Repeat in situ ablation versus extensive ablation for recurrent persistent atrial fibrillation.

Aims: Repeat ablation strategies for persistent atrial fibrillation (PerAF) are less well studied than initial ablation strategies. The efficacy of repeat ablation remains unclear, particularly regarding the potential advantages of extra-pulmonary vein (PV) extensive ablation compared with in situ ablation.

Methods and results: Patients with recurrent PerAF were randomized (1:1) to receive extra-PV extensive ablation (EXT group, n = 66) or repeat PV isolation (PVI) and linear ablation as the first procedure (In situ group, n = 66). The primary endpoint was freedom from atrial fibrillation (AF)/atrial tachycardia (AT) episodes lasting >30 s at 12 months. At 12 months, 44 patients (66.7%) in the EXT group were free from AF/AT recurrence, in contrast to 32 patients (48.5%) in the In situ group (log-rank P = 0.037; hazard ratio [HR] 0.587 [95% confidence interval [CI], 0.348-0.992]). The freedom from AF recurrence rate was significantly higher in the EXT group than in the In situ group (77.3% vs 60.6%, log-rank P = 0.027; HR 0.509 [95% CI, 0.278-0.932]).The safety endpoints showed no significant difference between the two groups (4.5% vs 6.1%, P = 0.716).

Conclusions: Among patients with PerAF undergoing repeat ablation, the EXT group demonstrated superior clinical efficacy compared with the In situ group, indicating that PV reconnection and linear lesion reconduction may not constitute the predominant mechanisms driving AF recurrence. These may still contribute significantly, but targeting additional non-PV substrates further improves outcomes.