Correlates of aortic stiffness progression in patients with resistant hypertension: importance of clinic and ambulatory blood pressure changes.

OBJECTIVES: Correlates of serial aortic stiffness changes were scarcely evaluated. We aimed to evaluate them in patients with resistant hypertension, with particular attention to the importance of changes in clinic and ambulatory blood pressures (BP).

METHODS: In a prospective study, two carotid-femoral pulse wave velocity (cf-PWV) measurements (three measures in each occasion) were performed with the Complior equipment in 442 resistant hypertensive patients over a mean follow-up of 4.6 years. Multivariable regressions assessed the independent correlates of changes in cf-PWV. All analyses were further adjusted for baseline cf-PWV and BP values, and for the time interval between measurements.

RESULTS: Carotid-femoral PWV had a median increase of 0.11 m/s per year (1.1% per year). Overall, 224 patients (51%) had an increase or persisted with high cf-PWV, whereas 218 (49%) reduced or persisted with low values. On multivariable regressions, both changes in clinic SBP (partial correlation 0.34, P < 0.001) and in 24-h SBP (partial correlation 0.40, P < 0.001) were correlates of changes in cf-PWV. This means that the white-coat effect, defined as the difference between clinic and daytime BPs, affected cf-PWV changes (partial correlation 0.19, P < 0.001). The other independent correlates of aortic stiffness progression were older age, presence of diabetes, higher waist circumference and worse renal function.

CONCLUSION: The exaggerated white-coat effect, by acutely increasing clinic BPs during cf-PWV examination, may partially obscure the beneficial effects of reducing ambulatory BP levels on aortic stiffness attenuation. Arterial stiffness measurements under ambulatory conditions may be needed to correctly assess aortic stiffness changes in resistant hypertensive patients.