Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Catheter ablation using pulmonary vein isolation (PVI) in an established treatment strategy for AF. Pulsed Field Ablation (PFA) is a non-thermal ablation modality which has recently been introduced in clinical practice with the aim of improving PVI efficacy and safety. The aim of this study is to analyse whether PFA generates a lower inflammatory reaction as compared to conventional radiofrequency ablation (RFA).

Pulmonary vein isolation represents the cornerstone of AF ablation. PFA is a novel non-thermal cardiac ablation modality which is currently studied in clinical trials for the treatment of AF with promising efficacy and safety results. PFA is reported to generate less collateral damage by inducing selective apoptosis of cardiomyocytes, while other structures such as nerves, vessels and oesophageal tissue remain spared. PFA lesions show more organized and homogeneous fibrosis on histopathological study as compared to thermal lesions. In a recent study conducted at Hôpital Haut-Lévêque, PFA was associated with 20% less acute oedema on magnetic resonance imaging. Therefore, PFA may generate a reduced inflammatory reaction which could translate into lower early recurrence rates, less post-procedural chest pain and improved clinical outcomes. Data on the systemic inflammation generated by PFA and RFA is still lacking.

The aim of this study is to analyse the inflammatory reaction after PFA and RFA in patients referred for first-time catheter ablation of paroxysmal AF. For this purpose, established biomarkers of systemic inflammation (leucocytosis, platelet-monocyte-complexes, inflammatory cytokines) will be determined in blood samples collected from patients treated with either PFA or RFA.

The collection of blood samples will be exclusively performed during routine blood drawing at three time points: at the beginning of the procedure (to define baseline values), at the end of the procedure (to measure acute inflammation) and the day following the procedure (to define inflammation occurring within 24 hours). Clinical signs of inflammation (fever, chest pain, pericardial fluid) and early arrhythmia recurrences will also be assessed the day after the ablation. On a routine 6-month follow-up visit, late arrhythmia recurrences will be registered. In a secondary analysis, the thrombogenic and pro-arrhythmogenic potential of both ablation modalities and the predictive value of inflammatory biomarkers for early and late recurrences will be assessed.

Inclusion Criteria:

• Age ≥ 18 years
• Patients with paroxysmal AF referred for first-time catheter ablation using PFA or RFA
• Non-opposition to participate

Exclusion Criteria:

• Age < 18 years
• Persons under judicial protection (guardianship, guardianship) or deprived of freedom
• Prior left atrial ablation
• Prior cardiac surgery comprising incision of the left atrium
• Prior myocardial infarction or stroke in the previous 30 days
• Acute or chronic inflammatory state: active smoking, auto-immune disease, active tumor disease, myocarditis
• Antiplatelet therapy (e.g. aspirine, clopidogrel) within the 7 last days
• Anti-inflammatory treatment (e.g. glucocorticoids, colchicine, cyclophosphamide, azathioprine, mycophenolic acid, antibodies) within the 7 last days

Patients with atrial fibrillation treated by catheter ablation