A recent randomized controlled trial examined if the addition of electrical posterior box isolation (POBI) to circumferential pulmonary vein isolation (CPVI) could improve outcomes of redo ablations in patients with reconnected pulmonary veins (PVs). The researchers, led by Daehoon Kim, MD, reported that CPVI with POBI, compared to CPVI alone, “did not improve rhythm outcomes or influence overall safety,” and actually had a longer ablation time.
The study, published in JACC Clinical Electrophysiology, randomized 150 prospective patients with PV reconnection who were undergoing redo procedures to either a CPVI with POBI group (n = 75) or a CPVI-alone group (n = 75). The primary endpoint of the trial was atrial fibrillation recurrence after one procedure, while secondary endpoints included recurrence pattern, cardioversion rate, and response to antiarrhythmic drugs.
The results showed that the rate of recurrence was not significantly different between the two treatment groups (30.7% vs. 30.7%; p = 0.828) after a median follow-up of 17 months. The authors also noted that, among the 46 patients with clinical recurrence, recurrences presenting 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 groups. The rate of major complications was similar between the groups (1.3% vs. 5.3%; p = 0.363); however, the total ablation time was significantly longer in the combination intervention group (median = 1,084 [interquartile range (IQR): 704–1,664] vs. 1,595 [IQR: 1,244–2,302] seconds; p < 0.001).
Ultimately, Dr. Kim and colleagues deemed that the addition of POBI appeared to be more of a detriment than an advantage in patients with reconnected PVs undergoing redo ablations for atrial fibrillation.