Impact on ganglionated plexi and arrhythmia recurrence of pulmonary vein isolation with pulsed field ablation compared to thermal energy

Pulmonary vein isolation (PVI) with thermal energy ablation is associated with an increase in heart rate (HR) after ablation due to concomitant modification of the ganglionated plexi (GPs), which may contribute to a reduction in arrhythmia recurrence. Pulsed-field ablation (PFA) is selective for the myocardium and has recently been shown to have only transient effects on the GPs. Whether this translates into a different risk of arrhythmia recurrence is still unknown.

To evaluate the effect of PFA versus thermal energy ablation on GPs and the impact on arrhythmia recurrence.

We retrospectively included consecutive patients with symptomatic paroxysmal AF who underwent first-time PVI with either the Pentaspline PFA ablation catheter or the Multielectrode Radiofrequency Balloon (RFB) catheter. Pre-ablation and 24-hour post-ablation ECGs in sinus rhythm were collected and analysed to assess resting HR. The effect of ablation on GPs was assessed by HR variation before and after ablation. Arrhythmia recurrence after ablation was defined as any atrial tachyarrhythmias (ATas) lasting >30 seconds occurring during follow-up after a 3-month blanking period.

A total of 117 patients (PFA group, n=49 vs. RFB group, n=68) were included in the analysis. Baseline patient characteristics were similar between the two groups (Figure 1). Procedure time was comparable, while fluoroscopy time was shorter in the RFB group (20 ± 8 vs 12 ± 8 minutes, p<0.001). Pre-ablation HRs in the PFA and RFB groups were 66 ± 10 bpm and 64 ± 11 bpm, respectively (p=0.6). At 24 hours post ablation, HR increased significantly more in the RFB group compared to the PFA group (14 ± 10 bpm vs 2 ± 7 bpm, p<0.001). After a mean follow-up of 14 ± 5 months, a total of 16 patients (14%) experienced ATas recurrence, with no difference between patients in the PFA and RFB groups (12% vs 15%, p=0.7; log-rank p=0.78, Figure 2).

Compared to thermal energy ablation, PVI with PFA is associated with a reduced effect on the GPs, as demonstrated by a lesser post-procedural HR increase. However, this did not translate into a different rate of arrhythmia recurrence at 1 year.

Baseline characteristics