The findings of electrocardiography in patients with cardiac amyloidosis

Current Therapies and Future Horizons in Cardiac Amyloidosis Treatment

PURPOSE OF REVIEW

Cardiac amyloidosis (CA) is a condition characterized by misfolding and extracellular deposition of proteins, leading to organ dysfunction. While numerous forms of CA exist, two subtypes dominate clinical prevalence: Transthyretin amyloid (ATTR) and immunoglobulin light chain amyloid.

RECENT FINDINGS

The current scientific landscape reflects the urgency to advance therapeutic interventions with over 100 ongoing clinical trials. Heart failure treatment is affected by CA phenotype with poor tolerance of otherwise frequently used medications. Treating comorbidities including atrial fibrillation and valvular disease remains a challenge in CA, driven by technical difficulties and uncertain outcomes. Tafamidis is the first ATTR-stabilizer approved with a rapidly growing rate of clinical use. In parallel, various new therapeutic classes are in late-stage clinical trials including silencers, antibodies and genetic therapy. Managing CA is a critical challenge for future heart failure care. This review delineates the current standard-of-care and scientific landscape of CA therapy.

Electrocardiographic abnormalities in patients with cardiomyopathies

Abnormalities in impulse generation and transmission are among the first signs of cardiac remodeling in cardiomyopathies. Accordingly, 12-lead electrocardiogram (ECG) of patients with cardiomyopathies may show multiple abnormalities. Some findings are suggestive of specific disorders, such as the discrepancy between QRS voltages and left ventricular (LV) mass for cardiac amyloidosis or the inverted T waves in the right precordial leads for arrhythmogenic cardiomyopathy. Other findings are less sensitive and/or specific, but may orient toward a specific diagnosis in a patient with a specific phenotype, such as an increased LV wall thickness or a dilated LV. A "cardiomyopathy-oriented" mindset to ECG reading is important to detect the possible signs of an underlying cardiomyopathy and to interpret correctly the meaning of these alterations, which differs in patients with cardiomyopathies or other conditions.

Electrocardiographic heterogeneity of patients with variant transthyretin amyloid cardiomyopathy: Genotype-phenotype correlations

BACKGORUND

Hereditary transthyretin(vATTR) cardiac amyloidosis has extremely different features according to the type of transthyretin(TTR) mutation. Data about electrocardiographic findings(ECG) in vATTR are limited and not informative of genotype correlation. Aim of this study is to analyze ECG characteristics and their correlation to clinical and echocardiographic aspects in patients with vATTR, focusing on different TTR mutations.

METHODS AND RESULTS

This is a multicentric, retrospective, observational study performed in six Italian referral centres. We divided patients in two groups, according to the previously described phenotypic manifestations of the TTR mutation. Of 64 patients with vATTR, 23(36%) had prevalent cardiac(PC) TTR mutations and 41(64%) patients had a prevalent neurological(PN) TTR mutations. Patients with PC mutations were more frequently males and older, with advanced NAC staging. At baseline ECG, atrial fibrillation was more common in patients with PC, while pacemaker induced rhythm in PN mutations. PQ and QRS durations were longer and voltage to mass ratio was lower in PC mutations. Different TTR mutations tend to have distinctive ECG features.

CONCLUSIONS

ECG in vATTR is extremely heterogeneous and the specific mutations are associated with distinct instrumental and clinical features. The differences between PN and PC vATTR are only partially explained by the different degree of cardiac infiltration.

Linear discriminant analysis on electrocardiogram achieved classification of cardiac involvement status in amyloid light-chain amyloidosis

OBJECTIVES

Cardiac amyloidosis (CA) is the most crucial determinant of amyloid light-chain (AL) amyloidosis patients' prognosis. We attempted cardiac involvement prediction by 12‑lead electrocardiograph (ECG) and echocardiography (UCG) in AL amyloidosis patients.

MATERIALS AND METHODS

Fifty patients with histologically confirmed AL amyloidosis underwent gadolinium-enhanced magnetic resonance imaging (Gd-MRI), and CA was assessed using late gadolinium enhancement. ECG and UCG parameters were measured on admission. Fisher's linear discriminant analysis was used to create a model for predicting CA using the ECG and UCG parameters.

RESULTS

Prediction by five ECG parameters [QTc(B), QRS-T-angle, III-QRS, aVF-QRS, and V3-R] showed the best performance. Average sensitivity and specificity in the modeling sets, utilizing a linear discriminator based on these five variables, were 99.2 % and 96.8 % and in validation sets, 94.2 % and 90.3 %, respectively. In addition, we tested this model on an additional 26-patient cohort and survival analysis using the Kaplan-Meier method, and significant differences between CA positively predicted and negatively predicted patients were observed.

CONCLUSION

Here, we suggest the application of a condensed classical multivariate statistical technique for the diagnosis of CA. It can be used as a guide to invasive endomyocardial biopsy for those in whom Gd-MRI is contraindicated and as a guide for repeat Gd-MRI in follow-up of AL amyloidosis.

