Prognostic implication of late gadolinium enhancement on cardiac MRI in light chain (AL) amyloidosis on long term follow up

Repeatability and reproducibility of cardiac manganese-enhanced magnetic resonance imaging

Manganese-enhanced magnetic resonance imaging can provide a surrogate measure of myocardial calcium handling. Its repeatability and reproducibility are currently unknown. Sixty-eight participants: 20 healthy volunteers, 20 with acute myocardial infarction, 18 with hypertrophic and 10 with non-ischemic dilated cardiomyopathy underwent manganese-enhanced magnetic resonance imaging. Ten healthy volunteers were re-scanned at 3 months. Native T1 values and myocardial manganese uptake were assessed for intra and inter-observer repeatability. Scan-rescan reproducibility was assessed in ten healthy volunteers. Intra-observer and inter-observer correlation was excellent in healthy volunteers for mean native T1 mapping [Lin's correlation coefficient (LCC) 0.97 and 0.97 respectively] and myocardial manganese uptake (LCC: 0.99 and 0.96 respectively). Scan-rescan correlation for native T1 and myocardial manganese uptake was also excellent. Similarly, intra-observer correlations for native T1 and myocardial manganese uptake in patients with acute myocardial infarction (LCC: 0.97 and 0.97 respectively), hypertrophic (LCC: 0.98 and 0.97 respectively) and dilated cardiomyopathy (LCC: 0.99 and 0.95 respectively) were excellent. Limits of agreement were broader in patients with dilated cardiomyopathy. Manganese-enhanced magnetic resonance imaging has high repeatability and reproducibility in healthy myocardium and high repeatability in diseased myocardium. However, further study is needed to establish robustness in pathologies with diffuse myocardial fibrosis.

Biomarkers in AL Amyloidosis

Systemic AL amyloidosis is a rare complex hematological disorder caused by clonal plasma cells which produce amyloidogenic immunoglobulins. Outcome and prognosis is the combinatory result of the extent and pattern of organ involvement secondary to amyloid fibril deposition and the biology and burden of the underlying plasma cell clone. Prognosis, as assessed by overall survival, and early outcomes is determined by degree of cardiac dysfunction and current staging systems are based on biomarkers that reflect the degree of cardiac damage. The risk of progression to end-stage renal disease requiring dialysis is assessed by renal staging systems. Longer-term survival and response to treatment is affected by markers of the underlying plasma cell clone; the genetic background of the clonal disease as evaluated by interphase fluorescence in situ hybridization in particular has predictive value and may guide treatment selection. Free light chain assessment forms the basis of hematological response criteria and minimal residual disease as assessed by sensitive methods is gradually being incorporated into clinical practice. However, sensitive biomarkers that could aid in the early diagnosis and that could reflect all aspects of organ damage and disease biology are needed and efforts to identify them are continuous.

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.

New developments in diagnosis, risk assessment and management in systemic amyloidosis

Amyloidosis is a group of disorders characterized by a misfolded protein that deposits in organs and compromise their function. Clinician should have a high index of suspicion because in most cases, the clinical picture is non-specific. Typing of amyloid is of utmost importance and should be an integral part of accurately diagnosing a patient. AL amyloidosis is the most common systemic amyloidosis in the western world in which the misfolded proteins are immunoglobulin light chains secreted by clonal plasma cells. New data about prognostication of AL amyloidosis patients are accumulating. The treatment goal is to eradicate the amyloidogenic plasma cell clone, by using high dose melphalan and/or novel agents (proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies against CD38). Early diagnosis is important for effectively treating the patient as late diagnosis hampers chances for organ recovery. ATTR amyloidosis is less recognized but is increasingly seen due to better recognition and improved diagnostic tools. New data about treatment options (patisiran, inotersen and tafamidis) have recently been published and are discussed.

Prognostic value of novel imaging parameters derived from standard cardiovascular magnetic resonance in high risk patients with systemic light chain amyloidosis

BACKGROUND

The differentiated assessment of functional parameters besides morphological changes is essential for the evaluation of prognosis in systemic immunoglobulin light chain (AL) amyloidosis.

