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BACKGROUND: In light-chain (AL) amyloidosis, whether functional status and heart failure-related quality of life (HF-QOL) correlate with cardiomyopathy severity, improve with therapy, and are associated with major adverse cardiac events (MACE) beyond validated scores is not well-known. OBJECTIVES: The authors aimed to: 1) correlate functional status and HF-QOL with cardiomyopathy severity; 2) analyze their longitudinal changes; and 3) assess their independent associations with MACE. METHODS: This study included 106 participants with AL amyloidosis, with 81% having AL cardiomyopathy. Functional status was evaluated using the NYHA functional class, the Karnofsky scale, and the 6-minute walk distance (6MWD), and HF-QOL using the MLWHFQ (Minnesota Living with Heart Failure Questionnaire). Cardiomyopathy severity was assessed by cardiac 18F-florbetapir positron emission tomography/computed tomography, cardiac magnetic resonance, echocardiography, and serum cardiac biomarkers. MACE were defined as all-cause death, heart failure hospitalization, or cardiac transplantation. RESULTS: NYHA functional class, Karnofsky scale, 6MWD, and MLWHFQ were impaired substantially in participants with recently diagnosed AL cardiomyopathy (P < 0.001), and correlated with all markers of cardiomyopathy severity (P ≤ 0.010). NYHA functional class, 6MWD, and MLWHFQ improved at 12 months in participants with cardiomyopathy (P ≤ 0.013). All measures of functional status and HF-QOL were associated with MACE (P ≤ 0.017), independent of Mayo stage for 6MWD and MLWHFQ (P ≤ 0.006). CONCLUSIONS: Functional status and HF-QOL were associated with AL cardiomyopathy severity, improved on therapy within 12 months, and were associated with MACE, independently of Mayo stage for 6MWD and MLWHFQ. They may be validated further in addition to prognostic scores and as surrogate outcomes for future studies.
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BACKGROUND: Positron emission tomography/computed tomography (PET/CT) with 18F-florbetapir, a novel amyloid-targeting radiotracer, can quantify left ventricular (LV) amyloid burden in systemic light-chain (AL) amyloidosis. However, its prognostic value is not known. OBJECTIVES: The authors' aim was to evaluate the prognostic value of LV amyloid burden quantified by 18F-florbetapir PET/CT, and to identify mechanistic pathways mediating its association with outcomes. METHODS: A total of 81 participants with newly diagnosed AL amyloidosis underwent 18F-florbetapir PET/CT imaging. Amyloid burden was quantified using 18F-florbetapir LV uptake as percent injected dose. The Mayo stage for AL amyloidosis was determined using troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and free light chain levels. Major adverse cardiac events (MACE) were defined as all-cause death, heart failure hospitalization, or cardiac transplantation within 12 months. RESULTS: Among participants (median age, 61 years; 57% males), 36% experienced MACE, increasing from 7% to 63% across tertiles of LV amyloid burden (P < 0.001). LV amyloid burden was associated with MACE (HR: 1.46; 95% CI: 1.16-1.83; P = 0.001). However, this association became nonsignificant when adjusted for Mayo stage. In mediation analysis, the association between LV amyloid burden and MACE was mediated by NT-proBNP (P < 0.001), a marker of cardiomyocyte stretch and heart failure, and a component of Mayo stage. CONCLUSIONS: In this first study to link cardiac 18F-florbetapir uptake to subsequent outcomes, LV amyloid burden estimated by percent injected dose predicted MACE in AL amyloidosis. This effect was not independent of Mayo stage and was mediated primarily through NT-proBNP. These findings provide novel insights into the mechanism linking myocardial amyloid deposits to MACE.
