Causes and Consequences of Longitudinal LV Dysfunction Assessed by 2D Strain Echocardiography in Cardiac Amyloidosis

Apical sparing pattern of left ventricular myocardial 99mTc-HMDP uptake in patients with transthyretin cardiac amyloidosis

BACKGROUND

A decreased longitudinal strain in basal segments with a base-to-apex gradient has been described in patients with cardiac amyloidosis (CA).

OBJECTIVES

Aim was to investigate the left ventricular (LV) regional distribution of early-phase 99mTc-Hydroxymethylene diphosphonate (99mTc-HMDP) uptake in patients with transthyretin-related cardiac amyloidosis (TTR-CA).

METHODS

All patients underwent a whole-body planar 99mTc-HMDP scintigraphy acquired at 10-min post-injection (early-phase) followed by a thorax SPECT/CT. The segmental uptake (expressed as % of maximal myocardial HMDP uptake) was investigated on the AHA 17-segment model and 3-segment model (basal, mid-cavity, apical).

RESULTS

Sixty-one TTR-CA patients were included of whom 29 were wild-type (wt-TTR-CA) and 32 had hereditary TTR-CA (m-TTR-CA). Early myocardial 99mTc-HMDP uptake occurred in all TTR-CA. In all patients, segmental analysis of the LV myocardial distribution of 99mTc-HMDP uptake showed an increased median uptake (interquartile range) in basal/mid-cavity segments compared to the lowest median uptake of apical segments (respectively, 79% [72%-86%] vs. 72% [64%-81%]; P < 10-6). This pattern was similar in wt-TTR-CA group (78% [70%-84%] vs. 70% [61%-81%]; P < 10-6), in m-TTR-CA group (80% [74%-86%] vs. 73 [66%-82%]; P < 10-7) and remained constant independently of the TTR mutation subtype with P ranging 10-5 to 0.03.

CONCLUSIONS

Early-phase myocardial scintigraphy identified regional distribution of 99mTc-HMDP uptake characterized by a base-to-apex gradient, corroborating echocardiographic, and cardiac magnetic resonance findings. This apical sparing pattern was similar across TTR-CA and TTR mutation subtypes.

Relative Apical Sparing of Myocardial Longitudinal Strain Is Explained by Regional Differences in Total Amyloid Mass Rather Than the Proportion of Amyloid Deposits

OBJECTIVES

This study sought to test whether relative apical sparing (RELAPS) of left ventricular (LV) longitudinal strain (LS) in cardiac amyloidosis (CA) is explained by regional differences in markers of amyloid burden (¹⁸F-florbetapir uptake by positron emission tomography [PET] and/or extracellular volume fraction [ECV] by cardiac magnetic resonance (CMR)].

BACKGROUND

Further knowledge of the pathophysiological basis for RELAPS can help understand the adverse outcomes associated with apical LS impairment.

METHODS

This was a prospective study of 32 subjects (age 62 ± 7 years; 50% males) with light chain CA. All subjects underwent two-dimensional echocardiography for LS estimation and ¹⁸F-florbetapir PET for quantification of LV florbetapir retention index (RI). A subset also underwent CMR (n = 22) for ECV quantification. Extracellular LV mass (LV mass*ECV) and total florbetapir binding (extracellular LV mass*florbetapir RI) were also calculated. All parameters were measured globally and regionally (base, mid, and apex).

RESULTS

There was a significant base-to-apex gradient in LS (-7.4 ± 3.2% vs. -8.6 ± 4.0% vs. -20.8 ± 6.6%; p < 0.0001), maximal LV wall thickness (15.7 ± 1.9 cm vs. 15.4 ± 2.9 cm vs. 10.1 ± 2.4 cm; p < 0.0001), and LV mass (74.8 ± 21.2 g vs. 60.8 ± 17.3 g vs. 23.4 ± 6.2 g; p < 0.0001). In contrast, florbetapir RI (0.089 ± 0.03 μmol/min/g vs. 0.097 ± 0.03 μmol/min/g vs. 0.085 ± 0.03 μmol/min/g; p = 0.45) and ECV (0.53 ± 0.08 vs. 0.49 ± 0.08 vs. 0.49 ± 0.07; p = 0.15) showed no significant base-to-apex gradient in the tissue concentration or proportion of amyloid infiltration, whereas markers of total amyloid load, such as total florbetapir binding (3.4 ± 1.7 μmol/min vs. 2.8 ± 1.5 μmol/min vs. 0.93 ± 0.49 μmol/min; p < 0.0001) and extracellular LV mass (40.0 ± 15.6 g vs. 30.2 ± 10.9 g vs. 11.6 ± 3.9 g; p < 0.0001), did show a marked base-to-apex gradient.

