Impairment of elastic properties of the aorta in bicuspid aortic valve: relationship between biomolecular and aortic strain patterns.

Abstract

Bicuspid aortic valve (BAV) is associated with aortic wall alterations. We aimed to detect any correlation between aortic elasticity and genetic and biomolecular patterns of elastin. Forty-nine BAV patients (mean age: 38 ± 17.05) were prospectively enrolled. A blood sample was drawn for analysis of a single nucleotide polymorphism of elastin gene (ELN rs2071307) responsible for misfolding of elastin, and for the amount of elastin soluble fragments (ESF) in the plasma. Aortic dimensions and elastic properties were determined by echocardiography, aortic stiffness (AS) by M-mode analysis, and longitudinal strain (LS) of the ascending aorta (AA) by speckle-tracking echocardiography; values of aortic strain were compared with 45 age-matched subjects (mean age: 33 ± 9.67) with tricuspid aortic valve (TAV). BAV patients had greater aortic dimensions [Valsalva sinus (P = 0.004), sinotubular junction (P = 0.013), AA (P < 0.001)] and stiffness (P = 0.002) but lower LS (P = 0.04) than those with TAV. Results from comparisons of mutated genotype patients (AA, n = 10) with heterozygous (GA, n = 21) and wild-types ones (GG, n = 16) revealed that the presence of mutation was associated with increased ESF (P = 0.010 GG vs. GA; P = 0.035 GA vs. AA), larger AA (P = 0.019 GG vs. GA; P = 0.001 GG vs. AA), and lower LS (P = 0.032 GG vs. AA). Patients with a dilated AA showed greater ESF (P < 0.001), greater AS (P = 0.007), and lower LS of the AA (P = 0.002) than those with a normal AA. The same parameters were not significantly different comparing patients with moderate or severe aortic valve disease and patients with less than moderate valve disease. Our results show a close correlation between genetic and biomolecular patterns of elastin and mechanical properties of the aorta in patients with BAV.