Statistical analysis
Statistical analysis was performed using IBMThe normality of the distribution of continuous variables was evaluated through the Shapiro–Wilk’s test and histogram analysis. Continuous variables were described by median (Mdn) and interquartile range (IQ) since normality was not found in any of them. Categorical variables were described by absolute and relative frequencies (%).The Mann–Whitney test was performed to compare continuous variables. The Chi-square test was used to compare categorical variables, although if the percentage of cells with < 5 expected counts were greater than 20%, Fisher’s exact test was preferred. Results with statistical significance were considered whenever the If two variables were dichotomous, Phi (φ) was presented, as measured of effect size, considering the small, medium, or large effect for absolute values close to 0.10, 0.30 and 0.50, respectively.Cox’s proportional hazards model with forward’s method was employed to evaluate the impact of RIC on the primary follow-up endpoint according to the period of the day in which PPCI was performed. Results are reported as hazard ratio (HR) and with a 95% of confidence interval (CI).