CONCLUSIONS

Segmental differences in the distribution of the total amyloid mass, rather than the proportion of amyloid deposits, appear to explain the marked regional differences in LS in CA. Although these 2 matrices are clearly related concepts, they should not be used interchangeably.

Multimodality Imaging in Restrictive Cardiomyopathies: An EACVI expert consensus document In collaboration with the "Working Group on myocardial and pericardial diseases" of the European Society of Cardiology Endorsed by The Indian Academy of Echocardiography

Restrictive cardiomyopathies (RCMs) are a diverse group of myocardial diseases with a wide range of aetiologies, including familial, genetic and acquired diseases and ranging from very rare to relatively frequent cardiac disorders. In all these diseases, imaging techniques play a central role. Advanced imaging techniques provide important novel data on the diagnostic and prognostic assessment of RCMs. This EACVI consensus document provides comprehensive information for the appropriateness of all non-invasive imaging techniques for the diagnosis, prognostic evaluation, and management of patients with RCM.

Prediction of subtle left ventricular systolic dysfunction in homozygous and heterozygous familial hypercholesterolemia: Genetic analyses and speckle tracking echocardiography study

BACKGROUND AND AIMS

Few studies have shown the direct effect of familial hypercholesterolemia (FH) on myocardial systolic function. Studies focused on heterozygote FH patients but not homozygote ones, and they did not perform genetic analyses. We aimed to evaluate all types of patients with FH using the potentially more sensitive speckle tracking echocardiography (STE) technique to identify early left ventricular (LV) dysfunction.

METHODS

Genetic analyses of patients with FH were conducted for LDL-receptor, PCSK9, and ApoB100. Nine homozygote, two compound heterozygote, and 82 heterozygote FH patients and 85 healthy subjects were prospectively studied. Longitudinal and circumferential strain measurements and conventional echocardiography findings were obtained.

RESULTS

LV ejection fractions were similar for all (homozygote, heterozygote, and control) groups. The LV average longitudinal strain (aLS) and average circumferential strain (aCS) levels were significantly reduced in the homozygote and heterozygote groups when compared with the controls (for aLS, P = .008 (<.001); for aCS, P =< .001). A significant inverse correlation was found between LDL-C levels and LS (P < .001, r = .728) and CS (P < .001, r = .642) for all FH patients.

CONCLUSIONS

This study demonstrates the potential of using systolic strain values obtained using 2D STE for determining lipotoxicity in the myocardium owing to hypercholesterolemia. Our study found that cardiac functions of homozygote patients who had the highest cholesterol levels were disrupted at very early ages. Therefore, starting lipid reduction treatment and early reverse LV remodelling therapy at early ages may be beneficial for high-risk patients.

Cardiac Structural and Functional Consequences of Amyloid Deposition by Cardiac Magnetic Resonance and Echocardiography and Their Prognostic Roles

OBJECTIVES

This cross-sectional study aimed to describe the functional and structural cardiac abnormalities that occur across a spectrum of cardiac amyloidosis burden and to identify the strongest cardiac functional and structural prognostic predictors in amyloidosis using cardiac magnetic resonance (CMR) and echocardiography.

BACKGROUND

Cardiac involvement in light chain and transthyretin amyloidosis is the main driver of prognosis and influences treatment strategies. Numerous measures of cardiac structure and function are assessed by multiple imaging modalities in amyloidosis.

METHODS

A total f 322 subjects (311 systemic amyloidosis and 11 transthyretin gene mutation carriers) underwent comprehensive CMR and transthoracic echocardiography. The probabilities of 11 commonly measured structural and functional cardiac parameters being abnormal with increasing cardiac amyloidosis burden were evaluated. Cardiac amyloidosis burden was quantified using CMR-derived extracellular volume. The prognostic capacities of these parameters to predict death in amyloidosis were assessed using Cox proportional hazards models.

