Determination of arterial compliance using blood pressure waveform analysis with the CR-2000 system: Reliability, repeatability, and establishment of normal values for healthy European population—the seven European sites study (SESS)

Background We determined the reliability and repeatability of measurements of arterial compliance (AC) and gender- and age-specific normal ranges for a healthy European population. Methods Three hundred eight healthy volunteers from seven sites were evaluated. Two measurements were taken during the first visit, repeated on a second visit 1 to 4 weeks later. We used the HDI/PulseWave CR-2000 for measurements of AC. Results Intravisit measurements, taken 5 min apart, differed by less than 3% (range, 0.36% to 2.97%). All intervisit measures differed by less than 4% (range, 0.24% to 3.67%); none of these differences was statistically significant. All correlation coefficients for pairs of AC parameters measured 5 min apart at the same visit were significant at P< .0001. Paired AC parameters at visit 1 and 2 were highly correlated (P< .0001). Repeated measures GLM (general linear model) failed to detect a significant association between either of the AC parameters and visit (first or second), time (first or second measure at the same visit), and visit-by-time (the interaction of the two preceding factors), suggesting that order of measure had no effect on the final value. Analysis of reliability was used to develop a strictly parallel model estimate of unbiased reliability. Both intravisit and intervisit estimates of reliability indicate good repeatability of measure and were significant (P< .0001). The AC values were found to differ significantly by age group, with an inverse association between each of the AC parameters and age group. Conclusions Measurement of the arterial waveform with the CR-2000 system is highly reproducible in healthy subjects.