Abstract Body (Do not enter title and authors here): Background: Cryoballoon ablation has been shown to be non-inferior to radiofrequency ablation in terms of efficacy and safety for atrial fibrillation (AF). However, the outcomes of newer cryoballoon ablation systems, such as PolarX, in patients with AF remain unclear.
Research Questions: This study aimed to assess whether the PolarX cryoballoon ablation system offers superior AF-free survival and fewer complications compared to the established Arctic Front Advance Pro (AFA-Pro) system, particularly in patients with persistent AF.
Methods: This retrospective cohort study included 217 consecutive patients diagnosed with AF who underwent cryoballoon ablation using either the AFA-Pro or PolarX systems at a single high-volume tertiary hospital between March 2023 and February 2024.
Results: Patients were divided into two groups based on the cryoballoon ablation system used: the AFA-Pro group (n=100) and the PolarX group (n=117). Among those with persistent AF (n=68), there were 32 in the AFA-Pro group and 36 in the PolarX group. In the total patient cohort, the PolarX system did not significantly improve AF-free survival compared to the AFA-Pro system [hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.32-1.25; p=0.18]. However, in the subgroup of patients with persistent AF, the PolarX system significantly improved AF-free survival compared to the AFA-Pro system (HR 0.26, 95% CI 0.08-0.80; p=0.01). The PolarX system was associated with a higher incidence of transient phrenic nerve palsy (PNP) compared to the AFA-Pro system [odds ratio (OR) 2.37, 95% CI 1.00-5.65; p=0.05], though it was not associated with permanent PNP. There were no significant differences in the rates of complications such as esophageal injury, cardiac tamponade, or vascular complications. Predictors of AF recurrence post-ablation included persistent AF (HR 2.80, 95% CI 1.41-5.56; p=0.01) and left atrium volume index (LAVI) (HR 1.03, 95% CI 1.00-1.06; p=0.04).
Conclusion: The PolarX cryoballoon ablation system demonstrates comparable safety and efficacy to the AFA-Pro system in treating atrial fibrillation. The PolarX cryoballoon ablation system is associated with better AF-free survival compared to the AFA-Pro system in patients with persistent AF. LAVI may be a predictor of AF recurrence post-cryoballoon ablation.