Background and purpose: Aortic stenosis, causing flow abnormalities, disturbs the normal hemodynamics in the common carotid arteries. The aim of the present study was to investigate the remodeling process of the common carotid arteries after surgical correction of aortic stenosis.
Methods: Eleven subjects with aortic stenosis were studied before and 1 and 6 months after aortic valve replacement. Arterial diameter, intima-media thickness (IMT), and flow velocity were measured by echo-Doppler examination. Shear stress, blood flow, and pulsatility index were calculated. Blood viscosity and hematocrit were measured by standard methods. A control group was also enrolled.
Results: Before surgery, compared with controls, patients had lower systolic peak velocity but higher mean and end-diastolic velocity. Arterial diameter, IMT, and blood flow were comparable in the 2 groups. Blood viscosity, hematocrit, wall shear stress, and pulsatility index were markedly lower in patients. After surgery, IMT was reduced (0.741+/-0.152 versus 0.627+/-0.108 mm before and 6 months after surgery, respectively; P<0.0001), and hematocrit and blood viscosity increased, leading to increased wall shear stress (mean wall shear stress, 7.83+/-1.97 versus 9.65+/-3.12 dyne/cm(2) before and 6 months after surgery, respectively; P<0.02).
Conclusions: The present results demonstrate that aortic valve replacement, in subjects with aortic stenosis, leads to reduction of the common carotid artery IMT. Wall shear stress is increased after the intervention and probably mediates the remodeling process.