P.054 Relationship Between, Blood Viscosity, Shear Stress and Arterial Stiffness in Patients with Arterial Hypertension

Abstract

The aim of the study was to investigate relationships between whole blood viscosity (WBW), ascending aorta shear stress (AASS) and carotid- femoral pulse wave velocity (PWV) in patients with arterial hypertension (HT).

Material and methods

Study group (G1): 43 pts. with primary HT - (age 53 ± 6.4yrs.) was compared with control group (G2): 15 normotensives (age - 55 ± 5.9 yrs.) Blood pressure using “Omron M5 I”, PWV using Complior^®de-vice, WBV using “Brookfield DV III+pro”, aortic diameter and flow velocity (required for AASS calculation) using VIVID 7 GE ultrasonograph were measured.

Results

SBP (152 ± 11.3 vs 124 ± 9.7 mmHg, p< 0.001), DBP (92 ± 6.1 vs 83 ± 5.2 mmHg, p< 0.001), WBV at shear rate 100-400/ s^-1 (5.1 ± 1.2 vs 4.3 ± 0.9 cP, p< 0.05) and, PWV (11.8 ± 1.7 vs 8.8 ± 1.6 m/s, p< 0.05) were higher in G1 than in G2 group. Mean AASS was higher (27.7 ± 5.3 vs 21 ± 4.3 dyne/cm², p< 0.05) in G1 than in G2 group. In G1 group PWV correlated positively with age: (r = 0.37, p< 0.39), SBP: (r = 0.45, p <0.05) and WBV: (r = 0.41, p<0.05), and negatively with AASS: (r = - 0.29, p< 0.05).

Conclusions

Hypertensive patients are characterized by stiffer aorta and higher WBW, as well as lower AASS. Low shear stress seems to be one of the factors responsible for aortic stiffness in hypertensive patients.