Left ventricular ejection time on echocardiography predicts long-term mortality in light chain amyloidosis

Advancing precision medicine in immunoglobulin light-chain amyloidosis: a novel prognostic model incorporating multi-organ indicators

To develop a more accurate prognostic model that incorporates indicators of multi-organ involvement for immunoglobulin light-chain (AL) Amyloidosis patients. Biopsy-proven AL amyloidosis patients between January 1, 2012, and February 28, 2023, were enrolled and randomly divided into a training set and a test set at a ratio of 7:3. Prognostic indicators that comprehensively cover cardiac, renal, and hepatic involvement were identified in the training set by random survival forest (RSF). Then, RSF and Cox models were established. The Concordance index (C-index) and integrated brier scores (IBS) were applied to evaluate the models' performance in the test set. Besides, the net reclassification index (NRI) and integrated discrimination improvement (IDI) were calculated. A total of 173 eligible patients were included. After a median follow-up of 25.9 (9.2, 50.3) months, 48 (27.7%) patients died. Creatine kinase-MB, estimated glomerular filtration rate ≤ 50 mL/min/1.73 m2, interventricular septum ≥ 15 mm, ejection fraction, alanine aminotransferase and Live involved were selected to develop prediction models. The RSF model based on the above indicators achieved C-index and IBS values of 0.834 (95% CI 0.725-0.915) and 0.151 (95% CI 0.1402-0.181), respectively. At last, the NRI and IDI of the RSF model were 0.301 (95% CI 0.048-0.546, P = 0.012) and 0.157 (95% CI 0.041-0.269, P < 0.001) at 5-year by comparing the RSF model with the Cox model which is based on the Mayo 2012 staging system. The RSF model that incorporates indicators of multi-organ involvement had a great performance, which may be helpful for physicians' decision-making and more accurate overall survival prediction.

Ventricular Function and Cardio-Ankle Vascular Index in Patients With Pulmonary Artery Hypertension

Aim

This study aims to evaluate the left ventricle (LV) systolic and diastolic function in patients with idiopathic pulmonary arterial hypertension (IPAH) and its correlation with systemic arterial stiffness assessed by cardio-ankle vascular index (CAVI).

Patient and methods

We included 37 patients with IPAH and 20 healthy people matched by age. All patients were assessed: vital signs, 6-minute walk test, NT-proBNP level, the CAVI, the right ventricular (RV) and LV function parameters, including ejection time (ET), tissue speckle-tracking values - global longitudinal strain (GLS) and strain rate (SR).

Results

The groups were matched by age, gender, BMI, office SBP and DBP. Patients with IPAH had higher heart rate, NT-proBNP level and lower ferritin level, GFR (CKD-EPI), SaO2 than healthy people. The mean CAVIleft was higher in IPAH patients than in the control group- 8.7±1.1 vs 7.5±0.9, P=0.007. Healthy people had significantly less E/e' and lower IVRT. LVET and RVET were shorter in IPAH patients. Patients with IPAH had mean LVGLS -(-17.6±4.8%) and 35.1% of them were with LVGLS ≤16% compared to healthy people -(-21.8±1.4%) and 0%, respectively. LVSR was significant less in IPAH patients, but in the normal range. We found significant correlations of CAVI with age, history of syncope, bilirubin, uric acid, total cholesterol, cardiac output, cardiac index, RVET, LVET and E/A. Multiple linear regression confirmed the independent significance for age (β=0.083±0.023, CI 0.033-0.133) and RVET (β=-0.018±0.005, CI -0.029 to -0.008) only. The risk to have CAVI ≥8 increased in 5.8 times in IPAH patients with RVET <248 ms (P=0.046). CAVI did not correlate with LVGLS and LVSR.

Conclusion

Significant worse systolic and diastolic LV functions were stated in pulmonary hypertensive patients compared to the control group. No LV GLS, no LV SR had significant associations with arterial stiffness evaluated by CAVI.

Significance of Left Ventricular Ejection Time in Primary Mitral Regurgitation

The optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains controversial. We aimed at evaluating the relation between left ventricular ejection time (LVET) and outcome in patients with moderate or severe chronic primary MR because of prolapse. Clinical, Doppler echocardiographic, and outcome data prospectively collected from 302 patients (median age 61 [54 to 74] years, 34% women) with moderate or severe primary MR were analyzed. Patients were retrospectively stratified by quartiles of LVET. The primary end point of the study was the composite of need for MV surgery or all-cause mortality. During a median follow-up time of 66 (25th to 75th percentile, 33 to 95) months, 178 patients reached the primary end point. Patients in the lowest quartile of LVET (<260 ms) were at high risk for adverse events compared with those in the other quartiles of LVET (global p = 0.005), whereas the rate of events was similar for the other quartiles (p = NS for all). After adjustment for clinical predictors of outcome, including age, gender, history of atrial fibrillation, MR severity, and current recommended triggers for MV surgery in asymptomatic primary MR, LVET <260 ms was associated with an increased risk of events (adjusted hazard ratio 1.49, 95% confidence interval 1.03 to 2.16, p = 0.033). In conclusion, we observed that shorter LVET is associated with increased risk of adverse events in patients with moderate or severe primary MR because of prolapse. Further studies are required to investigate whether shorter LVET has a direct effect on outcomes or is solely a risk marker in primary MR.

