Electrical Posterior Box Isolation in Repeat Ablation for Atrial Fibrillation A Prospective Randomized Clinical Study

OBJECTIVES This study investigated whether additional electrical posterior box isolation (POBI) may improve the rhythm outcome of repeat ablation in atrial fibrillation (AF). BACKGROUND Although electrically reconnected pulmonary veins (PVs) are the main mechanism of AF recurrence, it is unclear whether linear ablation in addition to circumferential PV isolation (CPVI) improves rhythm outcomes after repeat ablation. METHODS The authors prospectively randomized 150 patients with PV reconnection undergoing redo procedures to either a CPVI-alone group (n 75) or an additional POBI group (n 75). The primary endpoint was AF recurrence after a single procedure, and the secondary endpoints were recurrence pattern, cardioversion rate, and response to antiarrhythmic drugs. RESULTS After a median follow-up of 17 months, the clinical recurrence rate did not significantly differ between the CPVI-alone and additional-POBI groups (30.7% vs 30.7%; tog-rank P =0.828). Of the 46 patients with clinical recurrence, the recurrences as atrial tachycardia (8.7% vs 30.4%; P = 0.137) and cardioversion rates (21.7% vs 47.8%; P = 0.122) were not significantly different between the CPVI-atone and additional-POBI groups. Major complication rates did not differ between the 2 groups (1.3% vs 5.3%; P = 0.363), but the total ablation time was significantly longer in the additional-POBI group than in the CPVI-atone group (median: 1,084 [IQR: 704-1,664] vs 1,595 [IQR: 1,244-2302] seconds; P < 0.001). CONCLUSIONS Among patients undergoing redo AF ablation with reconnected PVs, the addition of POBI to CPVI did not improve rhythm outcomes or influence overall safety, whereas leading to a longer ablation time than that with CPVI atone. (C) 2022 by the American College of Cardiology Foundation.

Automated summary

This study found that adding POBI to CPVI did not improve rhythm outcomes or affect overall safety in patients undergoing redo AF ablation with reconnected PVs, but it led to a longer ablation time compared to CPVI alone.