The study of the influence of systolic blood pressure on discordance between brachial-ankle pulse wave velocity and carotid-femoral pulse wave velocity results

Abstract

Background: Pulse wave velocity (PWV) is related to cardiovascular disease and stroke as an independent risk factor that is available for estimating the arterial stiffness. There are two main causes of increased PWV. One is increased arterial stiffness derived from decreased elasticity, and the other is high systolic blood pressure (SPB) at the time when PWV is measured. Although the results of PWV appear abnormal on paper in patients with high SBP, it is hard to accurately determine if increased PWV is derived from arterial stiffness, high SBP or combination of both. The brachial-ankle PWV (baPWV) is more likely to be influenced by high blood pressure than carotid-femoral PWV (cfPWV), since baPWV includes some peripheral arterial components, which have less cushioning against high pressure than central arteries, in addition to central arterial components. So, it is feared that reliability of baPWV will decline in patients with high SBP.Methods: We studied 114 patients with acute brain infarction or transient ischemic attack (TIA) who underwent both baPWV and cfPWV measurements. We investigated the influence of SBP on discordance between baPWV and cfPWV results in patients with around 140 mmHg SBP.Results: 114 patients were divided into accordance and discordance groups by matching both PWV results. In total group, brachial artery SBP (bSBP) was 140.4±21.0mmHg, central artery SBP (cSBP) was 128.8±20.4mmHg. Both SBPs were higher in the accordance group (p=0.013, p=0.045), whereas there was no statistically significant difference in the other risk factors. The percentage of an abnormal cfPWV was higher in the accordance group (p<0.001). However, the percentage of an abnormal baPWV was higher in the discordance group (p=0.001). The bSPB was categorized into two groups (<144mmHg bSBP, and ≥144mmHg bSBP) based on 144mmHg bSBP. The cSBP also was categorized into two

groups (<133 mmHg cSBP, and ≥133 mmHg cSBP) based on 133 mmHg cSBP. In multivariate analysis, after adjusting for confounding factors, <144mmHg bSBP was independently associated with the discordance of PWV findings (p=0.037). However, <133mmHg cSBP was not associated with the discordance of PWV findings.Conclusion: It was found that baPWV was more affected by bSBP, and resulted in an abnormal finding in spite of a normal finding of the cfPWV measurement in the same subject with <144mmHg bSBP. Our study suggests that cfPWV is more useful than baPWV to estimate the arterial stiffness in patients with around 140mmHg bSBP.