Project description:Transthyretin cardiac amyloidosis (ATTR-CA) demonstrates progressive, potentially fatal, and infiltrative cardiomyopathy caused by extracellular deposition of transthyretin-derived insoluble amyloid fibrils in the myocardium. Two distinct types of transthyretin (wild type or variant) become unstable, and misfolding forms aggregate, resulting in amyloid fibrils. ATTR-CA, which has previously been underrecognized and considered to be rare, has been increasingly recognized as a cause of heart failure with preserved ejection fraction among elderly persons. With the advanced technology, the diagnostic tools have been improving for cardiac amyloidosis. Recently, the efficacy of several disease-modifying agents focusing on the amyloidogenic process has been demonstrated. ATTR-CA has been changing from incurable to treatable. Nevertheless, there are still no prognostic improvements due to diagnostic delay or misdiagnosis because of phenotypic heterogeneity and co-morbidities. Thus, it is crucial for clinicians to be aware of this clinical entity for early diagnosis and proper treatment. In this mini-review, we focus on recent advances in diagnosis and treatment of ATTR-CA.
Project description:Cardiac amyloidosis is thought to be a rare group of diseases caused by extracellular deposition of misfolded proteins in the extracellular cardiac matrix resulting in heart failure with preserved ejection fraction (HFpEF). This review focuses on the similarities and differences between the pathophysiology, clinical presentation and diagnostic tests of wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) compared to immunoglobulin light chain amyloidosis and hereditary cardiac amyloidosis. We address some obstacles to timely diagnosis and opportunities for management of the clinical symptoms as well as possibility of future novel disease modifying therapies.
Project description:Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized cause of heart failure (HF) and mortality worldwide. Advances in non-invasive diagnosis, coupled with the development of effective treatments, have shifted ATTR-CA from a rare and untreatable disease to a relatively prevalent condition that clinicians should consider on a daily basis. Amyloid fibril formation results from age-related failure of homoeostatic mechanisms in wild-type ATTR (ATTRwt) amyloidosis (non-hereditary form) or destabilizing mutations in variant ATTR (ATTRv) amyloidosis (hereditary form). Longitudinal large-scale studies in the United States suggest an incidence of cardiac amyloidosis in the contemporary era of 17 per 100 000, which has increased from a previous estimate of 0.5 per 100 000, which was almost certainly due to misdiagnosis and underestimated. The presence and degree of cardiac involvement is the leading cause of mortality both in ATTRwt and ATTRv amyloidosis, and can be identified in up to 15% of patients hospitalized for HF with preserved ejection fraction. Associated features, such as carpal tunnel syndrome, can preceed by several years the development of symptomatic HF and may serve as early disease markers. Echocardiography and cardiac magnetic resonance raise suspicion of disease and might offer markers of treatment response at a myocardial level, such as extracellular volume quantification. Radionuclide scintigraphy with 'bone' tracers coupled with biochemical tests may differentiate ATTR from light chain amyloidosis. Therapies able to slow or halt ATTR-CA progression and increase survival are now available. In this evolving scenario, early disease recognition is paramount to derive the greatest benefit from treatment.
Project description:Transthyretin amyloidosis (ATTR amyloidosis) is a heterogeneous disorder with cardiac, neurologic, and mixed phenotypes. We describe the phenotypic and genotypic profiles of this disease in continental Western Europe as it appears from the Transthyretin Amyloidosis Survey (THAOS). THAOS is an ongoing, worldwide, longitudinal, observational survey established to study differences in presentation, diagnosis, and natural history in ATTR amyloidosis subjects. At data cut-off, 1411 symptomatic subjects from nine continental Western European countries were enrolled in THAOS [1286 hereditary (ATTRm) amyloidosis; 125 wild-type ATTR (ATTRwt) amyloidosis]. Genotypes and phenotypes varied notably by country. Four mutations (Val122Ile, Leu111Met, Thr60Ala, and Ile68Leu), and ATTRwt, were associated with a mainly cardiac phenotype showing symmetric left ventricular (LV) hypertrophy, normal diastolic LV dimensions and volume, and mildly depressed LV ejection fraction (LVEF). Morphologic and functional abnormalities on echocardiogram were significantly more severe in subjects with cardiac (n = 210), compared with a mixed (n = 298), phenotype: higher median (Q1-Q3) interventricular septal thickness [18 (16-21) vs. 16 (13-20) mm; P = 0.0006]; and more frequent incidence of LVEF <50% (38.1 vs. 17.5%; P = 0.0008). Subjects with cardiac mutations or ATTRwt (or cardiac or mixed phenotype) had a lower survival rate than subjects in other genotype (or the neurologic phenotype) categories (P < 0.0001, for both). ATTR amyloidosis genotypes and phenotypes are highly heterogeneous in continental Western Europe. A geographic map of the different disease profiles and awareness that a subset of subjects have a dominant cardiac phenotype, mimicking hypertrophic cardiomyopathy, at presentation can facilitate the clinical recognition of this underdiagnosed disease. ClinicalTrials.gov: NCT00628745.
