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

Area of Science:

• Cardiovascular Medicine
• Medical Imaging
• Genetics and Genomics

Background:

• Bicuspid aortic valve (BAV) is a common congenital heart defect.
• Aortic dilation is a known complication of BAV.
• Specific BAV cusp fusion patterns, such as left-right (L-R) and right-non coronary (R-N), may have distinct implications for aortic disease.

Purpose of the Study:

• To compare the pattern and rate of aortic dilation in patients with isolated non-surgical BAV.
• To differentiate between L-R and R-N cusp fusion phenotypes regarding aortic dilation.
• To investigate if L-R and R-N fusion represent distinct pathological entities affecting the aorta.

Main Methods:

• Retrospective review of consecutive patients with BAV and at least two echocardiographic assessments (2006-2012).
• Exclusion of patients with significant valvular disease, aortic aneurysm (>50 mm), or unrepaired coarctation.
• Longitudinal analysis of aortic diameters (annulus, sinuses of Valsalva, sinotubular junction, ascending aorta) using mixed-effect models.

Main Results:

• Analysis of 590 echocardiograms in 212 patients (147 L-R, 65 R-N phenotype) with a median follow-up of 3.6 years.
• Larger baseline aortic diameters at the sinuses of Valsalva in the L-R group compared to the R-N group (33.8 ± 5.3 mm vs. 30.8 ± 4.8 mm; p < 0.001).
• Significantly higher rates of aortic dilation at the sinuses of Valsalva (0.41 ± 0.11 mm/year vs. 0.01 ± 0.08 mm/year; p < 0.001) and ascending aorta (0.58 ± 0.08 mm/year vs. 0.18 ± 0.09 mm/year; p < 0.001) in the L-R group.

Conclusions:

• Aortic dilation rates differ based on BAV cusp fusion patterns.
• The L-R cusp fusion phenotype is associated with faster rates of aortic sinus and ascending aortic dilation compared to the R-N phenotype.
• These findings support the concept of distinct pathological entities for different BAV cusp fusion patterns.