Coronary bifurcations have complex flow patterns including secondary flow zones and helical flow, which directly affect pathophysiological mechanisms such as the development of atherosclerosis. The objective of this study was to generate insights into the effects of curvature, bifurcation angle and the presence of stents on flow patterns and resulting haemodynamics in coronary left main bifurcations. The blood flow and associated metrics were modelled in both idealised and patient-specific bifurcations with varying curvature and bifurcation angles with and without stents, resulting in a total of 128 geometries considered. The results showed that larger curvature of bifurcating vessels has a significant influence on secondary flow, especially with distance to the bifurcation region, causing a skew, spin and asymmetry of Dean vortices, an increase in helical flow intensity with symmetry loss, and a decrease in adversely low time-average wall shear stress (TAWSS). Generally, asymmetric flow patterns coincided with adversely low TAWSS regions. In identical stented geometries, the presence of the stents induced local recirculation immediately adjacent to the stent struts, thus generating adversely low TAWSS in these areas, with some effect on the overall secondary flow. Overall, the effect of stents outweighed the effect of curvature and BA. This new knowledge contributes to a better understanding of the joint effects of curvature, bifurcation angle, and stents on flow patterns and haemodynamics in coronary bifurcations.

冠状动脉分叉具有复杂的流动模式，包括二次流动区和螺旋流动，直接影响动脉粥样硬化的发展等病理生理机制。本研究的目的是深入了解曲率、分叉角度和支架的存在对冠状动脉左主分叉的流动模式和由此产生的血流动力学的影响。血流和相关指标在理想化的和患者特定的分叉处建模，具有不同的曲率和分叉角度，有和没有支架，总共考虑了 128 种几何形状。结果表明，分叉血管较大的曲率对二次流有显着影响，尤其是与分叉区域距离较远时，会引起迪安涡的偏斜、自旋和不对称，螺旋流强度随着对称性损失的增加，以及不利的低时均壁剪切应力 (TAWSS) 的减少。通常，不对称流动模式与不利的低 TAWSS 区域相吻合。在相同的支架几何形状中，支架的存在会导致紧邻支架支柱的局部再循环，从而在这些区域产生不利的低 TAWSS，对整体二次流有一些影响。总体而言，支架的影响大于曲率和 BA 的影响。这一新知识有助于更好地理解曲率、分叉角度和支架对冠状动脉分叉流动模式和血流动力学的联合影响。不对称流动模式与不利的低 TAWSS 区域相吻合。在相同的支架几何形状中，支架的存在会导致紧邻支架支柱的局部再循环，从而在这些区域产生不利的低 TAWSS，对整体二次流有一些影响。总体而言，支架的影响大于曲率和 BA 的影响。这一新知识有助于更好地理解曲率、分叉角度和支架对冠状动脉分叉流动模式和血流动力学的联合影响。不对称流动模式与不利的低 TAWSS 区域相吻合。在相同的支架几何形状中，支架的存在会导致紧邻支架支柱的局部再循环，从而在这些区域产生不利的低 TAWSS，对整体二次流有一些影响。总体而言，支架的影响大于曲率和 BA 的影响。这一新知识有助于更好地理解曲率、分叉角度和支架对冠状动脉分叉流动模式和血流动力学的联合影响。支架的影响大于曲率和BA的影响。这一新知识有助于更好地理解曲率、分叉角度和支架对冠状动脉分叉流动模式和血流动力学的联合影响。支架的影响大于曲率和BA的影响。这一新知识有助于更好地理解曲率、分叉角度和支架对冠状动脉分叉流动模式和血流动力学的联合影响。