Project description:BackgroundWe sought to compare the long-term outcomes in patients with transthyretin cardiac amyloidosis (CA) compared to those with non-ischemic cardiomyopathy (NICM) from a large healthcare system database.MethodsPatients with CA or NICM were identified from SSM Healthcare System's data warehouse using ICD codes. Inclusion criteria included at least 6 months of follow-up. Outcomes studied were heart failure hospitalization (HFH), ventricular tachyarrhythmias (VTA), implantable cardiac defibrillator (ICD) and pacemaker (PM) placement. Multivariate logistic analysis and Kaplan-Meier survival curves were constructed.ResultsWe identified 231 patients with CA and 462 with NICM, matched for age, race, and gender. CA patients had higher incidence of peripheral vascular disease (48.5% vs. 35.5%) and coronary artery disease (10.4% vs. 6.1%). Mean follow-up was 48.1 ± 33.1 months. CA patients had a higher rate of HFH (57.6% vs. 46.1%) and a lower rate of ICD (1.7% vs. 5.9%). In the multivariate model, CA patients had significantly higher odds for HFH (odds ratio: 1.86; 95% confidence interval: 1.29 - 2.68). Kaplan-Meier survival curves showed a trend toward earlier HFH and later PM or ICD implantation in CA patients.ConclusionsIn this retrospective study from a large healthcare system database, compared to NICM, transthyretin CA patients had significantly higher rates of HFH, similar odds of VTA, and a lower likelihood of receiving an intracardiac device.
Project description:ObjectivesThe aim of this study was to characterize left atrial (LA) pathology in explanted hearts with transthyretin amyloid cardiomyopathy (ATTR-CM); LA mechanics using echocardiographic speckle-tracking in a large cohort of patients with ATTR-CM; and to study the association with mortality.BackgroundThe clinical significance of LA involvement in ATTR-CM is of great clinical interest.MethodsCongo red staining and immunohistochemistry was performed to assess the presence, type, and extent of amyloid and associated changes in 5 explanted ATTR-CM atria. Echo speckle tracking was used to assess LA reservoir, conduit, contractile function, and stiffness in 906 patients with ATTR-CM (551 wild-type (wt)-ATTR-CM; 93 T60A-ATTR-CM; 241 V122I-ATTR-CM; 21 other).ResultsThere was extensive ATTR amyloid infiltration in the 5 atria, with loss of normal architecture, vessels remodeling, capillary disruption, and subendocardial fibrosis. Echo speckle tracking in 906 patients with ATTR-CM demonstrated increased atrial stiffness (median [25th-75th quartile] 1.83 [1.15-2.92]) that remained independently associated with prognosis after adjusting for known predictors (lnLA stiff: HR: 1.23; 95% CI: 1.03-1.49; P = 0.029). There was substantial impairment of the 3 phasic functional atrial components (reservoir 8.86% [5.94%-12.97%]; conduit 6.5% [4.53%-9.28%]; contraction function 4.0% [2.29%-6.56%]). Atrial contraction was absent in 22.1% of patients whose electrocardiograms showed sinus rhythm (SR) "atrial electromechanical dissociation" (AEMD). AEMD was associated with poorer prognosis compared with patients with SR and effective mechanical contraction (P = 0.0018). AEMD conferred a similar prognosis to patients in atrial fibrillation.ConclusionsThe phenotype of ATTR-CM includes significant infiltration of the atrial walls, with progressive loss of atrial function and increased stiffness, which is a strong independent predictor of mortality. AEMD emerged as a distinctive phenotype identifying patients in SR with poor prognosis.
