1Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie Hamburg, Deutschland
Background: Pulsed-field ablation (PFA) is a new energy source integrated into single-shot devices enabling pulmonary vein isolation (PVI) during atrial fibrillation (AF) ablation. It has been demonstrated that PFA is noninferior to conventional thermal ablation. Conceptually, PFA preferentially damages cardiomyocytes and our prior data show that PFA causes less damage to neuronal tissue and reduced autonomic dysfunction than CBA. Here, we analyzed heart rate variability (HRV) as an additional parameter of intracardiac nervous system and whether the damage to neuronal tissue quantified by biomarker release and functional parameters might influence the recurrence rate of atrial fibrillation in PFA and CBA treated patients.
Methods: We prospectively included consecutive patients with paroxysmal AF undergoing index PVI applying PFA (n=65) or CBA (n=112). We quantified the ablation-dependent effect on intracardiac autonomic nervous system by comparing resting heart rate (HR), HRV and circulating concentrations of the neuronal biomarker S100B. Recurrent AF was detected using Holter ECGs, wearables and telephone interviews.
Results: Baseline characteristics did not differ between PFA and CBA (age 66 vs. 68 years, female 33% vs. 39%, CHADS-VASc Score 2.1 vs. 2.2, indexed LA volume 32 vs. 31 ml/m², BMI 27.3 vs. 27.4 kg/m²). After CBA-based PVI, HR increased (pre 63 vs. post 70 bpm, p<0.001) and HRV decreased (SDNN pre 54 vs. post 26 ms, p=0.007). After PFA-based PVI, HR and HRV remained stable (HR pre 63 vs. 64 bpm, p=0.591; HRV SDNN pre 37 vs. post 36 ms, p=0.890). In a direct comparison, the HR-increase and HRV-decrease observed after CBA-based PVI was significant compared to PFA (0.8 vs. 7.3 bpm, p<0.001 and SDNN -1 vs. 29 ms, p=0.003). We reported previously that PFA induced less S100B release (28 ng/dl) than CBA (68 ng/dl, p<0.001) and that PV reconnection rates in ReDo procedure were similar between PFA (40%) and CBA (40%). 1 year follow-up revealed freedom of AF in 79% after PFA and 73% after CBA (p=0.230). Dividing patients in upper and lower half of HR increase and S100B release after PVI, patients showed no difference in recurrence rates after CBA.
Conclusion: These data suggest that neurocardiac damage near the pulmonary veins seems not to contribute to freedom of AF recurrences after PVI.