RESULTS

Left ventricular mass and mitral annular plane systolic excursion by CMR along with strain and E/e' by echocardiography have high probabilities of being abnormal at low cardiac amyloid burden. Reductions in biventricular ejection fractions and elevations in biatrial areas occur at high burdens of infiltration. The probabilities of indexed stroke volume, myocardial contraction fraction, and tricuspid annular plane systolic excursion (TAPSE) being abnormal occur more gradually with increasing extracellular volume. Ninety patients (28%) died during a median follow-up of 22 months (interquartile range: 10 to 38 months). Univariable analysis showed that all imaging markers studied significantly predicted outcome. Multivariable analysis showed that TAPSE (hazard ratio: 1.46; 95% confidence interval: 1.16 to 1.85; p < 0.01) and indexed stroke volume (hazard ratio: 1.24; 95% confidence interval: 1.04 to 1.48; p < 0.05) by CMR were the only independent predictors of mortality.

CONCLUSIONS

Specific functional and structural abnormalities characterize different burdens of cardiac amyloid deposition. In a multimodality imaging assessment of a large cohort of amyloidosis patients, CMR-derived TAPSE and indexed stroke volume are the strongest prognostic cardiac functional markers.

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.

Cardiac Amyloidosis: Diagnosis and Treatment Strategies

Cardiac amyloidosis in the United States is most often due to myocardial infiltration by immunoglobulin protein, such as in AL amyloidosis, or by the protein transthyretin, such as in hereditary and senile amyloidosis. Cardiac amyloidosis often portends a poor prognosis especially in patients with systemic AL amyloidosis. Despite better understanding of the pathophysiology of amyloid, many patients are still diagnosed late in the disease course. This review investigates the current understanding and new research on the diagnosis and treatment strategies in patients with cardiac amyloidosis. Myocardial amyloid infiltration distribution occurs in a variety of patterns. Structural and functional changes on echocardiography can suggest presence of amyloid, but CMR and nuclear imaging provide important complementary information on amyloid burden and the amyloid subtype, respectively. While for AL amyloid, treatment success largely depends on early diagnosis, for ATTR amyloid, new investigational agents that reduce production of transthyretin protein may have significant impact on clinical outcomes. Advancements in the non-invasive diagnostic detection and improvements in early disease recognition will undoubtedly facilitate a larger proportion of patients to receive early therapy when it is most effective.

Abnormal Coronary Flow Velocity Reserve and Decreased Myocardial Contractile Reserve Are Main Factors in Relation to Physical Exercise Capacity in Cardiac Amyloidosis

BACKGROUND

The aim of the present study was to evaluate the clinical importance of echocardiographic coronary flow velocity reserve (CFVR), resting and exercise left ventricular global longitudinal strain (LVGLS), and myocardial work efficiency (MWE) in patients with cardiac amyloidosis (CA).

METHODS

The study population comprised 69 subjects: group A, 27 patients with CA confirmed by endomyocardial biopsy (CA positive); group B, 42 healthy control subjects. The amyloid phenotype in group A was as follows: patients with wild-type transthyretin-related amyloidosis (n = 10), carriers of the Danish familial transthyretin amyloidosis mutation with cardiac involvement (n = 5), and patients with amyloid light chain amyloidosis with cardiac involvement (n = 12). All subjects underwent comprehensive echocardiographic evaluation during rest and during symptom-limited, semisupine exercise testing. Furthermore, CFVR was assessed using Doppler echocardiography.

RESULTS

Patients with CA had significantly lower CFVR (1.7 ± 0.6 vs 3.9 ± 0.8, P < .0001), MWE (1.9 ± 1.0 vs 3.0 ± 0.7, P < .0001), and LVGLS magnitude (11% [10%-14%] vs 20% [18%-21%], P < .0001) than control subjects. Patients with CA showed severely reduced deformation and efficiency reserve compared with control subjects (ΔLVGLS 0.9 ± 2.8% vs 5.6 ± 2.3%, P < .0001; ΔMWE 2.5 ± 2.8 vs 8.8 ± 2.6, P < .0001). In patients with CA, a strong relation was seen between physical capacity by the metabolic equivalent of tasks test and CFVR (r = 0.55, P < .01), peak exercise LVGLS (r = 0.64, P < .0001), and peak exercise MWE (r = 0.60, P < .01).

