Novel Echocardiographic Methods to Characterize Heart Failure in ESRD

 描述(由申请人提供)：目前普通人群中的心力衰竭范例不能充分描述终末期肾病(ESRD)患者的心脏疾病谱。根据常规超声心动图方法，大多数终末期肾病患者的左心室射血分数正常，舒张期功能轻度受损。这一信息表明，大多数终末期肾病患者发生心力衰竭的风险较低。事实上，接受透析的患者心力衰竭和心血管死亡率极高。我们相信，现代超声心动图方法将捕捉到这一人群更广泛的收缩和舒张期功能，从而更好地了解心脏功能和风险。在这一人群中研究心力衰竭的另一个挑战是血液透析相关容量状态的变化对心功能的影响。这项研究的目的是使用两种新的方法收集与血液透析相关的一致时间的超声心动图数据。室腔弹性(刚度)是一种新的参数，可以通过对常规超声心动图图像的定量分析来非侵入性地计算，并且被认为与负荷条件无关。斑点跟踪超声心动图是一种最先进的成像和分析方法，它捕捉收缩和舒张期单个心脏节段的增量变形，因此是一种内在心肌力学的测量，而不是依赖于心室容量的整体心腔测量(如射血分数)。超声心动图将在ESRD队列中进行，该队列是K23奖的一部分，重点是ESRD的血管功能障碍。我们将研究200名参与者的血液透析情况；患者将在本周第一次透析后的第二天进行研究。其中20名患者还将在透析日进行研究，直接在透析前后进行研究，以检验新的回声参数在透析过程中与传统的容量依赖参数相比会发生变化的假设。我们将严格裁决心力衰竭住院治疗有别于因医疗不依从或错过透析而住院的情况。我们将比较新型超声心动图和传统超声心动图在预测两年心力衰竭住院和总死亡率方面的表现。

 DESCRIPTION (provided by applicant): The current paradigm for heart failure in the general population does not adequately describe the spectrum of cardiac disease in patients with end-stage renal disease (ESRD). Most patients with ESRD have normal left ventricular ejection fraction and mildly impaired diastolic function, as measured by conventional echocardiographic methods. This information suggests that most patients with ESRD have low risk for heart failure. In fact, patients on dialysis have an extremely high rate of heart failure and cardiovascular mortality. We believe that modern methods of echocardiography will capture a broader range of systolic and diastolic function in this population, and thus provide better insight into cardiac function and risk. Another challenge in studying heart failure in this population is the impact tha hemodialysis-related changes in volume status have on cardiac function. The aim of this study is to collect echocardiographic data with consistent timing relative to hemodialysis, using two novel methods. Ventricular chamber elastance (stiffness) is a novel parameter that can be calculated non-invasively using quantitative analysis of conventional echocardiographic images, and is thought to be independent of loading conditions. Speckle tracking echocardiography is a state-of-the-art imaging and analysis modality that captures incremental deformation of individual cardiac segments during systole and diastole and thus is a measure of intrinsic myocardial mechanics as opposed to global cardiac chamber measurements (such as ejection fraction) that depend on ventricular volumes. Echocardiography will be performed in an ESRD cohort that is being recruited as part of a K23 Award focused on vascular dysfunction in ESRD. We will study 200 participants on hemodialysis; patients will be studied the day after their first dialysis session of the week. Twenty of the patients will also be studied on a dialysis day, directly before and after dialysis, to test the hypothesis that novel echo parameters will vary les during dialysis than traditional, volume-dependent parameters. We will rigorously adjudicate heart failure hospitalizations distinct from hospitalizations due to medical non-compliance or missed dialysis. We will compare the performance of novel and conventional echocardiography for predicting two-year heart failure hospitalizations and overall mortality.