World Heart Federation Consensus on Transthyretin Amyloidosis Cardiomyopathy (ATTR-CM)

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and fatal condition that requires early diagnosis, management, and specific treatment. The availability of new disease-modifying therapies has made successful treatment a reality. Transthyretin amyloid cardiomyopathy can be either age-related (wild-type form) or caused by mutations in the TTR gene (genetic, hereditary forms). It is a systemic disease, and while the genetic forms may exhibit a variety of symptoms, a predominant cardiac phenotype is often present. This document aims to provide an overview of ATTR-CM amyloidosis focusing on cardiac involvement, which is the most critical factor for prognosis. It will discuss the available tools for early diagnosis and patient management, given that specific treatments are more effective in the early stages of the disease, and will highlight the importance of a multidisciplinary approach and of specialized amyloidosis centres. To accomplish these goals, the World Heart Federation assembled a panel of 18 expert clinicians specialized in TTR amyloidosis from 13 countries, along with a representative from the Amyloidosis Alliance, a patient advocacy group. This document is based on a review of published literature, expert opinions, registries data, patients' perspectives, treatment options, and ongoing developments, as well as the progress made possible via the existence of centres of excellence. From the patients' perspective, increasing disease awareness is crucial to achieving an early and accurate diagnosis. Patients also seek to receive care at specialized amyloidosis centres and be fully informed about their treatment and prognosis.

Postdevelopment Performance and Validation of the Artificial Intelligence-Enhanced Electrocardiogram for Detection of Cardiac Amyloidosis

BACKGROUND

We have previously applied artificial intelligence (AI) to an electrocardiogram (ECG) to detect cardiac amyloidosis (CA).

OBJECTIVES

In this validation study, the authors observe the postdevelopment performance of the AI-enhanced ECG to detect CA with respect to multiple potential confounders.

METHODS

Amyloid patients diagnosed after algorithm development (June 2019-January 2022) with a 12-lead ECG were identified (n = 440) and were required to have CA. A 15:1 age- and sex-matched control group was identified (n = 6,600). Area under the receiver operating characteristic (AUC) was determined for the cohort and subgroups.

RESULTS

The average age was 70.4 ± 10.3 years, 25.0% were female, and most patients were White (91.3%). In this validation, the AI-ECG for amyloidosis had an AUC of 0.84 (95% CI: 0.82-0.86) for the overall cohort and between amyloid subtypes, which is a slight decrease from the original study (AUC 0.91). White, Black, and patients of "other" races had similar algorithm performance (AUC >0.81) with a decreased performance for Hispanic patients (AUC 0.66). Algorithm performance shift over time was not observed. Low ECG voltage and infarct pattern exhibited high AUC (>0.90), while left ventricular hypertrophy and left bundle branch block demonstrated lesser performance (AUC 0.75 and 0.76, respectively).

CONCLUSIONS

The AI-ECG for the detection of CA maintained an overall strong performance with respect to patient age, sex, race, and amyloid subtype. Lower performance was noted in left bundle branch block, left ventricular hypertrophy, and ethnically diverse populations emphasizing the need for subgroup-specific validation efforts.

Anderson-Fabry disease cardiomyopathy: an update on epidemiology, diagnostic approach, management and monitoring strategies

Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by deficient activity of the enzyme alpha-galactosidase. While AFD is recognized as a progressive multi-system disorder, infiltrative cardiomyopathy causing a number of cardiovascular manifestations is recognized as an important complication of this disease. AFD affects both men and women, although the clinical presentation typically varies by sex, with men presenting at a younger age with more neurologic and renal phenotype and women developing a later onset variant with more cardiovascular manifestations. AFD is an important cause of increased myocardial wall thickness, and advances in imaging, in particular cardiac magnetic resonance imaging and T1 mapping techniques, have improved the ability to identify this disease non-invasively. Diagnosis is confirmed by the presence of low alpha-galactosidase activity and identification of a mutation in the GLA gene. Enzyme replacement therapy remains the mainstay of disease modifying therapy, with two formulations currently approved. In addition, newer treatments such as oral chaperone therapy are now available for select patients, with a number of other investigational therapies in development. The availability of these therapies has significantly improved outcomes for AFD patients. Improved survival and the availability of multiple agents has presented new clinical dilemmas regarding disease monitoring and surveillance using clinical, imaging and laboratory biomarkers, in addition to improved approaches to managing cardiovascular risk factors and AFD complications. This review will provide an update on clinical recognition and diagnostic approaches including differentiation from other causes of increased ventricular wall thickness, in addition to modern strategies for management and follow-up.