CONCLUSIONS

Patients with CA had a profound lack of CFVR and longitudinal myocardial deformation reserve compared with healthy control subjects. Both parameters were significantly associated with exercise capacity and may prove useful for evaluating cardiac performance in patients with CA.

Prognostic and Added Value of Two-Dimensional Global Longitudinal Strain for Prediction of Survival in Patients with Light Chain Amyloidosis Undergoing Autologous Hematopoietic Cell Transplantation

BACKGROUND

Autologous hematopoietic cell transplantation (HCT) is a first-line therapy for prolonging survival in patients with light-chain (AL) amyloidosis. Cardiac involvement is the most important determinant of survival. However, patients with advanced cardiac involvement have often been excluded from HCT because of high risk for transplantation-related mortality and poor overall survival. Whether baseline left ventricular global longitudinal strain (GLS) can provide additional risk stratification and predict survival after HCT in this high-risk population remains unclear. The aim of this study was to evaluate the prognostic implication of baseline GLS and the added value of GLS beyond circulating cardiac biomarkers for risk stratification in patients with AL amyloidosis undergoing HCT.

METHODS

Eighty-two patients with newly diagnosed AL amyloidosis who underwent upfront HCT between January 2007 and April 2014 were included in the study. Clinical, echocardiographic, and serum cardiac biomarker data were collected at baseline and 12 months following HCT. GLS measurements were performed using a vendor-independent offline system. The median follow-up time for survivors was 58 months.

RESULTS

Sixty-four percent of patients were in biomarker-based Mayo stage II or III. GLS, brain natriuretic peptide, troponin, and mitral E/A ratio were identified as the strongest predictors of survival (P < .0001). Other predictors included sex, creatinine, free AL, wall thickness, and ejection fraction. Mayo stage was significantly associated with outcome, with 5-year survival of 93%, 72% and 31% in stage I, II, and III patients, respectively. GLS of 17% was identified as the value that best discriminated survivors from nonsurvivors, and the application of this cutoff value provided further mortality risk stratification within each Mayo stage.

CONCLUSIONS

GLS is a strong predictor of survival in patients with AL amyloidosis undergoing HCT, potentially providing incremental value over serum cardiac biomarkers for risk stratification. GLS should be considered as a standard parameter along with serum cardiac biomarkers when evaluating eligibility for HCT or other investigational therapies.

Regional Variation in Technetium Pyrophosphate Uptake in Transthyretin Cardiac Amyloidosis and Impact on Mortality

OBJECTIVES

This study sought to investigate the regional uptake of technetium 99m-pyrophosphate (TcPYP) in transthyretin cardiac amyloidosis (ATTR) and its association with mortality.

BACKGROUND

TcPYP nuclear scintigraphy is a diagnostic and prognostic tool in ATTR. Echocardiography has identified a pattern of regional variation in longitudinal strain (LS) with a gradient of improved strain from base to apex in ATTR.

METHODS

Consecutive patients with ATTR were evaluated who underwent TcPYP nuclear scintigraphy with planar and attenuation corrected single-photon emission computed tomography (SPECT). Heart-to-contralateral lung (H/CL) ratio was calculated on planar images, and left ventricular (LV) uptake was determined in each of the 17 segments using SPECT. A measure of apical-sparing of myocardial TcPYP uptake, termed the apical-sparing ratio (ASR), was calculated as basal + mid / apical counts.

RESULTS

Overall, 54 patients with ATTR (age 78 ± 9 years, 76% male, 31% hereditary ATTR) were analyzed. There was increased TcPYP uptake in basal and mid relative to apical LV segments, and an apical-sparing LS pattern on echocardiography. The right ventricle similarly showed greater uptake in basal segments. There were 26 deaths over 1.8 years median follow-up. The ASR of TcPYP uptake was associated with age-adjusted all-cause mortality (p = 0.013) with worse prognosis seen at levels <2.75. Global LS was also prognostic (p = 0.01), whereas H/CL ratio and total LV uptake indexed to blood pool were not (p = 0.772 and p = 0.850, respectively). The prognostic utility of the ASR persisted in multivariable modeling (p = 0.003), whereas global LS did not.

