MATERIALS AND METHODS
The data source of this retrospective study was the National Inpatient
Sample (NIS) data registry that consisted of a complete set of
background, intra-operative, and postoperative information of the
patients undergoing PCI procedures. The collected information included
demographic characteristics, underlying cardiac risk factors, laboratory
findings at the time of admission, characteristics related to coronary
artery involvement, such as the severity of involvement and the number
of coronary arteries under the procedure, and intra- and postoperative
outcomes during hospitalization. Patients were classified into two
groups with ACKD and without this co-morbidity. The in-patient death
defined as death that occurred postoperatively during hospitalization
was the parameter of interest.
The Kolmogorov-Smirnov test was primarily used to assess the normality
states of the study variables. The Chi-square test was applied to
determine the statistical differences between categorical parameters,
while the t-test or Mann-Whitney U test was employed to assess the
difference between quantitative variables. To determine the values of
chronic renal failure to predict in-hospital death following PCI, the
multivariate logistic regression analysis was used with the presence of
baseline variables. P values of ≤ 0.05 were considered significant. The
statistical software SPSS version 28.0 for Windows (IBM, Armonk, New
York) was used for statistical analyses.