Prompt diagnosis of a wild-type transthyretin cardiac amyloidosis: Role of multimodality imaging

Amyloidosis cardiomyopathy is a rare and underdiagnosed disease characterized by amyloid fibril deposition in the myocardium. The diagnosis of cardiac amyloidosis is often delayed due to a lack of awareness and the necessity of biopsy to confirm the diagnosis. Recent advances in cardiovascular imaging modalities have enhanced earlier recognition of this disease. A 66-year-old man experiences progressive shortness of breath for two weeks. Laboratory testing was significant for an elevation of cardiac biomarkers (creatine kinase: 522 U/L, troponin I: 0.10 ng/mL) and NT-pro-BNP (5074 pg/mL). He was diagnosed with acute coronary syndrome and received stent deployment. Nonetheless, progressive shortness of breath recurred in 2 months. Transthoracic echocardiography (TTE) demonstrated an increased left ventricular (LV) wall thickness with apical sparing. Cardiac magnetic resonance (CMR) imaging demonstrated high native T1 value, increased extracellular volume fraction as well as diffused subendocardial late gadolinium enhancement. Technetium-99m pyrophosphate (99mTc-PYP) scintigraphy, endomyocardial biopsy (EMB), and the genetic study confirmed the diagnosis of wild-type transthyretin amyloidosis (ATTRwt). The nonspecific clinical manifestations, lack of diagnostic biomarkers, and the rarity of systemic amyloidosis usually lead to delayed diagnosis and treatment. Our objective is to emphasize the role of multimodalities imaging in reducing delays to the diagnosis of cardiac amyloidosis.

A systematic review and meta-analysis of the prevalence of transthyretin amyloidosis in heart failure with preserved ejection fraction

BACKGROUND

Heart failure with preserved ejection fraction is a complex clinical syndrome marked by different phenotypes and related comorbidities. Transthyretin amyloidosis is an underestimated phenotype. We aim to evaluate the prevalence of transthyretin amyloidosis in heart failure with preserved ejection fraction.

METHODS

This meta-analysis was conducted according to PRISMA guidelines. A search strategy was designed to utilize PubMed/Medline, EMBASE, and Google scholar to locate studies whose primary objective was to analyze the prevalence of transthyretin amyloidosis in heart failure preserved ejection fraction.

RESULTS

Of 271 studies initially identified, 5 studies comprising 670 patients were included in the final analysis. The prevalence of transthyretin amyloidosis was 11%. Patients with transthyretin amyloid cardiomyopathy were more likely to be males (RR 1.38; 95% CI 1.09 to 1.75; P<0.01; I²=37%), and more likely to have low voltage criteria on ECG (RR 2.98; 95% CI 1.03 to 8.58; P=0.04; I²=75%) compared with transthyretin negative group. They also have higher SMD of age (SMD 0.73; 95% CI 0.48 to 0.97; P<0.01; I²=0%), and NT-proBNP (SMD 0.48; 95% CI 0.02 to 0.93; P=0.04; I²=36%) compared with transthyretin negative group. On reported echocardiogram, they have higher SMD of mass index (SMD 0.77; 95% CI 0.27 to 1.27; P<0.01; I²=65%), posterior wall thickness (SMD 0.92; 95% CI 0.62 to 1.21; P<0.01; I²=0%), and septal wall thickness (SMD 1.49; 95% CI 0.65 to 2.32; P<0.01; I²=87%) compared with transthyretin negative group.

CONCLUSION

Transthyretin amyloidosis affects 11% of HFpEF patients. Therefore, screening HFpEF patients at risk of cardiac amyloidosis is warranted.

The revolution of ATTR amyloidosis in cardiology: certainties, gray zones and perspectives

Transthyretin (TTR) is a tetrameric protein synthesized mostly by the liver. As a result of gene mutations or as an ageing-related phenomenon, TTR molecules may misfold and deposit in the heart and in other organs as amyloid fibrils. Amyloid transthyretin cardiac amyloidosis (ATTR-CA) manifests typically as left ventricular pseudohypertrophy and/or heart failure with preserved ejection fraction and is an underdiagnosed disorder affecting quality of life and prognosis. This justifies the current search for novel tools for early diagnosis and accurate risk prediction, as well as for safe and effective therapies. In this review we will provide an overview of the main unsolved issues and the most promising research lines on ATTR-CA, ranging from the mechanisms of amyloid formation to therapies.

Diagnostic Tools for Cardiac Amyloidosis: A Pragmatic Comparison of Pathology, Imaging and Laboratories

Cardiac amyloidosis (CA) is a complex disease considered to be the most common underdiagnosed form of restrictive cardiomyopathy. Accumulation of misfolded proteins called amyloid fibrils in the extracellular space results in clinical deterioration and late diagnosis is associated with morbidity and mortality. Both types of this disease, light chain CA and transthyretin-related CA share many cardiac and extracardiac features that compromise multiple organs such as kidneys, musculoskeletal system, autonomic nervous system, and gastrointestinal tract. Early diagnosis and detection of CA are imperative. Clinicians should maintain a high degree of suspicion among patients with unexplained diastolic heart failure to implement different disease-altering therapies at the early stages of the disease. In this article, we provided a comprehensive review of multiple invasive and non-invasive cardiac imaging modalities with their respective degrees of sensitivities and specificity.