METHODS

Seventy-four subjects with AL amyloidosis and presence of late gadolinium enhancement (LGE) pattern typical for cardiac amyloidosis were analyzed. Long axis strain (LAS) and myocardial contraction fraction (MCF), as well as morphological and functional markers, were measured. The primary endpoint was death, while death and heart transplantation served as a composite secondary endpoint.

RESULTS

After a median follow-up of 41 months, 29 out of 74 patients died and 10 received a heart transplant. Left ventricular (LV) functional parameters were reduced in patients, who met the composite endpoint (LV ejection fraction 51% vs. 61%, LAS - 6.9% vs - 10%, GLS - 12% vs - 15% and MCF 42% vs. 69%; p <  0.001 for all). In unadjusted univariate analysis, LAS (HR = 1.05, p <  0.001) and MCF (HR = 0.96, p <  0.001) were associated with reduced transplant-free survival. Kaplan-Meier analyses showed a significantly lower event-free survival in patients with reduced MCF. MCF and LAS performed best to identify high risk patients for secondary endpoint (Log-rank test p <  0.001) in a combined model. Using sequential Cox regression analysis, the addition of LAS and MCF to LV ejection fraction led to a significant increase in the predictive power of the model (χ2 (df = 1) = 28.2, p <  0.001).

CONCLUSIONS

LAS and MCF as routinely available and robust CMR-derived parameters predict outcome in LGE positive AL amyloidosis. Patients with impaired LV function in combination with reduced LAS and MCF are at the highest risk for death and heart transplantation.

Right ventricular involvement evaluated by cardiac magnetic resonance imaging predicts mortality in patients with light chain amyloidosis

Few studies have focused on right ventricular (RV) involvement in cardiac amyloidosis (CA). We investigated the prognostic value of RV assessment by cardiovascular magnetic resonance (CMR) in CA. In 2011-2014, consecutive patients with suspected CA referred for CMR were retrospectively evaluated. Demographic and baseline clinical characteristics were collected. Healthy volunteers were matched for sex and age and served as controls. All subjects underwent a contrast-enhanced CMR examination. RV size, function, and late gadolinium enhancement (LGE) were analyzed. All deaths during follow-up were recorded. Sixty-one patients [37 males (60.7%), age 60 ± 11 years] were included; CA was diagnosed in 47 (77.0%) patients. CA patients displayed decreased biventricular ejection fraction, elevated left ventricular mass index, and increased biventricular end-systolic volume index (ESVi) compared with controls. A total of 27 deaths (57.4%) occurred in the CA group at 21-month median follow-up. Multivariable analysis demonstrated that RVESVi (HR 1.033, 95% CI 1.004-1.063, P = 0.026) and RV-LGE (HR 2.814, 95% CI 1.063-7.450, P = 0.037) were independent predictors of mortality in CA. For all amyloid patients, log NT-proBNP (HR 3.412; 95% CI 1.484-7.845; P = 0.004) and RV-LGE (HR 4.149; 95% CI 1.623-10.607; P = 0.003) were identified as independent predictors. RVESVi and RV-LGE are independent predictors of survival and evaluation of RV by CMR enables risk stratification in patients with CA.

Increased Prognostic Value of Query Amyloid Late Enhancement Score in Light-Chain Cardiac Amyloidosis

