William S. Middleton Memorial Veterans Hospital.
Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
J Hypertens. 2023 Apr 1;41(4):572-579. doi: 10.1097/HJH.0000000000003370. Epub 2023 Jan 17.
Vasodilation can paradoxically increase arterial stiffness in older, hypertensive adults. This study modeled increasing smooth muscle tone as a therapeutic strategy to improve central arterial dysfunction in hypertension using participant-specific simulations.
Participant-specific models of the carotid artery were parameterized from vascular ultrasound measures of nitroglycerin-induced vasodilation in 18 hypertensive veterans. The acute changes in carotid artery mechanics were simulated for changes of ±2, ±4, and ±6% in smooth muscle tone and ±5, ±10, and ±15 mmHg in mean arterial pressure (MAP). The chronic carotid artery adaptations were simulated based on the hypothesis that the carotid artery will remodel wall-cross sectional area to maintain mechanical homeostasis.
A 6% increase in smooth muscle tone acutely decreased carotid pulse wave velocity from 6.89 ± 1.24 m/s to 5.83 ± 1.73 m/s, and a 15 mmHg decrease in MAP decreased carotid pulse wave velocity to 6.17 ± 1.23 m/s. A 6% increase in smooth muscle tone acutely decreased wall stress from 76.2 ± 12.3 to 64.2 ± 10.4 kPa, and a 15 mmHg decrease in MAP decreased wall stress to 60.6 ± 10.7 kPa. A 6% increase in smooth muscle tone chronically decreased wall cross-sectional area from 18.3 ± 5.4 to 15.2 ± 4.9 mm 2, and a 15 mmHg decrease in MAP decreased wall cross-sectional area to 14.3 ± 4.6 mm 2 .
In participant-specific simulation, increasing smooth muscle tone can have a stronger or equivalent effect on carotid artery mechanics compared with decreasing blood pressure. Increasing central arterial smooth muscle tone may be a novel therapeutic target to improve central arterial dysfunction in older, hypertensive adults and should be a focus of future research.
血管扩张在老年高血压患者中可能会反常地增加动脉僵硬度。本研究通过采用特定于个体的模拟方法，将平滑肌张力增加建模为一种治疗策略，以改善高血压患者的中心动脉功能障碍。
对 18 名高血压退伍军人的血管超声测量的硝酸甘油诱导血管扩张进行分析，确定颈动脉的特定于个体的模型。模拟了动脉血压变化±2%、±4%和±6%，以及平均动脉压（MAP）变化±5mmHg、±10mmHg和±15mmHg 对颈动脉力学的急性变化。基于颈动脉会重塑壁横截面面积以维持力学平衡的假设，模拟了慢性颈动脉适应。
平滑肌张力增加 6%，可使颈动脉脉搏波速度从 6.89±1.24m/s 降低至 5.83±1.73m/s；MAP 降低 15mmHg，可使颈动脉脉搏波速度降低至 6.17±1.23m/s。平滑肌张力增加 6%，可使壁应力从 76.2±12.3kPa 降低至 64.2±10.4kPa；MAP 降低 15mmHg，可使壁应力降低至 60.6±10.7kPa。平滑肌张力增加 6%，可使壁横截面面积从 18.3±5.4mm2 降低至 15.2±4.9mm2；MAP 降低 15mmHg，可使壁横截面面积降低至 14.3±4.6mm2。
在特定于个体的模拟中，与降低血压相比，增加平滑肌张力对颈动脉力学具有更强或等效的作用。增加中心动脉平滑肌张力可能是改善老年高血压患者中心动脉功能障碍的一种新的治疗靶点，应成为未来研究的重点。
