Statistical analysis
For analysis, patients were categorized into two groups according to the
optimal cutoff value of SII level determined by using receiver operating
characteristics curve analysis (low SII group <451.01 or high
SII group ≥451.01). The SPSS 22.0 software (IBM Corp., Armonk, NY) was
used to perform all analyses. Continuous variables were reported as the
mean ± standard deviation (SD) and categorical data were reported as
frequencies and percentages. Differences in baseline characteristics
between two groups were compared using a χ2 test or Fisher’s exact test
for categoric data and an independent t -test or Kruskal-Wallis
test for continuous data, as appropriate. Kaplan-Meier survival curves
were used for cumulative incidence rates of primary and secondary
endpoints. The statistical differences between groups in Kaplan-Meier
curves were determined using the log-rank test. The predictive value of
SII level related to outcomes was assessed by the multivariable Cox
regression model with adjustment for potential confounders, including
age, diabetes mellitus, WBC, Hb, PLT, albumin, BUN, UA, Cr, HDL, eGFR,
D-dimer, CRP, ESR, LAD and LVEF. The hazard ratios (HRs) and 95%
confidence intervals (CIs) were also determined. All tests were 2-sided
and a p value <0.05 was considered statistically
significant.