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Compuestos de Anilina , Glicoles de Etileno , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas , Péptido Natriurético Encefálico , Fragmentos de Péptidos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Valor Predictivo de las Pruebas , Radiofármacos , Humanos , Femenino , Masculino , Persona de Mediana Edad , Anciano , Radiofármacos/administración & dosificación , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/diagnóstico por imagen , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/metabolismo , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/mortalidad , Pronóstico , Péptido Natriurético Encefálico/sangre , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/sangre , Factores de Riesgo , Función Ventricular Izquierda , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/metabolismo , Factores de Tiempo , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/metabolismo , Biomarcadores/sangre , Trasplante de Corazón/efectos adversos , Medición de Riesgo , Cardiomiopatías/diagnóstico por imagen , Cardiomiopatías/metabolismo , Cardiomiopatías/mortalidad , Cadenas Ligeras de Inmunoglobulina/metabolismoRESUMEN
BACKGROUND: In systemic light-chain (AL) amyloidosis, cardiac involvement portends poor outcomes. OBJECTIVES: The authors' objectives were to detect early myocardial alterations, to analyze longitudinal changes with therapy, and to predict major adverse cardiac events (MACE) in participants with AL amyloidosis using cardiac magnetic resonance imaging (MRI). METHODS: Recently diagnosed participants were prospectively enrolled. AL amyloidosis with and without cardiomyopathy (AL-CMP, AL-non-CMP) were defined based on abnormal cardiac biomarkers and wall thickness. MRI was performed at baseline, 6 months in all participants, and 12 months in participants with AL-CMP. MACE were defined as all-cause death, heart failure hospitalization, and cardiac transplantation. Mayo stage was based on troponin T, N-terminal pro-B-type natriuretic peptide, and difference in free light chains. RESULTS: This study included 80 participants (median age 62 years, 58% men). Extracellular volume (ECV) was abnormal (>32%) in all participants with AL-CMP and in 47% of those with AL-non-CMP. ECV tended to increase at 6 months (median +2%; AL-CMP P = 0.120; AL-non-CMP P = 0.018) and returned to baseline values at 12 months in participants with AL-CMP. Global longitudinal strain (GLS) improved at 6 months (median -0.6%; P = 0.048) and 12 months (median -1.2%; P < 0.001) in participants with AL-CMP. ECV and GLS were strongly associated with MACE (P < 0.001) and improved the prognostic value when added to Mayo stage (P ≤ 0.002). No participant with ECV ≤32% had MACE, while 74% of those with ECV >48% had MACE. CONCLUSIONS: In patients with systemic AL amyloidosis, ECV detects subclinical myocardial alterations. With therapy, ECV tends to increase at 6 months and returns to values unchanged from baseline at 12 months, whereas GLS improves at 6 and 12 months in participants with AL-CMP. ECV and GLS offer additional prognostic performance over Mayo stage. (Molecular Imaging of Primary Amyloid Cardiomyopathy [MICA]; NCT02641145).
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Neuropatías Amiloides Familiares , Cardiomiopatías , Cromosomas Humanos Y , Humanos , Neuropatías Amiloides Familiares/genética , Neuropatías Amiloides Familiares/mortalidad , Masculino , Cardiomiopatías/genética , Cromosomas Humanos Y/genética , Anciano , Femenino , Mosaicismo , Prealbúmina/genética , Persona de Mediana EdadRESUMEN
INTRODUCTION: Hereditary transthyretin amyloidosis (ATTRv, also referred to as hATTR; ORPHA 271861) and wild-type ATTR amyloidosis (ATTRwt; ORPHA 330001) are rare, progressive, systemic protein misfolding disorders with heterogeneous clinical presentations. ATTRv and ATTRwt amyloidosis are characterized by the deposition of amyloid fibrils in multiple organs including the heart, nerves, eyes, and soft tissues. The management of ATTR amyloidosis is complex because of its multisystemic nature and progression despite available treatment options. Morbidity is high and there are many unmet medical needs for patients. While contemporary ATTR amyloidosis cohorts are diagnosed earlier, have lower risk disease and lower mortality compared with the previous era, these advances coupled with the emergence of effective disease-modifying therapies have confounded the design of future prospective clinical trials and interpretation of historical control data. MAIN BODY: The Amyloidosis Forum is a public-private partnership between the US Food and Drug Administration Center for Drug Evaluation and Research and the nonprofit Amyloidosis Research Consortium ( www.arci.org ). This article summarizes proceedings from the 21 June 2023 Amyloidosis Forum on advancing drug development in ATTR amyloidosis in an evolving treatment landscape. The Forum focused on elements of clinical trial design to address these challenges and discussed their strengths and weaknesses from multiple stakeholder perspectives (i.e., patient, sponsor, statistician, clinician, and regulatory authorities). CONCLUSION: Given rapid evolution of natural history in ATTR amyloidosis, the utility of historical control data is limited. Leveraging contemporary real-world data is essential for clinical trial design. Evidence generation from clinical trials should address clinically relevant questions. Key factors in successful trial design must be informed by up-to-date data on natural history, prognostic factors, clinically meaningful thresholds, and sharing available clinical trial data. The Amyloidosis Forum includes the community of patients with ATTR amyloidosis, the physicians who treat them, and the sponsors and regulators who collectively stand ready to support further studies in order to develop novel effective therapies.
