Department of Internal Medicine II University of Yamanashi Chuo Yamanashi Japan.
J Am Heart Assoc. 2021 Jan 19;10(2):e018028. doi: 10.1161/JAHA.120.018028. Epub 2021 Jan 14.
Background The underlying pathophysiology of coronary artery spasm (CAS) remains unclear. We aim to determine whether coronary artery medial layer thickness is associated with CAS using optical coherence tomography. Methods and Results A total of 50 patients with previous myocardial infarction underwent optical coherence tomography of the left anterior descending artery: 20 with CAS and 30 without CAS. Intimal and medial layer areas were measured by planimetric analysis of optical coherence tomography images. The medial area/external elastic membrane (EEM) area was significantly greater in patients with than without CAS (0.13±0.01 versus 0.09±0.01, respectively, <0.01), whereas the intimal area/EEM area was similar in the 2 groups. In patients without CAS, the relationship of intimal area/EEM area with medial area/EEM area and coronary diameter response to intracoronary injection of acetylcholine was characterized by an inverted U-shaped curve (=-1.85+0.81+0.01, =0.43, <0.001) and a U-shaped curve (=2993.2-1359.6+117.1, =0.53, <0.001), respectively. Thus, the medial layer became thin and the contractile response became weak in coronary arteries with greater intimal area in the non-CAS patients. In contrast, in patients with CAS, the intimal area/EEM area had no significant relationship with the medial area/EEM area in either linear correlation analysis or quadratic regression analysis. Thus, even when the intimal layer thickened, the medial layer did not thin in patients with CAS. Conclusions The structural thickness of the coronary medial layer was increased in patients with CAS, which may provide mechanistic insight into the pathogenesis of CAS. Registration URL: https://www.upload.umin.ac.jp; Unique identifier: UMIN000018432.
冠状动脉痉挛（CAS）的潜在病理生理学机制尚不清楚。我们旨在通过光学相干断层扫描（OCT）来确定冠状动脉中层厚度是否与 CAS 相关。
共 50 例既往心肌梗死患者接受了左前降支 OCT 检查：20 例有 CAS，30 例无 CAS。通过 OCT 图像的平面分析测量内膜和中膜层面积。有 CAS 的患者中膜层面积/外弹力膜（EEM）面积显著大于无 CAS 的患者（分别为 0.13±0.01 与 0.09±0.01，<0.01），而两组患者的内膜层面积/EEM 面积相似。在无 CAS 的患者中，内膜层面积/EEM 面积与中膜层面积/EEM 面积和冠状动脉对乙酰胆碱注射的反应之间的关系呈倒 U 型曲线（=-1.85+0.81+0.01，=0.43，<0.001）和 U 型曲线（=2993.2-1359.6+117.1，=0.53，<0.001）。因此，在无 CAS 患者中，随着内膜层面积的增加，冠状动脉的中层变得更薄，收缩反应变得更弱。相比之下，在有 CAS 的患者中，线性相关分析或二次回归分析均显示内膜层面积/EEM 面积与中膜层面积/EEM 面积之间无显著关系。因此，即使内膜层增厚，CAS 患者的中膜层也不会变薄。
CAS 患者的冠状动脉中层结构厚度增加，这可能为 CAS 的发病机制提供了机制上的见解。
