Clinical outcomes of pulsed field versus radiofrequency ablation, incorporating posterior wall isolation, in persistent atrial fibrillation

BACKGROUND: Persistent atrial fibrillation (AF) remains challenging to treat with catheter ablation. The left atrial posterior wall (PW) may represent an important non-pulmonary vein (PV) substrate; however, randomised trials have not demonstrated improved outcomes with adjunctive PW isolation (PWI), potentially reflecting technical limitations of thermal ablation rather than a lack of mechanistic relevance. Pulsed-field ablation (PFA) is a non-thermal ablation modality that selectively targets myocardial tissue and may enable safer and more consistent PWI. We compared real-world outcomes of PFA and radiofrequency ablation (RFA) for combined PV isolation and PWI in patients with persistent AF. METHODS: 200 consecutive patients (100 PFA and 100 RFA) undergoing combined PVI and PWI were retrospectively followed for up to 12 months. Baseline characteristics were broadly similar; however, PFA patients had lower left ventricular ejection fraction (LVEF) (43.5% (35.5-55.5%) vs 47% (40-58), p=0.01) and higher CHA₂DS₂-VA risk score (3 (2-4) vs 2 (1-3), p=0.01). Primary outcomes were acute procedural success and freedom from recurrent atrial tachyarrhythmia (AT) at 6 and 12 months. RESULTS: PFA achieved near-universal PWI compared with RFA (99% vs RFA: 65%, p<0.005), with shorter procedure duration (106 vs 143.5 min, p<0.005), reduced left atrial dwell time (62 vs 98 min, p<0.005), and faster time to PVI and PWI (all p<0.005). Major non-vascular complications were uncommon (1.5%) and similar between groups. At 12 months, freedom from recurrent AT was higher with PFA (70% vs RFA 54%, p=0.03), with lower odds of first detected AT recurrence in adjusted time-to-event analysis (OR 0.46 (0.26-0.82), p=0.009). CONCLUSIONS: In this real-world cohort, PFA was associated with a higher rate of acute PWI and greater freedom from AT compared with RFA, without a signal of increased complications. Prospective randomised studies are needed to define the role of PWI delivered with PFA in patients with persistent AF, including those with reduced LVEF.