Local post-stenotic hemodynamics has critical influence in the atherosclerotic plaque progression occurring in susceptible arterial sites, in particular the left main coronary artery (LMCA) bifurcation. Understanding the effects of plaque morphological characteristics: stenosis severity (SS), eccentricity index (EI) and lesion length (LL) on the post-stenotic flow behavior can significantly improve treatment planning. In order to investigate these effects, we have employed computational fluid dynamics (CFD) simulations in twenty computer-generated and five patient-specific LMCA models and the hemodynamic parameters: velocity, pressure (P), wall pressure gradient (WPG), wall shear stress (WSS), time averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT) and helicity intensity (h₂) were analyzed. Our results revealed that the effect of stenosis eccentricity varied significantly for different values of stenosis severity and lesion length. Regions with low WSS, low TAWSS and high RRT were more prominent in models having higher stenosis severity. For smaller lesion length, at low and moderate stenosis severity, surface area with low TAWSS and high RRT decreased with increasing eccentricity index, whereas for high stenosis severity models, low TAWSS region and average RRT values increased with eccentricity. However, for models with longer lesion length, regions with high OSI and RRT overall increased gradually with eccentricity. The helicity intensity (h₂) of all models remained very low except at the most eccentric model with longer lesion length. The presence of very high helical flow in this model suggests the possibility of atheroprotective flow. It can be concluded that all plaque morphological characteristics covered under this investigation play an important role in plaque progression.

局部狭窄后血流动力学对发生在易感动脉部位的动脉粥样硬化斑块进展具有关键影响，特别是左冠状动脉主干 (LMCA) 分叉处。了解斑块形态特征：狭窄严重程度 (SS)、偏心率指数 (EI) 和病灶长度 (LL) 对狭窄后血流行为的影响可以显着改善治疗计划。为了研究这些影响，我们在 20 个计算机生成的和 5 个特定于患者的 LMCA 模型和血流动力学参数中采用了计算流体动力学 (CFD) 模拟：速度、压力 (P)、壁压力梯度 (WPG)、壁剪切应力 (WSS)、时间平均壁面剪应力 (TAWSS)、振荡剪切指数 (OSI)、相对停留时间 (RRT) 和螺旋强度 (h ₂) 进行了分析。我们的研究结果表明，狭窄程度和病变长度的不同值对狭窄偏心率的影响显着不同。低 WSS、低 TAWSS 和高 RRT 的区域在狭窄严重程度较高的模型中更为突出。对于较小的病变长度，在低和中度狭窄严重程度下，具有低 TAWSS 和高 RRT 的表面积随着偏心率指数的增加而减小，而对于高狭窄严重程度模型，低 TAWSS 区域和平均 RRT 值随着偏心率而增加。然而，对于病变长度较长的模型，具有高 OSI 和 RRT 的区域总体上随着偏心率而逐渐增加。螺旋强度（h ₂) 的所有模型仍然非常低，除了具有较长病变长度的最偏心模型。该模型中存在非常高的螺旋流动表明存在动脉粥样硬化保护流动的可能性。可以得出结论，本研究涵盖的所有斑块形态特征在斑块进展中都起着重要作用。