Clinical characteristics and pulse pressure variation according to the ambulatory arterial stiffness index(AASI).

Abstract

Background: Recently AASI was known to be a predictor for future cardiovascular event. But it`s biological mechanisms are not fully understood. Theoretically there are two occasions increasing AASI, i.e., high pulse pressure(PP) accompanied by low blood pressure(BP) and extremely low PP with high blood pressure can be postulated. We investigated the relationship between PP and AASI using PP variability parameters to testify how AASI is associated with extremes of PP. Methods: From the ABPM data of 120 never treated hypertensive patients, raw data were plotted to get an AASI and the mean and standard deviation of PP(PPmean and PPsd) were calculated. And mean and standard deviation of PP/SBP(PP/SBPmean and PP/SBPsd were also calculated. The number of measurement errors in ABPM data and the presence of consecutive errors were also checked. Group I was defined by the presence of LVH or regional wall motion abnormality. Group II was normal. Results: Age was 54.2± 16.1(19-95) and 55.8% was female. Aortic dimension was the only factor correlated with AASI(r=0.22, p<0.05). Age, gender, and pulse pressure from clinic blood pressure were not correlated with AASI. The correlation coefficients between PP and AASI were 0.370, 0.597, 0.562 for PPmean, PPsd, and PP/SBPsd, respectively (p<0.0001). PP/SBPmean has no correlation with AASI. But there was no relationship between numbers and/or consecutiveness of measurement errors and AASI. Group I was comprised of 7 RWMA patients and 35 LVH patients. In a case control design, AASI is higher in group I than group II(0.35 ±0.178 vs 0.46 ± 0.15, p=0.002) Conclusion: This study shows that PPsd has stronger relationship with AASI than PPmean and that AASI is associated with left ventricular or vascular changes.