Automatic quantification of myocardial motion in older adults

摘要 心力衰竭（HF）是心血管疾病（CVD）终末期的常见疾病 随后进行性心肌损伤或局部缺血。在65岁及以上的人群中， 动脉疾病（CAD）是HF的主要原因。虽然左心室射血分数低 (EF)是临床诊断HF的主要证据，受损的局部心肌功能障碍是 预期在早期阶段就能显示CAD的存在。 心脏变形分析（HDA）是一种先进的心肌运动分析技术，能够 在时间帧上自动跟踪心肌边界， 在现有电影图像上的功能和运动索引，无需额外扫描。在本研究中，我们将使用 HDA工具，用于分析CHARISMA研究的现有电影图像。从2009年到2012年，心脏MRI检查 （包括两腔、四腔和短轴视图的冠状动脉壁成像和电影MRI）和 同时对440名老年参与者（年龄：65 - MRI扫描时年龄为84岁），无记录的心血管疾病史。在目前的R 03项目中， （2019-2021），CHARISMA参与者将被随访10 - 12年。我们计划重新联系- 获得的局部心肌运动指数（位移、速度、应变和应变率）与临床 CHARISMA数据集中的结局、现有冠状动脉壁测量和实验室检查结果。我们将测试 总体假设，局部心肌运动指数有可能存在心血管风险， 无症状老年人。三个具体目标是：1）使用基线区域预测心血管事件 心肌运动指数; 2）将局部心肌运动指数与MRI衍生的冠状动脉特征相关联 重构;和3）确定局部心肌运动指数和传统的 CHARISMA研究中收集的心血管风险生物标志物/疾病。 本项目无需进行新的MRI扫描或实验室测试。通过成本效益高的方法， 本研究的目的是评价局部心肌运动的临床价值， 无症状老年人的心血管风险分层，心血管疾病的主要目标人群 预防这项研究也将帮助我们更好地了解受损的心肌之间的相关性， 功能/运动和亚临床CAD负担。此外，该结果将有助于定量选择 影像学生物标志物及其在未来临床中预测心血管事件的最佳截止点 问题研究

Abstract Heart failure (HF) is a common condition that represents the end stage of cardiovascular diseases (CVDs) subsequent to progressing myocardial damage or ischemia. In populations at ages 65 and older, coronary artery disease (CAD) serves as the leading cause of HF. Although low left ventricular (LV) ejection fraction (EF) is a major evidence for the diagnosis of HF in clinical practice, impaired regional myocardial dysfunction is expected to present the existence of CAD in its early stage. Heart deformation analysis (HDA) is a cutting-edge myocardial motion analysis technique that is able to automatically track the myocardium borders on time frames and calculate global and regional cardiac functional and motional indices on existing cine images without extra scans. In the present study, we will use the HDA tool to analyze existing cine images of CHARISMA study. From 2009 to 2012, cardiac MRI exams (including coronary wall imaging and cine MRI at two-chamber, four-chamber and short-axis views) and concurrent tests for traditional cardiovascular risk factors were performed on 440 older participants (age: 65 - 84 years old at the time of MRI scans) without documented history of CVDs. During the present R03 project (2019-2021), CHARISMA participants would have been followed-up for 10 - 12 years. We plan to relate newly- acquired regional myocardial motion indices (displacement, velocity, strain and strain rate) to clinical outcomes, existing coronary wall measures and results of lab tests in CHARISMA datasets. We will test the overall hypothesis that regional myocardial motion indices have the potential to present cardiovascular risk in asymptomatic elderly. Three specific aims are: 1) Predict cardiovascular events using baseline regional myocardial motion indices; 2) Relate regional myocardial motion indices to MRI-derived features of coronary remodeling; and 3) Determine correlations between regional myocardial motion indices and traditional cardiovascular risk biomarkers/conditions collected in CHARISMA study. No new MRI scans or lab tests are required in this project. Through a cost-effective approach, the immediate objective of the proposed project is to evaluate the clinical value of regional myocardial motion for cardiovascular risk stratification in asymptomatic older adults, a major target population of cardiovascular prevention. This study will also help us better understand the correlations between impaired myocardial function/motion and subclinical CAD burden. Furthermore, the results will facilitate the selection of quantitative imaging biomarkers and their optimal cut-off points for predicting cardiovascular events in future clinical studies.