Diagnostic and prognostic value of cardiac imaging in amyloidosis

Amyloidosis is an infiltrative disease caused by extracellular protein deposition that has accumulated a lot of scientific production in recent years. Different types of amyloidosis can affect the heart. Transthyretin amyloidosis and light chain amyloidosis are the two most common types of cardiac amyloidosis. These entities have a poor prognosis, so accurate diagnostic techniques are imperative for determining an early therapeutic approach. Recent advances in cardiac imaging and diagnostic strategies show that these tools are safe and can avoid the use of invasive diagnostic techniques to histological confirmation, such as endomyocardial biopsy. We performed a review on the diagnostic and prognostic implications of different cardiac imaging techniques in cardiac amyloidosis. We mainly focus on reviewing echocardiography, cardiac magnetic resonance, computed tomography and nuclear imaging techniques and the different safety measurements that can be done with each of them.

Left ventricular output indices in hospitalized heart failure: when "simpler" may not mean "better"

Assessment of left ventricular (LV) output in hospitalized patients with heart failure (HF) is important to determine prognosis. Although echocardiographic LV ejection fraction (EF) is generally used to this purpose, its prognostic value is limited. In this investigation LV-EF was compared with other echocardiographic per-beat measures of LV output, including non-indexed stroke volume (SV), SV index (SVI), stroke distance (SD), ejection time (ET), and flow rate (FR), to determine the best predictor of all-cause mortality in patients hospitalized with HF. A final cohort of 350 consecutive patients hospitalized with HF who underwent echocardiography during hospitalization was studied. At a median follow-up of 2.7 years, 163 patients died. Non-survivors at follow-up had lower SD, SVI and SV, but not ET, FR and LV-EF than survivors. At multivariate analysis, only age, systolic blood pressure, chronic kidney disease, chronic obstructive pulmonary disease, use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and SVI remained significantly associated with outcome [HR for SVI 1.13 (1.04-1.22), P = 0.003]. In particular, for each 5 ml/m² decrease in SVI, a 13% increase in risk of mortality for any cause was observed. SVI is a powerful prognosticator in HF patients, better than other per-beat measures, which may be simpler but partial or incomplete descriptors of LV output. SVI, therefore, should be considered for the routine echocardiographic evaluation of patients hospitalized with HF to predict prognosis.

Association between systolic ejection time and outcomes in heart failure by ejection fraction

AIMS

Worsening heart failure (HF) is associated with shorter left ventricular systolic ejection time (SET), but there are limited data describing the relationship between SET and clinical outcomes. Thus, the objective was to describe the association between SET and clinical outcomes in an ambulatory HF population irrespective of ejection fraction (EF).

METHODS AND RESULTS

We identified ambulatory patients with HF with reduced EF (HFrEF) and HF with preserved EF (HFpEF) who had an outpatient transthoracic echocardiogram performed between August 2008 and July 2010 at a tertiary referral centre. Multivariable logistic regression was used to evaluate the association between SET and 1-year outcomes. A total of 545 HF patients (171 HFrEF, 374 HFpEF) met eligibility criteria. Compared with HFpEF, HFrEF patients were younger [median age 60 years (25th-75th percentiles 50-69) vs. 64 years (25th-75th percentiles 53-74], with fewer females (30% vs. 56%) and a similar percentage of African Americans (36% vs. 35%). Median (25th-75th percentiles) EF with HFrEF was 30% (25-35%) and with HFpEF was 54% (48-58%). Median SET was shorter (280 ms vs. 315 ms, P < 0.001), median pre-ejection period was longer (114 ms vs. 89 ms, P < 0.001), and median relaxation time was shorter (78.7 ms vs. 93.3 ms, P < 0.001) among patients with HFrEF vs. HFpEF. Death or HF hospitalization occurred in 26.9% (n = 46) HFrEF and 11.8% (n = 44) HFpEF patients. After adjustment, longer SET was associated with lower odds of the composite of death or HF hospitalization at 1 year among HFrEF but not HFpEF patients.

CONCLUSION

Longer SET is independently associated with improved outcomes among HFrEF patients but not HFpEF patients, supporting a potential role for normalizing SET as a therapeutic strategy with systolic dysfunction.

