The AUC of GWE for predicting CAEs in MM patients treated with bortezomib-based therapy for 6 months follow-up was 0.896 (95% CI: 0.758–0.970, p < 0.05).

Conclusion

MM Patients with preserved EF had subclinical LV systolic dysfunction, which was worse in the thick wall group. LVMWI was presented as “apical sparing” in patients with MM. A lower LVGWE may have a predictive value for CAEs in patients with MM after 6 months of follow-up.

Features and evolution of patients with systemic amyloidosis and cardiac involvement

Objective

To estimate the prevalence of cardiac amyloidosis in patients with systemic amyloidosis. Compare survival rates based on whether they show cardiac involvement.

Methods

A retrospective cohort study of patients with systemic amyloidosis from the Institutional Amyloidosis Registry of the Hospital Italian of Buenos Aires from 2010 to 2019. Heart involvement is considered to be the presence of symptoms and/or images consistent with amyloidosis, and there is no other reason to explain it. All deaths due to causes were evaluated. The survival rate was estimated by Kaplan-Meier. Cox regression model was used to evaluate factors related to mortality. Heart transplantation was evaluated in a competitive risk regression model.

Results

The prevalence of heart involvement is 63%. For the group with heart damage, the death rate was 14/1,000 person-months, and for patients without damage, the death rate was 5/1,000 person-months. The 5-year overall survival rate for patients with heart involvement was 44%, while that for patients without damage was 67% (p = 0.02). The original HR for heart involvement was 2.09 (p = 0.02). Age showed that HRa was 1.06 (p <0.01). The sub-HR estimated by the competitive risk regression model are 1.86 (95% CI 0.99-3.49) p = 0.05.

Conclusion

Cardiac involvement is an important prognostic factor in patients with amyloidosis.

High Serum Carbohydrate Antigen (CA) 125 Level Is Associated With Poor Prognosis in Patients With Light-Chain Cardiac Amyloidosis

Background and Aims: Patients with light-chain cardiac amyloidosis (AL-CA) are characterized by high levels of serum carbohydrate antigen 125 (CA 125). However, studies have not explored the correlation between CA 125 and AL-CA. The aim of this study was to explore the clinical implications of an increase in CA 125 in patients with AL-CA.

Methods and Results: A total of 95 patients diagnosed with AL-CA at the Second Xiangya Hospital were enrolled in this study. Out of the 95 patients with AL-CA, 57 (60%) patients had elevated serum CA 125 levels. The mean age was 59.7 ± 10.0 years with 44 (77.2%) men in the high serum CA 125 group, and 61.8 ± 9.6 years with 28 (73.7%) men in the normal group. Patients with high CA 125 showed higher rates of polyserositis (79.3% vs. 60.5%, p = 0.03), higher levels of hemoglobin (117.4 ± 21.9 g/L vs. 106.08 ± 25.1 g/L, p = 0.03), serum potassium (4.11 ± 0.47 mmol/L vs. 3.97 ± 0.40 mmol/L, p = 0.049), low-density lipoprotein-cholesterol (3.0 ± 1.6 mmol/L vs. 2.3 ± 1.10 mmol/L, p = 0.01), and cardiac troponin T (96.0 pg/mL vs. 91.9 pg/mL, p = 0.005). The median overall survival times for patients with high or normal serum CA 125 were 5 and 25 months, respectively (p = 0.045). Multivariate Cox hazard analysis showed that treatment without chemotherapy (HR 1.694, 95% CI 1.121–2.562, p = 0.012) and CA 125 (HR 1.002, 95% CI 1.000–1.004, p = 0.020) was correlated with high all-cause mortality. The time-dependent receiver operating characteristic (t-ROC) curve showed that the prediction accuracy of CA 125 was not inferior to that of cardiac troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and lactate dehydrogenase (LDH) based on the area under the curve.

Conclusions: CA 125 is a novel prognostic predictor. High serum CA 125 values are correlated with low overall survival, and the accuracy of predicting prognosis is similar to that of traditional biomarkers in AL-CA.

Serial scanning with 99mTc-3, 3-diphosphono-1, 2-propanodicarboxylic acid (99mTc-DPD) for early detection of cardiac amyloid deposition and prediction of clinical worsening in subjects carrying a transthyretin gene mutation

BACKGROUND

To determine the capability of 99mTc-DPD scintigraphy to detect early cardiac involvement and predict clinical worsening in transthyretin (TTR) gene mutation patients.

METHODS

Eleven mutated subjects with normal interventricular septum (IVS) thickness, NT-proBNP level and no cardiac symptoms underwent three seriate 99mTc-DPD scans (visually and semiquantitatively analyzed), and was followed-up for 5-8-years.

