Statistical analyses
Due to differences in baseline characteristics between patients in the
linear ablation versus EGM-guided ablation groups, propensity-score
matching was used to identify a subsets of patients with similar
baseline characteristics. Patients were matched in a 1:1 ratio based
propensity scores. Propensity scores were calculated for each patient
using multivariable logistic regression with following 14 covariates:
age, gender, body mass index, AF duration, long-standing AF,
asymptomatic AF, the number of failed AADs, structure heart disease,
brain natriuretic peptide (BNP), estimated glomerular filtration rate,
hypertension, diabetes mellitus, congestive heart failure, CHADS2 score,
LA diameter (LAD) and left ventricular ejection fraction (LVEF), using a
caliper width equal to 0.2 of the standard deviation of the logit of the
propensity score. Quantitative data were expressed as the mean ±
standard deviation. Comparisons between groups were performed using an
unpaired Student’s t -test or Wilcoxon’s rank-sum test (based on
the distribution of the values). Comparisons of means from the same
individual were performed using a paired Student’s t -test.
Categorical data were compared by χ2 test.
Kaplan-Meier curves were used to analyze freedom from AAs, and groups
were compared using the log-rank test. The multivariable analysis was
described by Cox regression for the assessment of the predictors of AAs
recurrence after the initial CA procedure. All tests were 2-tailed, and
P values of <0.05 were considered to indicate statistical
significance. All of the statistical analyses were performed using the
MedCalc software package, version 11.2 (MedCalc Software, Mariakerke,
Belgium).