Department of Medicine, Cardiovascular Division, Veterans Affairs Boston Healthcare System, West Roxbury Campus, Boston, Massachusetts, United States of America.
Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
PLoS One. 2019 Jan 25;14(1):e0211152. doi: 10.1371/journal.pone.0211152. eCollection 2019.
In healthy arteries, blood flow is regulated by microvascular tone assessed by changes in blood flow volume and vascular resistance to endothelium-dependent and -independent vasodilators. We developed a novel method of using intravascular ultrasound (IVUS) and a Doppler flow wire to measure changes in blood flow volume and vascular resistance of the profunda arterial bed. We assessed the variability over 6 months in measuring microvascular endothelium-dependent dilation to acetylcholine and endothelium-independent dilation to adenosine in 20 subjects who were part of a larger study of Gulf War Illness without obstructive peripheral artery disease. Vasomotor function was assessed by Infusions of control (dextrose), acetylcholine (10-6M), adenosine (50μg), and nitroglycerin (25μg/ml). 400 IVUS and 240 flow velocity images were measured a mean 6 (SD = 2) months apart blind to measurement and infusion stage. The mean (SD) baseline profunda flow was 227 (172) ml/min and vascular resistance 4.6 x 104 (2.4 x 104) dynes-s/cm5. The intraclass correlation coefficients for 6-month variability for vascular function were excellent (range 0.827-0.995). Bland-Altman analyses showed mean differences of less than 2% for microvascular endothelium-dependent function (flow volume and resistance) and less than 1% for macrovascular endothelium-dependent function with acceptable limits of agreement. In 49 subjects assessing concurrent validity of the technique against atherosclerosis risk factors, we observed greater impairment in microvascular endothelium-dependent function per year of age (flow volume = -1.4% (p = 0.018), vascular resistance = 1.5% (p = 0.015)) and current smoking (flow volume = -36.7% (p = .006), vascular resistance = 50.0% (p<0.001)). This novel method of assessing microvascular vasomotor function had acceptable measurement reproducibility and validity.
在健康的动脉中，血流通过血管阻力和血流体积的变化来调节，这种变化取决于内皮细胞依赖和非依赖的血管扩张剂。我们开发了一种新的方法，使用血管内超声（IVUS）和多普勒血流导丝来测量深部动脉床的血流体积和血管阻力的变化。我们评估了 20 名受试者在 6 个月内的测量结果，这些受试者是海湾战争疾病的更大研究的一部分，他们没有阻塞性外周动脉疾病。血管舒缩功能通过输注对照（葡萄糖）、乙酰胆碱（10-6M）、腺苷（50μg）和硝酸甘油（25μg/ml）来评估。平均 6 个月（标准差=2 个月）进行了 400 次 IVUS 和 240 次血流速度图像测量，测量时对测量和输注阶段均为盲法。深部血流的平均（标准差）基线为 227（172）ml/min，血管阻力为 4.6 x 104（2.4 x 104）dynes-s/cm5。血管功能 6 个月变异性的组内相关系数非常好（范围 0.827-0.995）。Bland-Altman 分析显示，微血管内皮功能（血流体积和阻力）的平均差异小于 2%，大血管内皮功能的平均差异小于 1%，且一致性界限可接受。在 49 名评估该技术与动脉粥样硬化危险因素的同时有效性的受试者中，我们观察到，随着年龄的增长，微血管内皮依赖性功能每增加 1 年（血流体积减少 1.4%（p=0.018），血管阻力增加 1.5%（p=0.015））和当前吸烟（血流体积减少 36.7%（p=0.006），血管阻力增加 50.0%（p<0.001）），微血管内皮依赖性功能的损害更大。这种评估微血管血管舒缩功能的新方法具有可接受的测量重复性和有效性。
