Background:

Pulmonary vein isolation for atrial fibrillation is a hallmark of atrial fibrillation treatment and can be achieved by a variety of methodical approaches. While thermal ablation modalities, such as cryoballoon ablation, have been established as the standard of care over the past years, lately, pulsed field ablation has been suggested as a novel non-thermal tissue-specific ablation modality for pulmonary vein isolation. However, data comparing periprocedural and rhythm outcomes of patients undergoing pulmonary vein isolation for atrial fibrillation by either cryoballoon ablation or pulsed field ablation are sparse.

Aim:

This studies aim was to compare the efficacy and safety of pulsed field ablation and cryoballoon ablation for atrial fibrillation.
Methods:

Consecutive patients undergoing either pulsed field ablation or cryoballoon ablation for atrial fibrillation at our institution were included. The primary endpoint was time to death or recurrence of atrial fibrillation. Secondary endpoints were periprocedural complications and symptoms, left atrial volume index (LAVI) and NT-pro BNP serum levels at the end of follow-up.

Results:

We included 141 consecutive patients suffering from atrial fibrillation who underwent either pulsed field ablation (PFA group, 94 patients) or cryoballoon ablation (CB group, 47 patients) for atrial fibrillation.

Patients had a mean age of 63 years and were predominantly male (66.4%). Patients in the PFA group were more often diagnosed with arterial hypertension (PFA group: 73 out of 94 patients, CB group: 26 out of 47 patients; p=0.006) while patients in the CB group were more likely to suffer from diabetes mellitus (PFA group: 16 out of 93 patients, CB group: 15 out of 47 patients; p=0.048)

After a mean follow-up of 198 days there was no significant difference in survival without AF recurrence between the PFA- and the CB group (HR: 1.35, 95% CI 0.60-3.00; p=0.470). At the end of follow-up 84% of the PFA group and 77% of the CB group with paroxysmal AF, and 50% of the PFA group and 50% of the CB group with persistent AF were still free from AF. There was no significant difference in periprocedural complications (p=0.804). Apart from a lower use of contrast dye in the PFA group, there were no significant differences in the procedural parameters.

Remarkably, we observed decreased NT-pro BNP levels (PFA group baseline: 1106 ± 2479 pg/ml, PFA group follow-up: 1033 ± 1742 pg/ml; p=0.011), and a decrease in LAVI (PFA group baseline: 40 [31; 62], PFA group follow-up: 35 [29; 49]; p=0.015) in the PFA group at the end of follow-up, while there were no significant differences in the CB group.

Conclusion:

Here we show that pulsed field ablation (PFA) and cryoballoon ablation (CBA) pulmonary vein isolation in atrial fibrillation patients are both safe and of similar efficacy regarding recurrence of atrial fibrillation. However, we found that PFA, but not CBA, was associated with a decrease in NT-proBNP levels and left atrial volume index, suggesting that PFA rather than CBA induces left atrial reverse-remodeling. Possibly, this finding is related to the tissue-specific effects of PFA thereby avoiding collateral damage during ablation. Further studies have to verify our hypothesis.