CONCLUSIONS

There is decreased TcPYP uptake in apical as compared to mid and basal segments in the LV, mimicking apical-sparing LS seen on echocardiography. Regional distribution of LV TcPYP uptake is associated with mortality, whereas overall amount of uptake as measured by H/CL ratio and indexed LV SPECT uptake is not.

Inotropic myocardial reserve deficiency is the predominant feature of exercise haemodynamics in cardiac amyloidosis

AIMS

This study aimed to characterize invasive haemodynamics during exercise in subjects with cardiac amyloidosis (CA).

METHODS AND RESULTS

The study population numbered 44 subjects. Group A (CA-positive, n = 24) comprised wild-type transthyretin patients (n = 10), familial transthyretin amyloidosis mutation carriers (ATTRm) with cardiac involvement (n = 5), and light-chain amyloidosis patients with cardiac involvement (n = 9). Group B (CA-negative, n = 20) comprised four healthy ATTRm subjects without cardiac involvement documented by ¹¹ C-PIB positron emission tomography and 16 healthy controls. All subjects underwent a symptom-limited, semi-supine exercise test with expired gas analysis and simultaneous right heart catheterization. CA patients had lower peak oxygen consumption [15 ± 6 mL/min/kg bodyweight (bwt) vs. 33 ± 7 mL/min/kg bwt; P < 0.0001] than controls. Myocardial reserve during exercise was significantly reduced in CA patients as reflected in a small increase in stroke volume index (SVI) and cardiac index (CI) compared with controls [ΔSVI: 4 mL/m² (range: -1 to 8) vs. 14 mL/m² (range: 5-25); P < 0.0001; ΔCI: 2 ± 2 L/min vs. 7 ± 2 L/min; P < 0.0001]. During exercise, CA patients had significantly higher left and right ventricular filling pressures than controls. Furthermore, CA patients had severely impaired pulmonary arterial compliance (PAC) compared with controls [2.9 mL/mmHg (range: 2.1-4.5) vs. 7.5 mL/mmHg (range: 5.7-10.4); P < 0.0001].

CONCLUSIONS

Cardiac amyloid deposits are associated with severely reduced inotropic myocardial reserve and increased left and right ventricular filling pressures during exercise. Furthermore, CA subjects have severely reduced PAC, which may contribute to right heart failure and reduced exercise capacity.

Patterns of CMR measured longitudinal strain and its association with late gadolinium enhancement in patients with cardiac amyloidosis and its mimics

BACKGROUND

Regional variability of longitudinal strain (LS) has been previously described with echocardiography in patients with cardiac amyloidosis (CA), however, the reason for this variability is not completely evident. We sought to describe regional patterns in LS using feature-tracking software applied to cardiovascular magnetic resonance (CMR) cine images in patients with CA, hypertrophic cardiomyopathy (HCM), and Anderson-Fabry's disease (AFD) and to relate these patterns to the distribution of late gadolinium enhancement (LGE).

METHODS

Patients with CA (n = 45) were compared to LV mass indexed matched patients with HCM (n = 19) and AFD (n = 19). Peak systolic LS measurements were obtained using Velocity Vector Imaging (VVI) software on CMR cine images. A relative regional LS ratio (RRSR) was calculated as the ratio of the average of the apical segmental LS divided by the sum of the average basal and mid-ventricular segmental LS. LGE was quantified for the basal, mid, and apical segments using a threshold of 5SD above remote myocardium. A regional LGE ratio was calculated similar to RRSR.

RESULTS

Patients with CA had significantly had worse global LS (-15.7 ± 4.6%) than those with HCM (-18.0 ± 4.6%, p = 0.046) and AFD (-21.9 ± 5.1%, p < 0.001). The RRSR was higher in patients with CA (1.00 ± 0.31) than in AFD (0.79 ± 0.24; p = 0.018) but not HCM (0.84 ± 0.32; p = 0.114). In CA, a regional difference in LGE burden was noted, with lower LGE in the apex (31.5 ± 19.1%) compared to the mid (38.2 ± 19.0%) and basal (53.7 ± 22.7%; p < 0.001 for both) segments. The regional LGE ratio was not significantly different between patients with CA (0.33 ± 0.15) and AFD (0.47 ± 0.58; p = 0.14) but lower compared to those with HCM (0.72 ± 0.43; p < 0.0001). LGE percentage showed a significant impact on LS (p < 0.0001), with a 0.9% decrease in absolute LS for every 10% increase in LGE percentage.