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Neuropatías Amiloides Familiares , Desarrollo de Medicamentos , Humanos , Neuropatías Amiloides Familiares/tratamiento farmacológico , Benzoxazoles/uso terapéutico , OligonucleótidosRESUMEN
Background: Cardiac systolic dysfunction is a poor prognostic marker in light-chain (AL) cardiomyopathy, a primary interstitial disorder; however, its pathogenesis is poorly understood. Purpose: This study aims to analyze the effects of extracellular volume (ECV) expansion, a surrogate marker of amyloid burden on myocardial blood flow (MBF), myocardial work efficiency (MWE), and left ventricular (LV) systolic dysfunction in AL amyloidosis. Methods: Subjects with biopsy-proven AL amyloidosis were prospectively enrolled (April 2016-June 2021; Clinicaltrials.gov ID NCT02641145) and underwent cardiac magnetic resonance imaging (MRI) to quantify rest MBF by perfusion imaging, LV ejection fraction (LVEF) by cine MRI, and ECV by pre- and post-contrast T1 mapping. The MWE was estimated as external cardiac work from the stroke volume and mean arterial pressure normalized to the LV myocardial mass. Results: Rest MBF in 92 subjects (62 ± 8 years, 52 men) with AL amyloidosis averaged 0.87 ± 0.21â ml/min/g and correlated with MWE (r = 0.42; p < 0.001). Rest MBF was similarly low in subjects with sustained hematologic remission after successful AL amyloidosis therapy (n = 21), as in those with recently diagnosed AL amyloidosis. Both MBF and MWE decreased by ECV tertile (p < 0.01 for linear trends). The association of ECV with MWE comprised a direct effect (84% of the total effect; p < 0.001) on MWE from adverse interstitial remodeling assessed by ECV and an indirect effect (16% of the total effect; p < 0.001) mediated by MBF. There was a significant base-to-apex gradient of rest MBF in subjects with higher amyloid burden. Conclusions: In AL amyloidosis, both MBF and MWE decrease as cardiac amyloid burden and ECV expansion increase. Both structural and vascular changes from ECV expansion and myocardial amyloid burden appear to contribute to lower MWE.
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Neuropatías Amiloides Familiares , Disparidades en el Estado de Salud , Prealbúmina , Humanos , Neuropatías Amiloides Familiares/genética , Cardiomiopatías , Disparidades en Atención de Salud , Prealbúmina/genética , Prealbúmina/metabolismo , Estados Unidos , Persona de Mediana Edad , Lactante , Preescolar , Niño , Adolescente , Adulto Joven , Adulto , Anciano , Anciano de 80 o más AñosRESUMEN
BACKGROUND: The Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Populations study seeks to determine the prevalence of transthyretin cardiac amyloidosis (ATTR-CA) among older Black or Caribbean Hispanic individuals with heart failure and an increased wall thickness. We noticed varied recruitment percentages across the recruiting sites and sought to determine the factors associated with greater percentage enrollment of eligible participants. METHODS: The percentage of enrolled to eligible participants was calculated across study sites. Baseline demographic and clinical characteristics, health literacy, trust in providers, perceived discrimination, area deprivation index (ADI) and English proficiency were compared by site using Kruskal-Wallis's test or one-way ANOVA for continuous variables and the Chi-Square test or Fisher's exact test for categorical variables. Wilcoxon rank sum and Chi-Square tests, with multiple comparisons correction using the false discovery rate (FDR) method, were used as post-hoc analysis when results were statistically significant. RESULTS: Among the four recruiting sites, Boston Medical Center, Columbia University Irving Medical Center, Harlem Hospital and Yale University, which employed different recruitment approaches, the percentage of participants enrolled among eligible participants differed, with the highest rate at Harlem Hospital (n=149 of 310, 48%), followed by Yale University (n=27 of 67, 40%), Boston University (n=247 of 655, 38%), and Columbia University (n=137of 442, 32%), p <0.01. Direct recruitment by the primary cardiovascular care team providing clinical care was associated with higher percent enrolled across sites as were higher education levels and English proficiency. Enrollment differences across sites were not associated with the number of chronic diseases, physician trust, perceived discrimination, or health literacy. CONCLUSIONS: Recruitment of eligible under-represented minorities (URMs) in SCAN-MP was associated with approaches employed in recruitment, including direct initial contact by the primary cardiovascular care team providing the potential participant's clinical care. Such data may help improve approaches to more successful recruitment of URMs in clinical research.
