Statistical methods
Categorical data are presented as absolute values and percentages, and continuous data as mean ± standard deviation or median (1st–3rd quartile). Tests for significance were conducted using the chi-squared test for categorical variables and the unpaired t -test or Mann-Whitney U -test for continuous variables. Univariate and multivariate Cox proportional hazards regression analyses were used to determine clinical factors associated with the DHF. Variables with aP value ≤ 0.05 in the univariate models were included in the multivariate analysis. Kaplan-Meier analysis, log-rank test, and Cox proportional hazards regression analyses were used to investigate the association between the AF recurrence or late phase DHF requiring re-hospitalization and DHF.
All analyses were performed using commercial software (SPSS™ version 25, SPSS, Inc., Chicago IL, USA).