Aortopathy in patients with bicuspid aortic valve stenosis: role of aortic root functional parameters

OBJECTIVES: We prospectively examined functional characteristics of the aortic root and transvalvular haemodynamic flow in order to define factors associated with the severity of aortopathy in patients undergoing surgery for bicuspid aortic valve (BAV) stenosis.

METHODS: A total of 103 consecutive patients with BAV stenosis (mean age 61 ± 9 years, 66% male) underwent aortic valve replacement ± concomitant aortic surgery from January 2012 through March 2014. All patients underwent preoperative cardiac magnetic resonance imaging (MRI) in order to evaluate the systolic transvalvular flow and the following functional parameters: (i) angulation between the left ventricular outflow axis and the aortic root, (ii) geometrical orientation of residual aortic valve orifice and (iii) BAV cusp fusion pattern. MRI data were used to guide sampling of the ascending aorta during surgery [i.e. jet-sample from the area where the flow-jet impacts on the aortic wall and control sample from the opposite aortic wall (obtained from the aortotomy site)]. Aortopathy was quantified by means of a histological sum-score (0 to 21+) in each sample.

RESULTS: A significant correlation was found between histological sum-score in the jet-sample and the angle between the LV outflow axis and the aortic root (r = 0.6, P = 0.007). Moreover, there was a linear correlation between proximal aortic diameter and the angle between systolic flow-jet and ascending aortic wall (r = 0.5, P = 0.006). Logistic regression identified the angle between the LV outflow axis and the aortic root (OR 1.1, P = 0.04) and the angle between the flow-jet and the aortic wall (OR 1.2, P = 0.001) as independent predictors of an indexed proximal aortic diameter ≥22 mm/m(2).

CONCLUSIONS: Functional parameters of the aortic root may be used to predict the severity of aortopathy in patients with BAV stenosis, and may be useful in predicting future risk of aortic disease in such patients.