AF Cryoablation is an effective day case treatment: The United Kingdom PolarX versus AFA experience.

Abstract Background Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation for atrial fibrillation (AF). There are limited data on the PolarX Cryoballoon. Aims The study aimed to establish the safety, efficacy, and feasibility of same day discharge for Cryoballoon PVI. Methods Multi-centre study across 12 centres. Procedural metrics, safety profile and procedural efficacy of the PolarX Cryoballoon with the Artic Front Advance (AFA) Cryoballoon was compared in a cohort large enough to provide definitive comparative data. Results 1688 patients underwent PVI with cryoablation (50% PolarX and 50% AFA). Successful PVI was achieved with 1677 (99.3%) patients with 97.2% (n = 1641) performed as day case procedures with a complication rate of <1%. Safety, procedural metrics, and efficacy of the PolarX Cryoballoon was comparable to the AFA cohort. The PolarX Cryoballoon demonstrated a nadir temperature of 54.6 ± 7.6℃, temperature at 30-seconds of 38.6 ± 7.2℃, time to -40℃ of 34.1 ± 13.7 s and time to isolation (TTI) of 49.8 ± 33.2 s. Independent predictors for achieving PVI included time to reach -40 ℃ (OR 1.34; p < 0.001) and nadir temperature (OR 1.24; p < 0.001) with an optimal cut-off of ≤34 seconds (AUC 0.73; p < 0.001) and nadir temperature of ≤ -54.0℃ (AUC 0.71; p < 0.001) respectively. Conclusions This large-scale UK multicentre study has shown that Cryoballoon PVI is a safe effective day case procedure. PVI using the PolarX Cryoballoon was similarly safe, and effective as the AFA Cryoballoon. The cryoablation metrics achieved with the PolarX Cryoballoon were different to that reported with the AFA Cryoballoon. Modified cryoablation targets are required when utilizing the PolarX Cryoballoon.