Project description:AimCardiac troponins and natriuretic peptides are established for risk stratification in light-chain amyloidosis. Data on cardiac biomarkers in transthyretin amyloidosis (ATTR) are lacking.Methods and resultsPatients (n = 1617) with any of the following cardiac biomarkers, BNP (n = 1079), NT-proBNP (n = 550), troponin T (n = 274), and troponin I (n = 108), available at baseline in the Transthyretin Amyloidosis Outcomes Survey (THAOS) were analyzed for differences between genotypes and phenotypes and their association with survival. Median level of BNP was 68.0 pg/mL (IQR 30.5-194.9), NT-proBNP 337.9 pg/mL (IQR 73.0-2584.0), troponin T 0.03 μg/L (IQR 0.01-0.05), and troponin I 0.08 μg/L (IQR 0.04-0.13). NT-proBNP and BNP were higher in wild-type than mutant-type ATTR, troponin T and I did not differ, respectively. Non-Val30Met patients had higher BNP, NT-proBNP and troponin T levels than Val30Met patients, but not troponin I. Late-onset Val30Met was associated with higher levels of troponin I and troponin T compared with early-onset. 115 patients died during a median follow-up of 1.2 years. Mortality increased with increasing quartiles (BNP/NT-proBNP Q1 = 1.7%, Q2 = 5.2%, Q3 = 21.7%, Q4 = 71.3%; troponin T/I Q1 = 6.5%, Q2 = 14.5%, Q3 = 33.9%, Q4 = 45.2%). Three-year overall-survival estimates for BNP/NT-proBNP and troponin T/I quartiles differed significantly (p<0.001). Stepwise risk stratification was achieved by combining NT-proBNP/BNP and troponin T/I. From Cox proportional hazards model, age, modified body mass index, mutation (Val30Met vs. Non-Val30Met) and BNP/NT-proBNP (Q1-Q3 pooled vs. Q4) were identified as independent predictors of survival in patients with mutant-type ATTR.ConclusionsIn this ATTR patient cohort, cardiac biomarkers were abnormal in a substantial percentage of patients irrespective of genotype. Along with age, mBMI, and mutation (Val30Met vs. Non-Val30Met), cardiac biomarkers were associated with surrogates of disease severity with BNP/NT-proBNP identified as an independent predictor of survival in ATTR.Trial registrationClinicalTrials.gov NCT00628745.
Project description:Transthyretin cardiac amyloidosis (ATTR-CA) is a progressive disease characterized by the deposition of abnormal transthyretin protein fibrils in the heart, leading to cardiac dysfunction. Recent evidence suggests that sex differences may play a significant role in various steps of ATTR-CA, including clinical presentation, diagnostic challenges, disease progression, and treatment outcomes. ATTR-CA predominantly affects men, whereas women are older at presentation. Women generally present with a history of heart failure with preserved ejection fraction and/or carpal tunnel syndrome. When indexed, left ventricular (LV) wall thickness is equal, or even increased, than men. Women also have smaller LV cavities, more preserved ejection fractions, and apparently a slightly worse right ventricular and diastolic function. Given the under-representation on women in clinical trials, no data regarding sex influence on the treatment response are currently available. Finally, it seems there are no differences in overall prognosis, even if premenopausal women may have a certain level of myocardial protection. Genetic variations, environmental factors, and hormonal changes are considered as potential contributors to observed disparities. Understanding sex differences in ATTR-CA is vital for accurate diagnosis and management. By considering these differences, clinicians can improve diagnostic accuracy, tailor treatments, and optimize outcomes for both sexes with ATTR-CA.
Project description:Transthyretin-related cardiac amyloidosis is a progressive infiltrative cardiomyopathy that mimics hypertensive and hypertrophic heart disease and often goes undiagnosed. In the United States, the hereditary form disproportionately afflicts black Americans, who when compared with whites with wild-type transthyretin amyloidosis, a phenotypically similar condition, present with more advanced disease despite having a noninvasive method for early identification (genetic testing). Although reasons for this are unclear, this begs to consider the inadequate access to care, societal factors, or a biological basis. In an effort to improve awareness and explore unique characteristics, we review the pathophysiology, epidemiology, and therapeutic strategies for transthyretin amyloidosis and highlight diagnostic pitfalls and clinical pearls for identifying patients with amyloid heart disease.