BACKGROUND

Late gadolinium enhancement (LGE) pattern is a powerful imaging biomarker for prognosis of cardiac amyloidosis. It is unknown if the query amyloid late enhancement (QALE) score in light-chain (AL) amyloidosis could provide increased prognostic value compared with LGE pattern.Methods and Results:Seventy-eight consecutive patients with AL amyloidosis underwent contrast-enhanced cardiovascular magnetic resonance imaging. Patients with cardiac involvement were grouped by LGE pattern and analyzed using QALE score. Receiver operating characteristic curve was used to identify the optimal cut-off for QALE score in predicting all-cause mortality. Survival of these patients was analyzed with the Kaplan-Meier method and multivariate Cox regression. During a median follow-up of 34 months, 53 of 78 patients died. The optimal cut-off for QALE score to predict mortality at 12-month follow-up was 9.0. On multivariate Cox analysis, QALE score ≥9 (HR, 5.997; 95% CI: 2.665-13.497; P<0.001) and log N-terminal pro-brain natriuretic peptide (HR, 1.525; 95% CI: 1.112-2.092; P=0.009) were the only 2 independent predictors of all-cause mortality. On Kaplan-Meier analysis, patients with subendocardial LGE can be further risk stratified using QALE score ≥9.

CONCLUSIONS

The QALE scoring system provides powerful independent prognostic value in AL cardiac amyloidosis. QALE score ≥9 has added value to differentiate prognosis in AL amyloidosis patients with a subendocardial LGE pattern.

Right ventricular involvement evaluated by cardiac magnetic resonance imaging predicts mortality in patients with light chain amyloidosis

Few studies have focused on right ventricular (RV) involvement in cardiac amyloidosis (CA). We investigated the prognostic value of RV assessment by cardiovascular magnetic resonance (CMR) in CA. In 2011–2014, consecutive patients with suspected CA referred for CMR were retrospectively evaluated. Demographic and baseline clinical characteristics were collected. Healthy volunteers were matched for sex and age and served as controls. All subjects underwent a contrast-enhanced CMR examination. RV size, function, and late gadolinium enhancement (LGE) were analyzed. All deaths during follow-up were recorded. Sixty-one patients [37 males (60.7%), age 60 ± 11 years] were included; CA was diagnosed in 47 (77.0%) patients. CA patients displayed decreased biventricular ejection fraction, elevated left ventricular mass index, and increased biventricular end-systolic volume index (ESVi) compared with controls. A total of 27 deaths (57.4%) occurred in the CA group at 21-month median follow-up. Multivariable analysis demonstrated that RVESVi (HR 1.033, 95% CI 1.004–1.063, P = 0.026) and RV-LGE (HR 2.814, 95% CI 1.063–7.450, P = 0.037) were independent predictors of mortality in CA. For all amyloid patients, log NT-proBNP (HR 3.412; 95% CI 1.484–7.845; P = 0.004) and RV-LGE (HR 4.149; 95% CI 1.623–10.607; P = 0.003) were identified as independent predictors. RVESVi and RV-LGE are independent predictors of survival and evaluation of RV by CMR enables risk stratification in patients with CA.

Update on the Role of Cardiac Magnetic Resonance in Acquired Nonischemic Cardiomyopathies

Cardiomyopathies refer to a variety of myocardial disorders without underlying coronary artery disease, valvular heart disease, hypertension, or congenital heart disease. Several imaging modalities are available, but cardiac magnetic resonance (CMR) has now established itself as a crucial imaging technique in the evaluation of several cardiomyopathies. It not only provides comprehensive information on structure and function, but also can perform tissue characterization, which helps in establishing the etiology of cardiomyopathy. CMR is also useful in establishing the diagnosis, providing guidance for endomyocardial biopsy, accurate quantification of function, volumes, and fibrosis, prognostic determination, risk stratification, and monitoring response to therapy. In this article, we review the current role of CMR in the evaluation of several acquired nonischemic cardiomyopathies, particularly focusing on recent advances in knowledge. We also discuss in detail a select group of common acquired nonischemic cardiomyopathies.

Regression of cardiac amyloidosis following stem cell transplantation: a comparison between echocardiography and cardiac magnetic resonance imaging in long-term survivors

BACKGROUND

AL amyloidosis and multiple myeloma result in extracellular deposition of insoluble fibrillary protein in tissue and organs. Untreated median survival is very poor, and even worse with cardiac involvement. Chemotherapy and peripheral blood stem cell transplantation (PBSCT) have been shown to dramatically improve survival, with hematologic remission documented. Regression of cardiac changes has previously been shown, as assessed by echocardiography (TTE) and cardiac magnetic resonance imaging (CMR). This study is a comparison of TTE and CMR in long-term survivors of cardiac amyloidosis with regression.

