Cryoballoon Pulmonary Vein Isolation: Double Stack Vs Standard Ablation

Background: The results of pulmonary vein isolation (PVI) are limited by arrhythmia recurrence, which is most often due to failure to effectuate a durable contiguous circumferential transmural lesion around the pulmonary vein ostia.

Objective: We sought to determine if enhancing the index ablation line through the use of multiple cryoballoon diameters would be superior to standard ablation with bonus freeze.

Methods: We enrolled 226 consecutive patients referred for cryoballoon-based PVI. Patients underwent PVI either with the 28-mm Arctic Front Advance (Medtronic, Minneapolis, Mn) cryoballoon using two 4-minute freezes (standard group) or with the POLARx FIT (Boston Scientific, Marlborough, Ma) cryoballoon using 3-minute freezes in both the 28- and 31-mm-diameter configurations (double stack group). Patients were followed for up to 1 year. The primary outcome was atrial tachyarrhythmia recurrence, with peri-procedural complications, cardioversion, emergency department visit, hospitalization, and repeat ablation being secondary outcomes.

Results: A total of 226 patients were included (70% male; 47% with persistent atrial fibrillation [AF]). Patients in the double stack group had a significantly greater freedom from recurrent AF/atrial tachycardia/atrial flutter at 1 year (87.2% vs 68.9%; hazard ratio 0.41; 95% confidence interval 0.24-0.71; P=.008). Periprocedural complications were similar between the groups (5.2% vs 3.4%; P=.50). At 1 year, there was no difference in cardioversion (12.8% vs 20.3%; P=.20), emergency department visit (9.0% vs 15.5%; P=.22), or all-cause hospitalization (1.3% vs 2.7%; P=.66). Significantly less patients treated with double stack underwent repeat ablation (1.3% vs 13.5%; P=.002).

Conclusion: In a mixed cohort of patients with paroxysmal and persistent AF, cryoballoon ablation using the double stack technique is associated with lower rates of AF recurrence, aggregate healthcare utilisation, and lower rates of repeat ablation.