Are oscillometric PWV values truly interchangeable? A comparative study of brachial and equation-derived measurements

The carotid-femoral pulse wave velocity (cf-PWV) is the standard for arterial stiffness measurement. Other methods include brachial PWV (br-PWV) and equation-derived PWV (ePWV) calculated from cf-PWV studies. br-PWV can also be estimated (ebr-PWV). This study evaluated the correlation between br-PWV, ebr-PWV, and ePWV. It included 683 participants, who had their blood pressure (BP) and br-PWV measured. Ambulatory BP monitoring was also recorded. The ebr-PWV was calculated using a previously validated equation. Three different BP measurements were employed to calculate ePWV, incorporating age and mean BP: ePWV derived from office BP (ePWVOBP), ePWV derived from 24-h mean BP (ePWV24h) and ePWV derived from mean BP from br-PWV measurements (ePWVMoG). Concordance correlation coefficients (CCC) were used to assess agreement, while coefficients of determination (R 2 ) evaluated dependence on age and BP. Results showed that the mean br-PWV was 7.60 ± 1.74 m/s, lower than ebr-PWV (7.71 ± 1.85 m/s), ePWVOBP (8.99 ± 1.86 m/s), ePWV24h (8.30 ± 1.69 m/s), and ePWVMoG (8.96 ± 1.88 m/s) (all p < 0.001). Agreement was very strong between br-PWV and ebr-PWV (CCC = 0.984), but lower with ePWV methods. Bland–Altman analysis showed a small bias for ebr-PWV (-0.11 m/s) and larger differences for ePWV, with wider limits of agreement and evidence of proportional bias. Age and BP explained most of the variability across all PWV measures. In conclusion, although all PWV measures are strongly influenced by BP and age, br-PWV and ebr-PWV tend to underestimate values compared with other ePWV estimates. Therefore, oscillometric PWV values are not interchangeable with those obtained from cf-PWV-derived equations