Optimising cardiovascular care of patients with multiple myeloma

Multiple myeloma (MM) is the third most common haematological malignancy, with increasing prevalence over recent years. Advances in therapy have improved survival, changing the clinical course of MM into a chronic condition and meaning that management of comorbidities is fundamental to improve clinical outcomes. Cardiovascular (CV) events affect up to 7.5% of individuals with MM, due to a combination of patient, disease and treatment-related factors and adversely impact survival. MM typically affects older people, many with pre-existing CV risk factors or established CV disease, and the disease itself can cause renal impairment, anaemia and hyperviscosity, which exacerabate these further. Up to 15% of patients with MM develop systemic amyloidosis, with prognosis determined by the extent of cardiac involvement. Management of MM generally involves administration of multiple treatment lines over several years as disease progresses, with many drug classes associated with adverse CV effects including high rates of venous and arterial thrombosis alongside heart failure. Recommendations for holistic management of patients with MM now include routine baseline risk stratification including ECG and echocardiography and administration of thromboprophylaxis drugs for patients treated with immunomodulatory drugs. Close surveillance of high-risk patients with collaboration between haematology and cardiology is required, with prompt investigation in the event of CV symptoms, in order to identify and treat complications early. Decisions regarding discontinuation of cardiotoxic therapies should be made in a multidisciplinary setting, taking into account the severity of the complication, prognosis, expected benefits and the availability of effective alternatives.

Machine learning-derived electrocardiographic algorithm for the detection of cardiac amyloidosis

BACKGROUND

Diagnosis of cardiac amyloidosis (CA) requires advanced imaging techniques. Typical surface ECG patterns have been described, but their diagnostic abilities are limited.

OBJECTIVE

The aim was to perform a thorough electrophysiological characterisation of patients with CA and derive an easy-to-use tool for diagnosis.

METHODS

We applied electrocardiographic imaging (ECGI) to acquire electroanatomical maps in patients with CA and controls. A machine learning approach was then used to decipher the complex data sets obtained and generate a surface ECG-based diagnostic tool.

FINDINGS

Areas of low voltage were localised in the basal inferior regions of both ventricles and the remaining right ventricular segments in CA. The earliest epicardial breakthrough of myocardial activation was visualised on the right ventricle. Potential maps revealed an accelerated and diffuse propagation pattern. We correlated the results from ECGI with 12-lead ECG recordings. Ventricular activation correlated best with R-peak timing in leads V1-V3. Epicardial voltage showed a strong positive correlation with R-peak amplitude in the inferior leads II, III and aVF. Respective surface ECG leads showed two characteristic patterns. Ten blinded cardiologists were asked to identify patients with CA by analysing 12-lead ECGs before and after training on the defined ECG patterns. Training led to significant improvements in the detection rate of CA, with an area under the curve of 0.69 before and 0.97 after training.

INTERPRETATION

Using a machine learning approach, an ECG-based tool was developed from detailed electroanatomical mapping of patients with CA. The ECG algorithm is simple and has proven helpful to suspect CA without the aid of advanced imaging modalities.

Advances in Diagnosis and Treatment of Cardiac and Renal Amyloidosis

Diagnoses of amyloidosis are increasing annually, and advances in bone scintigraphy and cardiac MRI accompanied by development of nonbiopsy diagnostic criteria have specifically led to a huge increase in transthyretin amyloidosis cardiomyopathy (ATTR-CM) diagnoses worldwide. Tafamidis use is increasing, and there are several ongoing phase III clinical trials of novel agents that promise to transform the treatment landscape for patients with ATTR-CM. In systemic light chain (AL) amyloidosis, more effective chemotherapeutic agents continue to improve patient outcomes. Accelerating the removal of amyloid deposits to accompany these therapies remains the holy grail. However, in the meantime, early diagnosis is undoubtedly key in improving patient outcomes.

Cardiac Amyloidosis with Discordant QRS Voltage between Frontal and Precordial Leads

Among the different types, immunoglobulin light chain (AL) cardiac amyloidosis is associated with the highest morbidity and mortality. The outcome, however, is significantly better when an early diagnosis is made and treatment initiated promptly. We present a case of cardiac amyloidosis with left ventricular hypertrophy criteria on the electrocardiogram. After 9 months of follow-up, the patient developed low voltage in the limb leads, while still maintaining the Cornell criteria for left ventricular hypertrophy as well. The relative apical sparing by the disease process, as well as decreased cancellation of the opposing left ventricular walls could be responsible for this phenomenon. The discordance between the voltage in the frontal leads and precordial leads, when present in conjunction with other findings, may be helpful in raising the clinical suspicion of cardiac amyloidosis.

Expert consensus on the monitoring of transthyretin amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a life-threatening condition with a heterogeneous clinical presentation. The recent availability of treatment for ATTR-CM has stimulated increased awareness of the disease and patient identification. Stratification of patients with ATTR-CM is critical for optimal management and treatment; however, monitoring disease progression is challenging and currently lacks best-practice guidance. In this report, experts with experience in treating amyloidosis and ATTR-CM developed consensus recommendations for monitoring the course of patients with ATTR-CM and proposed meaningful thresholds and frequency for specific parameters. A set of 11 measurable features across three separate domains were evaluated: (i) clinical and functional endpoints, (ii) biomarkers and laboratory markers, and (iii) imaging and electrocardiographic parameters. Experts recommended that one marker from each of the three domains provides the minimum requirements for assessing disease progression. Assessment of cardiac disease status should be part of a multiparametric evaluation in which progression, stability or improvement of other involved systems in transthyretin amyloidosis should also be considered. Additional data from placebo arms of clinical trials and future studies assessing ATTR-CM will help to elucidate, refine and define these and other measurements.

