5.2: Arterial Stiffness is A Major Independent Determinant of Visit-To-Visit Variability in SBP: A 9.1 Year Follow-Up in Treated Hypertensives

Abstract

Objective and background

Aortic stiffening, which favours the wave propagation generated by changes in cardiac output, and exaggerates the early return of wave reflection generated by changes in vasomotor tone, can increase the variability in SBP.

Methods

Aortic stiffness was determined through carotid-femoral pulse wave velocity (PWV) in 95 patients (age 62.9±10.8 years) who attended the outpatient hypertension clinic at Pompidou hospital during a total follow-up of 9.1±3.6 yrs. PWV was determined after 5.5±2.7 yrs. Visit-to-visit variability in office SBP was expressed as standard deviation (SD) of measurements and SD/mean, and calculated during the entire follow-up (FU). 8.5±4.8 visits occurred before PWV measurements, and 6.4±5.4 visits after.

Results

SD of SBP was 13.5±4.3 mmHg during FU. PWV was 11.4±2.7 m/s. In univariate analysis, SD-SBP during FU was significantly related to PWV (P = 0.0007), age (P = 0.021), SBP (P = 0.033), MBP (P = 0.0016) and diabetes (P = 0.045). In multivariate robust regression analysis, PWV was a major determinant of SD-SBP (P = 0.018) during FU, explaining 11.2% of SD-SBP variance (and 51% of explained variance), independently of age, gender, SBP, HR, BMI, diabetes, and dyslipidemia, which were not significantly associated with SD-SBP. Similar findings were observed when SD/mean of SBP was used instead of SD-SBP.

Conclusion

Aortic stiffness was a strong independent determinant of visit-to-visi variability in SBP, whereas no classical CV risk factor was associated with SD-SBP in multivariate models. These results suggest that antihypertensive treatment should aim at normalizing aortic stiffness to better reduce visit-to-visit SBP variability.