Tissue Doppler and strain imaging: a new tool for early detection of cardiac amyloidosis

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.

A Review of Cardiac amyloidosis: Presentation, Diagnosis, and Treatment

Amyloidosis is a group of disorders that can affect almost any organ due to the misfolding of proteins with their subsequent deposition in various tissues, leading to various disease manifestations based on the location. When the heart is involved, amyloidosis can manifest with a multitude of presentations such as heart failure, arrhythmias, orthostatic hypotension, syncope, and pre-syncope. Diagnosis of cardiac amyloidosis can be difficult due to the non-specific nature of symptoms and the relative rarity of the disease. Amyloidosis can remain undiagnosed for years, leading to its high morbidity and mortality due to this delay in diagnosis. Newer imaging modalities, such as cardiac magnetic resonance imaging, advanced echocardiography, and biomarkers, make a timely cardiac amyloidosis diagnosis more feasible. Many treatment options are available, which have provided new hope for this patient population. This manuscript will review the pathology, diagnosis, and treatment options available for cardiac amyloidosis and provide a comprehensive overview of this complicated disease process.

Aortic Valve Stenosis and Cardiac Amyloidosis: A Misleading Association

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

Diagnosing Cardiac Amyloidosis: From Heart Failure to Electrical Storm

Cardiac amyloidosis is a condition when amyloid fibers are deposited in the extracellular space of the heart causing tachyarrhythmias, heart failure, or sudden cardiac death. We present a 71-year-old woman presenting with dyspnea on admission. Echocardiogram revealed diastolic heart failure and left ventricular hypertrophy with strain pattern concerning for an infiltrative process. She was discharged with diuretic therapy and scheduled for a cardiac magnetic resonance imaging. One week after discharge, she was readmitted with progressive shortness of breath and syncope. She was found to be in shock and had multiple episodes of cardiac arrest with both ventricular tachycardia and pulseless electrical activity. She developed electrical storm and eventually passed within 24 hours. Autopsy revealed gross cardiomegaly and left ventricular hypertrophy with Congo red staining revealing amyloid fibrils with apple-green birefringence. This case demonstrates the rapid progression of cardiac amyloidosis from acute-onset diastolic heart failure to uncontrollable ventricular tachycardia, and eventually death. We review the literature regarding multiple diagnostic modalities that facilitate the confirmation of cardiac amyloidosis.

Pseudoexfoliation syndrome: Are the eyes the mirror of the heart?

INTRODUCTION

Pseudoexfoliation syndrome (PEX) is a disease characterized by the accumulation of fibrillary material in the extracellular matrix in the eye and many tissues. Myocardial involvement occurs as in other storage diseases. Speckle tracking echocardiography is a quantitative echocardiography modality that enables the detection of subclinical changes that cannot be detected by standard echocardiographic evaluation. In this study, we aimed to evaluate potential subclinical myocardial dysfunction in PEX patients by speckle tracking echocardiography.

METHODS AND RESULTS

The study group consisting of 29 cardiac asymptomatic pseudoexfoliation syndromes and 30 healthy volunteers were included in this case-control cross-sectional study. Detailed echocardiographic evaluations and strain analyses of all participants were performed. Concerning standard echocardiographic parameters, there was only a marginally significant difference between the two groups in the e' mean wave, and it was lower in the PEX group than the control group (0.07 ± 0.03, 0.10 ± 0.08, respectively, P = .06). However, in strain echocardiography, the global longitudinal strain (GLS) value was observed to be significantly lower in the PEX group than the control group (-17.02 ± 2.02, -19.29 ± 2.26, respectively P < .001). GLS was observed to be an independent predictor in the multivariable logistic regression model made to determine independent predictors of PEX syndrome (OR = 0.59, CI = 0.418-0.832, P = .003).

CONCLUSION

Subclinical myocardial involvement in PEX syndrome, in which standard echocardiographic techniques are blinded, can be detected by the strain echocardiography. PEX causes deterioration in the deformation parameters of the left ventricle. Systemic involvement should not be forgotten in patients with PEX and cardiac functions should be monitored.

Predictors of cardiac involvement and survival in patients with primary systemic light-chain amyloidosis: roles of the clinical, chemical, and 3-D speckle tracking echocardiography parameters

Background

Light-chain (AL) amyloidosis is the most common type of systemic amyloidosis with poor prognosis. Currently, the predictors of cardiac involvement and prognostic staging systems are primarily based on conventional echocardiography and serological biomarkers. We used three-dimensional speckle tracking echocardiography (STE-3D) measurements of strain, hypothesizing that it could detect cardiac involvement and aid in prediction of mortality.

