The 31 mm cryoballoon mode achieved significantly higher complete pulmonary vein occlusion rates compared to the 28 mm mode (70.7% vs 56.7%, p=0.016).
Observational (n=150)
No
Does the 31 mm cryoballoon mode improve pulmonary vein occlusion compared to the 28 mm mode in patients undergoing ablation for atrial fibrillation?
The 31 mm cryoballoon mode significantly improves pulmonary vein occlusion rates compared to the 28 mm mode, particularly in superior pulmonary veins.
Odds Ratio: 2.41
Absolute Event Rate: 70.7% vs 56.7%
p-value: p=0.016
ABSTRACT Background Complete pulmonary vein (PV) occlusion is critical for successful cryoballoon ablation. The POLARx FIT size‐adjustable cryoballoon adjusts diameter from 28 to 31 mm. This study aimed to compare PV occlusion grades between balloon modes and identify anatomical predictors for optimal size selection. Methods This prospective study included 150 consecutive patients undergoing cryoballoon ablation for atrial fibrillation. PV occlusion was assessed using contrast injection (Grades I–IV) for both balloon sizes before ablation. Pre‐procedural computed tomography measurements included PV dimensions, ovality index, trunk length, and PV angles in frontal and transversal planes. Generalized Estimating Equations analysis accounted for within‐patient correlation. Results Complete occlusion in all four PVs was achieved in 106/150 patients (70.7%) with 31 mm versus 85/150 (56.7%) with 28 mm mode ( p = 0.016). Superior PVs demonstrated significantly higher occlusion rates (LSPV: 97.3% vs. 88.7%, p = 0.0002; RSPV: 93.3% vs. 71.3%, p < 0.0001), while inferior PVs showed no significant difference (LIPV: p = 1.000; RIPV: p = 0.070). GEE analysis identified 31 mm mode (OR 2.41, p < 0.001), smaller PV diameter (OR 0.59, p < 0.001), lower ovality index (OR 0.60, p < 0.001), and longer trunk length (OR 1.49, p = 0.001) as independent predictors of complete occlusion. Post hoc analysis revealed 3.3% of patients required different balloon sizes across their PVs. Acute PV isolation was achieved in all targeted PVs. Conclusion The 31 mm mode significantly improves occlusion rates, particularly in superior PVs, while 28 mm is adequate for inferior PVs. Larger PV diameter and higher ovality index predict incomplete occlusion, supporting preferential use of 31 mm mode for larger, more oval PVs. Validation in multicenter cohorts is required.
Yoshizawa et al. (2026) conducted an observational in Atrial fibrillation (n=150). 31 mm size-adjustable cryoballoon mode vs. 28 mm mode was evaluated on Complete occlusion in all four pulmonary veins (OR 2.41, p=0.016). The 31 mm cryoballoon mode achieved significantly higher complete pulmonary vein occlusion rates compared to the 28 mm mode (70.7% vs 56.7%, p=0.016).