Age related structural and functional changes in left ventricular performance in healthy subjects: a 2D echocardiographic study

Left ventricular (LV) adaptation to aging is currently poorly understood. We aimed to characterize age related changes in LV structure and function by studying a large group of healthy subjects across a wide age range. Prospectively enrolled healthy volunteers (n = 778, 327 females; age 18 to 100 years, mean age 49.8 ± 18.1 years), were divided into 4 age groups: 18 to 34 years (n = 165); 35 to 49 years (n = 242), 50 to 79 years (n = 334) and ≥ 80 years (n = 40). All subjects underwent clinical examination, as well as comprehensive transthoracic echocardiogram [TTE]. Body mass index, systolic blood pressure (BP), and left atrial volume (p < 0.0001) increased with age while diastolic BP (p < 0.0001) decreased over time. LV mass/body surface area (BSA) and relative wall thickness increased with age (p < 0.0001) coincident with worsening parameters of diastolic function (E/A and E/Em, p < 0.0001). The ejection fraction and Sm did not change significantly. Stroke volume, ejection time index, flow rate and stroke work significantly increased with age (p < 0.01). The arterial elastance (Ea), a measure of ventricular afterload, and ventricular elastance (Ees), an index of LV systolic stiffness did not change with age nor did their ratio (Ees/Ea) the latter being an expression of ventricular-arterial coupling. Age, gender and LVM were the main independent variables associated with LV systolic function. In conclusion, LV adaptation to aging in a healthy cohort is characterized by concentric LV remodeling, increased contractility and preserved ventricular-arterial coupling.

Role of echocardiography in assessing cardiac amyloidoses: a systematic review

Cardiac amyloidosis is a manifestation of one of several systemic amyloidoses, and is characterized by increased left-ventricular (LV) wall thickness and normal or decreased LV cavity size. Congestive heart failure in cardiac amyloidosis is characterized by a predominant diastolic LV dysfunction, and systolic dysfunction occurs only in late-stage disease. Echocardiography is a noninvasive, reproducible method for assessing cardiac morphology and function in cardiac amyloidosis, and some echocardiographic indices are prognostic for amyloidoses. This review describes the advances in echocardiography and its role in the diagnosis and management of cardiac amyloidoses. Our review suggests that LV longitudinal function and the cyclic variation of myocardial integrated backscatter may be the best predictors of adverse outcomes. In the future, new echocardiographic techniques, such as fully automated echocardiogram interpretation, should provide further useful information for assessing cardiac function and prognosis in cardiac amyloidosis patients.

Stem cell transplantation for immunoglobulin light chain amyloidosis

Systemic chemotherapy aimed at eradicating transformed plasma cells is the mainstay of treatment for immunoglobulin light chain amyloidosis (AL). Autologous stem cell transplantation (SCT) is a highly effective treatment for AL and can lead to long term survival in excess of 10 years in patients who achieve complete remission. Since AL is a unique disease characterized by multiple organ dysfunction, SCT poses unique challenges in this disease. Morbidity and mortality of SCT has remarkably improved over time primarily due to careful selection of patients and evolution of predictive and prognostic models based on serum immunoglobulin light chains and cardiac biomarkers. In this review we focus on the historical evolution of SCT as a treatment for AL and unique challenges it poses in the management of this rare disease and provide guidelines for managing these challenges.

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.

Monosialoganglioside-Containing Nanoliposomes Restore Endothelial Function Impaired by AL Amyloidosis Light Chain Proteins

BACKGROUND

Light chain amyloidosis (AL) is associated with high mortality, especially in patients with advanced cardiovascular involvement. It is caused by toxicity of misfolded light chain proteins (LC) in vascular, cardiac, and other tissues. There is no treatment to reverse LC tissue toxicity. We tested the hypothesis that nanoliposomes composed of monosialoganglioside, phosphatidylcholine, and cholesterol (GM1 ganglioside-containing nanoliposomes [NLGM1]) can protect against LC-induced human microvascular dysfunction and assess mechanisms behind the protective effect.

METHODS AND RESULTS

The dilator responses of ex vivo abdominal adipose arterioles from human participants without AL to acetylcholine and papaverine were measured before and after exposure to LC (20 μg/mL) with or without NLGM1 (1:10 ratio for LC:NLGM1 mass). Human umbilical vein endothelial cells were exposed for 18 to 20 hours to vehicle, LC with or without NLGM1, or NLGM1 and compared for oxidative and nitrative stress response and cellular viability. LC impaired arteriole dilator response to acetylcholine, which was restored by co-treatment with NLGM1. LC decreased endothelial cell nitric oxide production and cell viability while increasing superoxide and peroxynitrite; these adverse effects were reversed by NLGM1. NLGM1 increased endothelial cell protein expression of antioxidant enzymes heme oxygenase 1 and NAD(P)H quinone dehydrogenase 1 and increased nuclear factor, erythroid 2 like 2 (Nrf-2) protein. Nrf-2 gene knockdown reduced antioxidant stress response and reversed the protective effects of NLGM1.

