Statistical Analysis
Continuous variables were described with measures of central tendency
and dispersion (mean and standard deviation). Categorical variables were
described as frequencies or mode when appropriate. Continuous variables
were evaluated by t -test, and categorical variables compared withχ 2 or Fisher’s exact test. The cumulative
probability of survival free from atrial arrhythmia was displayed
according to the Kaplan–Meier method, with comparisons of cumulative
event rates by the log-rank test. Follow-up for all patients was
censored at one year after repeat ablation. A p-value of <
0.05 was considered statistically significant. All analyses were
performed using SPSS Statistics Software for Windows version 23.0 (IBM
Corporation, Armonk, New York).