Electrophysiology Fellow Queen's University Kingston, Ontario, Canada
Background: Catheter ablation is a well-established treatment for atrial fibrillation (AF) and is superior to antiarrhythmic drugs (AADs). However, the outcomes are less favourable in patients undergoing repeat (REDO) catheter ablation.
Objective: To assess the acute and long-term outcomes of repeat catheter ablation for AF, including procedural complications and factors predicting arrhythmia-free survival.
METHODS AND RESULTS: A retrospective analysis of patients who underwent repeat catheter ablation for AF between 2018 and 2020. Collected data included baseline demographics, type of atrial AF, LVEF, left atrial dimensions, use of ADDs, and procedural details such as reconnection location, additional ablation lines, and acute complications. Follow-up data was gathered, focusing on atrial arrhythmia recurrences after a 3-month blanking period.
Among the 104 patients, the presenting rhythm at the time of the procedure was AF in 47.6%, sinus rhythm in 44.6%, atrial flutter in 4.8%, and atrial tachycardia in 3.0%. Vein reconnection rates were significantly higher for right-sided veins (87.5%) compared to left-sided veins (52.9%) (p < 0.001). The specific rates of reconnection by location were as follows: left superior pulmonary vein in 44.2%, left inferior pulmonary vein in 41.4%, right inferior pulmonary vein in 71.2%, and right superior pulmonary vein in 81.7%. Additionally, 62.5% of patients had reconnections in two or more veins.
Non-pulmonary triggers were identified in 26% of patients, and 58.5% required further ablation beyond pulmonary vein isolation (PVI). These additional ablations targeted areas such as the posterior wall (34.3%), roof line (12.5%), cavotricuspid isthmus line (26%), and mitral isthmus line (15%).
The mean follow-up period after ablation was 18.1 ± 12.4 months, during which 29.8% of patients experienced recurrence. A comparative analysis of the recurrence and no-recurrence groups is shown in Table 1. Interestingly, there was no significant difference in recurrence rates between right- or left-sided vein reconnections (Fig 1). The only significant predictor of recurrence following a REDO PVI was an enlarged left atrium, with LA volume being higher in the recurrence group (42.9 ± 12.3 vs. 35.3 ± 12.1 mL/m², p = 0.04).
Conclusion: Pulmonary vein reconnection remains the most common cause of recurrent arrhythmia after ablation, with right venous reconnections predominating. In half of the patients, an additional ablation beyond PVI was performed, although extrapulmonary triggers were identified in only 26% of these cases. After a repeat procedure, 70.2% of patients were free of atrial arrhythmias, with left atrial enlargement being the only significant marker identified for recurrence.
