Clinical Implication of Aortic Wall Biopsy in Aortic Valve Disease with Bicuspid Valve Pathology

Background: Although unique aortic pathology related to bicuspid aortic valve (BAV) has been previously reported, clinical implications of BAV to aortopathy risk have yet to be investigated. We looked for potential differences in matrix protein expressions in the aortic wall in BAV patients. Methods: Aorta specimens were obtained from 31 patients: BAV group (n=27), tricuspid aortic valve (TAV) group (n=4). The BAV group was categorized into three subgroups: left coronary sinus-right coronary sinus (R+L group; n=13, 42%), right coronary sinus-non-coronary sinus (R+N group; n=8, 26%), and anteroposterior (AP group; n=6, 19%). We analyzed the expression of endothelial nitric oxide synthase (eNOS), matrix metalloproteinase (MMP)-9, and tissue inhibitor of matrix metalloproteinase (TIMP)-2. Results: Based on the mean value of the control group, BAV group showed decreased expression of eNOS in 72.7% of patients, increased MMP-9 in 82.3%, and decreased TIMP in 79.2%. There was a higher tendency for aortopathy in the BAV group: eNOS $(BAV:TAV)=53%{\pm}7%:57%{\pm}11%$, MMP-9 $(BAV:TAV)=48%{\pm}10%:38%{\pm}1%$. The AP group showed lower expression of eNOS than the fusion (R+L, R+N) group did; $48%{\pm}5%$ vs. $55%{\pm}7%$ (p=0.081). Conclusion: Not all patients with BAV had expression of aortopathy; however, for patients who had a suspicious form of bicuspid valve, aortic wall biopsy could be valuable to signify the presence of aortopathy.