CONCLUSION

The presence of marked "relative apical sparing" of LS along with a significant reduction in global LS seen in patients with CA on CMR cine analysis may provide an additional tool to differentiate CA from other cause of LVH. The concomitant presence of a base to apex gradient in quantitative LGE burden suggests that the regional strain gradient may be at least partially explained by the burden of amyloid deposition and fibrosis.

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.

Echo Parameters for Differential Diagnosis in Cardiac Amyloidosis: A Head-to-Head Comparison of Deformation and Nondeformation Parameters

BACKGROUND

A plethora of echo parameters has been suggested for distinguishing cardiac amyloidosis (CA) from other causes of myocardial thickening with, however, scarce data on their head-to-head comparison. This study aimed at comparing the diagnostic accuracy of various deformation and conventional echo parameters in differentiating CA from other hypertrophic substrates, especially in the gray zone of mild hypertrophy (maximum wall thickness ≤16 mm) or normal ejection fraction (EF).

METHODS AND RESULTS

=0.0002, respectively) independent of the CA type.

CONCLUSIONS

Our study demonstrated that in patients with thickened hearts, EF global longitudinal strain ratio has the best accuracy in detecting CA, even among the most "challenging" patient subgroups as those with mild hypertrophy and normal EF.

Addressing Common Questions Encountered in the Diagnosis and Management of Cardiac Amyloidosis

Advances in cardiac imaging have resulted in greater recognition of cardiac amyloidosis in everyday clinical practice, but the diagnosis continues to be made in patients with late-stage disease, suggesting that more needs to be done to improve awareness of its clinical manifestations and the potential of therapeutic intervention to improve prognosis. Light chain cardiac amyloidosis, in particular, if recognized early and treated with targeted plasma cell therapy, can be managed very effectively. For patients with transthyretin amyloidosis, there are numerous therapies that are currently in late-phase clinical trials. In this review, we address common questions encountered in clinical practice regarding etiology, clinical presentation, diagnosis, and management of cardiac amyloidosis, focusing on recent important developments in cardiac imaging and biochemical diagnosis. The aim is to show how a systematic approach to the evaluation of suspected cardiac amyloidosis can impact the prognosis of patients in the modern era.

Identification and Assessment of Cardiac Amyloidosis by Myocardial Strain Analysis of Cardiac Magnetic Resonance Imaging

BACKGROUND

We explored the usefulness of myocardial strain analysis on cardiac magnetic resonance imaging (CMR) scans for the identification of cardiac amyloidosis.Methods and Results:The 61 patients with systemic amyloidosis underwent 3.0-T CMR, including CMR tagging and late-gadolinium enhanced (LGE) imaging. The circumferential strain (CS) of LGE-positive and LGE-negative patients was measured on midventricular short-axis images and compared. Logistic regression modeling of CMR parameters was performed to detect patients with LGE-positive cardiac amyloidosis. Of the 61 patients with systemic amyloidosis 48 were LGE-positive and 13 were LGE-negative. The peak CS was significantly lower in the LGE-positive than in the LGE-negative patients (-9.5±2.3 vs. -13.3±1.4%, P<0.01). The variability in the peak CS time was significantly greater in the LGE-positive than in the LGE-negative patients (46.1±24.5 vs. 21.2±20.1 ms, P<0.01). The peak CS significantly correlated with clinical biomarkers. The sensitivity, specificity, and accuracy of the diagnostic model using CS parameters for the identification of LGE-positive amyloidosis were 93.8%, 76.9%, and 90.2%, respectively.

CONCLUSIONS

Myocardial strain analysis by CMR helped detect LGE-positive amyloidosis without the need for contrast medium. The peak CS and variability in the peak CS time may correlate with the severity of cardiac amyloid deposition and may be more sensitive than LGE imaging for the detection of early cardiac disease in patients with amyloidosis.

