Statistical Analysis
Continuous variables were assessed using median (interquartile range [IQR]), and categorical variables are presented as N (%). Wilcoxon rank-sum test was used to compare differences in continuous variables between BAV and TAV. Chi-square test and Fisher’s exact test were used for categorical variables, as appropriate.
To determine risk factors associated with rapid progression of AS, we dichotomized patients based on progression rate of mean gradient greater than (rapid progressor) or less than or equal to (slow progressor) the average annualized progression of mean gradient for the whole cohort, as previously described.10, 13 Univariate and multivariable logistic regression analysis was used to determine whether BAV is associated with rapid progression of AS. Variables with p<0.10 on univariate analysis were included in the multivariate model. Kaplan-Meier curves were generated to compare BAV and TAV patients for occurrence of surgical or transcatheter aortic valve replacement (AVR) after initial diagnosis of AS. Stepwise multivariable Cox proportional hazards model was used to assess the association of BAV with AVR, adjusting for potential confounders. P-values <0.05 were considered statistically significant. All statistical analyses were performed using RStudio, version 1.2.1335 (Boston, MA, USA).