Assessment of differences between repeated pulse wave velocity measurements in terms of ‘bias’ in the extrapolated cardiovascular risk and the classification of aortic stiffness: Is a single PWV measurement enough?

Abstract

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: p0.25, 0.26-0.49, 0.50-0.99 and X1 m s À1 . A difference X0.5 m s À1 (corresponding to 7.5% change in CVR, metaanalysis data from 412 000 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 À1 , respectively (P ¼ 0.319); BP and heart rate did not vary significantly. A good reproducibility between single measurements was observed (ICC40.94, s.d. ranged between 0.43 and 0.64 m s À1 ). A high percent with difference X0.5 m s À1 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 X0.5 m s À1 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 (j ¼ 0.85, Po0.001). 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.

Expert consensus document on the measurement of aortic stiffness in daily practice using carotid-femoral pulse wave velocity

“…This should be further investigated. Finally, one should keep in mind that as for BP measurement, standardization of patient conditions and repeated measurements is of utmost importance [1,22,23]. We advise to perform at least two measurements.…”

Validation of a novel and existing algorithms for the estimation of pulse transit time: advancing the accuracy in pulse wave velocity measurement

“…However, substantial differences in PWV values estimated by different "foot-to-foot" methods have been previously reported (8,22), even when PWV estimates are obtained from Federal Drug Administration-approved commercial apparatuses. Furthermore, it has been observed that a great variability exists among repeated PWV measurements on the same subject with a single device (26).…”

Physical Activity Correlates with Arterial Stiffness in Community-dwelling Individuals with Stroke

“…35 For older adults (60-69 years of age), a reference value of cfPWV as 10.3 m/s was derived from an algorithm to convert data obtained from various instrumentation (including the Complior device). 36 Therefore, among our participants of older adults with stroke, the degree to which cfPWV is elevated relative to nonstroke cohorts is greater than the 0.5-m/s difference that is considered to be clinically meaningful 37 and further highlights the multiple issues in the stroke population that affect cardiovascular health and increases their risk for recurrent events.…”