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

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.

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.

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).

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.