Statistical analysis
Statistical analysis was performed using IBM SPSS 21 statistical
software. Continuous and categorical variables are reported as
mean±standard deviation (SD) or as percentages, respectively. Continuous
variables were compared between two groups using the t-test and the
ANOVA model for repeated measures was performed and validated using
Mauchly’s test of sphericity with Greenhouse-Geisser correction. A
stepwise logistic regression multivariable analysis was performed, to
assess the simultaneous effect of several variables on the primary
outcome (PPI). The variables included in the analysis were LVEF, age,
sex, CRP, mean aortic PG, FACTS score, implantation depth (mean and
non-coronary cusp), valves types, bicuspid aortic valve, non-coronary
cusp calcification, NLR at any moment. A ROC curve analysis was applied
to find a cut point, if necessary. A p value (two sided) of less than
0.05 was considered significant.