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Background: Cardiac dysfunction in AL amyloidosis is thought to be partly related to the direct impact of AL LCs on cardiomyocyte function, with the degree of dysfunction at diagnosis as a major determinant of clinical outcomes. Nonetheless, mechanisms underlying LC-induced myocardial toxicity are not well understood. Methods: We identified gene expression changes correlating with human cardiac cells exposed to a cardiomyopathy-associated κAL LC. We then sought to confirm these findings in a clinical dataset by focusing on clinical parameters associated with the pathways dysregulated at the gene expression level. Results: Upon exposure to a cardiomyopathy-associated κAL LC, cardiac cells exhibited gene expression changes related to myocardial contractile function and inflammation, leading us to hypothesize that there could be clinically detectable changes in GLS on echocardiogram and serum inflammatory markers in patients. Thus, we identified 29 patients with normal IVSd but abnormal cardiac biomarkers suggestive of LC-induced cardiac dysfunction. These patients display early cardiac biomarker staging, abnormal GLS, and significantly reduced serum inflammatory markers compared to patients with clinically evident amyloid fibril deposition. Conclusion: Collectively, our findings highlight early molecular and functional signatures of cardiac AL amyloidosis, with potential impact for developing improved patient biomarkers and novel therapeutics.
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Importance: Systemic amyloidosis from transthyretin (ATTR) protein is the most common type of amyloidosis that causes cardiomyopathy. Observations: Transthyretin (TTR) protein transports thyroxine (thyroid hormone) and retinol (vitamin A) and is synthesized predominantly by the liver. When the TTR protein misfolds, it can form amyloid fibrils that deposit in the heart causing heart failure, heart conduction block, or arrhythmia such as atrial fibrillation. The biological processes by which amyloid fibrils form are incompletely understood but are associated with aging and, in some patients, affected by inherited variants in the TTR genetic sequence. ATTR amyloidosis results from misfolded TTR protein deposition. ATTR can occur in association with normal TTR genetic sequence (wild-type ATTR) or with abnormal TTR genetic sequence (variant ATTR). Wild-type ATTR primarily manifests as cardiomyopathy while ATTR due to a genetic variant manifests as cardiomyopathy and/or polyneuropathy. Approximately 50â¯000 to 150â¯000 people in the US have heart failure due to ATTR amyloidosis. Without treatment, heart failure due to ATTR amyloidosis is associated with a median survival of approximately 5 years. More than 130 different inherited genetic variants in TTR exist. The most common genetic variant is Val122Ile (pV142I), an allele with an origin in West African countries, that is present in 3.4% of African American individuals in the US or approximately 1.5 million persons. The diagnosis can be made using serum free light chain assay and immunofixation electrophoresis to exclude light chain amyloidosis combined with cardiac nuclear scintigraphy to detect radiotracer uptake in a pattern consistent with amyloidosis. Loop diuretics, such as furosemide, torsemide, and bumetanide, are the primary treatment for fluid overload and symptomatic relief of patients with ATTR heart failure. An ATTR-directed therapy that inhibited misfolding of the TTR protein (tafamidis, a protein stabilizer), compared with placebo, reduced mortality from 42.9% to 29.5%, reduced hospitalizations from 0.7/year to 0.48/year, and was most effective when administered early in disease course. Conclusions and Relevance: ATTR amyloidosis causes cardiomyopathy in up to approximately 150â¯000 people in the US and tafamidis is the only currently approved therapy. Tafamidis slowed progression of ATTR amyloidosis and improved survival and prevented hospitalization, compared with placebo, in people with ATTR-associated cardiomyopathy.
