Interplay of Myocardial Fibrosis and Cardiac TTR Amyloid in Age Related Cardiac Remodeling in MESA-Multi-Ethnic Study of Atherosclerosis

项目概要： 心肌纤维化的特征是细胞外基质在心肌内的积聚 并且已被确定为年龄相关的心脏重塑的主要决定因素之一。这 可表现为弥漫性间质纤维化增加或瘢痕样局灶性纤维化，并导致 心功能不全心脏甲状腺素运载蛋白淀粉样变性，特征为 另一方面，错误折叠的甲状腺素运载蛋白对心肌的影响已经成为一种重要的 导致心力衰竭和心血管疾病的加速重塑的原因，以及易患虚弱和 痴呆重要的是，FDA批准的新疗法（tafamaltine，inotersen）可能允许治疗 心脏淀粉样变突出需要早期发现。我们希望这项研究能够建立 在人群水平上量化纤维化和淀粉样变性的关键重要性， 临床检测和指导新策略的发展，以预防心力衰竭，心房颤动， 老年人心血管疾病的纤颤和并发症。因此，我们的具体目标是：目标1a） 确定淀粉样变性的存在以及测量的程度的横截面关联 通过Tc-PYP，在梅萨检查7中通过MRI T1标测测量心肌纤维化程度。 1b）确定淀粉样变性的存在和程度的横截面关联，以及 纤维化，心脏重塑的程度定义为结构和功能的改变， 在梅萨检查7.1c）处通过电影MRI的左心室和右心室构建预测模型 对于检查7中心脏淀粉样变性和进行性纤维化的存在以及程度， 通过结合风险因素暴露和基于表型的亚临床疾病轨迹， 在考试7之前从所有梅萨考试（1-6）中获得。在目标2a）中，我们将比较 梅萨考试5和7之间的ECV变化，以及程度 淀粉样变性的程度2b）比较4个国家12-14年的变化幅度 淀粉样变性引起的心室重构与进行性淀粉样变性引起的心室重构 纤维化2c）构建归因于以下因素的ECV 12-14年变化的纵向预测模型： 淀粉样变性与归因于进行性纤维化的ECV变化，使用所有表型变量 从梅萨考试1到5获得。我们建议使用2010-2012年期间获得的数据， 800人（400名男性和400名女性）作为梅萨5考试的一部分。作为该提案的一部分， 所有参与者将在检查7时进行重复MRI检查和Tc-99 m-PYP。这项研究利用了 已经获得的梅萨表型数据预测淀粉样变性和恶性进展 纤维化导致不利的重塑、CVD、虚弱和痴呆。

Project Summary: Myocardial fibrosis is characterized by the accumulation of extracellular matrix in the myocardium and has been identified as one of the main determinants of age related cardiac remodeling. This can manifest as either increased diffuse interstitial fibrosis or focal fibrosis as a scar and lead to cardiac dysfunction. Cardiac transthyretin amyloidosis characterized by infiltration of the myocardium by misfolded transthyretin protein, on the other hand, has emerged as an important cause of accelerated remodeling leading to heart failure and CVD, and predisposing to frailty and dementia. Importantly, novel FDA approved therapies (tafamidis, inotersen) may allow treatment of cardiac amyloidosis highlighting the need for early detection. We expect this study to establish the pivotal importance of quantifying fibrosis and amyloidosis at the population level to facilitate clinical detection and orient the development of novel strategies to prevent heart failure, atrial fibrillation and complications of CVD in older adults. Therefore, our specific aims are: Aim 1a) determine the cross-sectional associations of presence as well as extent of amyloidosis measured by Tc-PYP, with extent of myocardial fibrosis measured by MRI T1 mapping at MESA Exam 7. 1b) determine cross-sectional associations of presence and extent of amyloidosis as well as fibrosis, with magnitude of cardiac remodeling defined as structural and functional alterations of the left and right heart chambers by cine MRI at MESA Exam 7.1c) construct prediction models for presence as well as for extent of both cardiac amyloidosis and progressive fibrosis at Exam 7, by combining risk factor exposure and subclinical disease trajectories based on phenotypes obtained from all MESA Exams (1-6) prior to Exam 7. In Aim 2a) we will compare the magnitude of ECV change between MESA Exams 5 and 7 in the absence versus presence, as well as extent of amyloidosis measured at Exam 7. 2b) compare the magnitude of 12-14 year changes in 4 chamber cardiac remodeling attributed to amyloidosis versus those attributed to progressive fibrosis. 2c) construct longitudinal predictive models of 12-14 year change in ECV attributed to amyloidosis versus ECV changes attributed to progressive fibrosis, using all phenotypic variables obtained from MESA Exams 1 through 5. We propose to use data acquired during 2010-2012 in 800 individuals (400 men and 400 women) as part of the MESA 5 exam. As part of this proposal, all participants will undergo a repeat MRI exam and Tc-99m-PYP at Exam 7. This study leverages the already acquired MESA phenotypic data to predict amyloidosis and malignant progressive fibrosis leading to adverse remodeling, CVD, frailty and dementia.