New insights in the association between bicuspid aortic valve phenotype, aortic configuration and valve haemodynamics

Patients with a bicuspid aortic valve (BAV) present with various phenotypes of the valve, the aortic root (AoR) and/or the ascending aorta (AAo) and various valve haemodynamics (vHs). The aim of the present study was to investigate the association between the above parameters. Between February 1999 and April 2014, the preoperative aortographies of 828 surgical patients with BAV were evaluated. The exact BAV type was classified intraoperatively according to the number and spatial orientation of the raphes. On analysis of BAV phenotypes and aortic configurations, a weak pattern was revealed (P = 0.01) only for BAV type 0 and AoR dilatation. Including haemodynamics, certain significant patterns emerged: in insufficient BAVs, AoR dilatation was significantly more frequent in type 0, type 1 LR and type 1 RN, whereas AoR + AAo dilatation was more frequent in BAV type 1 LR. In stenotic BAVs, AAo dilatation alone was observed significantly more frequently in BAV type 1 LR and type 0. Combined vHs were associated with AAo and AoR + AAo dilatation in BAV type 2/unicuspid only. Associations between the two parameters, BAV type and aortic configuration, were only weak. With the inclusion of haemodynamics significant associations emerged but were not exclusive. In stenotic BAVs, aortic dilatation was more localized to AAo only, supporting the valve-related flow turbulence theory. Insufficient (even trace insufficient) BAVs and also combined lesions in BAV type 2/unicuspid were associated with a more extensive aortopathy (AoR + AAo) in younger patients, indicating a more aggressive gene-related aortopathy.