Changes in aortic root function after valve replacement in patients with aortic stenosis

Background Aortic elastic properties are compromised in various states that induce functional and histological changes in the aortic wall. Aortic stenosis is frequent and often requires replacement of the stenotic valve. The purpose of this study was to examine the effect of aortic valve replacement on the aortic root function. Methods 31 patients, mean ± SD age 67.2 ± 9.1 years with severe aortic stenosis, who underwent aortic valve replacement with a bileaflet mechanical prosthesis, were studied. Aortic root function indices such as aortic cross-sectional compliance (CSC), aortic root distensibility (ARD), and aortic stiffness index (ASI) were calculated with the use of M-mode echocardiography in three sessions: one preoperatively (pre-op), one on day 7 postoperatively (early post-op), and one 6 months postoperatively (late post-op). Results Aortic root function deteriorated early post-op (p < 0.001 for all) and returned towards pre-op levels late post-op (p = NS for all). CSC changed from 2.84 ± 1.98 to 1.37 ± 0.92, and 2.30 ± 1.11 cm2/mmHg, ARD from 2.21 ± 5.60 to 1.01 ± 0.67, and 1.79 ± 0.96 cm2/dyne, and ASI from 9.72 ± 5.60 to 24.65 ± 19.10, and 11.51 ± 7.85, respectively. Correlations were found between early changes in some aortic root indices and the degree of aortic stenosis, denoting that aortic function deteriorated less in more severe cases of aortic stenosis. None of the late changes were related to aortic valve or left ventricular indices. Conclusions Aortic valve replacement with a mechanical valve results in a significant but transient impairment of aortic distensibility.