3 Statistical analysis
Continuous variables are expressed as mean ± standard deviation.
Categorical variables are presented as percentile value. Unpaired t-test
was used to compare continuous variables. Categorical variables were
compared using either the chi-square test or Fisher’s exact test, as
appropriate. Multivariate logistic regression analysis was performed to
evaluate the impact of different type of irrigation system on
procedure-related ischemic complications. Covariates included in the
multivariate model were chosen based on the baseline characteristics of
each group and univariate logistic regression analysis. However, the
known risk factors of ischemic stroke or TIA, such as individual
components of the CHA2DS2-VASc score,
were included in multivariate analysis regardless of the results of
univariate analysis. Results were considered to be significant if the
p-value was <0.05 on a two-tailed test. All statistical
analyses were performed using SPSS version 24.0 (SPSS Inc., Armonk, NY,
USA).