Abnormal aortic elastic properties in adults with congenital valvular aortic stenosis

BACKGROUND: Abnormalities of the aortic root are common in patients with a bicuspid aortic valve. Our aim was to investigate the elastic properties of the aortic root in patients with congenital aortic valvular stenosis (AS) in comparison with age- and gender-matched controls, and to investigate the influence of stenosis severity and aortic size on aortic root elasticity.

METHODS: Thirty-two adults (mean age 30.4+/-7.5 years, 22 men) with congenital AS without previous cardiovascular surgery were prospectively studied. Aortic root elasticity indices such as aortic stiffness index (ASI), aortic root distensibility (ARD), and aortic strain were calculated with the use of M-mode echocardiography.

RESULTS: ASI was significantly higher in patients compared to controls, 8.5+/-8.4 versus 4.0+/-1.4, respectively (P<0.01). Other indices of aortic root elasticity were similar between patients and controls: ARD was 4.2+/-3.6 versus 4.3+/-1.9 x 10(-6) cm(2)/dynes, respectively, and aortic strain was 12.4+/-9.6 versus 13.5+/-5.0%, respectively (P=NS for all). Correlations were found between aortic size and indices of aortic elasticity (i.e., aortic strain and ARD), denoting that an increased aortic dimension is associated with a stiffer aorta. Interestingly, no correlations were found between indices of severity of AS and aortic elasticity, suggesting that an abnormal aortic elasticity is independent of stenosis severity.

CONCLUSIONS: Congenital AS results in abnormal aortic elastic properties, independent of stenosis severity. Furthermore, there seems to be a relationship between aortic dimensions and aortic stiffness.