RESULTS

Four long-term survivors with cardiac amyloidosis and regression of cardiac features on TTE were identified. Mean age was 60 years and average survival was 139 months from the time of diagnosis of cardiac involvement. Statistically significant regression of the cardiac features of cardiac amyloidosis were demonstrated on TTE. In these survivors, post-PBSCT structural assessments were similar between TTE and CMR. Classical strain imaging features of cardiac amyloidosis were only present in 50%. All patients had diffuse, patchy gadolinium enhancement on CMR after PBSCT.

CONCLUSIONS

Treatment of cardiac amyloidosis with chemotherapy and PBSCT may result in regression of abnormalities on TTE with marked improvement in survival. Post treatment, TTE and CMR structural assessments appear similar. Gadolinium imaging suggests that microscopic residual infiltration persists despite macroscopic regression. Significant cardiac improvements with prolonged survival are seen nonetheless. Multimodality imaging has a vital role in the management of cardiac amyloidosis.

Plasma hepatocyte growth factor is a novel marker of AL cardiac amyloidosis

BACKGROUND

Cardiac amyloidosis is an infiltrative cardiomyopathy that is challenging to diagnose. We hypothesized that the novel biomarkers hepatocyte growth factor (HGF), galectin-3 (GAL-3), interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF) would be elevated in cardiac amyloidosis and may be able to discriminate from non-cardiac systemic amyloidosis or other cardiomyopathies with similar clinical or morphologic characteristics.

METHODS

Patients were selected from the Vanderbilt Main Heart Registry according to the following groups: (1) amyloid light-chain (AL) cardiac amyloidosis (n = 26); (2) transthyretin (ATTR) cardiac amyloidosis (n = 7); (3) left ventricular hypertrophy (LVH) (n = 45); (4) systolic heart failure (n = 42); and (5) non-cardiac systemic amyloidosis (n = 7). Biomarkers were measured in stored plasma samples. Biomarkers' discrimination performance in predicting AL cardiac amyloidosis (i.e., Concordance index) was reported. A survival analysis was used to explore the relationship between HGF levels and mortality among AL cardiac amyloidosis patients.

RESULTS

HGF levels were markedly elevated in patients with AL cardiac amyloidosis (median = 622, interquartile range (IQR): 299-1228 pg/mL) compared with the other groups, including those with non-cardiac systemic amyloidosis (median = 134, IQR: 94-163 pg/mL, p < 0.001). HGF was not a specific marker for ATTR amyloidosis. Gal-3 was elevated in all groups with amyloidosis but could not differentiate between those with and without cardiac involvement. There was no difference in IL-6 or VEGF between those with AL cardiac amyloidosis compared to other groups (p = 0.13 and 0.057, respectively).

CONCLUSIONS

HGF may be a specific marker that distinguishes AL cardiac amyloidosis from other cardiomyopathies with similar clinical or morphologic characteristics. Further studies are necessary to determine whether HGF levels predict the likelihood of survival.

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.

LGE Provides Incremental Prognostic Information Over Serum Biomarkers in AL Cardiac Amyloidosis

OBJECTIVES

This study sought to determine the prognostic value of cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) in amyloid light chain (AL) cardiac amyloidosis.

BACKGROUND

Cardiac involvement is the major determinant of mortality in AL amyloidosis. CMR LGE is a marker of amyloid infiltration of the myocardium. The purpose of this study was to evaluate retrospectively the prognostic value of CMR LGE for determining all-cause mortality in AL amyloidosis and to compare the prognostic power with the biomarker stage.