Methods

We retrospectively analysed 74 consecutive patients with biopsy-proven AL amyloidosis. Among them, 42 showed possible cardiac involvement and 32 without cardiac involvement. LV global longitudinal strain (GLS), global radial strain, global circumferential strain and global area strain (GAS) measurements were obtained.

Results

The GLS and GAS were considered significant predictors of cardiac involvement. The cut-off values discriminating cardiac involvement were 16.10% for GLS, 32.95% for GAS. During the median follow-up of 12.5 months (interquartile range 4–25 months), 20 (27%) patients died. For the Cox proportional model survival analysis, heart rate, cardiac troponin T, NT-proBNP levels, E/e’, GLS, and GAS were univariate predictors of death. Multivariate Cox model showed that GLS ≤ 14.78% and cardiac troponin T ≥ 0.049 mg/l levels were independent predictors of survival.

Conclusions

STE-3D measurements of LV myocardial mechanics could detect cardiac involvement in patients with AL amyloidosis; GLS and cardiac biomarkers can provided prognostic information for mortality prediction.

Practical recommendations for the diagnosis and management of transthyretin cardiac amyloidosis

Cardiac amyloidosis (CA) is an infiltrative restrictive cardiomyopathy caused by accumulation in the heart interstitium of amyloid fibrils formed by misfolded proteins. Most common CA types are light chain amyloidosis (AL) caused by monoclonal immunoglobulin light chains and transthyretin amyloidosis (ATTR) caused by either mutated or wild-type transthyretin aggregates. Previously considered a rare disease, CA is increasingly recognized among patients who may be misdiagnosed as undifferentiated heart failure with preserved ejection fraction (HFPEF), paradoxical low-flow/low-gradient aortic stenosis, or otherwise unexplained left ventricular hypertrophy. Progress in diagnosis has been due to the refinement of cardiac echocardiographic techniques (speckle tracking imaging) and magnetic resonance (T1 mapping) and mostly due to the advent of bone scintigraphy that has enabled noninvasive diagnosis of ATTR, limiting the need for endomyocardial biopsy. Importantly, proper management of CA starts from early recognition of suspected cases among high prevalence populations, followed by advanced diagnostic evaluation to confirm diagnosis and typing, preferentially in experienced amyloidosis centers. Differentiating ATTR from other types of amyloidosis, especially AL, is critical. Emerging targeted ATTR therapies offer the potential to improve outcomes of these patients previously treated only palliatively.

Multiparametric Echocardiography Scores for the Diagnosis of Cardiac Amyloidosis

OBJECTIVES

This study aimed to investigate the accuracy of a broad range of echocardiographic variables to develop multiparametric scores to diagnose CA in patients with proven light chain (AL) amyloidosis or those with increased heart wall thickness who had amyloid was suspected. We also aimed to further characterize the structural and functional changes associated with amyloid infiltration.

BACKGROUND

Cardiac amyloidosis (CA) is a serious but increasingly treatable cause of heart failure. Diagnosis is challenging and frequently unclear at echocardiography, which remains the most often used imaging tool.

METHODS

We studied 1,187 consecutive patients evaluated at 3 referral centers for CA and analyzed morphological, functional, and strain-derived echocardiogram parameters with the aim of developing a score-based diagnostic algorithm. Cardiac amyloid burden was quantified by using extracellular volume measurements at cardiac magnetic resonance.

RESULTS

A total of 332 patients were diagnosed with AL amyloidosis and 339 patients with transthyretin CA. Concentric remodeling and strain-derived parameters displayed the best diagnostic performance. A multivariable logistic regression model incorporating relative wall thickness, E wave/e' wave ratio, longitudinal strain, and tricuspid annular plane systolic excursion had the greatest diagnostic performance in AL amyloidosis (area under the curve: 0.90; 95% confidence interval: 0.87 to 0.92), whereas the addition of septal apical-to-base ratio yielded the best diagnostic accuracy in the increased heart wall thickness group (area under the curve: 0.80; 95% confidence interval: 0.85 to 0.90).

CONCLUSIONS

Specific functional and structural parameters characterize different burdens of CA deposition with different diagnostic performances and enable the definition of 2 scores that are sensitive and specific tools with which diagnose or exclude CA.

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.