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Amiloidosis , Cardiomiopatías , Insuficiencia Cardíaca , Prealbúmina , Humanos , Amiloidosis/complicaciones , Amiloidosis/epidemiología , Amiloidosis/genética , Amiloidosis/metabolismo , Cardiomiopatías/etiología , Cardiomiopatías/genética , Cardiomiopatías/metabolismo , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/metabolismo , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas , Prealbúmina/genética , Prealbúmina/metabolismo , Negro o Afroamericano/etnología , Negro o Afroamericano/genética , Negro o Afroamericano/estadística & datos numéricos , Estados Unidos/epidemiología , África Occidental , Pliegue de ProteínaRESUMEN
AIMS: In systemic light-chain (AL) amyloidosis, quantification of right ventricular (RV) amyloid burden has been limited and the pathogenesis of RV dysfunction is poorly understood. Using 18F-florbetapir positron emission tomography/computed tomography (PET/CT), we aimed to quantify RV amyloid; correlate RV amyloid with RV structure and function; determine the independent contributions of RV, left ventricular (LV), and lung amyloid to RV function; and associate RV amyloid with major adverse cardiac events (MACE: death, heart failure hospitalization, cardiac transplantation). METHODS AND RESULTS: We prospectively enrolled 106 participants with AL amyloidosis (median age 62 years, 55% males) who underwent 18F-florbetapir PET/CT, magnetic resonance imaging, and echocardiography. 18F-florbetapir PET/CT identified RV amyloid in 63% of those with and 40% of those without cardiac involvement by conventional criteria. RV amyloid burden correlated with RV ejection fraction (EF), RV free wall longitudinal strain (FWLS), RV wall thickness, RV mass index, N-terminal pro-brain natriuretic peptide, troponin T, LV amyloid, and lung amyloid (each P < 0.001). In multivariable analysis, RV amyloid burden, but not LV or lung amyloid burden, predicted RV dysfunction (EF P = 0.014; FWLS P < 0.001). During a median follow-up of 28 months, RV amyloid burden predicted MACE (P < 0.001). CONCLUSION: This study shows for the first time that 18F-florbetapir PET/CT identifies early RV amyloid in systemic AL amyloidosis prior to alterations in RV structure and function. Increasing RV amyloid on 18F-florbetapir PET/CT is associated with worse RV structure and function, predicts RV dysfunction, and predicts MACE. These results imply a central role for RV amyloid in the pathogenesis of RV dysfunction.
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Compuestos de Anilina , Glicoles de Etileno , Tomografía Computarizada por Tomografía de Emisión de Positrones , Disfunción Ventricular Derecha , Humanos , Masculino , Femenino , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Estudios Prospectivos , Disfunción Ventricular Derecha/diagnóstico por imagen , Anciano , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/diagnóstico por imagen , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/complicaciones , Radiofármacos , Ventrículos Cardíacos/diagnóstico por imagenRESUMEN
BACKGROUND: In cardiac T1 mapping, a series of T1 -weighted (T1 w) images are collected and numerically fitted to a two or three-parameter model of the signal recovery to estimate voxel-wise T1 values. To reduce the scan time, one can collect fewer T1 w images, albeit at the cost of precision or/and accuracy. Recently, the feasibility of using a neural network instead of conventional two- or three-parameter fit modeling has been demonstrated. However, prior studies used data from a single vendor and field strength; therefore, the generalizability of the models has not been established. PURPOSE: To develop and evaluate an accelerated cardiac T1 mapping approach based on MyoMapNet, a convolution neural network T1 estimator that can be used across different vendors and field strengths by incorporating the relevant scanner information as additional inputs to the model. STUDY TYPE: Retrospective, multicenter. POPULATION: A total of 1423 patients with known or suspected cardiac disease (808 male, 57 ± 16 years), from three centers, two vendors (Siemens, Philips), and two field strengths (1.5 T, 3 T). The data were randomly split into 60% training, 20% validation, and 20% testing. FIELD STRENGTH/SEQUENCE: A 1.5 T and 3 T, Modified Look-Locker inversion recovery (MOLLI) for native and postcontrast T1 . ASSESSMENT: Scanner-independent MyoMapNet (SI-MyoMapNet) was developed by altering the deep learning (DL) architecture of MyoMapNet to incorporate scanner vendor and field strength as inputs. Epicardial and endocardial contours and blood pool (by manually drawing a large region of interest in the blood pool) of the left ventricle were manually delineated by three readers, with 2, 8, and 9 years of experience, and SI-MyoMapNet myocardial and blood pool T1 values (calculated from four T1 w images) were compared with conventional MOLLI T1 values (calculated from 8 to 11 T1 w images). STATISTICAL TESTS: Equivalency test with 95% confidence interval (CI), linear regression slope, Pearson correlation coefficient (r), Bland-Altman analysis. RESULTS: The proposed SI-MyoMapNet successfully created T1 maps. Native and postcontrast T1 values measured from SI-MyoMapNet were strongly correlated with MOLLI, despite using only four T1 w images, at both field-strengths and vendors (all r > 0.86). For native T1 , SI-MyoMapNet and MOLLI were in good agreement for myocardial and blood T1 values in institution 1 (myocardium: 5 msec, 95% CI [3, 8]; blood: -10 msec, 95%CI [-16, -4]), in institution 2 (myocardium: 6 msec, 95% CI [0, 11]; blood: 0 msec, [-18, 17]), and in institution 3 (myocardium: 7 msec, 95% CI [-8, 22]; blood: 8 msec, [-14, 30]). Similar results were observed for postcontrast T1 . DATA CONCLUSION: Inclusion of field strength and vendor as additional inputs to the DL architecture allows generalizability of MyoMapNet across different vendors or field strength. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 2.
