Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia; Department of Cardiology, Concord Hospital, The University of Sydney, Sydney, Australia.
Department of Medicine, Stanford School of Medicine, Stanford, CA, USA.
Int J Cardiol. 2021 Oct 1;340:7-13. doi: 10.1016/j.ijcard.2021.08.011. Epub 2021 Aug 8.
Atheromatous plaques tend to form in the coronary segments proximal to a myocardial bridge (MB), but the mechanism of this occurrence remains unclear. This study evaluates the relationship between blood flow perturbations and plaque formation in patients with an MB.
A total of 92 patients with an MB in the mid left anterior descending artery (LAD) and 20 patients without an MB were included. Coronary angiography, intravascular ultrasound, and coronary physiology measurements were performed. A moving-boundary computational fluid dynamics algorithm was used to derive wall shear stress (WSS) and peak residence time (PRT). Patients with an MB had lower WSS (0.46 ± 0.21 vs. 0.96 ± 0.33 Pa, p < 0.001) and higher maximal plaque burden (33.6 ± 15.0 vs. 14.2 ± 5.8%, p < 0.001) within the proximal LAD compared to those without. Plaque burden in the proximal LAD correlated significantly with proximal WSS (r = -0.51, p < 0.001) and PRT (r = 0.60, p < 0.001). In patients with an MB, the site of maximal plaque burden occurred 23.4 ± 13.3 mm proximal to the entrance of the MB, corresponding to the site of PRT.
Regions of low WSS and high PRT occur in arterial segments proximal to an MB, and this is associated with the degree and location of coronary atheroma formation.
动脉粥样硬化斑块易在心肌桥（MB）近端的冠状动脉节段形成，但这种情况发生的机制尚不清楚。本研究评估了 MB 患者血流扰动与斑块形成之间的关系。
共纳入 92 例左前降支（LAD）中段 MB 患者和 20 例无 MB 患者。进行冠状动脉造影、血管内超声和冠状动脉生理学测量。采用移动边界计算流体动力学算法得出壁面剪切应力（WSS）和峰值驻留时间（PRT）。MB 患者的 LAD 近端 WSS 较低（0.46±0.21 对 0.96±0.33 Pa，p<0.001），最大斑块负荷较高（33.6±15.0 对 14.2±5.8%，p<0.001）。LAD 近端斑块负荷与近端 WSS（r=-0.51，p<0.001）和 PRT（r=0.60，p<0.001）显著相关。在 MB 患者中，最大斑块负荷部位位于 MB 入口近端 23.4±13.3 mm，与 PRT 部位相对应。
低 WSS 和高 PRT 区域发生在 MB 近端的动脉节段，与冠状动脉粥样硬化形成的程度和部位有关。
