Prospective Evaluation of Superior Vena Cava Isolation as an Adjunct to Pulmonary Vein Re-Isolation During Paroxysmal Atrial Fibrillation Repeat Procedures.

Background: The superior vena cava (SVC) is a prominent non-pulmonary vein trigger of atrial fibrillation (AF). Its isolation has been shown to be effective in paroxysmal AF (PAF) originating from SVC.

Objective: In this study, focusing on repeat procedures for recurrent PAF post-PVI, we aimed to evaluate the added value of empirical SVC isolation to PV antral re-isolation, when at least one PV reconnection is demonstrated.

Methods: Patients with recurrent PAF referred for redo procedures, and exhibiting PV reconnection, were randomly assigned to undergo either PVI alone (group 1) or PVI and SVC isolation (group 2). The primary outcome was the recurrence rate at 1-year while procedural time, fluoroscopy time, complications rate, and the presence of scar during LA mapping were secondary outcomes.

Results: Eighty-two patients were randomized in the study (39 in group 1 and 43 in group 2). The median age was 65 ± 9 in group 1 and 62 ± 11 in group 2 (p = 0.3). The time from first AF episode to the repeat procedure was 76 and 52 months, respectively (p = 0.7). 31 patients in group 1 and 35 patients in group 2 had more than one reconnected vein. There were no significant differences in procedural and fluoroscopy times between groups. At 12-months, freedom from atrial tachyarrhythmia was achieved in 69% patients in group 1% and 76% patients in group 2 (HR 0.7, 95% CI: 0.3-1.7).

Conclusion: It is unknown whether empirical addition of SVC isolation to PVI improves freedom of recurrence for the treatment of recurrent PAF after previous PVI. Given the small study population, the addition of SVC isolation requires further investigation in a larger randomized trial.