Pulmonary vein reconnection predicts good clinical outcome after second catheter ablation for atrial fibrillation

Aims Although electrically reconnected pulmonary veins (PV) are the main mechanism of atrial fibrillation (AF) recurrence, PV isolation (PVI) is well-preserved in certain patients who undergo a repeat procedure. We explored the association between PV reconnection and clinical outcomes after a second ablation. Methods and results This observational cohort study included 143 patients (79.0% male, 56.1 ± 10.0 years old, 65.0% paroxysmal AF) who underwent a second procedure. Pulmonary vein isolation was well-maintained in 52 patients (PVP -' group, 36.4%), although the remaining 91 patients showed PV reconnection (PVP + group). After confirming PVI, we mapped non-PV triggers and conducted trigger ablation or additional linear ablation at redo-procedures. The proportion of females was higher (P = 0.030), and redo-ablation timing after the de novo procedure was later (P = 0.039) in the PVP -' group than in the PVP + group. Additional linear ablations were more likely to be performed in the PVP -' group (90.4 vs. 61.5%, P < 0.001). During the 18.4 ± 10.2 month follow-up after the redo-ablation, the PVP + group showed a lower clinical recurrence rate than the PVP -' group (log-rank P = 0.011). The number of reconnected PVs was independently associated with a lower recurrence of AF after the redo-ablation in the total study population (HR 0.56, 95% CI 0.34-0.95, P = 0.032), particularly for patients with paroxysmal AF (HR 0.41, 95% CI 0.19-0.87, P = 0.021). Conclusion Among patients who underwent redo-AF ablation, those with more PV reconnections showed better clinical outcomes than those with fewer PV reconnections. The mechanism of AF recurrence might be different in patients with lower numbers of PV reconnections during redo-procedures.