Transthyretin cardiac amyloidosis in aortic stenosis: Prevalence, diagnostic challenges, and clinical implications

Transthyretin cardiac amyloidosis (ATTR-CA) is a challenging and underdiagnosed cause of heart failure. Advances in cardiac imaging have enabled noninvasive diagnosis of ATTR-CA, causing the recent upsurge in disease awareness and detection. ATTR-CA has been increasingly recognized in patients with degenerative aortic stenosis (AS). With the growing number of elderly patients undergoing aortic valve intervention, the identification of ATTR-CA in this group of patients is of high clinical importance. Timely and correct diagnosis is essential for amyloid-directed therapies, as well as deciding on the AS treatment strategy. This review provides a comprehensive overview of the recent studies investigating coexistence of these two entities. We present the data on the prevalence of ATTR-CA in AS and their prognostic associations. As the diagnosis of ATTR-CA may be challenging, special attention is paid to the diagnostic utility of different imaging modalities, namely, echocardiography, cardiovascular magnetic resonance, nuclear imaging, and distinctive imaging features, in patients with dual pathology. We also present a flowchart summarizing integrated imaging in patients with suspected ATTR-CA.

Cardiac Amyloidosis: Updates in Imaging

PURPOSE OF REVIEW

We summarize key features pertaining to the two most commonly encountered types of cardiac amyloidosis (CA), monoclonal immunoglobulin light chain (AL) and transthyretin type (ATTR), expanding upon the clinical application and utility of various imaging techniques in diagnosing CA.

RECENT FINDINGS

Advances in imaging have led to earlier identification, improved diagnosis of CA and higher discriminatory power to differentiate CA from other hypertrophic phenocopies. The application of cardiac magnetic resonance imaging (CMR) has led to a deeper understanding of underlying pathophysiological processes in CA, owing largely to its intrinsic tissue characterization properties. The widespread adoption of bone scintigraphy algorithms has reduced the need for cardiac biopsy and improved diagnostic confidence in ATTR CA. As new treatments for CA are rapidly developing, there will be even greater reliance on imaging, as the requirement to diagnose disease earlier, monitor response and amend treatment strategies accordingly intensifies.

Echocardiographic Findings in Cardiac Amyloidosis: Inside Two-Dimensional, Doppler, and Strain Imaging

PURPOSE OF REVIEW

The aim is to provide a description of the most important echocardiographic features in systemic amyloidosis.

RECENT FINDINGS

Amyloidosis is a heterogeneous group of multisystem disorders, characterized by an extracellular deposition of amyloid fibrils. Several imaging tests are available for the diagnosis; however, echocardiography is the cornerstone of the non-invasive imaging modality for cardiac amyloidosis. So far, little is known about the diagnosis of cardiac amyloidosis through imaging modalities. We summarized the most important echocardiographic findings in cardiac amyloidosis. Hence, we offered a systematic report of the diagnostic performance of cardiac amyloidosis using echocardiography.

Right ventricular involvement in transthyretin amyloidosis

BACKGROUND

The extent of right ventricular (RV) involvement in transthyretin amyloidosis (ATTR) is unknown.

OBJECTIVES

This study sought to establish the degree of RV involvement in ATTR amyloidosis, and compare findings with RV involvement in hypertrophic cardiomyopathy (HCM).

METHODS

Forty-two patients with ATTR amyloidosis and echocardiographic evidence of cardiac amyloidosis (cardiac ATTR), 19 ATTR patients with normal left ventricular (LV) wall thickness (non-cardiac ATTR), 25 patients with diagnosed HCM and 30 healthy controls were included in this study. Echocardiographic measurements for conventional parameters, as well as RV global and segmental strain, were recorded.

RESULTS

When comparing RV structure and function between cardiac ATTR amyloidosis and HCM patients, only segmental strain differed between the two groups. In cardiac ATTR amyloidosis, we found an RV apex-to-base strain gradient with highest deformation in the apex. This pattern was reversed in patients with HCM.

CONCLUSIONS

RV involvement is common in cardiac ATTR patients. The present study also detected an RV apical sparing pattern in patients with ATTR cardiomyopathy, similar to what has previously been described for the left ventricle in these patients. This pattern was not seen in HCM patients. Further studies are needed to assess the clinical importance of these findings.

Right Atrial Deformation Analysis in Cardiac Amyloidosis - Results from the Three-Dimensional Speckle-Tracking Echocardiographic MAGYAR-Path Study

BACKGROUND

Light-chain (AL) cardiac amyloidosis (CA) is characterized by fibril deposits, which are composed of monoclonal immunoglobulin light chains. The right ventricle is mostly involved in AL-CA and impairment of its function is a predictor of worse prognosis.

OBJECTIVES

To characterize the volumetric and functional properties of the right atrium (RA) in AL-CA by three-dimensional speckle-tracking echocardiography (3DSTE).

METHODS

A total of 16 patients (mean age: 64.5 ± 10.1 years, 11 males) with AL-CA were examined. Their results were compared to that of 15 age- and gender-matched healthy controls (mean age: 58.9 ± 6.9 years, 8 males). All cases have undergone complete two-dimensional Doppler and 3DSTE. A two-tailed p value of less than 0.05 was considered statistically significant.