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Corazón , Miocardio , Humanos , Masculino , Estudios Retrospectivos , Corazón/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Ventrículos Cardíacos , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: CARS (Cardiac Amyloidosis Registry Study) is a multicenter registry established in 2019 that includes patients with transthyretin (ATTR, wild-type and variant) and light chain (AL) cardiac amyloidosis (CA) evaluated at major amyloidosis centers between 1997 and 2025. CARS aims to describe the natural history of CA with attention to clinical and diagnostic variables at the time of diagnosis, real-world treatment patterns, and associated outcomes of patients in a diverse cohort that is more representative of the at-risk population than that described in CA clinical trials. METHODS AND RESULTS: This article describes the design and methodology of CARS, including procedures for data collection and preliminary results. As of February 2023, 20 centers in the United States enrolled 1415 patients, including 1155 (82%) with ATTR and 260 (18%) with AL CA. Among those with ATTR, wild-type is the most common ATTR (71%), and most of the 305 patients with variant ATTR have the p.V142I mutation (68%). A quarter of the total population identifies as Black. More individuals with AL are female (39%) compared to those with ATTR (13%). CONCLUSIONS: CARS will answer crucial clinical questions about CA natural history and permit comparison of different therapeutics not possible through current clinical trials. Future international collaboration will further strengthen the validity of observations of this increasingly recognized condition.
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Aims: In systemic light-chain (AL) amyloidosis, cardiac involvement portends poor prognosis. Using myocardial characteristics on magnetic resonance imaging (MRI), this study aimed to detect early myocardial alterations, to analyze temporal changes with plasma cell therapy, and to predict risk of major adverse cardiac events (MACE) in AL amyloidosis. Methods and Results: Participants with recently diagnosed AL amyloidosis were prospectively enrolled. Presence of AL cardiomyopathy (AL-CMP vs. AL-non-CMP) was determined by abnormal cardiac biomarkers. MRI was performed at baseline and 6 months, with 12-month imaging in AL-CMP cohort. MACE was defined as all-cause death, heart failure hospitalization, or cardiac transplantation. Mayo AL stage was based on troponin T, NT-proBNP, and difference in free light chains. The study cohort included 80 participants (median age 62 years, 58% males). Median left ventricular extracellular volume (ECV) was significantly higher in AL-CMP (53% vs. 30%, p<0.001). ECV was abnormal (>32%) in all AL-CMP and in 47% of AL-non-CMP. ECV tended to increase at 6 months and decreased significantly from 6 to 12 months in AL-CMP (median -3%, p=0.011). ECV was strongly associated with MACE (p<0.001), and improved MACE prediction when added to Mayo AL stage (p=0.002). ECV≤32% identified a cohort without MACE, while ECV>48% identified a cohort with 74% MACE. Conclusions: In AL amyloidosis, ECV detects subclinical cardiomyopathy. ECV tends to increase from baseline to 6 months and decreases significantly from 6 and 12 months of plasma cell therapy in AL-CMP. ECV provides excellent risk stratification and offers additional prognostic performance over Mayo AL stage.