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.

Cardiac Amyloidosis for the Primary Care Provider: A Practical Review to Promote Earlier Recognition of Disease

Cardiac amyloidosis is increasingly recognized as an underdiagnosed cause of heart failure. Diagnostic delays of up to 3 years from symptom onset may occur, and patients may be evaluated by more than 5 specialists prior to receiving the correct diagnosis. Newly available therapies improve clinical outcomes by preventing amyloid fibril deposition and are usually more effective in early stages of disease, making early diagnosis essential. Better awareness among primary care providers of the clinical presentation and modern treatment landscape is essential to improve timely diagnosis and early treatment of this disease. In this review, we provide practical guidance on the epidemiology, clinical manifestations, diagnostic evaluation, and treatment of transthyretin and light chain cardiac amyloidosis to promote earlier disease recognition among primary care providers.

Cardiac Amyloid for the Internist

Cardiac amyloid is an uncommon cause of diastolic dysfunction the recognition of which requires the internist to have clinical suspicion to guide diagnosis and treatment. Cardiac amyloid is an infiltrative cardiomyopathy with significant morbidity and mortality. Appropriate diagnosis is important because management of cardiac amyloid differs from typical heart failure with preserved ejection fraction. An astute internist must be able to recognize common findings of cardiac amyloidosis. Here we present a case of a patient presenting with diastolic heart failure and the steps leading towards diagnosis and subsequent treatment.

Case report regarding the evolution of electrocardiographic and echocardiographic features in cardiac amyloidosis

Background

Cardiac amyloidosis is an important cause for heart failure with preserved ejection fraction. It is often under diagnosed due to the fact that clinicians do not always recognize the specific diagnostic findings associated with this disease, also leading to the wrong diagnosis. When left untreated further irreversible organ dysfunction occurs, with high morbidity and mortality rates.

Case summary

A 71-year-old patient presented with progressive exertional dyspnoea and angina pectoris at the outpatient clinic. Medical history noted a percutaneous coronary intervention of the right coronary artery due to stable angina pectoris. The electrocardiogram showed low voltage in the limb leads and pseudo-infarct pattern in the precordial leads. Echocardiographic findings included left and right ventricular hypertrophy, decreased left ventricular systolic function, restrictive diastolic function, and ‘relative’ apical sparing of the left ventricle. This led to the suspicion of cardiac amyloidosis, which was confirmed with a positive bone scintigraphy using ^99mTechnecium-DPD and the absence of monoclonal proteins. Treatment with Tafamidis was initiated.

Discussion

Electrocardiographic findings suggestive of cardiac amyloidosis are low voltage in the limb leads and/or a pseudo-infarct pattern in the precordial leads. Important echocardiographic findings are left and right ventricular hypertrophy, restrictive diastolic function, ‘relative’ apical sparing of the left ventricle and impaired left atrial strain. The next step in confirming the diagnosis is ^99mTechnecium PYP/DPD/HMDP bone scintigraphy and testing for monoclonal proteins. The diagnosis ATTR amyloidosis is confirmed by the combination of positive bone scintigraphy (Perugini Grade 2 or 3) and the absence of monoclonal proteins, without the necessity of performing an endomyocardial biopsy.

Cardiac Amyloidosis Detected on Imaging of Patients with Heart Failure

Case series

Patients: Male, 63-year-old • Female, 72-year-old • Female, 55-year-old

Final Diagnosis: Amyloid light-chain amyloidosis • cardiac amyloidosis • cardiomyopathy • heart failure • primary AL amyloidosis

Symptoms: Aphasia • dyspnea • heart failure • thrombosis • tongue mass

Medication: —

Clinical Procedure: Biopsy • chemotherapy • echocardiography

Specialty: Cardiology • Hematology

Role of Echocardiography in the Diagnosis of Light Chain Amyloidosis: A Case Report and Review of Literature

Amyloid light-chain (AL) amyloidosis is a rare disease with a broad clinical presentation that depends on the affected organ. Cardiac amyloidosis, a rare entity, can present as an isolated form of AL amyloidosis. This isolated form is considered a challenging diagnosis due to its broad nonspecific clinical presentation. In this article, we report a case of an adult male who presented with shortness of breath and was found to have many specific features of cardiac amyloidosis on echocardiography. In absence of other organ involvement, the results of the echocardiography directed us toward the diagnosis of AL cardiac amyloidosis. In addition, we highlight the role of echocardiography in the diagnosis of cardiac amyloidosis.

