2.5 | Statistical Analysis
Categorical variables were expressed as absolute numbers and percentages
and continuous variables were expressed as mean (SD) or median (IQR)
depending on the distribution. Kolmogorov-Smirnov test was used to
access the normal distribution.
The pre-operative variables were selected a priori (not a
stepwise method): age, gender,
hypertension, Diabetes Mellitus (DM), dyslipidemia, New York Heart
Association (NYHA) III/IV, Canadian Cardiovascular Society (CCS) scale
III/IV, LVEF <50%, renal disease, carotid artery disease,
respiratory disease, gastrointestinal disease, urgency surgery and
history of stroke. Categorical variables were compared using χ2 test.
Mann–Whitney U-test was used for independent samples not normally
distributed.
Variables with a univariate p <0.05 were included in
the Multivariable Cox Proportional Hazards Regression and Logistic
Regression models to identify risk factors for MACCE and follow-up
mortality. A probability value of p <0.05 was considered
statistically significant. All analyses were performed using IBM SPSS
Statistics for Windows, Version 22.0. (IBM Corp. Armonk, NY).