Objective Data on the efficacy of adjunctive interpulmonary isthmus ablation following completion of extensive encircling pulmonary vein isolation (EEPVI) on atrial fibrillation (AF) recurrence have still been insufficient. We aimed to compare the AF recurrence between EEPVI with and without adjunctive interpulmonary isthmus ablation.

Methods We enrolled 200 consecutive patients with paroxysmal AF (first session) who underwent EEPVI with double-Lasso technique. Patients were prospectively randomised into two groups: EEPVI with (group 1) and without (group 2) adjunctive interpulmonary isthmus ablation.

Results No differences were found in patients’ clinical and echocardiographic backgrounds, including arrhythmia status, between the two groups. No differences were also observed in complications (two groin haematoma in both groups). All patients in both groups reached the EEPVI endpoint. The AF recurrence rate between groups 1 (32/100, 32%) and 2 (33/100, 33%; p=1.0) was quite similar during the follow-up period (45±5 months; 36–54 months). The two groups showed identical Kaplan-Meier AF-free curves (p=0.460; NS). Similar pulmonary vein (PV) reconnection incidence was observed in both groups during the second session. Durable isolation between the superior and inferior PVs was confirmed in 88% (21/27) of patients in group 1, indicating that interpulmonary isthmus ablation maintained a non-conducting state in a considerable number of patients. Nevertheless, AF recurrence was identical between the two groups.

Conclusion The results of our study showed similar AF recurrence rates between the two groups, indicating that adjunctive interpulmonary isthmus ablation with EEPVI has no obvious effects on AF recurrence.