Bicuspid aortic valve morphology and its impact on aortic diameters-A systematic review with meta-analysis and meta-regression

Aim: To evaluate the impact of the 2 most common bicuspid aortic valve (BAV) morphology patterns [right-left (RL) vs right-noncoronary (RN) cusp fusion] on the aortic diameters and the impact of gender, aortic stenosis (AS), aortic regurgitation (AR), and age on the observed effects.

Methods: The PubMed databases was searched up to December 31, 2016 to identify studies investigating the morphology of BAV and aortic diameters. Inclusion criteria were as follows: the data on diameter of sinuses of Valsalva (SVD) and/or ascending aorta (AAD) and BAV morphology. The additional characteristics [gender, AS and AR (% of patients with moderate or severe AS/AR) and mean age] were collected to perform a meta-regression analysis.

Results: A total of 12 studies with 2192 patients with indexed AAD, 15 studies with 3104 patients with nonindexed AAD and 8 studies with 1271 patients with indexed SVD, and 16 studies with 3454 patients with nonindexed SVD were included. There was no difference between RL and RN group in indexed/nonindexed AAD-mean difference (MD): 0.06 mm/m² (95% CI: -0.65 to 0.77 mm/m² , P = .87) and -0.06 mm (95% CI: 1.10-0.97 mm, P = .91). Differently, the RL BAV was associated with larger indexed/nonindexed SVD than RN phenotype-MD: 1.66 mm/m² (95% CI: 0.83-2.49 mm/m² , P < .001) and 2.03 mm (95% CI: 0.97-3.09 mm, P < .001). Age, gender, AS, and AR had no influence on observed differences.

Conclusions: RL BAV phenotype is associated with larger SVD than RN BAV, and the observed differences are independent from aortic valve dysfunction degree, age, and gender.