Evaluation of relationships between results of electrocardiography and echocardiography in 341 chimpanzees (Pan troglodytes)

OBJECTIVE

To examine potential relationships between ECG characteristics and echocardiographic measures of cardiac structure in chimpanzees (Pan troglodytes).

ANIMALS

341 chimpanzees (175 males and 166 females) from 5 sanctuaries and 2 zoological collections.

PROCEDURES

Chimpanzees were anesthetized for routine health examinations between May 2011 and July 2017 as part of the International Primate Heart Project and, during the same anesthetic events, underwent 12-lead ECG and transthoracic echocardiographic assessments. Relationships between results for ECG and those for echocardiographic measures of atrial areas, left ventricular internal diameter in diastole (LVIDd), and mean left ventricular wall thicknesses (MLVWT) were assessed with correlational analysis, then multiple linear regression analyses were used to create hierarchical models to predict cardiac structure from ECG findings.

RESULTS

Findings indicated correlations (r = -0.231 to 0.310) between results for ECG variables and echocardiographic measures. The duration and amplitude of P waves in lead II had the strongest correlations with atrial areas. The Sokolow-Lyon criteria, QRS-complex duration, and R-wave amplitude in leads V₆ and II had the strongest correlations with MLVWT, whereas the Sokolow-Lyon criteria, QRS-complex duration, and S-wave amplitude in leads V₂ and V₁ had the strongest correlations with LVIDd. However, the ECG predictive models that were generated only accounted for 17%, 7%, 11%, and 8% of the variance in the right atrial end-systolic area, left atrial end-systolic area, MLVWT, and LVIDd, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that relationships existed between ECG findings and cardiac morphology in the chimpanzees of the present study; however, further research is required to examine whether the predictive models generated can be modified to improve their clinical utility.

Cardiac amyloidosis: in search of the ideal diagnostic tool

BACKGROUND

Cardiac amyloidosis (CA) is due to amyloid deposition in the myocardium. Transthyretin (ATTR) and light-chain (AL) amyloidosis are the main types of CA. Here, we present the clinical and imaging findings in patients with CA and discuss the controversies with the aim of finding the ideal diagnostic tool.

METHODS

Ten patients suspected of having CA on the basis of electrocardiographic (ECG) and echocardiographic findings were evaluated via cardiovascular magnetic resonance imaging (CMR; 1.5 T) using cine, late gadolinium enhancement (LGE), T1, T2 mapping, and extracellular volume fraction. N‑terminal pro-B-type natriuretic peptide (NT-proBNP) levels were also assessed in all patients.

RESULTS

All ten patients had an echocardiogram suggestive of CA. The CMR study documented ventricular hypertrophy leading to small ventricular volumes, as assessed by echocardiography. Diffuse subendocardial LGE, supporting the diagnosis of CA, was identified in all except one patient, who had subepicardial LGE due to myocarditis that was verified by endomyocardial biopsy (EMB). Right ventricular (RV) involvement was identified in four of the ten patients, whose condition deteriorated rapidly over the next 6 months. The NT-proBNP levels were >332 pg/ml in all except two patients. Light-chain amyloidosis was identified via fat tissue biopsy in two patients and through renal biopsy in one patient. In two patients with positive technetium-99m, EMB confirmed the diagnosis of ATTR.

CONCLUSION

NT-proBNP may be a sensitive but nonspecific biomarker for assessing CA. However, CMR is the only imaging modality that can assess the pathophysiologic background of cardiac hypertrophy and the severity of CA, irrespective of NT-proBNP level.

Amyloidosis cardiomyopathy: update in the diagnosis and treatment of the most common types

PURPOSE OF REVIEW

The present article provides an update about the recent advances in the diagnosis and management of the most common types of cardiac amyloidosis, including light chain, wild-type transthyretin (ATTRwt), and mutant transthyretin (ATTRm).

RECENT FINDINGS

The document reviews the utility of diagnostic tools including innovative echocardiographic indices, magnetic resonance T1 mapping and measurement of extracellular volume, and the role and validation of bone scintigraphy for the noninvasive assessment of ATTR amyloidosis. It summarizes the data about therapies for light chain amyloidosis including bortezomib regimens and also novel disease modifying therapies for ATTR amyloidosis such as gene silencers, transthyretin stabilizers, and degraders of amyloid fibrils.

SUMMARY

The present review provides the readers with the necessary tools in order to recognize and diagnose cardiac amyloidosis early and introduces the recent advances in management that are improving the outcomes of a condition that was considered to be untreatable.

Automated and Interpretable Patient ECG Profiles for Disease Detection, Tracking, and Discovery

Supplemental Digital Content is available in the text.

The ECG remains the most widely used diagnostic test for characterization of cardiac structure and electrical activity. We hypothesized that parallel advances in computing power, machine learning algorithms, and availability of large-scale data could substantially expand the clinical inferences derived from the ECG while at the same time preserving interpretability for medical decision-making.

Low voltage criteria EKG as a harbinger of systemic disease

AL amyloidosis is due to deposition of protein derived from immunoglobulin light chain fragments. It is a systemic disorder in which deposition of plasma proteins can adversely affect function of the heart, liver, kidneys, and peripheral nerves. Deposition in the heart results in a decrease in the amplitude of the electrical activity of the heart and can be an early clue to the diagnosis.

