Endothelial shear stress (ESS) identifies coronary plaques at high risk for progression and/or rupture leading to a future acute coronary syndrome. In this study an optimized methodology was developed to derive ESS, pressure drop and oscillatory shear index using computational fluid dynamics (CFD) in 3D models of coronary arteries derived from non-invasive coronary computed tomography angiography (CTA). These CTA-based ESS calculations were compared to the ESS calculations using the gold standard with fusion of invasive imaging and CTA. In 14 patients paired patient-specific CFD models based on invasive and non-invasive imaging of the left anterior descending (LAD) coronary arteries were created. Ten patients were used to optimize the methodology, and four patients to test this methodology. Time-averaged ESS (TAESS) was calculated for both coronary models applying patient-specific physiological data available at the time of imaging. For data analysis, each 3D reconstructed coronary artery was divided into 2 mm segments and each segment was subdivided into 8 arcs (45°).TAESS and other hemodynamic parameters were averaged per segment as well as per arc. Furthermore, the paired segment- and arc-averaged TAESS were categorized into patient-specific tertiles (low, medium and high). In the ten LADs, used for optimization of the methodology, we found high correlations between invasively-derived and non-invasively-derived TAESS averaged over segments (n = 263, r = 0.86) as well as arcs (n = 2104, r = 0.85, p < 0.001). The correlation was also strong in the four testing-patients with r = 0.95 (n = 117 segments, p = 0.001) and r = 0.93 (n = 936 arcs, p = 0.001).There was an overall high concordance of 78% of the three TAESS categories comparing both methodologies using the segment- and 76% for the arc-averages in the first ten patients. This concordance was lower in the four testing patients (64 and 64% in segment- and arc-averaged TAESS). Although the correlation and concordance were high for both patient groups, the absolute TAESS values averaged per segment and arc were overestimated using non-invasive vs. invasive imaging [testing patients: TAESS segment: 30.1(17.1–83.8) vs. 15.8(8.8–63.4) and TAESS arc: 29.4(16.2–74.7) vs 15.0(8.9–57.4) p < 0.001]. We showed that our methodology can accurately assess the TAESS distribution non-invasively from CTA and demonstrated a good correlation with TAESS calculated using IVUS/OCT 3D reconstructed models.

内皮剪切应力 (ESS) 可识别具有进展和/或破裂风险的冠状动脉斑块，从而导致未来的急性冠状动脉综合征。在这项研究中，开发了一种优化的方法，在源自非侵入性冠状动脉计算机断层扫描血管造影 (CTA) 的冠状动脉 3D 模型中使用计算流体动力学 (CFD) 推导出 ESS、压降和振荡剪切指数。这些基于 CTA 的 ESS 计算与使用金标准结合侵入性成像和 CTA 的 ESS 计算进行了比较。在 14 名患者中，创建了基于左前降支 (LAD) 冠状动脉的侵入性和非侵入性成像的患者特异性 CFD 模型。十名患者用于优化该方法，四名患者测试该方法。应用成像时可用的患者特定生理数据，计算两种冠状动脉模型的时间平均 ESS (TAESS)。对于数据分析，将每个 3D 重建冠状动脉分为 2 mm 段，每个段细分为 8 个弧（45°）。TAESS 和其他血流动力学参数对每个段以及每个弧进行平均。此外，成对的分段和弧平均 TAESS 被分类为患者特定的三分位数（低、中和高）。在用于优化方法的 10 个 LAD 中，我们发现有创衍生的和非侵入衍生的 TAESS 之间的高度相关性在各段上平均（每个 3D 重建的冠状动脉被分成 2 mm 段，每个段被细分为 8 个弧（45°）。TAESS 和其他血流动力学参数被平均每个段以及每个弧。此外，成对的分段和弧平均 TAESS 被分类为患者特定的三分位数（低、中和高）。在用于优化方法的 10 个 LAD 中，我们发现有创衍生的和非侵入衍生的 TAESS 之间的高度相关性在各段上平均（每个 3D 重建的冠状动脉被分成 2 mm 段，每个段被细分为 8 个弧（45°）。TAESS 和其他血流动力学参数被平均每个段以及每个弧。此外，成对的分段和弧平均 TAESS 被分类为患者特定的三分位数（低、中和高）。在用于优化方法的 10 个 LAD 中，我们发现有创衍生的和非侵入衍生的 TAESS 之间的高度相关性在各段上平均（n  = 263, r  = 0.86) 以及弧 ( n  = 2104, r  = 0.85, p  < 0.001)。在r  = 0.95（n  = 117 个片段，p  = 0.001）和r  = 0.93（n  = 936 个弧，p = 0.001)。在前 10 名患者中，使用分段方法比较两种方法的 TAESS 三个类别中有 78% 的总体一致性高，而弧平均的一致性为 76%。在四名测试患者中，这种一致性较低（分段和弧平均 TAESS 分别为 64% 和 64%）。尽管两个患者组的相关性和一致性都很高，但使用非侵入性与侵入性成像时，每个节段和弧的平均绝对 TAESS 值被高估了[测试患者：TAESS 节段：30.1(17.1–83.8) vs. 15.8(8.8– 63.4) 和 TAESS 弧：29.4(16.2–74.7) vs 15.0(8.9–57.4) p  < 0.001]。我们表明，我们的方法可以准确地从 CTA 无创评估 TAESS 分布，并证明与使用 IVUS/OCT 3D 重建模型计算的 TAESS 具有良好的相关性。