Cardiac amyloidosis mimicking severe aortic valve stenosis - a case report demonstrating diagnostic pitfalls and role of dobutamine stress echocardiography

Background

Aortic valve stenosis is a common finding diagnosed with high sensitivity in transthoracic echocardiography, but the examiner often finds himself confronted with uncertain results in patients with moderate pressure gradients and concomitant systolic heart failure. While patients with true-severe low-gradient aortic valve stenosis with either reduced or preserved left ventricular systolic function are primarily candidates for valve replacement, there is a relevant proportion of patients with pseudo-severe aortic valve stenosis anticipated not to benefit but actually rather deteriorate by interventional therapy or surgery.

Case presentation

In this article we present a case report of a male patient with pseudo-severe aortic valve stenosis due to cardiac amyloidosis highlighting the diagnostic schedule. The patient underwent stress echocardiography because of discrepant findings in transthoracic echocardiography and cardiac catheterization regarding the severity of aortic valve stenosis. After evaluation of the results, it became clear that he had a need for optimum heart failure medication and implantation of a cardiac resynchronization therapy defibrillator.

Conclusion

Due to the pitfalls in conventional as well as invasive diagnostics at rest, Stress echocardiography should be considered part of the standard optimum diagnostic spectrum in all unclear or borderline cases in order to confirm the correct diagnosis and constitute optimal therapy.

Value of tissue Doppler-derived Tei index and two-dimensional speckle tracking imaging derived longitudinal strain on predicting outcome of patients with light-chain cardiac amyloidosis

Prognosis of patients with light-chain cardiac amyloidosis (AL-CA) is poor. Speckle tracking imaging (STI) derived longitudinal deformation parameters and Doppler-derived left ventricular (LV) Tei index are valuable predictors of outcome in patients with AL-CA. We estimated the prognostic utility of Tei index and deformation parameters in 58 comprehensively phenotyped patients with AL-CA after a median follow-up of 365 days (quartiles 121, 365 days). The primary end point was all-cause mortality. 19 (33%) patients died during follow-up. Tei index (0.89 ± 0.29 vs. 0.61 ± 0.16, p < 0.001) and E to global early diastolic strain rate ratio (E/GLSR_dias) were higher while global longitudinal systolic strain (GLS_sys) was lower in non-survivors than in survivors (all p < 0.05). Tei index, NYHA functional class, GLS_sys and E/GLSR_dias were independent predictors of all-cause mortality risk, and Tei index ≥0.9 (HR 7.01, 95% CI 2.43–20.21, p < 0.001) was the best predictor of poor outcome. Combining Tei index and GLS_sys yielded the best results on predicting death within 1 year (100% with Tei index ≥0.9 and GLS_sys ≤13%) or survival (95% with Tei index ≤0.9 and GLS_sys ≥13%). We conclude that 1-year mortality risk in AL-CA patients can be reliably predicted using Tei index or deformation parameters, with combined analysis offering best performance.

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.

Myocardial strain pattern in patients with cardiac amyloidosis secondary to multiple myeloma: a cardiac MRI feature tracking study

Cardiac MRI is frequently used in the diagnosis of cardiac amyloidosis. Feature tracking is a novel method of analyzing myocardial strain at the myocardial borders. We investigated myocardial deformation mechanics of both the right and left ventricles in patients with multiple myeloma with suspected cardiac amyloidosis. Comprehensive strain analysis was performed in 43 patients with multiple myeloma and suspected cardiac amyloidosis. MRI strain by feature tracking was measured using 2D cardiac performance analysis MR software (Tomtec, Germany). Global longitudinal (GLS) and global circumferential (GLC) strain were calculated in endo and epicardium. In addition, right ventricular longitudinal strain was measured in the endocardium only. All patients later underwent endomyocardial biopsy. Average wall thickness in biopsy proven cardiac amyloidosis group (22 patients) was 1.4 ± 0.4 cm with wall thickness ≤ 1.2 cm in 36 %. LGE was present in all patients with biopsy confirmed disease. There was significantly decreased global longitudinal strain and strain rate in the epicardial and endocardial layers. Global circumferential strain was significantly reduced in the epicardial layer but not the endocardium. GLS was significantly decreased at the base in both layers compared to the mid and apical regions of the myocardium. However, the base to apex GLS gradient was suggestive of apical sparing in the endocardial layer among patients with amyloidosis (-8.2 ± 2 vs. -2.7 ± 1; p = 0.001) but not the epicardial layer. Apical sparing was evident even in those with normal thickness CA. This feature tracking MRI analysis sheds light on strain mechanics in a cohort of multiple myeloma associated cardiac amyloidosis with a significant number of cases with normal LV wall thickness and explains mechanism of apical sparing effect.

