Department of Biomedical Engineering, University of Texas, San Antonio, Texas, USA.
Department of Biological Sciences, University of Texas, San Antonio, Texas, USA.
Pulm Circ. 2015 Mar;5(1):90-100. doi: 10.1086/679703.
Pulmonary hypertension (PH) is a devastating disease affecting approximately 15-50 people per million, with a higher incidence in women. PH mortality is mostly attributed to right ventricle (RV) failure, which results from RV hypotrophy due to an overburdened hydraulic workload. The objective of this study is to correlate wall shear stress (WSS) with hemodynamic metrics that are generally accepted as clinical indicators of RV workload and are well correlated with disease outcome. Retrospective right heart catheterization data for 20 PH patients were analyzed to derive pulmonary vascular resistance (PVR), arterial compliance (C), and an index of wave reflections (Γ). Patient-specific contrast-enhanced computed tomography chest images were used to reconstruct the individual pulmonary arterial trees up to the seventh generation. Computational fluid dynamics analyses simulating blood flow at peak systole were conducted for each vascular model to calculate WSS distributions on the endothelial surface of the pulmonary arteries. WSS was found to be decreased proportionally with elevated PVR and reduced C. Spatially averaged WSS (SAWSS) was positively correlated with PVR (R (2) = 0.66), C (R (2) = 0.73), and Γ (R (2) = 0.5) and also showed promising preliminary correlations with RV geometric characteristics. Evaluating WSS at random cross sections in the proximal vasculature (main, right, and left pulmonary arteries), the type of data that can be acquired from phase-contrast magnetic resonance imaging, did not reveal the same correlations. In conclusion, we found that WSS has the potential to be a viable and clinically useful noninvasive metric of PH disease progression and RV health. Future work should be focused on evaluating whether SAWSS has prognostic value in the management of PH and whether it can be used as a rapid reactivity assessment tool, which would aid in selection of appropriate therapies.
肺动脉高压（PH）是一种毁灭性疾病，影响约每百万人中有 15-50 人，女性发病率更高。PH 患者的死亡率主要归因于右心室（RV）衰竭，这是由于 RV 因液压工作量过大而发生的心肌肥厚导致的。本研究的目的是将壁面切应力（WSS）与血流动力学指标相关联，这些指标通常被认为是 RV 工作量的临床指标，并且与疾病结果密切相关。分析了 20 名 PH 患者的回顾性右心导管检查数据，以得出肺血管阻力（PVR）、动脉顺应性（C）和波反射指数（Γ）。使用患者特定的对比增强 CT 胸部图像对个体肺动脉树进行重建，直到第七代。对每个血管模型进行模拟峰值收缩期血流的计算流体动力学分析，以计算肺动脉内皮表面的 WSS 分布。发现 WSS 与升高的 PVR 和降低的 C 成比例降低。空间平均 WSS（SAWSS）与 PVR 呈正相关（R²=0.66），与 C 呈正相关（R²=0.73），与 Γ 呈正相关（R²=0.5），并且与 RV 几何特征也显示出有希望的初步相关性。在近端血管（主肺动脉、右肺动脉和左肺动脉）的随机横截面上评估 WSS，这是可以从相位对比磁共振成像中获得的数据类型，没有显示出相同的相关性。总之，我们发现 WSS 有可能成为 PH 疾病进展和 RV 健康的可行且临床有用的非侵入性指标。未来的工作应集中评估 SAWSS 在 PH 管理中的预后价值，以及它是否可作为快速反应性评估工具，这将有助于选择适当的治疗方法。