CONCLUSIONS

NLGM1 protects against LC-induced human microvascular endothelial dysfunction through increased nitric oxide bioavailability and reduced oxidative and nitrative stress mediated by Nrf-2-dependent antioxidant stress response. These findings point to a potential novel therapeutic approach for light chain amyloidosis.

Regional myocardial microvascular dysfunction in cardiac amyloid light-chain amyloidosis: assessment with 3T cardiovascular magnetic resonance

BACKGROUND

Coronary microvascular dysfunction is highly prevalent in patients with amyloid light-chain (AL) cardiac amyloidosis (AL-CA). The aim of this study was to clarify the feasibility of first-pass perfusion imaging using 3 T cardiovascular magnetic resonance (CMR) for evaluating the difference in left ventricular (LV) regional myocardial microvascular function among normal subjects and in patients with AL-CA. The amyloidosis patients were classified into those with impaired systolic function [LV ejection fraction (LVEF) < 50 %] and those with preserved systolic function.

METHODS

In total, 32 patients with biopsy-proven AL-CA, including 11 AL-CA patients with systolic dysfunction, 21 AL-CA patients with preserved systolic function, and 25 healthy subjects, underwent CMR examination. LV regional myocardial perfusion parameters included upslope, time to maximum signal intensity (TTM) and max signal intensity (MaxSI) were compared among the three patient groups. Receiver operating characteristic analysis was performed to determine whether perfusion parameters could be used in discriminating regional myocardial microvascularity between AL-CA patients and normal subjects.

RESULTS

The patients with AL-CA had significantly reduced first-pass perfusion upslope and MaxSI, and increased TTM compared with the normal subjects (all P < 0.01). Compared with the patients with AL-CA and preserved LVEF, the patients with AL-CA and impaired systolic function had a longer TTM in the basal (47.05 ± 16.59 vs. 39.68 ± 19.11; P = 0.002) and mid-ventricular (44.61 ± 16.34 vs. 37.74 ± 18.25; P = 0.002) segments; lower upslope in the basal (2.41 ± 1.32 vs. 3.60 ± 1.68; P < 0.0001), mid-ventricular (2.82 ± 1.34 vs. 4.15 ± 2.02; P < 0.0001), and apical (3.71 ± 1.38 vs. 4.97 ± 2.55; P = 0.004) segments; and lower MaxSI (31.67 ± 15.23 vs. 37.96 ± 11.15; P < 0.0001) in the basal segment. The ROC curve analysis revealed that the first-pass upslope, TTM, and MaxSI may be used as indicators for differentiating microcirculation between AL-CA patients with preserved or impaired systolic function and normal subjects.

CONCLUSIONS

The differences in LV regional myocardial microvascular function among normal subjects, AL-CA patients with systolic dysfunction, and AL-CA patients with preserved systolic function can be monitored using first-pass perfusion CMR.

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

OBJECTIVES

The aim of this study was to compare left ventricular longitudinal strain (LS) evaluated by 2-dimensional echocardiography with cardiac magnetic resonance (CMR) in cardiac amyloidosis (CA), establish correlations between histological and imaging findings, and assess the prognostic usefulness of LS measurement and CMR.

BACKGROUND

CA is a condition with a poor prognosis due chiefly to 3 forms of amyloidosis: light-chain amyloidosis (AL), hereditary transthyretin (M-TTR), and wild-type transthyretin (WT-TTR). Two-dimensional echocardiography measurement of LS has been reported to detect early left ventricular systolic dysfunction. The pathophysiological underpinnings, regional distribution, and prognostic significance of LS in CA are unclear.

METHODS

All patients underwent echocardiography, and 53 underwent CMR. The native hearts of the 3 patients who received heart transplants were subjected to histological examination. For each of the 17 left ventricular segments in the American Heart Association model, we evaluated LS, late gadolinium enhancement (LGE) by CMR, and cardiac amyloid deposition. Univariate and multivariate analyses were performed at 6 months to identify variables associated with major adverse cardiac events (MACE).

RESULTS

We studied 79 patients with CA; 26 had AL, 36 M-TTR, and 17 WT-TTR. Mean LS was -10 ± 4%. Both LS and amyloid deposits showed a basal-to-apical gradient. The mean LS and number of segments with LGE were similar across the 3 CA types. LS correlated with LGE and amyloid burden (r = 0.72). LGE was seen in the 6 basal segments in all WT-TTR patients. During the median follow-up of 11 months (range 4 to 17 months), 36 (46%) patients experienced MACE. Independent predictors of MACE were apical LS (cutoff, -14.5%), N-terminal pro-B-type natriuretic peptide (cutoff, 4,000 ng/l), and New York Heart Association functional class III to IV heart failure.