RESULTS

Significant differences could be demonstrated in RA volumes respecting cardiac cycle. Total (19.2 ± 9.3% vs. 27.9 ± 10.7%, p = 0.02) and active atrial emptying fractions (12.1 ± 8.1 vs. 18.6 ± 9.8%, p = 0.05) were significantly decreased in AL-CA patients. Peak global (16.7 ± 10.3% vs. 31.2 ± 19.4%, p = 0.01) and mean segmental (24.3 ± 11.1% vs. 38.6 ± 17.6%, p =0.01) RA area strains, together with some circumferential, longitudinal and segmental area strain parameters, proved to be reduced in patients with AL-CA. Global longitudinal (4.0 ± 5.2% vs. 8.2 ± 5.5%, p = 0.02) and area (7.8 ± 8.1% vs. 15.9 ± 10.3%, p = 0.03) strains at atrial contraction and some circumferential and area strain parameters at atrial contraction were reduced in AL-CA patients.

CONCLUSION

Significantly increased RA volumes and deteriorated RA functions could be demonstrated in AL-CA.

Cardiac amyloidosis: The great masquerader

Cardiac amyloidosis is an elusive condition that is notorious for mimicking various cardiovascular conditions that present with left ventricular hypertrophy (LVH). The hypertrophy in amyloidosis is typically diffuse; however, rare reports of echocardiographic resemblances with hypertrophic cardiomyopathy (HCM) exist, such as asymmetric septal hypertrophy and left ventricular outflow tract obstruction. Cardiac MRI can help differentiate amyloidosis from hypertrophic cardiomyopathy in unclear situations. This differentiation from HCM and other forms of cardiomyopathy has important treatment implications. Here we present the case of a 76-year-old man with cardiomyopathy who had echocardiographic features of asymmetric hypertrophic cardiomyopathy but was correctly diagnosed with amyloidosis with the help of cardiac MRI and ECG.

Left Ventricular Myocardial Deformation on Cine MR Images: Relationship to Severity of Disease and Prognosis in Light-Chain Amyloidosis

Purpose To measure left ventricular (LV) myocardial strain with cine magnetic resonance (MR) imaging and a deformable registration algorithm (DRA) and to assess the prognostic value of myocardial strain in patients with light-chain (AL) amyloidosis. Materials and Methods In this prospective study, 78 consecutive patients with AL amyloidosis who underwent contrast material-enhanced cardiac MR imaging were enrolled at West China Hospital. LV myocardial strains and late gadolinium enhancement (LGE) were evaluated. Association between myocardial strain and all-cause mortality was analyzed with the stepwise Cox regression model. Results Global longitudinal strain (GLS) and global circumferential strain (GCS) were significantly lower in the no or nonspecific LGE group compared with the subendocardial LGE and transmural LGE groups (mean GLS, -10% ± 3 [standard deviation] vs -7% ± 3 vs -4% ± 1; P < .001) (mean GCS, -13% ± 3 vs -11% ± 3 vs -7% ± 2; P < .001). GLS and GCS were reduced in patients without clinical cardiac amyloidosis (mean GLS, -13% ± 3 vs -16% ± 2; P = .005) (mean GCS, -16% ± 1 vs -19% ± 2; P = .02). Circumferential and radial strains were impaired in basal segments in accordance with the distribution of LGE. Multivariate Cox analysis revealed that GCS (hazard ratio [HR] = 1.16 per 1% absolute decrease; 95% confidence interval [CI]: 1.03, 1.31; P = .02) and the presence of transmural LGE (HR = 1.75; 95% CI: 1.10, 2.80; P = .02) were independent predictors of all-cause mortality after adjustment for LV ejection fraction, right ventricular ejection fraction, LV mass index, GLS, and global radial strain. Conclusion Strain parameters derived with cine MR imaging-based DRA may be a new noninvasive imaging marker with which to evaluate the extent of cardiac amyloid infiltration and may offer independent prognostic information for all-cause mortality in patients with AL 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.

Recent Advances in Cardiovascular Imaging Relevant to the Management of Patients with Suspected Cardiac Amyloidosis

Cardiac amyloidosis is a form of infiltrative cardiomyopathy typically presenting with progressive heart failure. The clinical presentation and morphological findings often overlap with other cardiovascular diseases, and frequently results in misdiagnosis and consequent under-reporting. Cardiovascular imaging is playing an increasingly important diagnostic and prognostic role in this referral population, and is reducing the reliance on endomyocardial biopsy as a confirmatory testing. Advancements across multiple cardiac imaging modalities, including echocardiography, magnetic resonance imaging, nuclear imaging, and computed tomography, are improving diagnostic accuracy and offering novel approaches to sub-type differentiation and prognostication. This review explores recent advancements in cardiac imaging for the diagnosis, typing, and staging of cardiac amyloidosis, with a focus on new and evolving techniques. Emphasis is also placed on the promise of non-invasive cardiac imaging to provide value across the spectrum of this clinical disease, from early disease identification (prior to the development of increased wall thickness) through to markers of advanced disease associated with early mortality.

