Pulse Wave Velocity Comparing Estimated and Direct Measures of Path Length in Older Women

Abstract

Background: Carotid-femoral Pulse Wave Velocity (cfPWV) is the gold-standard measure of arterial stiffness. Accuracy of non-invasive cfPWV as meters per second is impeded by surface estimates of aortic length. Our aim was to compare cfPWV measured using distance estimated from surface measurements with distance traced along the length of the aorta using Magnetic Resonance Imaging (MRI) in a cohort of older women.Methods: Seventy-four women were recruited from the TwinsUK cohort. cfPWV was measured using the SphygmoCor system (SphygmoCor-PWV). The path between carotid and femoral sites was estimated from surface measurements between the sternal notch and femoral artery applanation point. Aortic distance was measured with MRI to obtain MRI-PWV. cfPWV was recalculated using MRI obtained distance.Results: Mean ± standard deviation SphygmoCor-PWV was 9.9 ± 2.1 m/s and MRI-PWV 7.63 ± 1.97 m/s (mean difference 2.2 ± 1.96 m/s, p < 0.001). Distances were considerably higher using surface measures for the SphygmoCor (55.2 ± 3.0, 95% confidence interval 54.4-55.9 cm) compared with MRI (39.9 ± 3.2, 39.2-40.7 cm) with a mean difference of 15.2 cm (14.3-16.2 cm, p < 0.001). Transit times were also marginally longer with the SphygmoCor. When SphygmoCor-PWV was Recalculated using MRI-obtained aortic distance (rec-PWV), the difference between SphygmoCor-PWV and rec-PWV reduced to 0.5 m/s (7.13 ± 1.46 vs. 7.63 ± 1.97 m/s, p = 0.08). Conclusion:In these older women, the PWV difference between SphygmoCor and MRI is substantial but reduced when using MRI length estimates. Important differences between PWV measured by Sphygmocor and MRI are mainly due to accuracy of distance measurements, which may need re-addressing in guidelines.

Non‐Invasive Assessment of Damping of Blood Flow Velocity Pulsatility in Cerebral Arteries With MRI

“…This is also reflected in the lower damping index found by the authors between those vascular segments (1.31 ± 0.30 vs. 2.1 ± 0.81 in this study). The proximal measures of pressure and arterial stiffness assessed in this study were similar to those reported in the literature 19,22–25 . Slight differences were likely due to the fact that we included participants with variable levels of risk factors and vascular events, which assured us of the required variation in the measures of proximal pressure and arterial stiffness.…”

“…The proximal measures of pressure and arterial stiffness assessed in this study were similar to those reported in the literature. 19 , 22 , 23 , 24 , 25 Slight differences were likely due to the fact that we included participants with variable levels of risk factors and vascular events, which assured us of the required variation in the measures of proximal pressure and arterial stiffness. In case of too little variation in the measurements, observed variability would only be noise and not contain information from which relations can be inferred.…”

Abdominal Aortic Wall Mechanics - Stress, Strain and Stiffness in A Medical Perspective : An Experimental Study in Man

“…This observation was corroborated by Weir-McCall et al (2017), who noted that cfPWV was approximately 30% higher than MRI-PWV in a diverse group of elderly individuals. In a similar manner, Ludovica et al (2020) reported that cfPWV was roughly 17% higher than MRI-PWV in a cohort of elderly females (Weir-McCall et al, 2017;Ludovica et al, 2020). Podolec et al (2007) discovered that regional cfPWV was approximately 28% higher than local aortic PWV, which was recorded as 7.4 m/s in a group of middle-aged to elderly individuals diagnosed with stable angina but without coronary artery stenosis (Podolec et al, 2007).…”