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BACKGROUND: Clonal hematopoiesis (CH), which results from an array of nonmalignant driver gene mutations, can lead to altered immune cell function and chronic disease, and has been associated with worse outcomes in patients with heart failure (HF) with reduced ejection fraction. However, the role of CH in the prognosis of HF with preserved ejection fraction (HFpEF) has been understudied. This study aimed to characterize CH in patients with HFpEF and elucidate its causal role in a murine model. METHODS: Using a panel of 20 candidate CH driver genes and a variant allele fraction cutoff of 0.5%, ultradeep error-corrected sequencing identified CH in a cohort of 81 patients with HFpEF (mean age, 71±6 years; ejection fraction, 63±5%) and 36 controls without a diagnosis of HFpEF (mean age, 74±7 years; ejection fraction, 61.5±8%). CH was also evaluated in a replication cohort of 59 individuals with HFpEF. RESULTS: Compared with controls, there was an enrichment of TET2-mediated CH in the HFpEF patient cohort (12% versus 0%, respectively; P=0.02). In the HFpEF cohort, patients with CH exhibited exacerbated diastolic dysfunction in terms of E/e' (14.9 versus 11.7, respectively; P=0.0096) and E/A (1.69 versus 0.89, respectively; P=0.0206) compared with those without CH. The association of CH with exacerbated diastolic dysfunction was corroborated in a validation cohort of individuals with HFpEF. In accordance, patients with HFpEF, an age ≥70 years, and CH exhibited worse prognosis in terms of 5-year cardiovascular-related hospitalization rate (hazard ratio, 5.06; P=0.042) compared with patients with HFpEF and an age ≥70 years without CH. To investigate the causal role of CH in HFpEF, nonconditioned mice underwent adoptive transfer with Tet2-wild-type or Tet2-deficient bone marrow and were subsequently subjected to a high-fat diet/L-NAME (Nω-nitro-l-arginine methyl ester) combination treatment to induce features of HFpEF. This model of Tet2-CH exacerbated cardiac hypertrophy by heart weight/tibia length and cardiomyocyte size, diastolic dysfunction by E/e' and left ventricular end-diastolic pressure, and cardiac fibrosis compared with the Tet2-wild-type condition. CONCLUSIONS: CH is associated with worse heart function and prognosis in patients with HFpEF, and a murine experimental model of Tet2-mediated CH displays greater features of HFpEF.
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Insuficiencia Cardíaca , Disfunción Ventricular Izquierda , Humanos , Ratones , Animales , Anciano , Anciano de 80 o más Años , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/tratamiento farmacológico , Volumen Sistólico , Función Ventricular Izquierda , Hematopoyesis Clonal/genética , Disfunción Ventricular Izquierda/genéticaRESUMEN
Background: Myocardial immunoglobulin light-chain (AL) amyloid deposits trigger heart failure, cardiomyocyte stretch and myocardial injury, leading to adverse cardiac outcomes. Positron emission tomography/computed tomography (PET/CT) with 18 F-florbetapir, a novel amyloid-targeting radiotracer, can quantify left ventricular (LV) amyloid burden, but its prognostic value is not known. Therefore, we aimed to evaluate the prognostic value of LV amyloid burden quantified by 18 F-florbetapir PET/CT and to identify mechanistic pathways mediating its association with outcomes. Methods: Eighty-one participants with newly-diagnosed systemic AL amyloidosis were prospectively enrolled and underwent 18 F-florbetapir PET/CT. LV amyloid burden was quantified using 18 F-florbetapir LV percent injected dose (%ID). Mayo AL stage was determined using troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and difference between involved and uninvolved free light chain levels. Major adverse cardiac events (MACE) were defined as all-cause death, heart failure hospitalization, or cardiac transplantation within 12 months. Results: Among participants (median age 61 years, 57% males), 36% experienced MACE. Incidence of MACE increased across tertiles of LV amyloid burden from 7% to 63% (p<0.001). LV amyloid burden was significantly associated with MACE in univariable analysis (hazard ratio 1.45, 95% confidence interval 1.15-1.82, p=0.002). However, this association became non-significant in multivariable analyses adjusted for Mayo AL stage. Mediation analysis showed that the association between 18 F-florbetapir LV %ID and MACE was primarily mediated by NT-proBNP (p<0.001), a marker of cardiomyocyte stretch and component of Mayo AL stage. Conclusion: In this first study to link cardiac 18 F-florbetapir uptake to subsequent outcomes, LV amyloid burden estimated by LV %ID predicted MACE in AL amyloidosis. But this effect was not independent of Mayo AL stage. LV amyloid burden was associated with MACE primarily via NT-pro-BNP, a marker of cardiomyocyte stretch and component of Mayo AL stage. These findings provide novel insights into the mechanism through which myocardial AL amyloid leads to MACE. Clinical Perspective: In systemic light-chain (AL) amyloidosis, cardiac involvement is the key determinant of adverse outcomes. Usually, prognosis is based on the Mayo AL stage, determined by troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and the difference between involved and uninvolved immunoglobulin free light chain levels (dFLC). Cardiac amyloid burden is not considered in this staging. In the present study, we used the amyloid-specific radiotracer 18 F-florbetapir to quantify left ventricular (LV) amyloid burden in 81 participants with newly-diagnosed AL amyloidosis and evaluated its prognostic value on major adverse outcomes (MACE: all-cause death, heart failure hospitalization, or cardiac transplantation within 12 months). We found that higher LV amyloid burden by 18 F-florbetapir positron emission tomography/computed tomography (PET/CT) was strongly associated with MACE. However, this association became non-significant after adjustment for the Mayo AL stage. Mediation analysis offered novel pathophysiological insights, implying that LV amyloid burden leads to MACE predominantly through cardiomyocyte stretch and light chain toxicity (by NT-proBNP), rather than through myocardial injury (by troponin T), also considering the severity of plasma cell dyscrasia (by dFLC). This mediation by NT-proBNP may explain why the association with outcomes was non-significant with adjustment for Mayo AL stage. Together, these results establish quantitative 18 F-florbetapir PET/CT as a valid method to predict adverse outcomes in AL amyloidosis. These results support the use of 18 F-florbetapir PET/CT to measure the effects of novel fibril-depleting therapies, in addition to plasma cell therapy, to improve outcomes in systemic AL amyloidosis.
