Introduction: Bicuspid aortic valve (BAV) related aor-topathy represents an imperfectly understood disor-der. Recent studies suggest that the type of valve dys-function (aortic stenosis versus regurgitation) result in distinct hemodynamics in the ascending aorta and influence the risk for aortic events, but the data are still scarce.
Objective: To assess the differences in the elastic pro-perties of the ascending aorta between pts with BAV and severe aortic stenosis (AS) and those with BAV and significant aortic regurgitation (AR).
Methods: We prospectively enrolled 23 consecuti-ve pts with BAV and isolated severe AS (40±9 yrs, 11 men, indexed aortic valve area <0.6 cm2/m2) with no more than mild aortic regurgitation (BAV-AS group) and 19 age-matched pts with moderate-severe aortic regurgitation (36±10 yrs, 16 men) (BAV-AR group). A comprehensive echocardiography was performed in all patients. Aortic stiffness index (beta) was calculated using a validated formula based on the ascending aorta diameters (measured by M mode echocardiography) and blood pressure values measured at the time of the echocardiographic examination. Aortic strain and dis-tensibility were also assessed at the level of the ascen-ding aorta.
Results: T here were no significant differences betwe-en groups regarding age (p=0.1) and body mass index (p=0.5). The degree of systemic hypertension and the systolic and diastolic blood pressure values measured at the time of echocardiography were similar betwe-en groups (p>0.1). Patients in the BAV-AR group had larger indexed LV end diastolic and end systolic volu-mes (p<0.001) but there were no significant differences regarding LV mass index and LVEF between groups (p>0.1 for all). Global longitudinal LV strain was signi-ficantly impaired in pts in the BAV-AS group vs BAV-AR group (-15±4 vs. -19±2%, p<0.001).The ascending aorta diameters were not significantly different betwe-en BAV-AS and BAV-AR groups (34.6±6.5 vs 36.6±5.6 mm, p=0.3) but aortic beta index was significantly higher in the BAV-AR group (15.5±8.4 vs. 8.3±5.4, p=0.002). The aortic strain and distensibility were also significantly lower in these patients compared to pati-ents in the BAV-AS group (p=0.03 and 0.003, respec-tively). Increased aortic stiffness was positively corre-lated to larger aortic diameters in the BAV-AS group (p<0.001, r=0.7) but not in the BAV-AR group (p=0.5). Conclusions: Patients with BAV and significant aortic regurgitation have an increased aortic stiffness when compared to patients of comparable age, with BAV and severe aortic valve stenosis, despite similar ascending aorta diameters. Our data support the hypothesis that these two phenotypic variants of BAV patients repre-sent distinct clinical and morphological entities.