Limitations
There are several limitations to the present study. First, this was a retrospective single-center study with a small study population. Although, there were several clinical backgrounds that influenced the renal function, we consider that the propensity score matching reduced the biases of the variables related to the eGFR. A further large-scale prospective study will be needed to clarify these issues. Second, the freedom from AF more than 3 months after the ablation might have been possibly overestimated, as asymptomatic episodes of recurrence of AF could not have been evaluated by regular twelve lead electrocardiograms and 24-hour Holter monitoring.