Statistical analysis
Continuous variables have been presented as means ± standard deviation or median values [first quartile, third quartile], and categorical variables have been expressed as proportions. For comparisons between groups, ANOVA as well as Kruskal-Wallis tests were used for continuous variables, while χ2 tests were used for comparisons of categorical variables. Then, we performed the Kaplan–Meier (KM) method and log-rank tests to determine survival differences between four groups. The Cox proportional hazards model was applied to calculate the hazard ratio (HR) and 95% confidence interval (CI) for each group of the cohort. In the adjusted full model, we regrouped the study population by combining all individuals with normal PR intervals and calculating the median HR for each group. We did 3 sensitivity analyses to assess the robustness of our findings. Subgroup analyses were also performed in clinically relevant subgroups and interactions were tested. Missing data on covariates were accounted for using a multiple imputation approach. All data analysis was performed by using R statistical software (R, version 4.2.1)