Patterns of Aortic Dilatation in Patients with Bicuspid Aortic Valves: A Comparative Study with Marfan and Annuloaortic Ectasia

Aims: To define, in bicuspid aortic valve (BAV), ascending aorta dilatation patterns and progression rates vs. other aortopathies (Marfan Syndrome-MFS, Annulo-Aortic-Ectasia-AAE). Methods and results: Aortic dilatation progression was evaluated in two tertiary-care centers (US and European) by repeated echocardiography ≥2 years apart in adults with BAV (n=353) matched to MFS (n=50) and AAE (n=51) for gender, blood pressure and follow-up time. At baseline, aortic dilatation was present in 87% of BAV with predominant dilatation of the tubular-ascending-aorta (60%) irrespective of BAV morphology, while predominant Valsalva-sinuses dilatation (27%) was independently linked to typical (right-left fusion) BAV morphology (p<0.04). After 3.6±1.2 years, aortic dilatation rate in BAV was higher than population-expected for all aortic levels (p=0.005) and was maximal at the tubular-ascending-aorta for BAV (0.42±0.6mm/y) and AAE (0.20±0.3mm/y), while predominant at Valsalva-sinuses for MFS (0.49±0.5mm/y). Maximal aortic dilatation rate was similar between BAV and MFS (p>0.40) and lower in AAE (p=0.02) but was heterogeneous in BAV, with 43% of BAV exhibiting no dilatation progression (vs. 20% of MFS, p=0.01) (figure). Aortic dilatation rate was not related to baseline aortic size or BAV type (all models p>0.40). Conclusion: Tubular-ascending-aorta dilatation is frequent with BAV, irrespective of valve morphology, while Valsalva-sinuses dilatation is less common and associated with typical BAV morphology. Aortic dilatation progresses slower in AAE and equally fast in BAV and MFS, with a significant proportion of BAV not progressing at all. However, patterns of aortic dilatation are different, predominant for tubular-ascending-aorta in BAV vs. Valsalva-sinuses in MFS. Baseline aortic diameter does not predict progression rate, systematic follow-up is therefore warranted in BAV patients. Different valvulo-aortic phenotypes and patterns/rates of aortic dilatation underscore possible mechanistic and outcome differences between aortopathies.