Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, Maryland, United States of America.
PLoS One. 2013;8(3):e58047. doi: 10.1371/journal.pone.0058047. Epub 2013 Mar 11.
Our objective is to test the hypothesis that coronary endothelial function (CorEndoFx) does not change with repeated isometric handgrip (IHG) stress in CAD patients or healthy subjects.
Coronary responses to endothelial-dependent stressors are important measures of vascular risk that can change in response to environmental stimuli or pharmacologic interventions. The evaluation of the effect of an acute intervention on endothelial response is only valid if the measurement does not change significantly in the short term under normal conditions. Using 3.0 Tesla (T) MRI, we non-invasively compared two coronary artery endothelial function measurements separated by a ten minute interval in healthy subjects and patients with coronary artery disease (CAD).
Twenty healthy adult subjects and 12 CAD patients were studied on a commercial 3.0 T whole-body MR imaging system. Coronary cross-sectional area (CSA), peak diastolic coronary flow velocity (PDFV) and blood-flow were quantified before and during continuous IHG stress, an endothelial-dependent stressor. The IHG exercise with imaging was repeated after a 10 minute recovery period.
In healthy adults, coronary artery CSA changes and blood-flow increases did not differ between the first and second stresses (mean % change ±SEM, first vs. second stress CSA: 14.8%±3.3% vs. 17.8%±3.6%, p = 0.24; PDFV: 27.5%±4.9% vs. 24.2%±4.5%, p = 0.54; blood-flow: 44.3%±8.3 vs. 44.8%±8.1, p = 0.84). The coronary vasoreactive responses in the CAD patients also did not differ between the first and second stresses (mean % change ±SEM, first stress vs. second stress: CSA: -6.4%±2.0% vs. -5.0%±2.4%, p = 0.22; PDFV: -4.0%±4.6% vs. -4.2%±5.3%, p = 0.83; blood-flow: -9.7%±5.1% vs. -8.7%±6.3%, p = 0.38).
MRI measures of CorEndoFx are unchanged during repeated isometric handgrip exercise tests in CAD patients and healthy adults. These findings demonstrate the repeatability of noninvasive 3T MRI assessment of CorEndoFx and support its use in future studies designed to determine the effects of acute interventions on coronary vasoreactivity.
我们的目的是检验以下假设，即在 CAD 患者或健康受试者中，反复等长握力（IHG）应激不会改变冠状动脉内皮功能（CorEndoFx）。
对内皮依赖性应激源的冠状动脉反应是血管风险的重要衡量标准，这种反应可以响应环境刺激或药物干预而发生变化。如果在正常条件下，在短期内测量值没有显著变化，则评估急性干预对内皮反应的影响才具有有效性。本研究使用 3.0T（T）磁共振成像（MRI）技术，在健康受试者和冠状动脉疾病（CAD）患者中，在 10 分钟间隔内比较了两种冠状动脉内皮功能的测量方法。
在商用 3.0T 全身 MR 成像系统上研究了 20 名健康成年受试者和 12 名 CAD 患者。在连续 IHG 应激期间（内皮依赖性应激源），在开始前和开始时量化了冠状动脉的横截面积（CSA）、舒张末期冠状动脉血流速度（PDFV）和血流。在 10 分钟恢复期后，重复 IHG 运动和成像。
在健康成年人中，第一次和第二次应激的冠状动脉 CSA 变化和血流增加没有差异（平均百分比变化±SEM，第一次与第二次应激 CSA：14.8%±3.3%比 17.8%±3.6%，p=0.24；PDFV：27.5%±4.9%比 24.2%±4.5%，p=0.54；血流：44.3%±8.3%比 44.8%±8.1%，p=0.84）。CAD 患者的冠状动脉血管反应也没有差异（第一次与第二次应激的平均百分比变化±SEM，第一次应激比第二次应激：CSA：-6.4%±2.0%比-5.0%±2.4%，p=0.22；PDFV：-4.0%±4.6%比-4.2%±5.3%，p=0.83；血流：-9.7%±5.1%比-8.7%±6.3%，p=0.38）。
在 CAD 患者和健康成年人中，反复等长握力运动测试中 MRI 测量的 CorEndoFx 保持不变。这些发现证明了非侵入性 3T MRI 评估 CorEndoFx 的可重复性，并支持其在未来旨在确定急性干预对冠状动脉反应性影响的研究中使用。