A 63-year-old male admitted for volume overload was found to have nephrotic range proteinuria, progressive renal insufficiency (Creatinine 4.0 increased from his baseline 0.9), and hypoalbuminemia. On exam, he had diffuse anasarca and peripheral neuropathy. A renal biopsy showed AL amyloidosis, lambda related, involving the glomeruli, interstitium, and arterial walls. Bone marrow biopsy showed 30% plasma cells with lambda light chain predominance. Serum free light chains were elevated. Lamda was 11.50 mg/dL and kappa was 5.12 mg/dL. In retrospective review of his chart, an EKG with low voltage and anterior pseudo-infarct pattern was first apparent on an admission for stroke two years prior. Echocardiogram showed mild concentric left ventricular hypertrophy. The patient was started on chemotherapy with Bortezomib.

The differential of a low-voltage EKG includes many common pulmonary and chest wall (COPD, obesity) as well as pericardial diseases (effusions), but also important rarer infiltrative diseases including sarcoidosis and amyloidosis. Amyloidosis of the heart can cause progressive irreversible heart failure, but its progress can be altered if identified early. Physicians should consider amyloidosis when faced with a low-voltage EKG along with systemic symptoms including nephrotic range proteinuria, peripheral neuropathy, hepatosplenomegaly, and macroglossia.

Emerging Techniques for Cardiovascular PET

The application of positron emission tomography (PET) to cardiac disease has yielded tremendous developments in the evaluation of coronary artery, myocardial, and valvular heart disease over the past several decades. These advances have included development of new radiotracers, incremental technological improvements, and coupling of PET with other non-invasive cardiac imaging modalities. The current era has seen rapid, successive and wide-ranging advances in PET myocardial perfusion and metabolic imaging. This review will address emerging techniques in cardiovascular PET imaging, including the measurement of absolute myocardial blood flow (MBF), use of novel tracers, and other advances in heart failure, infection imaging, and valvular disease.

Cardiac amyloidosis: A case report and review of literature

BACKGROUND

Cardiac amyloidosis, a disease caused by the precipitation of amyloid proteins in the myocardial extracellular matrix has been historically difficult to diagnose due to lack of specific clinical manifestations and necessity of biopsy to demonstrate amyloid deposition. However, advances in cardiovascular imaging techniques have facilitated earlier recognition of this disease. In addition, while once thought of as incurable, treatment strategies are emerging for cardiac amyloidosis, making early diagnosis essential.

CASE SUMMARY

We outline the case of a 73 years old African American female who was admitted with sudden onset shortness of breath and found to be in cardiogenic shock. Cardiac amyloidosis was suspected due to discordance between electrocardiogram and echocardiogram findings and this was subsequently confirmed with the aid of scintigraphy and an endomyocardial biopsy.

CONCLUSION

Our objective is to highlight the diagnostic evaluation and clinical implications of cardiac amyloidosis.

Recent advances in the noninvasive strategies of cardiac amyloidosis

The heart, like any organ in the body, is susceptible to amyloid deposition. Although more than 30 types of protein can cause amyloidosis, only two types commonly deposit in the ventricular myocardium: amyloid light chain and amyloid transthyretin. Amyloid cardiomyopathy is usually a major determinant of patient outcomes, and the diagnosis of heart involvement can be often relatively under-diagnosed, owing to nonspecific presenting symptoms and signs at a subclinical stage. The diagnosis of cardiac amyloidosis is usually performed by endomyocardial biopsy; however, the invasive nature and related high-risk complications restrict its wide use in clinical settings. Recently, with the advent of innovative techniques used for evaluating cardiac amyloidosis, noninvasive methods become increasingly important, especially in earlier diagnosis, distinguishing typing, risk prediction and response to treatment. Here, we will review recent developments in the noninvasive methods used in the assessment of cardiac amyloidosis, focused on the laboratory biomarkers and imaging modalities.

Amyloid cardiomyopathy

Amyloidosis is a heterogeneous group of diseases characterized by the deposition of amyloid. It is caused by extracellular deposition of insoluble fibrils with beta-pleated sheet configuration. The protein misfolding abnormalities result in amyloid fibrils and may manifest as primary, secondary, or familial amyloidosis. Amyloid deposition can occur in multiple organs (eg, heart, liver, kidney, skin, eyes, lungs, nervous system) resulting in a variety of clinical manifestations. Cardiac involvement can occur as part of a systemic disease or as a localized phenomenon. Cardiac involvement in all types of amyloidosis represents a major negative prognostic factor. Early diagnosis, multi-disciplinary cooperation and proper therapy are key aspects of care for patients with amyloid cardiomyopathy. Early diagnosis is crucial, especially in AL amyloidosis, as patients with advanced heart disease are unsuitable candidates for modern, effective hematological treatment including autologous stem cell transplantation. Despite signal development in diagnostics and therapy, the prognosis for patients with advanced cardiac involvement remains poor. This article is an overview of amyloidosis, providing information about the characteristics of cardiac amyloidosis, and present a structured approach to diagnosis, treatment and prognosis of this condition.