RESULTS

Six patients showed no myocardial accumulation in all scans. Increased IVS thickness occurring in one patient 4 years after the last scan was the only abnormal finding in these patients; no cardiac symptoms developed during the follow-up. In three patients, cardiac radiotracer uptake was found at enrollment; other laboratory/instrumental abnormal findings occurred later and cardiac symptoms developed during the follow-up period. Two patients had a negative 99mTc-DPD scan at enrollment and showed cardiac uptake in the following scans. Increased mean left-ventricular (LV) wall thickness was found 3 years after positive scintigraphy; NT-proBNP increased later in one patient. These patients developed cardiac symptoms during the follow-up period.

CONCLUSIONS

99mTc-DPD scan detects cardiac involvement in subjects with TTR gene mutation earlier than ECG, echocardiography and biochemical markers, occurring some years before the fulfillment of current diagnostic criteria for cardiac amyloidosis. A positive 99mTc-DPD scan predicts cardiac symptoms onset.

Cardiac Amyloidosis: Diagnostic Tools for a Challenging Disease

Amyloidosis is a group of diseases in which amyloid fibrils build up in tissues, leading to organ dysfunction. Cardiac involvement is observed in immunoglobulin light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR) and, when it occurs, the prognosis worsens. Cardiac tissue infiltration can lead to restrictive cardiomyopathy with clinical signs of diastolic heart failure, without reduction of ejection fraction (HFpEF). The aim of multiple and less invasive diagnostic tests is to discern peculiar characteristics and reach the diagnosis without performing an invasive endomyocardial biopsy. These diagnostic tools allow early diagnosis, and they are crucial to best benefit from target therapy. In this review article, we describe the mechanism behind amyloid fibril formation, infiltration of tissues, and consequent clinical signs, focusing on the diagnostic tools and the red flags to obtain a diagnosis.

Cardiac Amyloidosis: Presentations, Diagnostic Work-up and Collaborative Approach for Comprehensive Clinical Management

Cardiac amyloidosis is a systemic disease characterized by continuous deposition of misfolded proteins called amyloid fibrils in the extracellular space which result in restrictive cardiomyopathy. The most common form of cardiac amyloidosis is light chain (AL) cardiac amyloidosis, a result of continuous deposition of misfolded monoclonal immunoglobulin light chains. Transthyretin-related cardiac amyloidosis (ATTR) results from a point mutation in the transthyretin gene in an autosomal dominant fashion and presents phenotypically similar to AL cardiac amyloidosis. Cardiac amyloidosis is being increasingly recognized due to the advancements in diagnostic cardiac imaging and pharmacotherapy. Clinicians should maintain a high index of suspicion among patients with unexplained diastolic heart failure because earlier diagnosis will allow for the implementation of disease-altering therapy. With established targeted drug therapies and further breakthroughs in immunotherapy, the potential impact of diagnostic and therapeutic advancements on morbidity and mortality of patients with cardiac amyloidosis is promising.

AL type cardiac amyloidosis: a devastating fatal disease

Introduction

Cardiac amyloidosis is a rare entity with a grave prognosis. Due to the low index of suspicion secondary to non-specific symptoms, it is often diagnosed at an advanced stage with multi-organ involvement.

Methods

We report a case of systemic AL amyloidosis with predominant cardiac and renal involvement associated with multiple myeloma.

Case Summary

A 60-year-old male presented with progressive anasarca, orthopnea and weight gain over 8 months. On clinical examination, 3+ pitting edema was found in bilateral extremities and scrotum. Serum N-type proBNP and troponin T were elevated, and EKG showed diffuse low voltage QRS, right axis deviation, and 1^st degree AV block. Echocardiography revealed granular myocardium, biventricular hypertrophy, bi-atrial dilation and apical sparing pattern on global longitudinal strain which was suggestive of cardiac amyloidosis. Light chain assessment showed elevated kappa and lambda chains with kappa to lambda ratio of 16.2. Endomyocardial biopsy revealed AL type cardiac amyloidosis, and bone marrow biopsy confirmed the diagnosis of multiple myeloma. He received six cycles of bortezomib, cyclophosphamide, and dexamethasone but continued to deteriorate. He experienced an episode of cardiac arrest following which he had a return of spontaneous circulation but due to poor prognosis, the family opted for pursuing comfort measures only.

Conclusions

Cardiac involvement in AL type amyloidosis imparts significant morbidity and mortality. The management of cardiac amyloidosis entails a multidisciplinary approach with an emphasis on cardiology and oncology. Despite the novel diagnostic modalities and treatment regimens, the outcome for AL-type cardiac amyloidosis remains poor.

AL-amyloidosis with cardiac involvement. Diagnostic capabilities of non-invasive methods

There are presented the literature data and a description of the clinical course of the disease in isolated/predominant cardiac amyloidosis. Amyloid cardiomyopathy is the most common phenocopy of hypertrophic cardiomyopathy. The modern possibilities of non-invasive diagnostics using osteoscintigraphy for the differential diagnosis between amyloid cardiomyopathy caused by AL- and transthyretin amyloidosis are described in detail.