Statistical Analysis
Continuous variables are presented as the mean ± SD and categorical variables as the number and percentage of patients. Two-group comparisons were performed with either Student’s t -test or the Mann–Whitney U test according to the results of the Shapiro–Wilk normality test. Categorical variables were compared using Fisher’s exact test. The cumulative atrial tachyarrhythmia recurrence-free survival was evaluated using the Kaplan–Meier method, and curves were compared using the log-rank test. Hazard ratios were used to determine the impact of the timing of the last ER on long-term atrial tachyarrhythmia recurrence and were calculated using a Cox proportional hazards model.
A p value < 0.05 was considered statistically significant. When comparing three groups, Bonferroni correction was used, and a p value < 0.017 was considered significant. Analyses were performed using IBM SPSS Statistics software version 21, (IBM Corporation, Armonk, NY).