Cardiac amyloidosis: pathogenesis, clinical context, diagnosis and management options

Amyloidosis covers a group of disorders that can manifest in virtually any organ system in the body and is thought to be secondary to misfolding of extracellular proteins with subsequent deposition in tissues. The precursor protein that is produced in excess defines the specific amyloid type. This requires histopathological confirmation using Congo-red dye with its characteristic demonstration of green birefringence under cross-polarized light. There are three main types of amyloidosis associated with cardiac involvement: light-chain (AL), familial or senile (ATTR), and secondary (AA) amyloidosis. The frequency of cardiac involvement and prognosis varies among each type. Amyloid cardiomyopathy commonly manifests as heart failure and the presenting features are usually dyspnoea, oedema, angina, pre-syncope and syncope. The diagnosis of cardiac amyloidosis is very hard and can easily be misdiagnosed. Although the imaging studies (such as echocardiography and cardiovascular magnetic resonance) may guide the diagnosis, tissue biopsy is needed for confirmation. Management of cardiac amyloidosis initially is to treat the underlying heart failure. Pacemaker implantation is usually required in patients with any conduction abnormalities. Transplantation is the next step with worsening heart failure. However, the aim of any treatment in amyloidosis, irrespective of type, is to prevent further deposition of amyloid while managing concurrent symptoms. In this manuscript, we will discuss the pathogenesis of cardiac amyloidosis, diagnostic methods and management options.

Transthyretin Cardiac Amyloidosis in Older Adults: Optimizing Cardiac Imaging to the Corresponding Diagnostic and Management Goal

PURPOSE OF REVIEW

Transthyretin cardiac amyloidosis is increasingly recognized as an important cause of heart failure in older adults. Many cardiac imaging modalities have evolved to evaluate transthyretin cardiac amyloidosis and include 2D echocardiography with tissue Doppler and speckle-strain imaging, nuclear scintigraphy, cardiac magnetic resonance imaging, and positron emission tomography. The purpose of this review is to highlight the optimal selection of advanced cardiac imaging techniques with corresponding diagnostic goals including raising suspicion, making an early diagnosis, and subtyping transthyretin cardiac amyloid, as well as management goals including assessment of ventricular impairment, prognosticating, and monitoring disease progression. Potential benefits of optimizing cardiac imaging in the elderly patient with transthyretin cardiac amyloidosis may include enhanced and earlier diagnosis and refined long-term management.

RECENT FINDINGS

Advances in cardiac imaging techniques are changing diagnostic and management algorithms for transthyretin cardiac amyloidosis.

SUMMARY

With a new era of novel therapeutics, enhanced recognition, and earlier diagnosis approaching, selecting the appropriate non-invasive cardiac imaging modality will be essential for optimal care in the elderly patient with transthyretin cardiac amyloidosis.

Cardiac Amyloidosis: An Updated Review With Emphasis on Diagnosis and Future Directions

Cardiac amyloidosis occurs because of abnormal protein (amyloid) deposition in the cardiac tissue. Even with advanced diagnostic techniques and treatments, the prognosis of amyloidosis remains poor. The diagnosis of cardiac amyloidosis particularly needs to be in the differential in patients presenting with heart failure with preserved ejection fraction. This entity remains underdiagnosed due to lack of suspicion on the part of many clinicians. Involvement of cardiac tissue is the utmost determinant factor for available treatment options and prognosis. Many cases of cardiac amyloidosis usually remain undiagnosed or diagnosed only in advanced stages when treatment options are limited and associated with poor survival. Hence, early recognition of cardiac amyloidosis is indispensable in halting the disease process before irreversible changes occur. The purpose of this review is to summarize the recent updates in the evaluation and management of cardiac amyloidosis and to discuss potential future treatments options.

Quantitative assessment of systolic and diastolic function in patients with LGE negative systemic amyloidosis using CMR

OBJECTIVES

In clinical routine myocardial affection in amyloidosis is assessed by qualitative late gadolinium enhancement (LGE). Recent studies suggest that early cardiac involvement in amyloidosis may be overlooked by qualitative LGE assessment. The aim of this study was to assess possible early cardiac involvement in LGE negative AL patients by means of systolic and diastolic strain assessment and quantitative enhancement.

