One-Year Success Rates of a Stable, Low Pressure Cryoballoon for the Treatment of Paroxysmal Atrial Fibrillation: Results of the Prospective, International, Multicenter POLAR ICE Study.

Introduction: Pulmonary vein isolation (PVI) using a cryoballoon is well-established for the treatment of paroxysmal atrial fibrillation (PAF). Compared to other available technologies, the usage of a stable, low-pressure cryoballoon (POLARx, Boston Scientific) has demonstrated lower nadir temperatures and longer thawing times. However, 1-year efficacy and safety still needs to be proven. The aim of the POLAR ICE Study was to evaluate 1-year efficacy and safety outcomes of cryoballoon ablation in patients with paroxysmal atrial fibrillation.

Methods: POLAR ICE, a prospective, non-randomized, international, multicenter study to examine safety and efficacy of the novel cryoballoon for paroxysmal atrial fibrillation and de novo PVI, enrolled 399 patients across 19 centers, between August 2020 and May 2021, of which 11 were redo patients (previous treatment in the LA) and 10 were non-PAF patients.

Results: This study treated 391 patients with the novel cryoballoon. After 12 months, freedom from atrial fibrillation could be demonstrated in 88.1% and freedom from any arrhythmia in 83.5%. Long-term primary composite safety events occurred in four (1.0%) patients, including one (0.26%) death (9.5 months post-index, cause unknown), one (0.26%) stroke, one (0.26%) myocardial infarction, and one (0.26%) persistent PNP (0.26%). AAD usage showed a significant decrease over the course of the study. Biophysical parameters nadir temperature (p = 0.008) and thaw time (p = 0.053) were predictive of 12-month freedom from recurrence.

Conclusion: In this prospective, non-randomized, international, multicenter study, isolation of the pulmonary veins using a stable, low pressure cryoballoon was highly effective and safe in patients treated for paroxysmal atrial fibrillation.