Relationship between blood pressure parameters and pulse wave velocity in normotensive and hypertensive subjects: invasive study

Abstract

Blood pressure (BP) is one of the most important contributing factors to pulse wave velocity (PWV), a classic measure of arterial stiffness. Although there have been many non-invasive studies to show the relation between arterial stiffness and BP, the results are controversial. The aim of this study is to evaluate the role of BP as an influencing factor on PWV using invasive method. We observed 174 normotensive and untreated hypertensive subjects using coronary angiography. Arterial stiffness was assessed through aorto-femoral PWV by foot-to-foot velocity method using fluid-filled system. And BP was measured by pressure wave at the right common femoral artery. From univariate analysis, age, diabetes mellitus (DM), hypertension, waist, waist-to-hip ratio, total cholesterol-tohigh-density lipoprotein cholesterol ratio, systolic BP (SBP), pulse pressure (PP) and mean arterial pressure (MAP) showed significant association with PWV. To avoid multiple colinearity among SBP, PP and MAP, we performed multiple regression analysis predicting PWV thrice. Age, DM and each BP were significantly and consistently correlated to PWV. In the first and third modules, compared to age, SBP and MAP were less strong predictors, respectively. However, PP was the stronger predictor than age and DM in the second module. Lastly, we simultaneously forced MAP and PP with other variables in the fourth multivariate analysis. Age, DM and PP remained significantly correlated with PWV, but the significance of MAP was lost. This is the first invasive study to suggest that PP has the strongest correlation with PWV among a variety of BP parameters.

Evidence for Pressure‐Independent Sympathetic Modulation of Central Pulse Wave Velocity

“…For example, in 8 males the application of LBNP at −80 mm Hg or pre‐syncope threshold (group mean: −68 mm Hg) resulted in marked increases in cf‐PWV of ≈2.5 m/s, which related strongly to increases in low‐frequency power of systolic blood pressure,26 an indirect estimate of peripheral sympathetic outflow 43. However, although mean arterial pressure was unchanged during LBNP, this study noted trends for reductions in systolic blood pressure and failed to report pulse pressure changes,26 the strongest correlate of central PWV 10, 11. An examination of LBNP at 50% of maximum noted increases in cf‐PWV of 0.7 m/s, but these failed to reach statistical significance, most likely because of the small sample size.…”

“…The difference in blood pressure responses between the pressure stimuli may highlight the critical need to maintain appropriate perfusion pressure in the face of blood loss (LBNP) but the benefit of increasing venous return and perfusion pressure (LBPP) during conditions such as exercise. Surprisingly, PWV did not change during LBPP despite the acknowledged pressure dependency 8, 9, 10, 11. We speculate that this could be the result of divergent effects of LBPP on mean blood pressure (distending) and pulse pressure (pulsatile) responses, or alternatively, that the small magnitude (≤4 mm Hg) changes in blood pressure are not sufficient to evoke detectable changes in PWV.…”

“…Harvey and colleagues30 also reported that cf‐PWV was decreased in postmenopausal but not younger women during complete ganglionic blockade, though these changes were abolished with statistical adjustment for reductions in mean arterial pressure. Each of these observations is confounded by the fact that distending or pulsatile pressure can impact measures of PWV10, 11; however, noting a primary role of blood pressure on measures of vascular stiffness does not also preclude a lesser independent role of peripheral sympathetic activation that may be obscured by the experimental designs and limited sample sizes. Finally, each of the prior studies also reported differences in heart rate, which may also impact PWV measurements 45…”

“…Arterial stiffening can involve the interplay of both mechanical (eg, blood pressure changes) and structural (eg, vessel wall composition) processes that acutely or chronically affect arterial viscoelasticity through changes in the stress–strain relationship 5, 6. An important consideration for experimentally probing potential mechanisms responsible for arterial stiffening is the known blood pressure dependency of central PWV measurements7; systolic blood pressure, mean arterial pressure, and pulse pressure are all strongly associated positively with central PWV 8, 9, 10, 11…”

To what extent does aortic pulse wave velocity estimate early atherosclerosis in Kurosawa and Kusanagi-hypercholesterolemic rabbits?

“…7 Many investigators have confirmed that PWV was correlated with age, [8][9][10] systolic blood pressure (SBP), 11,12 and diastolic blood pressure (DBP). 11,13 Katsuda et al 14 demonstrated previously that PWV in the entire aorta (AoPWV) in young Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits, an animal model of familial hypercholesterolemia 15 showed a slight (about 10%) but significant increase compared with that in age-matched control rabbits, and that SBP and DBP were also significantly higher in the KHC rabbit group than in the control group.…”