CONCLUSIONS

Basal-to-apical LS abnormalities are similar across CA types and reflect the amyloid burden. Apical LS independently predicts MACE.

Assessment of cardiovascular function from multi-Gaussian fitting of a finger photoplethysmogram

Monitoring of cardiovascular function on a beat-to-beat basis is fundamental for protecting patients in different settings including emergency medicine and interventional cardiology, but still faces technical challenges and several limitations. In the present study, we propose a new method for the extraction of cardiovascular performance surrogates from analysis of the photoplethysmographic (PPG) signal alone.We propose using a multi-Gaussian (MG) model consisting of five Gaussian functions to decompose the PPG pulses into its main physiological components. From the analysis of these components, we aim to extract estimators of the left ventricular ejection time, blood pressure and vascular tone changes. Using a multi-derivative analysis of the components related with the systolic ejection, we investigate which are the characteristic points that best define the left ventricular ejection time (LVET). Six LVET estimates were compared with the echocardiographic LVET in a database comprising 68 healthy and cardiovascular diseased volunteers. The best LVET estimate achieved a low absolute error (15.41   ±   13.66 ms), and a high correlation (ρ = 0.78) with the echocardiographic reference.To assess the potential use of the temporal and morphological characteristics of the proposed MG model components as surrogates for blood pressure and vascular tone, six parameters have been investigated: the stiffness index (SI), the T1_d and T1_2 (defined as the time span between the MG model forward and reflected waves), the reflection index (RI), the R1_d and the R1_2 (defined as their amplitude ratio). Their association to reference values of blood pressure and total peripheral resistance was investigated in 43 volunteers exhibiting hemodynamic instability. A good correlation was found between the majority of the extracted and reference parameters, with an exception to R1_2 (amplitude ratio between the main forward wave and the first reflection wave), which correlated low with all the reference parameters. The highest correlation ([Formula: see text] = 0.45) was found between T1_2 and the total peripheral resistance index (TPRI); while in the patients that experienced syncope, the highest agreement ([Formula: see text] = 0.57) was found between SI and systolic blood pressure (SBP) and mean blood pressure (MBP).In conclusion, the presented method for the extraction of surrogates of cardiovascular performance might improve patient monitoring and warrants further investigation.

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.

Left Ventricular Ejection Time Derived From the Common Carotid Artery Doppler Waveform: Association With Left Ventricular Ejection Fraction and Prediction of Heart Failure

OBJECTIVES

Left ventricular ejection time (LVET) is measured from blood pressure tracings as the interval from end diastole to the dicrotic notch and shows associations with left ventricular ejection fraction (LVEF) and heart failure. LVET can be measured on common carotid artery Doppler waveforms. We therefore studied the possible associations of common carotid artery LVET with LVEF measured by echocardiography and heart failure.

METHODS

We performed a retrospective study of 110 patients who had transthoracic echocardiography and carotid Doppler evaluations within 1 day of each other. LVEF was determined by the biplane modified Simpson method. LVET was measured from left common carotid artery Doppler tracings. Linear regression was used to evaluate associations between LVET and LVEF. We also used logistic regression with LVEF of less than 40% as a cut point for heart failure to generate a receiver operating characteristic curve, estimate the area under the curve, and calculate sensitivity and specificity.

RESULTS

LVET was associated with LVEF (P < .0001). The area under the curve of LVET for heart failure was 0.81 (95% confidence interval [CI], 0.72-0.87), and the sensitivity and specificity were 76.9% (95% CI, 65.4%-88.4%) and 65.5% (95% CI, 53.4%-77.8%), respectively, for LVET of 321 milliseconds.

CONCLUSIONS

LVET measured on common carotid artery Doppler tracings decreases with LVEF and is strongly associated with prevalent heart failure. Based on what is known of blood pressure-measured LVET, common carotid artery Doppler waveform-derived LVET could be used to serially monitor cardiac function.

Echocardiographic assessment of the cardiac amyloidoses

Cardiac amyloidosis is a cardiomyopathy characterized by increased left ventricular (LV) wall thickness and normal or decreased LV cavity size. Congestive heart failure in cardiac amyloidosis is generally considered a predominantly diastolic phenomenon, with systolic dysfunction only occurring in late-stage disease. Echocardiography is a noninvasive, reproducible method of assessing cardiac features and function in cardiac amyloidosis, and some echocardiographic indices are prognostic for the amyloidoses, with M-mode and 2-dimensional echocardiography able to detect increased LV wall thickness. Moreover, Doppler flow measurements can incrementally assess diastolic LV dysfunction, which is characteristic of cardiac amyloidosis, and provide important prognostic information. Additionally, tissue Doppler imaging can detect subtle changes in both systolic and diastolic LV function, which cannot be detected by Doppler flow measurements, and LV longitudinal strain assessed by color tissue Doppler and speckle tracking echocardiography can provide more accurate LV functional and prognostic information than tissue Doppler imaging. This review describes the advances in echocardiography and its crucial role in the diagnosis and management of cardiac amyloidosis.

