Prospective evaluation of antral lesion size of the 31-mm size of a novel size-adjustable cryoballoon: Results of the BETTER-FIT study

Background

A novel size-adjustable cryoballoon can deliver cryotherapy with a 28- or 31-mm balloon size. However, data on antral lesion size with the 31-mm balloon size are scarce.

Objective

The purpose of this study was to evaluate the antral lesion size of cryoablation with the 31-mm balloon size.

Methods

This prospective single-center study included patients with paroxysmal atrial fibrillation undergoing first-time pulmonary vein isolation (PVI). All pulmonary veins (PVs) were first ablated with the 31-mm balloon size. The 28-mm balloon size was only used as bailout. Pre- and postablation left atrial ultrahigh-definition mapping was performed to assess the antral lesion area. Secondary outcome measures were procedural efficacy including balloon occlusion grade.

Results

Complete PVI was achieved in all 80 PVs in 20 patients (mean age 59.7 ± 10.7 years, 75% male). More than one-third of the posterior wall was ablated (35.4% ± 13.8%), and the isolated surface area was 68.7% ± 8.5%. Lateral and septal circumferential antral lesion areas were 12.1 ± 2.0 cm² and 19.1 ± 4.7 cm², respectively. One patient demonstrated inadvertent overlap of the antral lesions on the roof. There was a trend toward lower complete balloon occlusion in the right superior PV with the 31-mm balloon size in comparison to the 28-mm size (75% and 90%, P = .08).

Conclusion

Cryoablation with the 31-mm size of a novel size-adjustable cryoballoon results in a large antral lesion. In small atria there is the potential for leaving a small nonablated corridor on the roof when using the 31-mm balloon in both superior PVs, which may be proarrhythmogenic.