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Patients with advanced cardiac immunoglobulin light chain (AL) amyloidosis have a poor prognosis. Early hematologic and cardiac responses can prolong survival, but predictors of these outcomes have yet to be clarified. We report on 142 patients with newly diagnosed stage IIIb AL amyloidosis. After a median follow-up of 60 months, the median overall survival (OS) was 9 months. Independent baseline factors associated with shorter OS were symptom onset to diagnosis >6 months (hazard ratio [HR], 1.94; P = .003); bone marrow plasmacytosis ≥ 10% (HR, 1.98; P = .01); troponin I > 0.635 ng/mL (HR, 1.62; P = .04); New York Heart Association class III or IV (HR, 1.67; P = .04); and 6-minute walk test distance < 200 m (HR, 1.85; P = .01). Early hematologic (within 1 month) and cardiac (within 3 months) responses were significantly associated with longer survival. In a 1-month landmark analysis, patients with a hematologic very good partial response, partial response, and no response had a median OS of 47, 25, and 5 months, respectively (P < .0001). Patients with cardiac response at 3 months had significantly longer OS (47 vs 11 months; P < .0001). On multivariable modeling, bortezomib use was associated with early hematologic and cardiac responses and longer OS. Symptom onset to diagnosis duration of >6 months and difference between the involved and uninvolved free light chain > 350 mg/L were independently associated with lower odds of an early cardiac response. This study identified factors predictive of treatment outcomes and survival in advanced cardiac AL amyloidosis.
Asunto(s)
Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas , Humanos , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/diagnóstico , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/terapia , Estudios Retrospectivos , Cadenas Ligeras de Inmunoglobulina , Resultado del Tratamiento , Modelos de Riesgos ProporcionalesRESUMEN
Background Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed cause of heart failure (HF) among patients ≥60 years of age. Although the V122I (valine to isoleucine substitution at position 122 of the transthyretin protein) variant associated with hereditary ATTR-CM is present in 3.4% of self-identified Black individuals in the United States (or 1.5 million people), the phenotypic penetrance is not known. Methods and Results The SCAN-MP (Screening for Cardiac Amyloidosis With Nuclear Imaging in Minority Populations) study is a currently accruing prospective multisite study designed to determine the prevalence of ATTR-CM using technetium-99m-pyrophosphate imaging in older (≥60 years of age) self-identified Black and Hispanic individuals with HF. Calculations of the penetrance and prevalence of the V122I allele, along with analyses of functional, biochemical, and echocardiographic parameters, were performed for the first 278 Black participants in SCAN-MP. The prevalence of ATTR-CM was 6.8% (95% CI, 4.2-10.5; n=19 cases), of whom 63% were ATTR wild-type. The prevalence of V122I was 6.5% (n=18 carriers), of whom 7 had ATTR-CM, yielding a phenotypic penetrance of 39% (95% CI, 17-64). V122I carriers with ATTR-CM evidenced more advanced HF than carriers without ATTR-CM. Prealbumin concentration was lowest among V122I carriers with ATTR-CM (12.9 mg/dL) versus carriers without ATTR-CM (21.0 mg/dL) and HF controls (25.0 mg/dL, P<0.0001). Conclusions Among older Black individuals with HF and increased left ventricular wall thickness, of those with ATTR-CM, 63% had wild-type, and of those with V122I, the phenotypic penetrance of ATTR-CM was 39% (95% CI, 17-64), suggesting that genotype alone is insufficient for diagnosis. Prealbumin concentration may be useful to identify V122I carriers with ATTR-CM. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03812172.