Identification of prognostic markers in transthyretin and AL cardiac amyloidosis

BACKGROUND

The prognosis of amyloidosis is known to depend heavily on cardiac function and may be improved by identifying patients at highest risk for adverse cardiac events.

AIMS

Identify predictors of mortality in patients with cardiac light-chain amyloidosis (AL), hereditary transthyretin amyloidosis (m-TTR), or wild-type transthyretin amyloidosis (WT-TTR) to prompt physician to refer these patients to dedicated centers.

METHODS AND RESULTS

Observational study. About 266 patients referred for suspected cardiac amyloidosis (CA) in two French university centers were included. About 198 patients had CA (AL = 118, m-TTR = 57, and WT-TTR = 23). Their median (25th-75th percentile) age, NT-proBNP left ventricular ejection fraction were, respectively, 68 years (59-76), 2339 pg mL^-1 (424-5974), and 60% (48-66). About 31% were in NYHA class III-IV. Interventricular septal thickness was greater in the m-TTR and WT-TTR groups than in the AL group (p < 0.0001). Median follow-up in survivor was 26 months (15-44) and 87 (44%) patients died. By multivariate analysis, independent predictors of mortality for AL amyloidosis were the following: age, cardiac output and NT-proBNP; for TTR amyloidosis was: NT-proBNP. When all amyloidosis were combined NT-proBNP, low cardiac output and pericardial effusion were independently associated with mortality.

CONCLUSION

NT-proBNP is a strong prognosticator in the three types of cardiac amyloidosis. High NT-proBNP, low cardiac output, and pericardial effusion at the time of screening should prompt physician to refer the patients to amyloidosis referral center.

Prevalence, Severity, and Prognostic Value of Sleep Apnea Syndromes in Cardiac Amyloidosis

STUDY OBJECTIVES

To assess prevalence, severity, and prognostic value of sleep-disordered breathing (SDB), in the three main cardiac amyloidosis (CA) types, i.e., light-chain (AL), transthyretin-related familial (m-TTR), or senile (WT-TTR).

METHODS

Patients consecutively referred for CA diagnosis work-up underwent cardiac assessment and nocturnal polygraphy. SDB was defined as apnea-hypopnea index (AHI) ≥ 5/h. Multivariate analysis was used to identify predictors of a major adverse cardiac event (MACE) defined as death, heart transplantation and acute heart failure.

RESULTS

Seventy CA patients were included (31 AL, 22 m-TTR, 17 WT-TTR). The mean ± standard deviation age and left ventricular ejection fraction were 71 ± 12 years and 49% ± 13% and median (interquartile range) N terminal pro brain natriuretic peptide (NT-proBNP) was 3,932 (1,607; 7,028) pg/mL. The prevalence of SDB was 90% without difference between amyloidosis types. SDB was central in 27% and obstructive in 73%. AL had less frequent severe SDB compared to m-TTR and WT-TTR (P = 0.015) but longer time with peripheral capillary oxygen saturation (SpO2) < 90% (P = 0.037). After a median follow-up of 7.5 (2.8; 14.9) months, 49% patients experienced MACE. Time with nocturnal SpO2 < 90% was the only independent predictor of MACE. The best-identified threshold was 30 min. Values > 30 min were associated with bad prognosis (Log-rank χ(2): 8.01, P value = 0.005). Using binomial logistic regression, determinants of time with nocturnal SpO2 < 90% were New York Heart Association class (P = 0.011), and log-NT-proBNP (P = 0.04) but not AHI.

CONCLUSIONS

In CA population, prevalence of SDB is high (90%) and dominated by the obstructive pattern. Bad prognosis in this population was driven by nocturnal desaturation, reflecting heart failure severity and respiratory involvement.