Limitations
The current study had several limitations, the first of which is that it is not free from the intrinsic limitations of a retrospective analysis. There were significant differences in the baseline characteristics between the AF nonrecurrence and AF recurrence groups, although the results were adjusted for such covariates. A causal relationship between the lower incidence of the primary endpoint and sinus rhythm maintenance by catheter ablation is therefore not clear. Second, although the AF recurrence rate of this study was comparable to that of previous reports,21, 22 we cannot deny that asymptomatic AF recurrence might have been overlooked.