Morphologic and Functional Markers of Aortopathy in Patients With Bicuspid Aortic Valve Insufficiency Versus Stenosis

BACKGROUND: Bicuspid aortic valve (BAV)-associated aortopathy is heterogeneous and still insufficiently defined. We prospectively analyzed the morphologic and functional variables of aortopathy in patients undergoing operations for BAV insufficiency (BAV-AI) vs stenosis (BAV-AS).

METHODS: A total of 172 consecutive patients (71% male, 59 ± 10 years) underwent aortic valve replacement with or without proximal aortic operation for BAV-AS (n = 137), and BAV-AI (n = 35) from January 2012 through December 2014. All patients underwent preoperative cardiac magnetic resonance imaging to evaluate morphologic and functional variables of the aortic root. Magnetic resonance imaging data were used to guide sampling of aortic tissue intraoperatively (ie, from the area where flow jet impacts on the aortic wall [jet sample] and the opposite aortic wall [control sample]). Aortic wall lesions were graded based on the histologic sum score (range, 0 to 21). Expression and severity of aortopathy were quantified by means of proximal aortic phenotype, indexed aortic diameters, and a sum score.

RESULTS: Cross-sectional aortic diameters were significantly larger in the BAV-AI group vs the BAV-AS group (47 ± 8 mm vs 41 ± 8 mm, p = 0.001). Moreover, root dilatation phenotype was more frequent in the BAV-AI group (27% vs 6%, p = 0.01) and was associated with a significantly larger aortic annulus diameter (32 ± 3 mm vs 27 ± 3 mm, p < 0.001). The histologic sum score was significantly different between the study groups (3.7 ± 2.6 BAV-AI vs 2.5 ± 1.4 BAV-AS, p = 0.03). Logistic regression revealed a significant association between BAV-AI and indexed aortic diameter exceeding 22 mm/m2 (odds ratio, 4.7; p = 0.007).

CONCLUSIONS: Our study demonstrates that BAV functional phenotype correlates significantly with the expression and severity of bicuspid aortopathy.