Prognostic value of high-sensitivity cardiac troponin T in patients with endomyocardial-biopsy proven cardiac amyloidosis

OBJECTIVE

To investigate prognostic predictors of long-term survival of patients with cardiac amyloidosis (CA), and to determine predictive value of high-sensitivity cardiac troponin T (hs-cTnT) in CA patients.

METHODS

We recruited 102 consecutive CA cases and followed these patients for 5 years. We described their clinical characteristics at presentation and used a new, high-sensitivity assay to determine the concentration of cTnT in plasma samples from these patients.

RESULTS

The patients with poor prognosis showed older age (56 ± 12 years vs. 50 ± 15 years, P = 0.022), higher incidences of heart failure (36.92% vs. 16.22%, P = 0.041), pericardial effusion (60.00% vs. 35.14%, P = 0.023), greater thickness of interventricular septum (IVS) (15 ± 4 mm vs. 13 ± 4 mm, P = 0.034), higher level of hs-cTnT (0.186 ± 0.249 ng/mL vs. 0.044 ± 0.055 ng/mL, P = 0.001) and higher NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels (11,742 ± 10,464 pg/mL vs. 6,031 ± 7,458 pg/mL, P = 0.006). At multivariate Cox regression analysis, heart failure (HR: 1.78, 95%CI: 1.09-2.92, P = 0.021), greater wall thickness of IVS (HR: 1.44, 95%CI: 1.04-3.01, P = 0.0375) and higher hs-cTnT level (HR: 6.16, 95%CI: 2.20-17.24, P = 0.001) at enrollment emerged as independent predictors of all-cause mortality.

CONCLUSIONS

We showed that hs-cTnT is associated with a very ominous prognosis, and it is also the strongest predictor of all-cause mortality in multivariate analysis. Examination of hs-cTnT concentrations provides valuable prognostic information concerning long-term outcomes.

Nanoliposomes protect against AL amyloid light chain protein-induced endothelial injury

CONTEXT

A newly-recognized pathogenic mechanism underlying light chain amyloidosis (AL) involves endothelial dysfunction and cell injury caused by misfolded light chain proteins (LC). Nanoliposomes (NL) are artificial phospholipid vesicles that could attach to misfolded proteins and reduce tissue injury.

OBJECTIVE

To test whether co-treatment with NL reduces LC-induced endothelial dysfunction and cell death.

METHODS

Abdominal subcutaneous adipose arterioles from 14 non-AL subjects were cannulated; dilator response to acetylcholine and papaverine were measured at baseline and following 1-hour exposure to LC (20 µg/mL, 2 purified from AL subjects' urine, 1 from human recombinant LC [AL-09]) ± NL (phosphatidylcholine/cholesterol/phosphatidic acid 70/25/5 molar ratio) or NL alone. Human aortic artery endothelial cells (HAEC) were exposed to Oregon Green-labeled LC ± NL for 24 hours and intracellular LC and apoptosis (Hoechst stain) were measured. Circular dichroism spectroscopy was performed on AL-09 LC ± NL to follow changes in secondary structure and protein thermal stability.

RESULTS

LC caused impaired dilation to acetylcholine that was restored by NL (control - 94.0 ± 1.8%, LC - 65.0 ± 7.1%, LC + NL - 95.3 ± 1.8%, p ≤ 0.001 LC versus control or LC + NL). NL protection was inhibited by L-NG-nitroarginine methyl ester. NL increased the beta sheet structure of LC, reduced endothelial cell internalization of LC and protected against LC-induced endothelial cell death.

CONCLUSIONS

LC induced human adipose arteriole endothelial dysfunction and endothelial cell death, which were reversed by co-treatment with NL. This protection may partly be due to enhancing LC protein structure and reducing LC internalization. Nanoliposomes represent a promising new class of agents to ameliorate tissue injury from protein misfolding diseases such as AL.

