De novo pulmonary vein isolation in women with paroxysmal atrial fibrillation: a comparison between pulsed field vs thermal ablation

Background Women are frequently underrepresented in studies investigating atrial fibrillation (AF) ablation. In addition, the comparative efficacy and safety of pulsed-field ablation (PFA) versus conventional thermal ablation techniques in women remain inadequately characterized. Purpose We evaluated the safety and long-term outcomes of de novo paroxysmal AF ablation in female patients using PFA versus thermal-based technologies. Methods Consecutive female patients with paroxysmal AF undergoing de novo pulmonary vein isolation (PVI), enrolled in the ATHENA-CHARISMA registries, were compared by means of a propensity score matching according to thermal ablation systems (radiofrequency [RF] or cryoablation [Cryo]) or the Farapulse PFA system (ratio 1:1:1). Results One-thousand one female patients (mean age 63±10 years, mean LVEF 60.8±6%) were included: 376 (37.6%) underwent Cryo ablation, 342 (34.2%) RF ablation, and 283 (28.3%) PFA. Propensity score matching yielded 684 patients (228 per group). The Kaplan-Meier estimated freedom from AF at 1-year follow-up was 84.9%, with similar rate between PFA and conventional thermal energy (Cryo and RF) and among energy sources considering separately: 86.8% with PFA vs 84% with thermal energy (log-rank p-value: 0.642); 84.6% with Cryo, and 83.3% with RF (overall log-rank p-value: 0.839). At multivariate logistic analysis adjusted for baseline confounders indexed left atrial volume was associated with AF recurrence (HR=1.03, 95%CI: 1.002 to 1.05, p=0.0328). Recurrence free-rate from atrial tachycardia/atrial flutter (AT/AFL) after the 90-day blanking period was 93.9%: 96.1% with PFA vs 92.8% with thermal energy (log-rank p-value: 0.185); 94.3% with Cryo (OR=0.68, 95%CI: 0.28 to 1.62, p=0.385 vs PFA), and 91.2% with RF (OR=0.43, 95%CI: 0.19 to 0.98, p=0.039 vs PFA), overall log-rank p-value=0.182 with a trend in favor of PFA vs RF, log-rank p-value=0.082. Overall complication rate was 3.4% and it was significantly higher after thermal ablation (4.6%) than PFA (0.9%, OR=5.5, 95%, CI: 1.3 to 23.5, p=0.0227). Conclusion In female patients with de novo paroxysmal AF, ablation using the Farapulse PFA system was associated with a lower complication rate compared to thermal ablation modalities. At the one-year follow-up, AF freedom rates were comparable across all ablation techniques. However, AT and AFL recurrences were twice as frequent in the RF ablation group compared to PFA, with a trend toward higher recurrence rates in the Cryo group compared to PFA.