INTRODUCTION
Electrical isolation of the pulmonary veins (PVI) is a radical treatment for paroxysmal atrial fibrillation (PAF). Despite the acute success of PVI, recurrence of atrial tachyarrhythmia is common. Recurrence of atrial tachyarrhythmias within the first 3 months after an atrial fibrillation (AF) ablation procedure is defined as early recurrence (ER). ER is distinguished from late recurrence (LR) of atrial tachyarrhythmia, because only half of patients with ER also have LR.1 Accordingly, guidelines and expert consensus statements do not recommend early re-ablation during the first 3 months. However, some studies have shown that ER occurring in a later period was more strongly associated with long-term ablation failure in patients who underwent PVI using local electrode attenuation and impedance drop-guided radiofrequency catheter ablation (RFCA) and more than 90% of patients with ER during the 3rd month post-ablation develop LR.2, 3
Recently, the conventional ablation procedure has been replaced by contact force (CF) technology for PVI, and some studies have shown that CF-guided PVI is more effective in reducing AF recurrence than the conventional non-CF-guided PVI.4 However, the significance of ER episodes after CF-guided ablation in terms of LR remains unclear. Therefore, the objective of this study was to compare the significance of ER as a risk factor for LR in patients with paroxysmal AF (PAF) treated by CF and non-CF-guided ablation procedures.