Pulmonary Clinic, University Hospital Zurich, Zurich, Switzerland.
Hypertens Res. 2012 Feb;35(2):228-33. doi: 10.1038/hr.2011.168. Epub 2011 Oct 13.
Arterial tonometry is a method to assess arterial stiffness and has become a valuable tool in the stratification of cardiovascular risk. The arterial tonometry-derived augmentation index (AIx) is a marker of arterial stiffness and an independent predictor of mortality. As the AIx is relatively cumbersome to obtain, simpler methods such as analysis of pulse waves obtained by digital photoplethysmography have been proposed to estimate arterial stiffness. The objective of this study is to compare the usefulness of the stiffness index (SI) derived from digital photoplethysmography and the AIx derived from radial tonometry for stratification of cardiovascular risk. We studied 83 subjects with a heterogeneous cardiovascular risk profile and determined the ability of the two devices to differentiate subjects with low from subjects with high cardiovascular risk estimated by the Europe (EU)-heart score. Failure rate in both devices was similar (3.6%). AIx and SI were modestly correlated (r=0.48, P<0.001) and both indexes correlated with the EU-score (r=0.54, P<0.001) and (r=0.56, P<0.001), respectively. Both devices discriminated accurately between subjects with high cardiovascular risk (upper tertile of the EU-score) and low cardiovascular risk (lower tertile). However, only the SI differentiated significantly between subjects with intermediate risk (middle tertile) and high risk (upper tertile). Compared with the AIx, assessment of the SI derived by digital photoplethysmography is simple and possibly yields an advantage in risk stratification of subjects with intermediate and high cardiovascular risk. Therefore, digital pulse wave analysis may be a valuable tool to estimate arterial stiffness in large clinical studies.
动脉张力测定法是一种评估动脉僵硬度的方法，已成为心血管风险分层的有价值的工具。动脉张力测定衍生的增强指数（AIx）是动脉僵硬度的标志物，也是死亡率的独立预测因子。由于 AIx 相对繁琐，因此已经提出了更简单的方法，例如通过数字光体积描记法分析脉搏波，以估计动脉僵硬度。本研究的目的是比较数字光体积描记法衍生的僵硬度指数（SI）和桡动脉张力测定衍生的 AIx 在心血管风险分层中的有用性。我们研究了 83 名具有异质心血管风险特征的受试者，并确定了这两种设备区分欧洲心脏评分（EU-heart score）估计的低心血管风险和高心血管风险受试者的能力。两种设备的失败率相似（3.6%）。AIx 和 SI 中度相关（r=0.48，P<0.001），并且两个指数均与 EU 评分相关（r=0.54，P<0.001）和（r=0.56，P<0.001）。两种设备都能准确地区分高心血管风险（EU 评分的上三分位数）和低心血管风险（下三分位数）的受试者。然而，只有 SI 能够在中间风险（中间三分位数）和高风险（上三分位数）的受试者之间显著区分。与 AIx 相比，数字光体积描记法评估的 SI 简单，并且在中间和高心血管风险的受试者风险分层方面可能具有优势。因此，数字脉搏波分析可能是评估动脉僵硬度的大型临床研究的有价值的工具。
