升主动脉扩张及主动脉瓣功能障碍对二叶式 主动脉瓣患者主动脉弹性影响的磁共振成像研究.

Objective To study the effects of ascending aorta dilatation and aortic valve dysfunction on the elasticity of the middle ascending aorta (mid-AA) and proximal descending aorta (PDA) in patients with bicuspid aortic valve (BAV) by using magnetic resonance imaging (MRI). Methods From Oct 2019 to Mar 2021, a total of 130 BAV patients and 30 healthy volunteers from Zhongshan Hospital, Fudan University were prospectively undergone 3.0 T MRI for aortic distensibility. BAV patients were categorized into 4 groups according to the diameter of ascending aorta and aortic valve function as follows: BAV with normal or mild aortic valve dysfunction and nondilated ascending aorta (AA) (BAV-CTL, n=30), BAV with normal or mild aortic valve dysfunction and dilated AA (Dilated BAV-NF, n=40), BAV with moderate to severe aortic stenosis and dilated AA (Dilated BAV-AS, n=30), and BAV with moderate to severe aortic insufficiency and dilated AA (Dilated BAV-AI, n=30). The cross-sectional areas and distensibility of mid-AA and PDA were assessed at the level of right pulmonary artery.Student’s t test and Mann-Whitney U test were used to compare the continuous variables between the groups, while chi-square test or Fisher exact test was used to compare the categorical variables. Results Dilated BAV-NF group had decreased mid-AA distensibility［2.77 (IQR: 1.45-6.26) vs. 1.52 (IQR: 1.08-2.19), P=0.004] than BAV-CTL group. Compared with the Dilated BAV-NF, Dilated BAV-AI had elevated distensibility at mid- AA and PDA［mid-AA: 1.52 (IQR: 1.08-2.19) vs. 2.29 (IQR: 1.60-4.08), P=0.006；PDA: 3.70 (IQR: 2.89-4.70) vs. 4.79 (IQR: 2.93-6.80), P=0.024]. Compared with the Dilated BAV-AS, Dilated BAV-AI again showed elevated distensibility at mid-AA and PDA［mid-AA: 1.60 (IQR: 0.99-2.26) vs. 2.29 (IQR: 1.60-4.08), P=0.022；PDA: 3.73 (IQR: 2.38-4.40) vs. 4.79 (IQR: 2.93-6.80), P=0.014]. Conclusion Ascending aorta dilatation and aortic insufficiency are the main factors affecting aortic elasticity in patients with BAV. The effect of aortic dilatation on aortic elasticity is limited to the ascending aorta, while the effect of aortic insufficiency on aortic elasticity is more extensive. [ABSTRACT FROM AUTHOR]