3D echocardiography to evaluate ischemic mitral regurgitation in humans.

描述（由申请人提供）：缺血性二尖瓣返流（IMR）是心肌梗死的常见并发症，与长期生存率差相关。无论治疗如何，发生IMR的患者发生充血性心力衰竭（CHF）的风险显著增加，并且在冠状动脉血运重建术后发生明显更严重的心脏病。IMR二尖瓣修复术后的结果令人失望，经验丰富的中心报告修复后6个月的失败率高达50%。最近报告的成像数据表明，修复前和修复后IMR与二尖瓣环扩张和变平相关，阻止了正常的瓣膜贴壁并允许血液流动。二尖瓣修复失败的详细基础和梗死诱导的重构对二尖瓣环形状的影响迄今尚未完全研究。我们的目的是评估瓣成形环形状对IMR病例中人类二尖瓣力学和二尖瓣修复耐久性的影响，并证明使用准确再现自体二尖瓣环鞍形的瓣成形环可提高修复耐久性。为了实现这些目标，我们将利用一种新的技术：高分辨率，定量，三维超声心动图对人类二尖瓣进行全面成像。这项新兴技术将使我们能够量化导致IMR发展的三种几何病理：瓣环扩张、瓣环扁平化和瓣叶栓系，因此，预测哪些患者将从二尖瓣修复术与置换术中受益。我们将利用实时三维超声心动图（rt-3DE）建立IMR的定量参数。我们的目标是以之前成像技术无法实现的空间分辨率来表征IMR中瓣环重塑的性质。此外，我们将评估瓣环成形术形状对修复耐久性的影响。将使用标准扁平瓣成形环或反映自体瓣环形状的鞍形环修复人类IMR。对于两个瓣膜组，将使用修复前和修复后测量的rt：-3DE参数评估二尖瓣返流程度和修复后即刻、12个月和24个月的二尖瓣特征。尽管有最好的药物和手术治疗，梗死诱导的CHF的五年生存率接近50%，并且由此产生的医疗保健系统的压力是惊人的。本项目的主要目的是开发一种临床相关、无创、功能强大的成像模式，用于在IMR病例中询问二尖瓣，并利用该技术描述临床有效、相关的外科治疗。

DESCRIPTION (provided by applicant): Ischemic mitral regurgitation (IMR) is a frequent complication of myocardial infarction that is associated with poor long-term survival. Irrespective of treatment, patients who develop IMR are at significantly increased risk for congestive heart failure (CHF) and have markedly worse prognoses following coronary revascularization. Results following mitral valve repair for IMR have been disappointing, and experienced centers report failure rates as high as 50% at 6 months post-repair. Recently reported imaging data suggests that pre- and post-repair IMR are associated with dilatation and flattening of the mitral valve annulus, preventing normal valve apposition and allowing regurgitant blood flow. The detailed basis for the failure of mitral valve repair and the effect of infarction-induced remodeling on mitral annular shape has been incompletely studied to date. Our aim is to assess the of impact of annuloplasty ring shape on human mitral valve mechanics and mitral valve repair durability in cases of IMR and show that the use of an annuloplasty ring that accurately reproduces the saddle shape of the native mitral annulus increases repair durability. To accomplish these goals we will utilize a novel technology: high-resolution, quantitative, 3-dimensiorial echocardiography for comprehensive imaging of the human mitral valve. This emerging technology will allow us to quantify the three geometric pathologies that contribute to the development of IMR: annular dilation, annular flattening, and leaflet tethering, and, therefore, predict which patients will benefit from mitral valve repair versus replacement. We will utilize real-time three-dimensional echocardiography (rt-3DE) to establish quantitative parameters of IMR. We aim to characterize the nature of annular remodeling in IMR with a spatial resolution not possible with previous imaging technology. In addition, we will assess the effects of ring annuloplasty shape on repair durability. IMR will be repaired in humans with either a standard fiat annuloplasty ring or a saddle ring that reflects native annular shape. For both valve groups, rt:-3DEparameters measured pre- and post-repair will be used to assess the degree of MR and characteristics of the mitral valve immediately, at 12 months, and at 24 months post-repair. The five-year survival for infarction-induced CHF approaches 50% despite best medical and surgical therapy, and the resultant strain on the healthcare system is staggering. The primary objective of this project is to develop a clinically relevant, noninvasive, powerful imaging modality for interrogating the mitral valve in cases of IMR, and to utilize this technique to delineate clinically effective, relevant surgical therapy.