Echo-tracking assessment of carotid artery stiffness in patients with aortic valve stenosis

Abstract

Background: There is little information about mechanical properties of large arteries in patients (pts) with aortic stenosis (AS).

Methods: Nineteen patients with AS (aortic valve area: 0.88 +/- 0.29 cm(2)) and 24 control subjects without AS but with a similar distribution of risk factors were recruited. beta index, pressure-strain elastic modulus (Ep), arterial compliance (AC), augmentation index (AIx), and local pulse-wave velocity (PWV) were obtained at the level of right common carotid artery (CCA) by a real time echo-tracking system. Time to dominant peak of carotid diameter change waveform, corrected for heart rate (tDPc), and maximum rate of rise of carotid diameter (dD/dt) were measured. Systemic arterial compliance (SAC) was also calculated. Parameters of AS severity (mean gradient, valve area, stroke work loss [SWL]) were determined.

Results: tDPc was higher in patients with AS than in controls (7.9 +/- 0.6 vs. 6.6 +/- 0.7, P < 0.0001) while dD/dt was lower (5.3 +/- 3.6 mm/s vs. 7.8 +/- 2.8 mm/s, P = 0.01). AIx was significantly higher in AS group (32.5 +/- 13.6% vs. 20.6 +/- 12.2%, P = 0.005) and had a linear correlation both with tDPc (r = 0.63, P < 0.0001) and with dD/dt (r =-0.38, P = 0.01). There was a significant correlation between carotid AC and SAC (r = 0.49, P = 0.03), but only carotid AC was related to SWL (r = 0.51, P = 0.02), while SAC was not (P = 0.26).

Conclusions: AIx was the only parameter of arterial rigidity found to be higher in patients with AS than in controls. Carotid AC showed a significant correlation with SAC and it seemed to be more closely related to AS severity than to SAC.