Hays Allison G, Iantorno Micaela, Schär Michael, Mukherjee Monica, Stuber Matthias, Gerstenblith Gary, Weiss Robert G
Department of Medicine, Division of Cardiology, Johns Hopkins University, 600 N Wolfe St., Baltimore, MD, 21287, USA.
Department of Radiology, Division of Magnetic Resonance Research, Johns Hopkins University, 600 N. Wolfe St., Baltimore, MD, 21287, USA.
J Cardiovasc Magn Reson. 2017 Jul 6;19(1):51. doi: 10.1186/s12968-017-0358-2.
Coronary endothelial function (CEF) in patients with coronary artery disease (CAD) varies among coronary segments in a given patient. Because both coronary vessel wall eccentricity and coronary endothelial dysfunction are predictors of adverse outcomes, we hypothesized that local coronary endothelial dysfunction is associated with local coronary artery eccentricity.
We used 3 T coronary CMR to measure CEF as changes in coronary cross-sectional area (CSA) and coronary blood flow (CBF) during isometric handgrip exercise (IHE), a known endothelial-dependent stressor, in 29 patients with known CAD and 16 healthy subjects. Black-blood MRI quantified mean coronary wall thickness (CWT) and coronary eccentricity index (EI) and CEF was determined in the same segments.
IHE-induced changes in CSA and CBF in healthy subjects (10.6 ± 6.6% and 38.3 ± 29%, respectively) were greater than in CAD patients 1.3 ± 7.7% and 6.5 ± 19.6%, respectively, p < 0.001 vs. healthy for both measures), as expected. Mean CWT and EI in healthy subjects (1.1 ± 0.3 mm 1.9 ± 0.5, respectively) were less than those in CAD patients (1.6 ± 0.4 mm, p < 0.0001; and 2.6 ± 0.6, p = 0.006 vs. healthy). In CAD patients, we observed a significant inverse relationship between stress-induced %CSA change and both EI (r = -0.60, p = 0.0002), and CWT (r = -0.54, p = 0.001). Coronary EI was independently and significantly related to %CSA change with IHE even after controlling for mean CWT (adjusted r = -0.69, p = 0.0001). For every unit increase in EI, coronary CSA during IHE is expected to change by -6.7 ± 9.4% (95% confidence interval: -10.3 to -3.0, p = 0.001).
There is a significant inverse and independent relationship between coronary endothelial macrovascular function and the degree of local coronary wall eccentricity in CAD patients. Thus anatomic and physiologic indicators of high-risk coronary vascular pathology are closely related. The noninvasive identification of coronary eccentricity and its relationship with underlying coronary endothelial function, a marker of vascular health, may be useful in identifying high-risk patients and culprit lesions.
冠心病（CAD）患者的冠状动脉内皮功能（CEF）在同一患者的不同冠状动脉节段中存在差异。由于冠状动脉血管壁偏心性和冠状动脉内皮功能障碍均为不良预后的预测因素，我们推测局部冠状动脉内皮功能障碍与局部冠状动脉偏心性相关。
我们使用3T冠状动脉磁共振成像（CMR），在29例已知CAD患者和16名健康受试者中，将等长握力运动（IHE，一种已知的内皮依赖性应激源）期间冠状动脉横截面积（CSA）和冠状动脉血流量（CBF）的变化作为CEF的测量指标。黑血MRI定量分析平均冠状动脉壁厚度（CWT）和冠状动脉偏心指数（EI），并在相同节段测定CEF。
正如预期的那样，健康受试者中IHE诱导的CSA和CBF变化（分别为10.6±6.6%和38.3±29%）大于CAD患者（分别为1.3±7.7%和6.5±19.6%），两种测量指标与健康受试者相比均p<0.001。健康受试者的平均CWT和EI（分别为1.1±0.3mm和1.9±0.5）低于CAD患者（1.6±0.4mm，p<0.0001；2.6±0.6，与健康受试者相比p=0.006）。在CAD患者中，我们观察到应激诱导的CSA变化百分比与EI（r=-0.60，p=0.0002）和CWT（r=-0.54，p=0.001）之间均存在显著的负相关关系。即使在控制平均CWT后，冠状动脉EI与IHE期间的CSA变化百分比仍独立且显著相关（调整后r=-0.69，p=0.0001）。EI每增加一个单位，IHE期间冠状动脉CSA预计变化-6.7±9.4%（95%置信区间：-10.3至-3.0，p=0.001）。
CAD患者的冠状动脉内皮大血管功能与局部冠状动脉壁偏心程度之间存在显著的负向且独立的关系。因此，高危冠状动脉血管病变的解剖学和生理学指标密切相关。冠状动脉偏心性及其与潜在冠状动脉内皮功能（血管健康标志物）关系的无创识别，可能有助于识别高危患者和罪犯病变。
