Project description:Cardiac amyloidosis is a form of restrictive cardiomyopathy resulting in heart failure and potential risk on arrhythmia, due to amyloid infiltration of the nerve conduction system and the myocardial tissue. The prognosis in this progressive disease is poor, probably due the development of cardiac arrhythmias. Early detection of cardiac sympathetic innervation disturbances has become of major clinical interest, because its occurrence and severity limits the choice of treatment. The use of iodine-123 labelled metaiodobenzylguanidine ([I-123]MIBG), a chemical modified analogue of norepinephrine, is well established in patients with heart failure and plays an important role in evaluation of sympathetic innervation in cardiac amyloidosis. [I-123]MIBG is stored in vesicles in the sympathetic nerve terminals and is not catabolized like norepinephrine. Decreased heart-to-mediastinum ratios on late planar images and increased wash-out rates indicate cardiac sympathetic denervation and are associated with poor prognosis. Single photon emission computed tomography provides additional information and has advantages for evaluating abnormalities in regional distribution in the myocardium. [I-123]MIBG is mainly useful in patients with hereditary and wild-type ATTR cardiac amyloidosis, not in AA and AL amyloidosis. The potential role of positron emission tomography for cardiac sympathetic innervation in amyloidosis has not yet been identified.
Project description:Cardiac involvement has a profound effect on the prognosis of patients with systemic amyloidosis. Therapeutic methods for suppressing the production of causative proteins have been developed for ATTR amyloidosis and AL amyloidosis, which show cardiac involvement, and the prognosis has been improved. However, a method for removing deposited amyloid has not been established. Methods for reducing cytotoxicity caused by amyloid deposition and amyloid precursor protein to protect cardiovascular cells are also needed. In this review, we outline the molecular mechanisms and treatments of cardiac amyloidosis.
Project description:Amyloidosis refers to a range of protein misfolding disorders that can cause organ dysfunction through progressive fibril deposition. Cardiac involvement often leads to significant morbidity and mortality and increasingly has been recognized as an important cause of heart failure. The two main forms of cardiac amyloidosis, light chain (AL) and transthyretin (ATTR) amyloidosis, have distinct mechanisms of pathogenesis. Recent insights have led to the development of novel pharmacotherapies with the potential to significantly impact each disease. This review will summarize the preclinical and clinical data for these emerging treatments for AL and ATTR amyloidosis.
Project description:AimsCardiac resynchronization therapy (CRT) is highly effective in dilated cardiomyopathy (DCM) patients with impaired left ventricular ejection fraction (LVEF) and left bundle block branch. In cardiac amyloidosis (CA) patients, left ventricular dysfunction and conduction defects are common, but the potential of CRT to improve cardiac remodelling and survival in this particular setting remains undefined. We investigated cardiovascular outcomes in CA patients after CRT implantation in terms of CRT echocardiographic response and major cardiovascular events (MACEs).Methods and resultsOur retrospective study included 47 CA patients implanted with CRT devices from January 2012 to February 2020, in nine French university hospitals (77 ± 6 years old, baseline LVEF 30 ± 8%) compared with propensity-matched (1:1 for age, LVEF at implantation, and CRT indication) DCM patients with a CRT device. CA patients had lower rates of CRT response (absolute delta LVEF ≥ 10%) compared with DCM patients (36% vs. 70%, P = 0.002). After multivariate Cox analysis, CA was independently associated with MACE (hospitalization for heart failure/cardiovascular death) [hazard ratio (HR) 3.73, 95% confidence interval (CI) 1.85-7.54, P < 0.001], along with the absence of CRT response (HR 3.01, 95% CI 1.56-5.79, P = 0.001). The presence of echocardiographic CRT response (absolute delta LVEF ≥ 10%) was the only predictive factor of MACE-free survival in CA patients (HR 0.36, 95% CI 0.15-0.86, P = 0.002).ConclusionCompared with a matched cohort of DCM patients, CA patients had a lower rate of CRT response and consequently a worse cardiovascular prognosis after CRT implantation. However, CRT could be beneficial even in CA patients given that CRT response was associated with better cardiac outcomes in this population.
Project description:Cardiac amyloidosis can result from any of the systemic amyloidoses. The disease is often characterized by a restrictive cardiomyopathy although the particular signs and symptoms depend in part on the underlying cause. In addition to managing the symptoms of heart failure, treatment options vary depending on the etiology of amyloid deposition. It is therefore critical to identify the cause of cardiac amyloidosis before initiating definitive therapy. We present a patient with presumed immunoglobulin (AL) amyloidosis who had a circulating lambda monoclonal protein, but a bone marrow biopsy with kappa predominant plasma cells. This unusual finding called into question the diagnosis of AL amyloidosis and highlights the importance and difficulty of determining the cause of cardiac amyloid deposition before initiating treatment. We review the different forms of cardiac amyloidosis and propose a diagnostic algorithm to help identify the etiology of cardiac amyloid deposition before beginning therapy.
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.
Project description:Amyloidosis is a heterogeneous group of diseases characterized by localized or systemic deposition of insoluble extracellular fibrillary proteins in organs and tissues. Several types of amyloid can infiltrate the heart resulting in a restrictive cardiomyopathy, heart failure, and atrial and ventricular arrhythmias. Scintigraphy is a noninvasive method that may facilitate early diagnosis, distinguish various forms of cardiac amyloid, and may be useful in following disease burden. The amyloid-specific tracers presented in this article have been used with planar imaging and/or single-photon emission computed tomography. To date, there are no approved cardiac amyloid tracers although investigational tracers are currently under examination. This article serves to review the current nuclear imaging modalities available in the detection of cardiac amyloid.
Project description:Wild-type transthyretin cardiac amyloidosis (ATTRwt), formerly called senile cardiac amyloidosis (SCA), is almost exclusively a disorder of older adults. As the population ages, the diagnosis of ATTRwt will increase, making it the most common form of cardiac amyloidosis. An important precondition to reduce underdiagnosis and misdiagnosis is to maintain a high index of suspicion for cardiac amyloidosis. Several clues can be gleaned from the clinical history, physical exam, electrocardiography, and noninvasive imaging techniques. Nuclear scintigraphy agents using 99mTc-phosphate derivatives combined with assessment for monoclonal proteins are eliminating the need for tissue confirmation in ATTR. Morbidity and mortality from ATTRwt cardiac amyloid is high and the emergence of numerous therapies based on a biologic understanding of the pathophysiology of this condition, including drugs to inhibit the synthesis of TTR, stabilize TTR, and degrade or extract amyloid, provides new hope for those afflicted. This review briefly covers the epidemiology, pathophysiology, and clinical manifestations, as well as diagnostic strategies and treatment, of ATTR in older adults.
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.