Timmins Lucas H, Gupta Divya, Corban Michel T, Molony David S, Oshinski John N, Samady Habib, Giddens Don P
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Drive, Suite W 200, 30322-4600, Atlanta, GA, USA.
Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA.
Cardiovasc Eng Technol. 2015 Mar;6(1):25-35. doi: 10.1007/s13239-014-0198-2. Epub 2014 Oct 28.
Cardiac allograft vasculopathy (CAV) is one of the leading causes of morbidity and morality in orthotopic heart transplant (HTx) patients. While disturbed flow patterns have been linked to the spatial localization of atherosclerosis, the role of hemodynamics in CAV development has not been examined. HTx patients (n = 5) requiring percutaneous coronary intervention (PCI) for a focal, epicardial lesion were studied. Angiographic images were retrospectively obtained from baseline (i.e., in the presence of no observed disease) and follow-up catheterizations (i.e., at the time of PCI; 12.4 ± 2.6 years post-HTx). Patient-specific computational models were created from baseline images. Computational fluid dynamic techniques were employed to quantify the hemodynamic environment, which was expressed as normalized time-averaged WSS (TAWSSnorm; measure of temporal WSS magnitude) and normalized WSS angle deviation (WSSADnorm; measure of instantaneous WSS vector oscillation) values. Baseline hemodynamic and follow-up angiographic data were co-registered to investigate the association between WSS and subsequent occlusive CAV lesion location. Results indicate a high degree of co-localization between baseline low WSS data and follow-up occlusive CAV lesion. Local minima in TAWSSnorm were located 2.5 ± 0.6 mm from the site of PCI. Furthermore, local maxima in WSSADnorm were located 3.9 ± 0.7 mm from the site of PCI. In 3 patients, the occlusive lesion formed in a region that was subjected to both low and oscillatory WSS at baseline. There was discernable spatial co-localization between baseline disturbed flow patterns and follow-up CAV lesions requiring PCI. These results suggest a role of fluid mechanics in the development of focal, flow-limiting CAV lesions.
心脏移植血管病变（CAV）是原位心脏移植（HTx）患者发病和死亡的主要原因之一。虽然紊乱的血流模式与动脉粥样硬化的空间定位有关，但血流动力学在CAV发展中的作用尚未得到研究。对5例因局灶性心外膜病变需要进行经皮冠状动脉介入治疗（PCI）的HTx患者进行了研究。回顾性地从基线（即未观察到疾病时）和随访导管插入术（即PCI时；HTx后12.4±2.6年）获取血管造影图像。根据基线图像创建患者特异性计算模型。采用计算流体动力学技术量化血流动力学环境，以归一化时间平均壁面切应力（TAWSSnorm；时间壁面切应力大小的度量）和归一化壁面切应力角度偏差（WSSADnorm；瞬时壁面切应力矢量振荡的度量）值表示。将基线血流动力学数据和随访血管造影数据进行配准，以研究壁面切应力与随后的闭塞性CAV病变位置之间的关联。结果表明，基线低壁面切应力数据与随访闭塞性CAV病变之间存在高度共定位。TAWSSnorm的局部最小值位于距PCI部位2.5±0.6 mm处。此外，WSSADnorm的局部最大值位于距PCI部位3.9±0.7 mm处。在3例患者中，闭塞性病变形成于基线时同时受到低壁面切应力和振荡壁面切应力作用的区域。基线紊乱的血流模式与需要PCI的随访CAV病变之间存在明显的空间共定位。这些结果表明流体力学在局灶性、限流性CAV病变的发展中起作用。