METHODS

51 individuals (17 Patients with LGE positive light-chain amyloidosis (AL) (Group A), 17 Patients with LGE negative systemic AL (Group B), and 17 healthy controls (Group C)) were investigated. SSFP-Cine sequences were acquired in short axis slices as well as horizontal long axis views. Standard CMR parameters as well as Feature Tracking (FT) derived systolic and diastolic circumferential and longitudinal strain parameters were calculated. Additionally, contrast enhanced MRI images were analyzed to quantitatively determine the extent of enhancement.

RESULTS

AL patients with and without LGE both had significantly lower early diastolic strain rate (EDSR) values and peak systolic longitudinal strain (PSLS) values than healthy controls (EDSR: Group A 63.1±17.6; Group B: 74.46±11.8; Group C: 86.82±12.7; F(2.48)=10.7 p<0.001); (PSLS: Group A: -13.44±1.9%; Group B: -20.31±1.2%; Group C: -23.11±1.4%; F(2.48)=167.6; p<0.001). Analysis of quantitative LGE enhancement revealed increased enhancement in qualitative LGE negative AL patients compared to healthy controls (Group A: 19.6±8.9%; Group B: 8.2±3.9%; Group C: 2.4±1.3% F(2.48)=52.2; p<0.001).

CONCLUSION

CMR strain analysis detects early systolic and diastolic strain impairment in AL patients lacking qualitative LGE enhancement.

Diagnosis, Prognosis, and Therapy of Transthyretin Amyloidosis

Transthyretin amyloidosis is a fatal disorder that is characterized primarily by progressive neuropathy and cardiomyopathy. It occurs in both a mutant form (with autosomal dominant inheritance) and a wild-type form (with predominant cardiac involvement). This article guides clinicians as to when the disease should be suspected, describes the appropriate diagnostic evaluation for those with known or suspected amyloidosis, and reviews the interventions currently available for affected patients.

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.

The role of echocardiography in the non-invasive diagnosis of cardiac amyloidosis

INTRODUCTION

The diagnosis of cardiac amyloidosis (CA) is usually performed by endomyocardial biopsy; however, possible sampling errors and procedural risks such as cardiac tamponade, malignant arrhythmias and bleeding risk, limit its use. Therefore, a non-invasive diagnostic method appears to be necessary.

MATERIALS AND METHODS

Echocardiography plays an important role in this need. Conventional two-dimensional echocardiography appears able to detect some specific and distinguishing signs of cardiac amyloid infiltration.

RESULTS AND CONCLUSIONS

Of these, thickened right and left ventricular (LV) myocardium, normal or small LV cavity size in contrast to enlarged biatrial cavities, diffuse hyper-refractile 'granular sparkling' appearance and 'mismatch' ECG/ECHO are the most specific findings. The magnitude of cyclic variation recorded with integrated backscatter reflects structural changes in the myocardium. In patients with CA, this magnitude is reduced because myocardial amyloid infiltration is characterized by a reduction of number of "contractile" fibers. Other informations concerning LV dysfunction CA-related can be obtained by Tei index. Finally, new echocardiographic imaging modalities, such as tissue Doppler, Doppler-based strain, speckle tracking imaging and three-dimensional echocardiography, can provide some findings regarding the preclinical stages of LV dysfunction when other echocardiographic measurements are showing normal; however, these are unable to provide a non-invasive diagnosis of cardiac amyloidosis.

Echocardiographic and biohumoral characteristics in patients with AL and TTR amyloidosis at diagnosis

BACKGROUND

Few studies have analyzed the clinical and echocardiographic differences between light-chain (AL) and transthyretin (TTR) amyloidosis.

HYPOTHESIS

The aim of the present research was to compare, in a real-world setting, the clinical and echocardiographic profiles of these kinds of amyloidosis, at the time of diagnosis, using new-generation echocardiography.

METHODS

Seventy-nine patients with AL and 48 patients with TTR amyloidosis were studied.

RESULTS

According to the criterion of mean left ventricular (LV) thickness >12 mm, 45 AL (C-AL) and all TTR patients had cardiac amyloidotic involvement, whereas 34 AL patients did not. TTR patients had increased right ventricular (RV) and LV chambers with increased RV and LV wall thickness and reduced LV ejection fraction and fractional shortening. Furthermore, TTR patients showed lower N-terminal pro Brain Natriuretic Peptide concentrations and New York Heart Association functional class when compared with C-AL.

CONCLUSIONS

Our data show that at time of first diagnosis, TTR patients have a more advanced amyloidotic involvement of the heart, despite less severe symptoms and biohumoral signs of heart failure. We can hypothesize that we observed different diseases at different stages. In fact, AL amyloidosis is a multiorgan disease with quick progression rate, that becomes rapidly symptomatic, whereas TTR amyloidosis might have a slow progression rate and might remain poorly symptomatic for a greater amount of time.

