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).