Background:
The value of cryoballoon ablation (CB) for paroxysmal atrial fibrillation (AF) has been well established, however, safety and efficacy of CB in persistent AF (PerAF) is less known.

Material and methods:
We aimed to assess efficacy of CB in PerAF in comparison to RF ablation and to identify predictors of successful CB ablation in PerAF performed in a medium volume centre. Of 303 AF ablations, 92 (30%) procedures were done in patients with PerAF: 38 CB (mean age 58±9 years, all first-time procedures) and 54 RF ablations of which in 18 (33%) patients (mean age 57±12 years) this was the first-time procedure. The patients were prospectively followed (mean 13 ± 7 months) by repeated Holter ECG and outpatient visits.

Results:
After first-time procedure, recurrences of AF were noted in 13 (34.2%) patients from the CB group and in 15 (83.3%) from the RF group (p <0.0006). None of analysed CB procedural parameters predicted the outcome. Of 12 CB patients with recurrences, 4 patients underwent repeated successful RF ablation, resulting in 78% efficacy after two procedures. Of 15 RF patients with unsuccessful first ablation, 4 had second successful RF ablation (38.8% efficacy after 2 procedures) and another 2 have partial improvement (50% efficacy when these patients are included). The remaining patients are waiting for redo procedure.

Conclusions:
CB of PerAF as an initial ablation attempt is safe, relatively effective (65.8%) and may be successfully performed in a medium volume centre. When recurrences occur, second RF-based procedure increases the overall success rate to 78%.