Statistical analysis
Analysis was performed using SPSS software, version 22(IBM Corp., Armonk, NY, USA). Descriptive statistics were presented as mean ± standard deviation for continuous variables and frequency and percentage for categorical variables. The X2 and Fisher’s test were used to compare subgroups. Kaplan- Meier method was applied to draw survival curves and calculate 10-year survival statistics. Linear regression analysis was used to analyze changes in the ascending aorta. Model selection was based on Akaike’s information criterion. All statistical tests were 2 sided with the alpha level set at 0.05 for statistical significance.