Comparison of Cryoballoon Ablation Methods in Pulmonary Vein Isolation

Abstract

Background and Objectives: Cryoballoon ablation is a well-established therapy for atrial fibrillation (AF), enabling pulmonary vein isolation (PVI) using a single-shot technique. The two primary systems-Medtronic Arctic Front and the newer Boston Scientific POLARx-differ in design and performance characteristics, but few direct comparisons exist. This study aimed to compare the biophysical parameters and mid-term outcomes of the POLARx and Arctic Front cryoballoon systems. Materials and Methods: In a retrospective analysis of 200 patients who underwent cryoballoon ablation for paroxysmal or persistent AF, patients were grouped by ablation system: POLARx (n = 107) and Arctic Front (n = 93). Key parameters including nadir balloon temperatures, time to reach -40 °C, procedure duration, dose area product (DAP), complication rates, and recurrence of AF were assessed. Results: The POLARx system achieved significantly lower nadir temperatures in all pulmonary veins compared to Arctic Front (left superior PV: -57.6 ± 5.0 °C vs. -50.1 ± 5.7 °C, p < 0.001). Time to reach -40 °C was also shorter with POLARx (left superior PV: 23.3 ± 7.3 s vs. 33.3 ± 11.5 s, p < 0.001). Despite these advantages, procedure time was longer in the POLARx group (64.7 ± 14.8 min vs. 51.6 ± 19.7 min, p < 0.001). AF recurrence at 11.8 months was similar (33.6% in POLARx vs. 39.8% in Arctic Front, p = 0.93). Phrenic nerve palsy occurred in 5.0% (POLARx) and 4.3% (Arctic Front), with no cases of cardiac tamponade. Conclusions: While both systems demonstrated similar efficacy and safety, POLARx was associated with superior cooling kinetics and biophysical performance.

Keywords: atrial fibrillation; cryoballoon ablation; pulmonary vein isolation.

Figure 1

Freezing characteristics of each pulmonary vein on a time–temperature graph. The blue-colored lines refer to Boston Scientific POLARx (labeled as 1), while the green-colored lines refer to Medtronic Arctic Front (labeled as 2). LSPV—left superior pulmonary vein; LIPV—left inferior pulmonary vein; RSPV—right superior pulmonary vein; RIPV—right inferior pulmonary vein. The POLARx system achieved a steeper temperature drop within a shorter time than the Arctic Front system frame across all veins within the same freezing duration, reflecting quicker cooling dynamics.