Re-do ablation procedure characteristics after pulmonary vein isolation using pulsed field ablation for atrial fibrillation

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (PAF). A few small clinical studies and registries have reported an initial clinical success rate of approx. 80% after 1 year. Here, we present the results from re-do ablation after PVI using PFA for AF. METHODS: In symptomatic AF patients, re-do ablation in conscious sedation using a contact force sensing catheter and 45W RF energy was performed. In all patients, pre- and post-ablation high-density bipolar voltage 3D maps using a pentaspline diagnostic catheter were performed. Procedural parameters and acute success were assessed. RESULTS: Eighteen patients (age 67 years; 17% female; 56% PAF) from a total of 304 patients (age 67 years; 42% female; 47% PAF) (6%) treated with PFA as initial AF therapy underwent a re-do ablation 212 days after the index procedure. Mean CHA2DS2-VASc-score was 1,7 in the re-do group vs. 2,5 in the index procedure group. Mean duration since first AF diagnosis and BMI were not significantly different. In 12/18 (67%) patients, reconnection of at least 1 PV was found (LSPV 2x; LIPV 4x; RSPV 2x; RIPV 2x, left carina 4x; right carina 2x). All reconnected PVs were successfully reisolated. In 11/18 (61%) of patients, an atrial flutter (AFL) or tachycardia (AT) was identified (roof 5x; mitral isthmus 5x; anterior/septal 3x; cavotricuspid isthmus 5x). In 5/12 (42%) of patient with reconnection of at least 1 PV, AT/AFL occurred. In contrast, in all 6 patients (100%) with persistently isolated PVs AT/AFL occurred. All tachycardias were successfully ablated. CONCLUSIONS: Re-do ablation rate after PFA for AF was relatively low (6%), involving mostly male patients. PV reconnection rate was 67%, site of PV reconnection was predominantly left-sided. In 61%, predominantly left-sided AT/AFL occurred. Notably, in all patients with persistently isolated PVs AT/AFL was observed.