Contribution of Electrocardiogram in the Differentiation of Cardiac Amyloidosis and Nonobstructive Hypertrophic Cardiomyopathy

Due to similar manifestations of hypertensive ventricular walls and abnormal ventricular compliance, it is difficult to differentiate cardiac amyloidosis (CA) and nonobstructive hypertrophic cardiomyopathy (NOHCM) clinically. The purpose of the study was to investigate the value of electrocardiography (ECG) in the differentiation of the two diseases.

METHODS

We enrolled 46 consecutive patients with CA and 64 patients with NOHCM and compared their ECG characteristics.Compared with NOHCM patients, the ECG of CA patients showed more low voltage on limb leads (50% versus 1.6%), atrioventricular block (21.7% versus 4.7%), pseudo-infarct pattern (84.8% versus 39.1%), and longer QRS duration (104 ± 25 versus 98 ± 14 ms) (all P < 0.05). The QRS complex voltage of avR demonstrated the highest diagnostic performance (sensitivity 89%, specificity 94%, cut-off value 0.45mV) as assessed by ROC analysis. The combination of the R wave voltage of I and avR reached a sensitivity of 95% and a specificity of 87% for the diagnosis of amyloidosis.Compared with NOHCM patients, CA patients showed more ECG characteristics of low voltage on limb leads, pseudo-infarct pattern, atrioventricular block, and longer QRS duration. The combination of the R wave voltage of I, avR, and QRS was of diagnostic value in the differentiation of CA from NOHCM.

Discordant Electrocardiogram Left Ventricular Wall Thickness and Strain Findings in Influenza Myocarditis

A 42-year-old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.

Improving strategies for the diagnosis of cardiac amyloidosis

Amyloidosis refers to a group of rare but potentially fatal, protein misfolding diseases. The heart is frequently involved in the most common types, that is, immunoglobulin light chain and transthyretin amyloidosis and is the single most important predictor of patient outcomes. A major limitation in improving patient outcomes, in addition to developing novel therapeutics, is the late diagnosis of the disease. Once suspected, an organ for biopsy should be targeted and the amyloid type should be identified by mass spectrometry. An endomyocardial biopsy should be offered if cardiac involvement is in doubt. Echocardiography, MRI and nuclear imaging can provide valuable diagnostic and prognostic information and can secure the diagnosis if amyloid has been identified in an extracardiac tissue.

Atrial fibrillation in amyloidotic cardiomyopathy: prevalence, incidence, risk factors and prognostic role

BACKGROUND

Although atrial fibrillation (AF) is a known complication of amyloidotic cardiomyopathy (AC), a precise pathophysiological and prognostic characterization is not available. We therefore aimed to assess prevalence, incidence, risk factors and prognostic significance of AF in light-chain (AL), hereditary transthyretin-related (m-ATTR) and non-mutant transthyretin-related (wt-ATTR) AC.

METHODS

Retrospective study of 262 patients with AC (123 AL, 94 m-ATTR, 45 wt-ATTR) from a single center.

RESULTS

AF prevalence was 15% (AL 9%, m-ATTR 11%, wt-ATTR 40%). During a median follow-up of 1.2 years 11 patients developed AF (2.1% person-years). Age, heart failure (HF), left ventricular (LV) ejection fraction, renal involvement, left atrial size and right atrial pressure were independently associated with AF. AF was associated with incident HF but not with increased mortality. All AF patients were prescribed warfarin and none suffered thromboembolic events.

CONCLUSIONS

In AC the prevalence of AF varies widely according to etiology with a mean value of 15% that reaches 40% in wt-ATTR amyloidosis. Age, HF, LV ejection fraction, left atrial size and right atrial pressure were the main independent risk factors, while wall thickness and etiology were not the main independent risk factors. AF does not seem to impact all-cause mortality but was strongly associated with prevalent and incident HF.

Recent advances in the diagnosis and management of cardiac amyloidosis

The heart is commonly involved in various forms of amyloidosis and cardiomyopathy is a major cause of morbidity and mortality in these patients. Diagnosis of cardiac amyloidosis is often delayed due to nonspecific presenting symptoms and failure to recognize early signs of amyloid heart disease on routine cardiac imaging. Treatment of cardiac amyloidosis depends upon the type of amyloid protein. Systemic chemotherapy with or without stem cell transplantation is used to treat immunoglobulin-related amyloidosis and liver transplantation is used for familial transthyretin amyloidosis in select patients. Clinical trials with siRNA for the treatment of transthyretin amyloid cardiomyopathies and amyloid protein stabilizers are ongoing. Prognosis depends on the type of amyloid protein with poorer outcomes noted in immunoglobulin light-chain amyloidosis. Supportive care forms the cornerstone of management and advancements in cardiac imaging and proteomics are expected to positively impact our ability to diagnose, prognosticate and treat cardiac amyloidosis.