Biomedical Engineering Unit, 1st Department of Cardiology, Hippokration Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
J Hum Hypertens. 2012 Oct;26(10):594-602. doi: 10.1038/jhh.2011.76. Epub 2011 Aug 11.
Currently, there is no recommendation regarding the minimum number of pulse wave velocity (PWV) measurements to optimize individual's cardiovascular risk (CVR) stratification. The aim of this study was to examine differences between three single consecutive and averaged PWV measurements in terms of the extrapolated CVR and the classification of aortic stiffness as normal. In 60 subjects who referred for CVR assessment, three repeated measurements of blood pressure (BP), heart rate and PWV were performed. The reproducibility was evaluated by the intraclass correlation coefficient (ICC) and mean±s.d. of differences. The absolute differences between single and averaged PWV measurements were classified as: ≤0.25, 0.26-0.49, 0.50-0.99 and ≥1 m s(-1). A difference ≥0.5 m s(-1) (corresponding to 7.5% change in CVR, meta-analysis data from >12 000 subjects) was considered as clinically meaningful; PWV values (single or averaged) were classified as normal according to respective age-corrected normal values (European Network data). Kappa statistic was used to evaluate the agreement between classifications. PWV for the first, second and third measurement was 7.0±1.9, 6.9±1.9, 6.9±2.0 m s(-1), respectively (P=0.319); BP and heart rate did not vary significantly. A good reproducibility between single measurements was observed (ICC>0.94, s.d. ranged between 0.43 and 0.64 m s(-1)). A high percent with difference ≥0.5 m s(-1) was observed between: any pair of the three single PWV measurements (26.6-38.3%); the first or second single measurement and the average of the first and second (18.3%); any single measurement and the average of three measurements (10-20%). In only up to 5% a difference ≥0.5 m s(-1) was observed between the average of three and the average of any two PWV measurements. There was no significant agreement regarding PWV classification as normal between: the first or second measurement and the averaged PWV values. There was significant agreement in classification made by the average of the first two and the average of three PWV measurements (κ=0.85, P<0.001). Even when high reproducibility in PWV measurement is succeeded single measurements provide quite variable results in terms of the extrapolated CVR and the classification of aortic stiffness as normal. The average of two PWV measurements provides similar results with the average of three.
目前，对于优化个体心血管风险（CVR）分层，尚没有关于脉搏波速度（PWV）测量的最小次数的建议。本研究旨在比较三种连续单次和平均 PWV 测量之间的差异，包括外推的 CVR 和正常的主动脉僵硬度分类。在 60 名因 CVR 评估而就诊的患者中，进行了三次重复的血压（BP）、心率和 PWV 测量。通过组内相关系数（ICC）和差异的均值±标准差评估重复性。将单次和平均 PWV 测量之间的绝对差异分为：≤0.25、0.26-0.49、0.50-0.99 和≥1 m/s。差值≥0.5 m/s（对应于 CVR 变化 7.5%，来自>12000 名患者的荟萃分析数据）被认为具有临床意义；根据各自的年龄校正正常值（欧洲网络数据），将 PWV 值（单次或平均）分类为正常。使用 Kappa 统计评估分类之间的一致性。第一次、第二次和第三次测量的 PWV 分别为 7.0±1.9、6.9±1.9、6.9±2.0 m/s（P=0.319）；BP 和心率无显著差异。单次测量之间具有良好的可重复性（ICC>0.94，标准差范围为 0.43-0.64 m/s）。在以下情况下，观察到任意两对三次单次 PWV 测量之间的差值≥0.5 m/s 的比例较高（26.6-38.3%）：任何一对三次单次 PWV 测量之间；第一次或第二次单次测量与前两次平均之间（18.3%）；任何单次测量与三次测量的平均值之间（10-20%）。仅在 5%的情况下，三次平均 PWV 测量与任意两次平均 PWV 测量之间的差值≥0.5 m/s。第一次或第二次测量与平均 PWV 值之间的 PWV 正常分类无显著一致性。前两次平均 PWV 值与第一次和第二次平均 PWV 值之间的分类具有显著一致性（κ=0.85，P<0.001）。即使在 PWV 测量具有较高可重复性的情况下，单次测量在预测外推的 CVR 和主动脉僵硬度正常分类方面也会产生相当大的差异。两次 PWV 测量的平均值与三次 PWV 测量的平均值提供相似的结果。
