A Prospective Study of REPeat Ablation In Patients With Recurrent PERSistent Atrial Fibrillation: Pulmonary Vein Isolation vs. Adjunct Posterior Wall Isolation (REPAIR PERS-AF Study)

This study aims to find a optmal strategy for repeat ablation for recurrent persistent AF after previous persistent AF ablation involving only PVI. PVI is an evident and well documented target for AF ablation. Many other ablation approaches beyond PVI have been reported. PWI is one of the frequently applied methods. However, this appoach has not been studied in randomized clinical trials for recurrent persistent AF after index procedure, thus evidence is demanded for guidance of clinical practice for AF ablation.

The purpose of this study is to clarify this matter by comparing PVI alone strategy with the approach of PVI plus PWI in patients with recurrent persistent AF after index ablation procedure. Since previous clinical studies have shown better outcomes of ablation among patients with normal left atrium (LA) than those with sick LA, ablation strategies in this study will be selected based on voltage mapping of the LA, avoiding unnecessary ablation applications.

The investigators hypothesize that PVI is good enough for patients with normal LA (normal voltage ≥0.5 mV); Among patients with low voltage/scar (voltage \< 0.5 mV), PVI plus PWI is superior to PVI alone.

This study is a prospective, multi-center, open-labeled, partly randomized study. After enrollment, patients will receive a voltage mapping of the LA which is routine for all AF ablation procedures. Based on the mapping results, patients will be stratified into two strata, normal voltage (≥ 0.5 mV) and low voltage (\< 0.5 mV) in the LA posterior wall. Patients with normal voltage in the LA posterior wall will be directly assigned to arm 1 receiving PVI alone treatment (avoid unnecessary ablation of healthy myocardium). Patients with low voltage will be 1:1 randomized in arms 2 and 3 receiving either PVI alone or PVI + PWI treatment.

1. Arm 1: Normal voltage in LA posterior wall - PVI alone 2. Arm 2: Low voltage in LA posterior wall - PVI alone 3. Arm 3: Low voltage in LA posterior wall - PVI + PWI

Three Norwegian University Hospitals, including Haukeland University Hospital, Bergen, St. Olavs Hospital, Trondheim, and University Hospital of North Norway, Tromsø, will participate in this study. The study is expected to last 3 years, 24 months for enrollment and each patient will be followed for a period of 12 months.

In order to minimize bias, subjects will be randomized next to the LA mapping. Patients will be analyzed according to their initial randomization, that is intention-to-treat, even if they never start the treatment, or discontinue, or cross over the group.

Patents will be followed in out-patient clinic at 3, 6 and 12 months after the treatment.

• Complications and adverse events [Time frame: 12 months]
• Procedure time [Time frame: During the procedure]
• Ablation time [Time frame: During the procedure]
• Fluoroscopy time [Time frame: During the procedure]
• Quality of life assessment 1 [Time frame: 12 months]
• Quality of life assessment 2 [Time frame: 12 months]
• Frequency of atypical atrial flutter [Time frame: 12 months]