Cryoballoon ablation reduces PV automaticity retention compared to radiofrequency ablation in PAF

This randomized controlled trial compared cryoballoon ablation (CBA) with radiofrequency ablation (RFA) in 100 consecutive patients with paroxysmal atrial fibrillation (PAF) undergoing initial catheter ablation. Fifty patients were assigned to each group. The primary outcome was atrial tachyarrhythmia recurrence; secondary outcomes included pulmonary vein (PV) automaticity, PV excitability, ipsilateral PV crosstalk, local capture, fluoroscopy time, and ablation time. Follow-up occurred at 3, 6, and 12 months with an average of 13 months.

Results showed that PV automaticity retention was significantly higher in the RFA group (33/50, 66%) compared to the CBA group (17/50, 34%) (p = 0.027). The number of PVs exhibiting stable automaticity was also higher with RFA (51/198 vs 19/197, p < 0.0001). Ipsilateral PV crosstalk was more common in the RFA group (7/17 vs 0/2), but this did not reach statistical significance (p = 0.5088). Local capture with low-frequency pacing occurred in 46% of RFA patients versus 2% of CBA patients (p < 0.0001).

Fluoroscopy time was shorter with RFA (p = 0.0003), while ablation time was longer with RFA (p < 0.0001). Despite these differences, atrial tachyarrhythmia recurrence rates were similar between groups. Safety data, including adverse events and tolerability, were not reported.

Limitations include the lack of reported safety outcomes and the relatively small sample size. The similar recurrence rates suggest that the observed electrophysiological differences may not translate into improved clinical outcomes. Clinicians should interpret these findings cautiously when choosing ablation modality for PAF.