The mosaic of the cardiac amyloidosis diagnosis: role of imaging in subtypes and stages of the disease

Cardiac amyloidosis is a rare, infiltrative cardiomyopathy that presents with thickened ventricular walls and progressive heart failure. The morphological findings and clinical features are shared with many other diseases (i.e. hypertrophic cardiomyopathy, 'athlete's heart,' Fabry disease, and hypertensive cardiomyopathy), and misdiagnosis occurs frequently. Cardiologists have many instruments that can help reach a correct diagnosis in a relatively short time. As tiles of a mosaic are placed to create an image, thoughtful and smart use of the different diagnostic tools available allows the opportunity to identify amyloid infiltration of the myocardium. When the myocardium is involved, prognosis is poor, so identification of its involvement is crucial for disease management. The diagnostic process begins with an accurate evaluation of clinical elements and includes cardiovascular imaging (echocardiography, magnetic resonance, and nuclear medicine), electrocardiography, serological assays, and myocardial biopsy; only the appropriate integration of these instruments can reveal the diagnosis to an expert physician. The latest improvements in non-invasive diagnostic techniques with increased diagnostic power have reduced the need for biopsy.

Biohumoral markers as predictor of right ventricular dysfunction in AL Amyloidosis

AIM

In AL amyloidosis, the importance of right ventricle (RV) involvement has recently been underlined and its role in predicting prognosis has been emphasized. Little is known about the relationship between RV involvement, N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin levels. Aim of our study was to clarify the relationship between NT-proBNP and troponin and RV involvement and analyze their independent value as predictors of RV dysfunction.

METHODS AND RESULTS

We examined 76 consecutive patients with biopsy-proven AL amyloidosis. Each patient received complete clinical evaluation, troponin I, NT-proBNP assay and comprehensive echocardiographic evaluation. Considering a tricuspidal annulus plane systolic excursion (TAPSE) value <16 mm, 23 patients (30%) presented RV systolic dysfunction, whereas 53 (70%) did not. Patient with reduced TAPSE had thicker left ventricle (LV) walls and RV free walls, reduced LV fractional shortening, impaired LV diastolic function and worse LV and RV myocardial performance index. For RV dysfunction the best predictive value for NT-proBNP was identified as 2977 ng/l with sensitivity and specificity of 87% and 84%, respectively; best cut-off for troponin I was identified as 0.085 ng/l, with sensitivity and specificity of 85% and 90% respectively. At multivariable logistic regression analysis, both NT-proBNP and troponin I emerged as independent predictors of RV dysfunction presence but troponin appears to have a higher predictive power.

CONCLUSION

Our study demonstrated that cut-off values of 2977 ng/ml for NT-proBNP and 0.085 ng/l for troponin were able to identify a subgroup of AL patients with RV dysfunction. Troponin I is more accurate and seems to be the best biohumoral marker of RV dysfunction.

Cardiac amyloidosis: the heart of the matter

Amyloidosis comprises a unique group of diseases that share in common the extracellular deposition of insoluble fibrillar proteins in organs and tissue including the heart. Cardiac amyloidosis could be primary a part of systemic acquired amyloidosis, or a result of heredofamilial amyloidosis. Although the infiltration of the heart from different types of amyloid results in restrictive cardiomyopathy that manifests with refractory congestive heart failure and conduction abnormalities, unequivocal identification of the deposited amyloidogenic protein is mandatory in order to avoid misdiagnosis and inappropriate treatment. Recent developments in imaging techniques and extracardiac tissue biopsy have minimized the need for invasive endomyocardial biopsy for amyloidosis. Despite advances in treatment, the prognosis of a patient with amyloidosis is still poor and depends upon the underlying disease, and the type and degree of dysfunction of the involved organs. Thus, early diagnosis is mandatory because patients with advanced disease are usually too ill for intensive therapy. This review outlines current approaches to diagnosis, assessment of disease severity, and treatment of cardiac amyloidosis.

Transthyretin familial amyloid polyneuropathy

TTR FAP is characterized by phenotypic and genotypic heterogeneity. The severity of polyneuropathy along with autonomic dysfunction and heart involvement makes it a life-threatening disease. This protein is mainly produced by the liver. Molecular genetic testing is essential in the diagnostic strategy. TTR-Val30Met is the most frequent substitution, resulting in a guanine to cytosine mutation in exon 2 of the gene. It is virtually the only variant detected in Portugal, Brazil, and Sweden. By contrast, as many as 30 different TTR variants are reported in Japan and in other European countries. A less severe phenotype with late onset has been reported. Diagnosis should be performed as early as possible since upcoming pharmacological therapeutic approaches are now available, in addition to liver transplantation.