Clinical and imaging predictors of 1-year and long-term mortality in light chain (AL) amyloidosis: a 5-year follow-up study

Light chain amyloidosis (AL) involves multiorgan failure induced by amyloidogenic light chain proteins, and is associated with high mortality. We aimed to identify clinical, laboratory, and imaging parameters that would predict 1-year and long-term AL mortality. Forty-four biopsy-proven AL patients (61.5 ± 12 years, 20 females) underwent clinical evaluation including laboratory assays, echocardiography, and contrast cardiac magnetic resonance imaging (CMR, n = 31) prior to chemotherapy. Patients were prospectively followed for median duration of 62.7 months (interquartile range 35.5 months). Clinical and laboratory parameters were compared between 1-year survivors and nonsurvivors. Univariate Kaplan-Meier survival plots were calculated followed by stepwise logistic regression analysis to assess independent predictors of long-term survival. Eighteen (40.9 %) patients died within 1 year and an additional 10 subjects died during long-term follow-up. Patients who expired within 1 year presented with more advanced class of heart failure, higher alkaline phosphatase and uric acid, lower limb lead voltage on electrocardiography, shorter left ventricular ejection time (ET) on echocardiography, and a higher proportion of late gadolinium enhancement on CMR. On multivariable analysis, only ET ≤240 ms on echocardiography (hazard ratio (HR) 5.07, 95 % confidence interval (CI) 1.83-14.1, P = 0.002) and New York Heart Association functional class II-IV presentation (HR 1.0058, 95 % CI 1.0014-1.0103, P = 0.01) were independent predictors of AL mortality. In conclusion, AL amyloidosis is associated with high 1-year and long-term mortality. Among clinical, laboratory, and imaging parameters tested, an echocardiographic finding of ET ≤240 ms has independent and additive prognostic value to clinical heart failure evaluation in determining long-term survival of AL patients. This result may be important in the early identification of patients at risk.

Multi-Gaussian fitting for the assessment of left ventricular ejection time from the photoplethysmogram

The Left ventricular ejection time (LVET) is one of the primary surrogates of the left ventricular contractility and stroke volume. Its continuous monitoring is considered to be a valuable hypovolumia prognostic parameter and an important risk predictor in cardiovascular diseases such as cardiac and light chain amyloidosis. In this paper, we present a novel methodology for the assessment of LVET based the Photoplethysmographic (PPG) waveform. We propose the use of Gaussian functions to model both systolic and diastolic phases of the PPG beat and consequently determine the onset and offset of the systolic ejection from the analysis of the systolic phase 3(rd) derivative. The results achieved by the proposed methodology were compared with the algorithm proposed by Chan et al. [1], revealing better estimation of LVET (15.84 ± 13.56 ms vs 23.01 ± 14.60 ms), and similar correlation with the echocardiographic reference (0.73 vs 0.75).

Protective role of clusterin in preserving endothelial function in AL amyloidosis

Misfolded immunoglobulin light chain proteins (LC) in light chain amyloidosis (AL) are toxic to vascular tissues. We tested the hypothesis that chaperone protein clusterin preserves endothelial function and cell survival during LC exposure.

METHODS

LC (20 μg/mL) were given to human aortic endothelial cells (EC) for 24-h and clusterin protein/gene expression and secretion were measured. DNA fragmentation was measured with/without recombinant clusterin (Clu, 300 ng/mL). Adipose arterioles (non-AL subjects) were tested for dilator responses to acetylcholine/papaverine at baseline and after 1-h of LC ± Clu.

RESULTS

LC reduced EC clusterin secretion, protein and gene expression while increasing DNA fragmentation. Clu attenuated LC-induced DNA fragmentation and restored dilator response to acetylcholine (logEC50: control -7.05 ± 0.2, LC + Clu -6.53 ± 0.4, LC -4.28 ± 0.7, p < 0.05 versus control, LC + Clu).

CONCLUSIONS

LC induced endothelial cell death and dysfunction while reducing clusterin protein/gene expression and secretion. Exogenous clusterin attenuated LC toxicity. This represents a new pathobiologic mechanism and therapeutic target for AL amyloidosis.

Comparison of right ventricular longitudinal strain imaging, tricuspid annular plane systolic excursion, and cardiac biomarkers for early diagnosis of cardiac involvement and risk stratification in primary systematic (AL) amyloidosis: a 5-year cohort study

AIMS

To determine the role of assessing right ventricular (RV) function, using standard echocardiography and Doppler myocardial imaging (DMI), in the early diagnosis of cardiac amyloidosis and in the prediction of mortality.

METHODS AND RESULTS

Patients with primary systemic (AL) amyloidosis seen at our institution from 1 February 2004 through 31 October 2005 (N=249) were categorized by left ventricular thickness and E' velocity and compared with 38 age- and sex-matched controls. Standard echocardiographic and DMI examination were used to measure echocardiographic parameters of RV function: systolic tissue velocity, strain rate, and strain were determined for basal and middle RV free wall segments. Patients were followed up for the endpoint of mortality. RV tricuspid annular plane systolic excursion (TAPSE) and all DMI measurements were lower in patients with AL amyloidosis and normal echocardiography results (AL-normal-echo group) than controls. A bivariate model including strain of the basal segment of the RV free wall and TAPSE was the best for distinguishing AL-normal-echo patients from controls. Male sex [hazard ratio (HR), 2.2; P=0.005], brain natriuretic peptide levels (HR 1.4; P=0.003), troponin T levels (HR 1.6; P=0.01), pleural effusion (HR 3.6; P<0.001), E/A ratio (HR 1.3; P=0.006), RV systolic pressure (HR 1.02; P=0.01), and RV strain rate of the middle segment (HR 1.3; P=0.02) were independent predictors of death.

