Biomechanical risk factors for vascular disease in hypertensive patients according to ultrasound morphology of peripheral artery atherosclerosis

Abstract

Aim. To evaluate endothelial shear rate and circumferential wall tension in patients with hypertension based on severity of atherosclerotic lesions in peripheral arteries. Methods. The study included 85 patients with hypertension (46 men and 39 women) aged 57.1±11.7. All patients underwent a duplex scanning of carotid arteries and lower limb arteries. Measurements of endothelial shear rate and circumferential wall tension were performed at the site of the common carotid artery (CCA). The peak blood flow velocity and the diastolic diameter of the blood vessel were measured in the M-mode. The shear rate was calculated using the Hagen-Poiseuille equation. Circumferential wall tension was determined in accordance with the Laplace's law. Patients were divided into four groups using the ultrasonic morphological classification of the arterial wall by G. Belcaro et al. Results. In class III patients, the shear rate was significantly lower than in class I patients (402±107 s⁻¹ vs. 538±123 s⁻¹, respectively, p = 0.001). An increased number of points (by G. Belcaro et al. classification) was associated with a decreased shear rate in CCA (r = −0.281; p = 0.01). Class III (5.68±1.12 dyne/cm×10⁴) and class IV (6.19±1.31 dyne/cm×10⁴) patients had significantly higher values of the circumferential wall tension than class I patients (4.90±1.00 dyne/cm×10⁴). The endothelial shear rate inversely correlated with the circumferential wall tension (r = −0.289; p = 0.007). Conclusion. In patients with hypertension and peripheral artery atherosclerosis, nonlinear changes in the endothelial shear rate and the increased circumferential wall tension paralleled the increasing severity of peripheral atherosclerosis.