Background: Although the ectopic foci responsible for initiating AF are usually located in the pulmonary veins (PVs), non-PV sources can initiate AF in approximately 11% of unselected patients with paroxysmal or persistent AF. The superior vena cava (SVC) is one of the most frequent non-PV origins for initiating AF. This study aims to investigate the efficacy of empirical SVC isolation in redo AF ablation procedures.

Methods: Consecutive patients undergoing redo AF ablation procedures using the high-power short-duration protocol (HPSD) (50W; ablation index-guided; target AI 350 for posterior wall ablation, AI 450 for anterior wall ablation; CARTO 3 Mapping System) were included. Patients with SVC isolation were compared to patients without SVC isolation. Periprocedural parameters and complications were recorded and analysed. Short-term endpoints included intrahospital AF recurrence, midterm endpoint AF freedom after 3 months and long-term endpoint AF freedom after 12 months.

Results: A total of 276 patients underwent repeat ablation for AF (67  10 years; 57% male; 32% paroxysmal AF). Patients were divided into two groups: redo procedures with SVC isolation vs redo procedure without SVC isolation. Baseline characteristics did not differ significantly between the two groups. Median procedure time was 85.4  27.1minutes with ablation times of 14.0  8.5 minutes. Intrahospital AF recurrence occurred in 12% of the patients (13% SVC vs. 10% No-SVC; p=0.416). At 3 months follow-up, 82% of all patients were free from AF recurrences (78% SVC vs 85% No-SVC; p=0.164). After 12 months, 52% of all patients were free from AF recurrence (50% SVC vs 53% No-SVC; p=0.684) with no significant difference between the two groups. Using multivariable regression models, increased ablation time was the only predictor of AF recurrence after 12 months. No complications related to SVC isolation were noted. 

Conclusions: In our series of repeat AF ablation procedures, the addition of empirical SVC isolation to PVI and LA substrate modification did not influence AF recurrence rate. This strategy can however be safe and useful in patients in whom SVC is identified as a trigger of AF.