CONCLUSION

DMI measures of the RV can identify early impairment of cardiac function or stratify risk of death in patients with AL amyloidosis. Further studies with longer follow-up are warranted to confirm these results.

Human microvascular dysfunction and apoptotic injury induced by AL amyloidosis light chain proteins

Light chain amyloidosis (AL) involves overproduction of amyloidogenic light chain proteins (LC) leading to heart failure, yet the mechanisms underlying tissue toxicity remain unknown. We hypothesized that LC induces endothelial dysfunction in non-AL human microvasculature and apoptotic injury in human coronary artery endothelial cells (HCAECs). Adipose arterioles (n = 34, 50 ± 3 yr) and atrial coronary arterioles (n = 19, 68 ± 2 yr) from non-AL subjects were cannulated. Adipose arteriole dilator responses to acetylcholine/papaverine were measured at baseline and 1 h exposure to LC (20 μg/ml) from biopsy-proven AL subjects (57 ± 11 yr) without and with antioxidant cotreatment. Coronary arteriole dilation to bradykinin/papaverine was measured post-LC exposure. HCAECs were exposed to 1 or 24 h of LC. LC reduced dilation to acetylcholine (10(-4) M: 41.6 ± 7 vs. 85.8 ± 2.2% control, P < 0.001) and papaverine (81.4 ± 4.6 vs. 94.8 ± 1.3% control, P < 0.01) in adipose arterioles and to bradykinin (10(-6) M: 68.6 ± 6.2 vs. 90.9 ± 1.6% control, P < 0.001) but not papaverine in coronary arterioles. There was an increase in superoxide and peroxynitrite in arterioles treated with LC. Adipose arteriole dilation was restored by cotreatment with polyethylene glycol-superoxide dismutase and tetrahydrobiopterin but only partially restored by mitoquinone (mitochondria-targeted antioxidant) and gp91ds-tat (NADPH oxidase inhibitor). HCAECs exposed to LC showed reduced NO and increased superoxide, peroxynitrite, annexin-V, and propidium iodide compared with control. Brief exposure to physiological amounts of LC induced endothelial dysfunction in human adipose and coronary arterioles and increased apoptotic injury in coronary artery endothelial cells likely as a result of oxidative stress, reduced NO bioavailability, and peroxynitrite production. Microvascular dysfunction and injury is a novel mechanism underlying AL pathobiology and is a potential target for therapy.

Independent predictors of survival in primary systemic (Al) amyloidosis, including cardiac biomarkers and left ventricular strain imaging: an observational cohort study

BACKGROUND

The prognostic value of Doppler myocardial imaging, including myocardial velocity imaging, strain, and strain rate imaging, in patients with primary (AL) amyloidosis is uncertain. The aim of this longitudinal study was to identify independent predictors of survival, comparing clinical data, hematologic and cardiac biomarkers, and standard echocardiographic and Doppler myocardial imaging measures in a cohort of patients with AL amyloidosis.

METHODS

A total of 249 consecutive patients with AL amyloidosis were prospectively enrolled. The primary end point was all-cause mortality, and during a median follow-up period of 18 months, 75 patients (30%) died. Clinical and electrocardiographic data, biomarkers (brain natriuretic peptide and cardiac troponin T) and standard echocardiographic and longitudinal systolic and diastolic Doppler myocardial imaging measurements for 16 left ventricular segments were tested as potential independent predictors of survival.

RESULTS

Age (hazard ratio [HR], 1.03; P = .03), New York Heart Association class III or IV (HR, 2.47; P = .01), the presence of pleural effusion (HR, 1.79; P = .08), brain natriuretic peptide level (HR, 1.29; P = .01), ejection time (HR, 0.99; P = .13), and peak longitudinal systolic strain of the basal anteroseptal segment (HR, 1.05; P = .02) were independent predictors in the final model.

CONCLUSIONS

Multivariate survival analysis identified independent predictors of clinical outcome in patients with AL amyloidosis: New York Heart Association class III or IV, presence of pleural effusion, brain natriuretic peptide level > 493 pg/mL, ejection time < 273 ms, and peak longitudinal systolic basal anteroseptal strain less negative than or equal to -7.5% defined a high-risk group of patients.