METHODS

Seventy-six patients with histologically proven AL amyloidosis underwent CMR LGE imaging. LGE was categorized as global, focal patchy, or none. Global LGE was considered present if it was visualized on LGE images or if the myocardium nulled before the blood pool on a cine multiple inversion time (TI) sequence. CMR morphologic and functional evaluation, echocardiographic diastolic evaluation, and cardiac biomarker staging were also performed. Subjects' charts were reviewed for all-cause mortality. Cox proportional hazards analysis was used to evaluate survival in univariate and multivariate analysis.

RESULTS

There were 40 deaths, and the median study follow-up period was 34.4 months. Global LGE was associated with all-cause mortality in univariate analysis (hazard ratio = 2.93; p < 0.001). In multivariate modeling with biomarker stage, global LGE remained prognostic (hazard ratio = 2.43; p = 0.01).

CONCLUSIONS

Diffuse LGE provides incremental prognosis over cardiac biomarker stage in patients with AL cardiac amyloidosis.

Impact of cardiac magnetic resonance imaging in non-ischemic cardiomyopathies

Non-ischemic cardiomyopathies include a wide spectrum of disease states afflicting the heart, whether a primary process or secondary to a systemic condition. Cardiac magnetic resonance imaging (CMR) has established itself as an important imaging modality in the evaluation of non-ischemic cardiomyopathies. CMR is useful in the diagnosis of cardiomyopathy, quantification of ventricular function, establishing etiology, determining prognosis and risk stratification. Technical advances and extensive research over the last decade have resulted in the accumulation of a tremendous amount of data with regards to the utility of CMR in these cardiomyopathies. In this article, we review CMR findings of various non-ischemic cardiomyopathies and focus on current literature investigating the clinical impact of CMR on risk stratification, treatment, and prognosis.

Prognostic role of MR imaging in nonischemic myocardial disease

The role of cardiac magnetic resonance (MR) imaging as a prognostic tool in patients with ischemic heart disease is well established. However, an increasing body of data now demonstrates that cardiac MR imaging can provide prognostic information in a variety of nonischemic and diffuse myocardial diseases including myocarditis, dilated and hypertrophic cardiomyopathies, sarcoidosis, amyloidosis, and arrhythmogenic right ventricular cardiomyopathy. Cardiac MR imaging can also supply incremental information above established prognostic indicators, providing an additional tool for use in the prediction of disease progression, response to treatment, and risk stratification.

Comparison of different types of cardiac amyloidosis by cardiac magnetic resonance imaging

OBJECTIVES

We sought to determine cardiac morphological and functional differences between light-chain (AL), mutant-type transthyretin (ATTRmt) and wild-type TTR (ATTRwt) amyloidosis using contrast-enhancement cardiac magnetic resonance imaging (CE-CMR). Finally, we attempted to establish the diagnostic and prognostic impact of these findings.

INTRODUCTION

The most common forms of cardiac amyloid are AL and ATTR amyloidosis, but the clinical courses of these variants are quite heterogeneous. While CE-CMR is used to evaluate patients with cardiac amyloidosis, its ability to predict prognosis in these patients is debatable.

METHODS

About 130 patients with cardiac amyloidosis (AL, n = 62; ATTRmt, n = 30, ATTRwt, n = 33) were assessed by CE-CMR (cardiac morphology, cardiac function, late gadolinium enhancement).

RESULTS

Left ventricular (LV) mass, basal and mid-ventricular maximal wall thickness, and thickness of the inter-atrial septum were higher in ATTRwt when compared to AL and ATTRmt amyloidosis. Tricuspid annular excursion was lower in ATTRwt amyloidosis than in AL amyloidosis. CE was observed in 94.6% of the patients (AL 80.6%; ATTRmt 90%; ATTRwt 87.9%) with significant differences in quality and intensity between the groups. Differentiation of amyloid types was achieved by combination of age, number of organs, the presence of inferolateral CE-CMR, thickness of inter-atrial septum and troponin T. Overall 1-year-survival rates were 93.3, 93.9 and 70.5% in ATTRwt, ATTRmt and AL amyloidosis, respectively. LV mass, mitral annular excursion and NT-proBNP in AL amyloidosis, LV mass maximal apical wall thickness and troponin T in ATTRwt amyloidosis, and finally NT-proBNP and renal function in ATTRmt amyloidosis were independent predictors of outcome.

