Strategies in Patients Undergoing Repeat AF Ablation (TRAP-AF)

The aim of the proposed research project is to compare the efficacy of three different ablation strategies in patients with atrial fibrillation (AF) who are undergoing their first repeat catheter ablation for recurrent AF.

Reconnection of the pulmonary veins (PV) is generally responsible for AF recurrence in most cases. However, in a growing subset of patients undergoing repeat ablation for recurrent AF, the PVs are chronically isolated and no other non-PV triggers of AF can be identified. The investigators have previously shown that empirically ablating at known common non-PV trigger sites for AF can improve arrhythmia free survival beyond PVI. The left atrial (LA) posterior wall is also increasingly being isolated in AF patients undergoing catheter ablation. However, long term arrhythmia free survival in AF patients undergoing LA posterior wall isolation is not consistently better than PVI alone. The objective of this study therefore is to assess whether performing empiric ablation of common non-PV trigger sites or achieving LA posterior wall isolation can improve arrhythmia free survival in AF patients who are undergoing repeat AF ablation and in whom the PV remain chronically isolated and/or do not demonstrate AF. The investigators propose to do this as prospective, randomized three arm study.

In all arms, patients are undergoing first redo AF ablation and the pulmonary veins are chronically isolated and no non-PV triggers elicited during provocation. Arm 1- Cavo-tricuspid isthmus (CTI) ablation with adjustment and/or optimization of antiarrhythmic drug regimen where possible (control arm)

In all arms, patients are undergoing first redo AF ablation and the pulmonary veins are chronically isolated and no non-PV triggers elicited during provocation. Arm 2-LA Posterior wall isolation by creation of a LA roof and floor line

In all arms, patients are undergoing first redo AF ablation and the pulmonary veins are chronically isolated and no non-PV triggers elicited during provocation. Arm 3-empiric ablation of common sites of non-PV triggers of AF in both the right and left atria.

Freedom from atrial arrhythmias off antiarrhythmic medications at 1 year after 1 repeat ablation procedure. Subjects are seen at 6 weeks, 6 months and 1 year post procedure with ECG at each visit and monitors at 6 months and one year to assess efficacy. Information regarding medications, health status, arrhythmia symptoms, and ECG and monitor results documented.

Composite: Freedom from atrial arrhythmias at 1 year after 1 repeat ablation procedure off antiarrhythmic medications; AF related interventions and hospitalizations (electrical cardioversion, increase or change in antiarrhythmic medication, repeat ablation, hospitalization for complication, etc). Subjects are seen at 6 weeks, 6 months and 1 year post procedure with ECG at each visit and monitors at 6 months and one year to assess efficacy. Information regarding medications, health status, hospitalizations (including repeat ablations and cardioversion), arrhythmia symptoms, and ECG and monitor results documented.

Inclusion Criteria: All patients undergoing first redo AF ablation who have chronically isolated pulmonary veins and no non-PV triggers with provocation testing (randomized intra-procedure). Exclusion Criteria: Patients in whom ≥1 PVs have reconnected and AF triggers can be elicited from the reconnected PV. Patients who demonstrated non-PV triggers for AF. Patients who have experienced arrhythmia recurrence post ablation where the recurrent arrhythmia is other than atrial fibrillation or typical atrial flutter Failure to obtain informed consent Patients with a mechanical mitral valve