Does shear stress modulate both plaque progression and regression in the thoracic aorta?
Does shear stress modulate both plaque progression and regression in the thoracic aorta?
复制标题
DOI：
10.1016/j.jacc.2004.12.026
复制
发表时间：
2005-03-15
影响因子：
24
通讯作者：
Badimon, JJ
中科院分区：
文献类型：
--
作者：
Wentzel, JJ;Corti, R;Badimon, JJ
本研究的目的是研究剪切应力（SS）在斑块消退中的作用。背景：低振荡的SS有利于动脉粥样硬化病变的发展。在降胸主动脉中，斑块分布和SS之间的关系从未被描述过。降脂治疗导致的斑块消退与逆转动脉粥样硬化机制有关。因此，我们研究了SS在斑块消退中的作用。磁共振成像（MRI）提供了一个独特的机会，非侵入性研究形态学和血流动力学。方法横截面图像的动脉粥样硬化斑块在降胸主动脉的10个无症状，hyperteremic患者获得基线和24个月后开始降脂治疗，使用黑血序列的1.5 T的临床MRI系统（5 mm X 780 Am X 780 Am）。得出每个象限的平均壁厚（WT）。结果平均WT随离主动脉弓距离的增加而降低（3.0 ± 0.7 mm vs. 2.5 ± 0.3 mm; p < 0.05），从近端到远端呈螺旋状。在8名健康志愿者的胸主动脉中进行相位对比MRI，以获得典型的平均SS分布。剪切应力预测WT的位置（r（2）= 0.29，p < 0.05），但不能预测斑块消退。斑块消退的最佳预测因素是基线WT。结论我们的数据显示WT和平均低SS位置之间的关联支持局部血流动力学在胸降主动脉粥样硬化病变发展中的作用。此外，SS似乎不是降脂干预后斑块消退的主要预测因素。因此，我们的数据表明，其他机制参与脂质逆转机制。(c)2005年，美国心脏病学会基金会。
OBJECTIVES The purpose of this study was to investigate the role of shear stress (SS) in plaque regression.BACKGROUND A condition favorable to the development of atherosclerotic lesions is low oscillating SS. In the descending thoracic aorta, the relationship between plaque distribution and SS has never been characterized. The regression of plaque as the result of lipid-lowering therapy is associated with reverse atherogenic mechanisms. Therefore, we investigated the role of SS in plaque regression. Magnetic resonance imaging (MRI) provides a unique opportunity to noninvasively study morphology and hemodynamics.METHODS Cross-sectional images of atherosclerotic plaques in the descending thoracic aorta of 10 asymptomatic, hypercholesteremic patients were acquired at baseline and 24 months after starting lipid-lowering therapy by using a black-blood sequence on a 1.5-T clinical MRI system (5 mm X 780 Am X 780 Am). Average wall thickness (WT) was derived per quadrant. The aorta was subdivided in segments 2 cm in length starting 1 cm from the aortic arch.RESULTS Average WT decreased with increasing distance from the arch (3.0 +/- 0.7 mm vs. 2.5 +/- 0.3 mm; p < 0.05) and showed a helical pattern from the proximal to distal segments. Phase-contrast MRI was performed in the thoracic aorta of eight healthy volunteers to derive typical average SS distribution. Shear stress predicted the location of WT (r(2) = 0.29, p < 0.05) but did not predict plaque regression. The best predictor of plaque regression was baseline WT.CONCLUSIONS Our data showing an association between WT and average low SS locations support the role of local hemodynamics in the development of atherosclerotic lesions in descending thoracic aorta. Furthermore, SS does not seem to be the major predictor for plaque regression by lipid-lowering interventions. Therefore, our data suggest that other mechanisms are involved in the lipid-reversal mechanism. (c) 2005 by the American College of Cardiology Foundation.