Background: Catheter ablation with the cryoballoon (CB) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging clinical outcome data. The novel POLARx CB incorporates unique features, which may translate into improved safety, efficacy and outcome. The ICE-AGE 1 study aimed to assess efficacy, safety, and one-year clinical follow-up of the POLARx CB in comparison to the Arctic Front Advanced Pro CB (AF-CB4).

Methods: A total of 103 consecutive patients with paroxysmal or persistent atrial fibrillation (AF) who underwent POLARx based PVI (POLARx group) were prospectively enrolled and were compared to 102 consecutive patients previously treated with the AF-CB4 (AF-CB4 group).

Results: The mean age was 68.7 ± 10.2 (POLARx) and 65.7 ± 12 (AF-CB4, p = 0.0551) years. A total of 412 (POLARx) and 404 (AF-CB4) pulmonary veins (PV) were identified. All PVs, except for one PV in the POLARx group, were successfully isolated. A significant difference regarding the mean minimal CB temperature reached using the POLARx CB (-56.1 ± 8.3°C) and AF-CB4
(-46.9 ± 10.1°C) was observed (p<0.0001). Real-time PVI was visualized in 71% of PVs in the POLARx group and 46% of them in the AF-CB4 group (p<0.001). The mean procedure time was comparable: 54.5 ± 17.1 min for POLARx and 59.4 ± 18.6 min for AF-CB4 (p=0.0509). No differences were observed in terms of periprocedural complications. There were comparable rates in freedom of atrial fibrillation (AF) or atrial tachycardia (AT) recurrence after 12 months, beyond a 90-day long blanking period: 78.9% in the POLARx group vs. 77.2% in the AF-CB4 group (p=0.804).

Conclusions: The novel POLARx CB showed similar safety, efficacy and one year recurrence free survival rates compared to the AF-CB4. A higher rate of real-time electrical PV recordings and significantly lower balloon temperatures were observed using the POLARx as compared to AF-CB4.