Statistical Analysis
BITA and SITA groups were compared with the Fisher’s exact test for
categorical variables, and the Mann-Whitney U test for continuous
variables. Overall and MACE-free survival were estimated using the
Kaplan-Meier method. Statistical differences were analyzed using the
log-rank test. Univariate and multivariate analyses of the prognostic
factors of overall survival were performed using the Cox proportional
hazard models. Preoperative, operative, and postoperative variables were
included in the univariate analysis. Age, sex, and variables with P
value < 0.05 in the univariate analysis were included as
variables in the multivariate analysis. P values < 0.05 were
considered statistically significant. All statistical analyses were
performed using EZR (Saitama Medical Center, Jichi Medical University,
Saitama, Japan), which is a graphical user interface for R (version
3.3.3; The R foundation for Statistical Computing, Vienna,
Austria)16.