CONCLUSIONS

This study demonstrates that CE-CMR can highlight morphological and functional differences between different types of cardiac amyloidosis. In addition, CE-CMR and cardiac biomarkers provide useful prognostic information in patients with cardiac amyloidosis.

The prognostic impact of myocardial late gadolinium enhancement

Cardiovascular magnetic resonance using late gadolinium enhancement (LGE) provides a unique opportunity to assess myocardial tissue in vivo. LGE enables tissue characterization in ischemic and nonischemic cardiomyopathies and other cardiac diseases. LGE is associated with adverse clinical outcomes across a range of different cardiac conditions and may improve risk stratification for death, sudden cardiac death, or serious adverse events beyond traditional prognostic markers. Generally, matching data for the prognostic impact of LGE are frequently reached in cardiac disorders. In other diseases, only a limited number of trials are available, but it is anticipated that the prognostic impact of delayed enhancement will become evident. The development and validation of new cardiovascular magnetic resonance methods for diffuse myocardial fibrosis measurements would even improve the prognostic impact of LGE. The evaluation of diffuse myocardial fibrosis has a great potential in large-scale diseases, including their initial phases, with the possibility to identify patients at risk for subsequent development of clinical heart failure, to assess repeatedly the stage and progression of cardiac diseases, and to monitor the effect of treatment.

Role of cardiac MRI in the assessment of nonischemic cardiomyopathies

In this review, we will highlight the role of late gadolinium enhancement, along with other strengths available by cardiac MRI, in determining the underlying etiology of various nonischemic cardiomyopathies. Furthermore, we will also emphasize how late gadolinium enhancement may serve as a novel risk stratification tool to further impact patient care.

Subclinical Myocardial Disease in Heart Failure Detected by CMR

Noninvasive cardiac imaging plays a central role in the assessment of patients with heart failure at all stages of disease. Moreover, this role can be even more important for individuals with asymptomatic cardiac functional or structural abnormalities-subclinical myocardial disease - because they could have benefits from early interventions before the onset of clinical heart failure. In this sense, cardiac magnetic resonance offers not only precise global cardiac function and cardiac structure, but also more detailed regional function and tissue characterization by recent developing methods. In this section, some of the main methods available for subclinical myocardial disease detection are reviewed in terms of what they can provide and how they can improve heart failure assessment.

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.

Quantification of extracellular matrix expansion by CMR in infiltrative heart disease

OBJECTIVES

The aim of this study was to perform direct quantification of myocardial extracellular volume fraction (ECF) with T1-weighted cardiac magnetic resonance (CMR) imaging in patients suspected to have infiltrative heart disease.

BACKGROUND

Infiltrative heart disease refers to accumulation of abnormal substances within the myocardium. Qualitative assessment of late gadolinium enhancement (LGE) remains the most commonly used method for CMR evaluation of patients suspected with myocardial infiltration. This technique is widely available and can be performed in a reproducible and standardized manner. However, the degree of extracellular matrix expansion due to myocardial infiltration in the intercellular space has, to date, not been amenable to noninvasive quantification with LGE.

METHODS

We performed 3-T CMR in 38 patients (mean age 68 ± 15 years) who were referred for assessment of infiltrative heart disease and also in 9 healthy volunteers as control subjects. The T1 quantification by Look-Locker gradient-echo before and after contrast determined segmental myocardial partition coefficients. The ECF was obtained by referencing the tissue partition coefficient for gadolinium to the plasma volume fraction in blood, derived from serum hematocrit. Cine CMR and LGE imaging in matching locations were also performed.

