Association between critical limb ischemia and arterial stiffness measured by brachial artery oscillometry

Abstract Background Elevated arterial stiffness is associated with increased cardiovascular mortality. The relationship between arterial stiffness and critical limb ischemia (CLI) is not well established. Objectives The objective of this study is to analyze the relationship between arterial stiffness indices and the degree of limb ischemia measured by the ankle-brachial index (ABI). Methods A cross-sectional study comparing patients with CLI and controls. Arterial stiffness was measured using brachial artery oscillometry. The arterial stiffness indices pulse wave velocity (PWV) and augmentation index normalized to 75 beats/min (AIx@75) were determined. Multiple linear regression was applied to identify predictors of arterial stiffness indices. Results Patients in the CLI group had higher PWV (12.1±1.9 m/s vs. 10.1±1.9 m/s, p < 0.01) and AIx@75 (31.8±7.8% vs. 17.5±10.8%, p < 0.01) than controls. Central systolic pressure was higher in the CLI group (129.2±18.4 mmHg vs. 115.2±13.1 mmHg, p < 0.01). There was an inverse relationship between AIx@75 and ABI (Pearson coefficient = 0.24, p = 0.048), but there was no relationship between ABI and PWV (Pearson coefficient = 0.19, p = 0.12). In multiple regression analysis, reduced ABI was a predictor of elevated levels of AIx@75 (β = -25.02, p < 0.01). Conclusions Patients with CLI have high arterial stiffness measured by brachial artery oscillometry. The degree of limb ischemia, as measured by the ABI, is a predictor of increased AIx@75. The increased AIx@75 observed in CLI may have implications for the prognosis of this group of patients with advanced atherosclerosis.

摘要 背景：动脉僵硬度升高与心血管死亡率增加密切相关，然而动脉僵硬度与重症肢体缺血（critical limb ischemia, CLI）之间的关联尚未得到充分阐明。
目的：本研究旨在分析动脉僵硬度指标与经踝臂指数（ankle-brachial index, ABI）测定的肢体缺血程度之间的关联。
方法：本研究为横断面研究，对重症肢体缺血（CLI）患者与对照人群进行对比。采用肱动脉振荡法测定动脉僵硬度，测定的动脉僵硬度指标包括脉搏波速度（pulse wave velocity, PWV）以及校正至75次/分钟的增强指数（augmentation index normalized to 75 beats/min, AIx@75）。采用多元线性回归分析识别动脉僵硬度指标的预测因子。
结果：重症肢体缺血（CLI）组患者的脉搏波速度（PWV，12.1±1.9 m/s 相较于10.1±1.9 m/s，p<0.01）与校正至75次/分钟的增强指数（AIx@75，31.8±7.8% 相较于17.5±10.8%，p<0.01）均显著高于对照组。CLI组患者的中心收缩压亦显著升高（129.2±18.4 mmHg 相较于115.2±13.1 mmHg，p<0.01）。AIx@75与ABI呈负相关（Pearson相关系数=0.24，p=0.048），但ABI与PWV未观察到显著关联（Pearson相关系数=0.19，p=0.12）。多元回归分析显示，ABI降低是AIx@75升高的显著预测因子（β=-25.02，p<0.01）。
结论：重症肢体缺血（CLI）患者经肱动脉振荡法测定的动脉僵硬度更高。经ABI测定的肢体缺血程度是AIx@75升高的预测因子。CLI患者中观察到的AIx@75升高，可能对这类晚期动脉粥样硬化患者的预后具有重要临床意义。