Echocardiographic evaluation of systolic and diastolic function in patients with cardiac amyloidosis

The typical appearance of cardiac amyloidosis using standard echocardiographic techniques is usually a late finding only in patients with relatively advanced stages of the disease. Early noninvasive identification of cardiac amyloidosis is of growing clinical importance. Newer echocardiographic techniques, including tissue Doppler imaging and deformation imaging (strain rate imaging and 2-dimensional speckle tracking), are powerful tools for quantifying regional myocardial motion and deformation. Using these advanced techniques, early functional impairment in cardiac amyloidosis may be detectable when the results of standard echocardiography are still normal or inconclusive. This review provides a comprehensive overview of the different echocardiographic approaches for the assessment of systolic and diastolic function in patients with cardiac amyloidosis. Special attention is paid to regional myocardial function assessed by tissue Doppler imaging, strain rate imaging, and 2-dimensional speckle-tracking imaging.

Three-dimensional simultaneous strain-volume analysis describes left ventricular remodelling and its progression: a pilot study

AIMS

Three-dimensional (3D)-echocardiography speckle imaging allows the evaluation of frame-by-frame strain and volume changes simultaneously. The aim of the present investigation was to describe the strain-volume combined assessment in different patterns of cardiac remodelling.

METHODS AND RESULTS

Fifty patients received a 3D acquisition. Patients were classified as follows: healthy subjects (CNT), previous AMI, and normal ejection fraction (EF; group A); ischaemic cardiomyopathy with reduced EF (group B); hypertrophic/infiltrative cardiomyopathy (group C). Values of 3D strain were plotted vs. volume for each frame to build a strain-volume curve for each case. Peak of radial, longitudinal, and circumferential systolic strain (Rεp, Lεp, and Cεp, respectively), slopes of the curves (RεSl, LεSl, CεSl), and strain to end-diastolic volume (EDV) ratio (Rε/V, Lε/V, Cε/V) were computed for the analysis. Strain-volume curves of the CNT group were steep and clustered, whereas, due to progressive dilatation and reduction of strains, progressive flattening could be demonstrated in groups A and B. Quantitative data supported visual assessment with progressive lower slopes (P< 0.05 for RεSl, CεSl, P= 0.06 for LεSl) and significantly lower ratios (P< 0.01 for Rε/V, Lε/V, and Cε/V). Group C showed an opposite behaviour with slopes and ratios close to those of normal subjects. Correlation coefficients between EDV and slopes of the curves were significant for all the directions of strain (CεSl: r = 0.891; RєSl: r = 0.704; LєSl: r = 0.833; P< 0.0001 for all).

CONCLUSION

We measured left ventricular volumes and strain by 3D-echo and obtained strain-volume curve to evaluate their behaviour in remodelling. A distinctive and progressive pattern consistent with pathophysiology was observed. The analysis here shown could represent a new non-invasive method to assess myocardial mechanics and its relationship with volumes.

Rotational mechanics of the left ventricle in AL amyloidosis

AIMS

The aim of this study was to investigate whether alterations in left ventricular (LV) twisting and untwisting motion could be induced by cardiac involvement in patients with immunoglobulin light-chain (AL) systemic amyloidosis.

METHODS AND RESULTS

Forty-five patients with AL amyloidosis and 26 control subjects were evaluated. After standard echocardiographic measurement and two-dimensional (2D) speckle tracking echocardiography, LV rotation at both basal and apical planes, twisting, twisting rate, and longitudinal strain were measured. Tissue Doppler imaging (TDI) derived early diastolic peak velocity at septal mitral annulus (E') was also evaluated. Twenty-six of 45 patients with systemic amyloidosis were classified as having cardiac amyloidosis (CA) if the mean value of the LV wall thickness was ≥ 12 mm or not (NCA) if this value was not reached. In NCA patients, both LV twist and untwisting rate were increased while they were decreased in CA patients making them similar to the control group. Longitudinal strain was reduced only in CA patients. Impaired relaxation as indicated by E' values was progressively reduced in the course of the disease.

CONCLUSIONS

Both twisting and untwisting motions are increased in patients with AL systemic amyloidosis with no evidence of cardiac involvement while they are reduced in patients with evident amyloidosis cardiac involvement. This finding suggests that impaired LV relaxation induces a compensatory mechanism in the early phase of the disease, which fails in more advanced stage when both twisting and untwisting rates are reduced. The increase in LV rotational mechanics could be a marker of subclinical cardiac involvement.