RESULTS

Seventeen patients (45%) had cardiac amyloidosis (CA) (biopsy-confirmed or clinically highly probable), 20 (53%) had a non-amyloid cardiomyopathy, and 1 had lysosomal storage disease. Median global ECF was substantially higher in CA patients (0.49) compared with non-amyloid cardiomyopathy patients (0.33, p < 0.0001) and volunteers (0.24, p = 0.0001). The ECF strongly correlated with visually assessed segmental LGE (r = 0.80, p < 0.0001) and LV mass index (r = 0.69, p < 0.0001), reflecting severity of myocardial infiltration. In patients with CA, ECF was highest in segments with LGE, although it remained elevated in segments without qualitative LGE.

CONCLUSIONS

The CMR ECF quantification identified substantial expansion of the interstitial space in patients with CA compared with volunteers. Further studies using this technique for diagnosis and assessment of the severity of myocardial infiltration are warranted.

Prognosis assessment of cardiac involvement in systemic AL amyloidosis by magnetic resonance imaging

BACKGROUND

Cardiac involvement is one of the most important prognostic factors in systemic AL amyloidosis. The aim of our study was to assess the role of cardiovascular magnetic resonance (CMR) imaging in prognosis evaluation in AL amyloidosis.

METHODS

We retrospectively analyzed 29 consecutive patients with AL amyloidosis who had undergone CMR. Clinical, laboratory, echocardiographic, and CMR characteristics were compared between CMR-positive (ie, with CMR signs of cardiac localization of AL amyloidosis) and CMR-negative patients. Univariate and multivariate analyses were performed to assess the prognostic value of positive CMR in comparison with other prognostic factors.

RESULTS

CMR was positive in 11 patients (38%). The overall survival rates for CMR-positive patients were 28%, 14%, and 14% versus 84%, 77%, and 45% at 1, 2, and 5 years, respectively, for CMR-negative patients (P=.002). Late gadolinium enhancement patterns, biventricular hypertrophy, and pericardial effusion on CMR were more frequent in nonsurvivors. Congestive heart failure, abnormal echocardiography, Eastern Cooperative Oncology Group grade >1, brain natriuretic peptide, and left ventricular ejection fraction <55% also were associated with a decreased survival. The presence of congestive heart failure was the only significant variable associated with survival on multivariate analysis.

CONCLUSION

We found that the presence of a positive CMR in AL amyloidosis was associated with a significantly increased risk of death, in particular of cardiac origin, but was not independent of clinical congestive heart failure.

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

OBJECTIVE

Light chain amyloidosis (AL) is associated with high mortality. The aim was to identify echocardiographic parameters that predict AL long-term mortality.

METHODS

Forty-two subjects with biopsy-proven AL (43% were female; aged 61 +/- 12 years) underwent echocardiography and were followed 29 +/- 16 months (median 29.4 months). Standard echocardiographic and clinical parameters and heart failure (HF) class were tested using univariate/multivariable Cox proportional hazard regression analyses to identify markers of mortality.

RESULTS

Twenty-three subjects died, with a 1-year mortality of 44%. Univariate predictors of mortality were HF class (P < .001), left ventricular systolic ejection time (ET) (P = .002), alkaline phosphatase (P < .001), and aspartate and alanine aminotransferase (P = .003 each). On multivariable analysis, only HF class (hazard ratio [HR] 4.86; 95% confidence interval [CI], 1.58-14.9; P = .006), ET (10 ms increase; HR 0.87; CI, 0.78-0.97; P = .01), and alkaline phosphatase (10 U/L increase; HR 1.04; CI, 1.01-1.06; P = .01) were prognostic. ET <or= 240 ms had a sensitivity of 61% and a specificity of 90% in predicting 1-year mortality and a sensitivity of 73% and a specificity of 90% in predicting 1-year cardiac mortality.

CONCLUSION

AL amyloidosis was associated with high long-term mortality. Among echocardiographic and clinical parameters, only ET and alkaline phosphatase had incremental value to HF class in predicting mortality. This may be useful to identify high-risk patients.