Aortic dilatation patterns and rates in adults with bicuspid aortic valves: a comparative study with Marfan syndrome and degenerative aortopathy

Background Bicuspid aortic valve (BAV) is related to aortic dilatation, but patterns/rates are conflicting with no comparison among aneurysms of different aetiology. We sought to define ascending aorta dilatation patterns/progression rates in BAV versus other aortopathies (Marfan syndrome (MFS), degenerative aortopathy (DA)). Design and setting Retrospective, observational study. Aortic dilatation progression was evaluated in two tertiary care centres (US and European) by repeated echocardiography ≥2 years apart in adults with BAV (n=353), matched to MFS (n=50) and DA (n=51) for gender, blood pressure, and minimum follow-up time. Results At baseline, ascending aortic dilatation was present in 87% of BAV cases: tubular ascending aorta in 60% (irrespective of BAV morphology), and Valsalva sinuses dilatation in 27% (independently linked to typical BAV morphology and male gender (p=0.0001)). After 3.6±1.2 years, the aortic dilatation rate in BAV was higher than expected for the population for all aortic levels (p=0.005) and was maximal at the tubular ascending aorta for BAV (0.42±0.6 mm/year) and DA (0.20±0.3 mm/year), and was maximal at the Valsalva sinuses for MFS (0.49±0.5 mm/year). Maximal aortic dilatation rate was similar between BAV and MFS (p>0.40) and lower in DA (p=0.02) but was heterogeneous in BAV, with 43% of BAV not progressing (vs 20% of MFS, p=0.01). Aortic dilatation rate was not proportionally related to baseline aortic size or BAV type (all models p>0.40). Conclusions In patients with BAV, tubular ascending aorta dilatation is the most common pattern and exhibits the fastest growing rate, irrespective of valve morphology and function. Dilatation of the Valsalva sinuses is less common and associated with typical BAV morphology and male gender. Aortic dilatation progresses equally fast in BAV (tubular segment) and MFS (Valsalva sinuses), but a significantly higher proportion of BAV patients does not progress at all, irrespective of BAV type. Baseline aortic diameter does not proportionally predict progression rate; systematic follow-up is therefore warranted in patients with BAV.