Background: The fourth generation arctic front cryoballon (AF-CB4) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging clinical outcome data. The POLARx cryoballoon 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 novel POLARx cryoballoon in comparison to the AF-CB4.

Methods: A total of 47 consecutive patients with paroxysmal or persistent atrial fibrillation (AF) were prospectively enrolled, underwent POLARx based PVI (POLARx group) and were compared to 48 consecutive patients previously treated with the fourth generation AF-CB (AF-CB4 group).

Results: A total of 188 (POLARx) and 192 (AF-CB4) pulmonary veins (PV) were identified and all PVs were successfully isolated utilizing the POLARx and AF-CB4, respectively. A significant difference regarding the mean minimal cryoballoon temperatures reached using the AF-CB4 and POLARx (-50±4°C vs. -56±6°C, p<0.01) was observed. Real-time PVI was visualized in 79% of POLARx patients and 48% of AF-CB4 patients (p<0.001). Utilizing the POLARx a shorter median procedure time (POLARx: 47 (33, 52) minutes vs. AF-CB4: 56 (48, 62) minutes (p<0.01) was found. No differences were observed for periprocedural complications. A total of 3/47 patients of POLARx group and 5/48 of AF-CB4 group were lost to follow-up (p>0.05). The one-year recurrence free survival was: POLARx: 36/45 patients (80%) and AF-CB4: (33/43 (77%), p>0.05.

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