An XFM Interventional Guidance System for Cardiac Resynchronization Therapy

描述(由申请人提供)：充血性心力衰竭(CHF)影响着500多万美国人，是主要的死亡原因和最常见的住院原因。近50%的CHF患者将在确诊后5年内死亡，这一死亡率高于大多数形式的癌症。心脏再同步治疗(CRT)已成为治疗不同步的CHF患者的一种很有前途的治疗方法，试验表明，成功放置起搏器电极后，患者的症状和心泵效率得到显著改善。今天，仅使用X射线成像来指导CRT起搏器电极的放置，但这种方式为医生提供的功能和解剖信息很少。引线放置是通过相对“盲目”的转向来执行的，这导致了20%的程序失败率，并可能解释了30%以上的无响应率。另一方面，MRI提供了独特的软组织对比，无需使用电离辐射来描绘冠状静脉的形态，量化心肌不同步，并识别疤痕组织。人们普遍认为，这些因素是CRT临床结果的关键决定因素，它们应该用于CRT的患者选择、程序规划和指导。本项目的目标是开发一种“X射线与磁共振融合”(XFM)图像引导系统，将术前MR静脉成像、机械不同步和心肌存活与术中X线图像相结合，以指导CRT手术。这些措施将允许医生在放置导联时实时将冠状静脉和左心室导联的位置与周围软组织特征直接联系起来。我们推测，这种XFM引导系统将有助于更有效地放置起搏器导线，最终导致CRT应答率的增加。该项目将分为三个主要的具体目标：(1)开发一种心脏磁共振成像方法，以创建冠状动脉静脉解剖、机械不同步和心肌存活的单一3D表示(2)开发一种XFM介入引导系统，该系统可在EP实验室中实时将MR衍生的测量结果覆盖在实时X射线图像上并补偿呼吸运动(3)通过活体动物实验验证XFM CRT系统，随后进行首次人类临床研究。该项目将结合独特的磁共振成像方法和最先进的介入成像指导，以解决美国的主要死亡原因之一。公共卫生相关性：充血性心力衰竭(CHF)影响着500多万美国人，是主要的死亡原因和最常见的住院原因。心脏再同步治疗(CRT)已成为治疗不同步的CHF患者的一种很有前途的治疗方法，试验表明，成功放置起搏器电极后，患者的症状和心泵效率得到显著改善。今天，仅使用X射线成像来指导CRT起搏器电极的放置，但这种方式为医生提供的功能和解剖信息很少，这可能解释了30%以上的无反应率。该项目的目标是开发一种“X射线融合磁共振”(XFM)图像引导系统，将术前MRI获得的静脉成像、机械不同步和心肌存活与术中X射线图像相结合，以指导CRT手术，以提高患者的应答率。

DESCRIPTION (provided by applicant): Congestive heart failure (CHF) affects over 5 million Americans and is a major cause of death and the most common reason for hospitalization. Nearly fifty percent of CHF patients will die within 5 years of diagnosis, which is a higher mortality than most forms of cancer. Cardiac resynchronization therapy (CRT) has emerged as a promising therapy for CHF patients with dyssynchrony and has been shown in trials to significantly improve symptoms and cardiac pump efficiency when pacemaker leads are placed successfully. Today, X-ray imaging alone is used to guide placement of pacemaker leads for CRT, but this modality provides little functional and anatomic information to the physician. Lead placement is performed by steering relatively "blindly" which contributes to a procedural failure rate of 20% and may explain a non-response rate of more than 30%. On the other hand, MRI offers unique soft tissue contrast without the use of ionizing radiation for depicting coronary vein morphology, quantifying myocardial dyssynchrony, and identifying scar tissue. It is widely believed that these elements are key determinants of clinical outcomes for CRT and that they should be used for patient selection, procedural planning, and guidance of CRT. The objective of this project is to develop an "X-ray fused with MR" (XFM) image guidance system for integrating pre-procedural MR-derived vein imaging, mechanical dyssynchrony and myocardial viability with intra-procedural X-ray images to guide CRT procedures. These measures will allow the physician to directly relate the positions of the coronary vein and left ventricular leads with the surrounding soft tissue characteristics in real-time during lead placement. We hypothesize that this XFM guidance system will facilitate more effective placement of the pacemaker leads, ultimately leading to an increase in CRT responder rates. This project will be divided into three main Specific Aims: (1) to develop a cardiac MR imaging methodology for creating a single 3D representation of coronary vein anatomy, mechanical dyssynchrony, and myocardial viability (2) to develop an XFM interventional guidance system that provides real-time overlay of MR derived measures on live X-ray images with compensation of respiratory motion in the EP lab (3) to validate XFM CRT system with in vivo animal experiments followed by first in human clinical study. This project will bring together unique MR imaging methods and state of the art interventional image guidance to address one of the leading causes of death in the United States. PUBLIC HEALTH RELEVANCE: Congestive heart failure (CHF) affects over 5 million Americans and is a major cause of death and the most common reason for hospitalization. Cardiac resynchronization therapy (CRT) has emerged as a promising therapy for CHF patients with dyssynchrony and has been shown in trials to significantly improve symptoms and cardiac pump efficiency when pacemaker leads are placed successfully. Today, X-ray imaging alone is used to guide placement of pacemaker leads for CRT, but this modality provides little functional and anatomic information to the physician, which may explain a non-response rate of more than 30%. The objective of this project is to develop an "X-ray fused with MR" (XFM) image guidance system for integrating pre-procedural MRI-derived vein imaging, mechanical dyssynchrony and myocardial viability with intra- procedural X-ray images to guide CRT procedures, with the goal of improving patient response rates.