Comparative Study of Arctic Front Advance Pro and POLARx Cryoballoons for Linear Ablation of the Left Atrial Roof

BACKGROUND: The effectiveness of cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to pulmonary vein isolation (PVI) using a novel cryoballoon catheter, POLARx, remains unclear. METHODS: This study compared the efficacy of LA roof line ablation and PVI using POLARx (Boston Scientific) or AFA-Pro (Medtronic) in 100 patients with persistent atrial fibrillation. The right superior pulmonary vein (PV) anchoring and raise-up techniques were consistently used for LA roof line ablation, and rapid right ventricular pacing was applied if the cryoballoon temperature did not reach -40°C. RESULTS: Complete conduction block at the LA roof could be obtained in all patients with POLARx and in 98.0% of patients with AFA-Pro. Rapid right ventricular pacing was needed in 64.0% of patients with AFA-Pro and in no patients with POLARx. During LA roof line ablation, the nadir cryoballoon temperature was significantly lower with POLARx than with AFA-Pro (right: -54.2°C ± 4.4°C vs. -46.0°C ± 5.4°C; central: -56.8°C ± 4.4°C vs. -45.7°C ± 4.8°C; left: -56.1°C ± 4.3°C vs. -46.1°C ± 5.7°C), and the cryoballoon temperature reached -40°C earlier with POLARx than with AFA-Pro (right: 30.8 ± 7.4 s vs. 74.1 ± 37.7 s; central: 28.2 ± 5.2 s vs. 62.9 ± 30.9 s; left: 29.8 ± 5.8 s vs. 69.6 ± 40.7 s). CONCLUSION: The nadir cryoballoon temperature with POLARx was approximately 10°C lower than with AFA-Pro, consistently dropping below -40°C during LA roof line CBA. Thus, a complete conduction block of the LA roof line can be easily accomplished using right superior PV anchoring and the raise-up techniques without the need for rapid right ventricular pacing with POLARx.