Aortic dilation rates in patients with biscuspid aortic valve: correlations with cusp fusion phenotype.

Background and aim of the study: The study aim was to compare the pattern and rate of aortic dilation in patients with isolated non-surgical bicuspid aortic valve (BAV) with left-right fusion (L-R) and right-non coronary fusion (R-N). Although the etiology and optimal management of aortic dilation associated with BAV remain the subject of debate, recent data have suggested that L-R and R-N cusp fusion phenotypes represent distinct pathological entities. Methods: Consecutive patients with BAV and at least two echocardiographic assessments made between 2006 and 2012 were reviewed. Patients with hemodynamically significant valvular disease, aortic aneurysm (>50 mm) or unrepaired aortic coarctation were excluded. Longitudinal analyses of the aortic annulus, sinuses of Valsalva, sinotubular junction and ascending aortic diameters were performed using mixed-effect models. Results: A total of 590 echocardiographic studies was analyzed in 212 patients (mean age 33 +/- 14 years), of which 147 had L-R phenotype and 65 had R-N phenotype. The median follow up was 3.6 years. Baseline aortic diameters at the sinuses of Valsalva were larger in patients with L-R compared to R-N fusion (33.8 +/- 5.3 mm versus 30.8 +/- 4.8 mm; p <0.001). At this level, the rate of aortic dilation was higher with L-R versus R-N fusion (0.41 +/- 0.11 mm/year versus 0.01 +/- 0.08 mm/year; p <0.001). The rate of proximal ascending aortic dilation was also higher with L-R versus R-N fusion (0.58 +/- 0.08 mm/year versus 0.18 +/- 0.09 mm/year; p <0.001). Conclusion: Aortic dilation rates vary according to the pattern of BAV cusp fusion, with faster rates of aortic sinus and ascending aortic dilation associated with the L-R compared to R-N phenotype.