Safety, workflow, and efficacy of atrial fibrillation ablation in women: pulsed field vs conventional thermal ablation

Abstract Background Women are typically underrepresented in randomized clinical trials, including those focused on atrial fibrillation (AF). The efficacy and safety of pulsed field ablation (PFA) compared to conventional thermal ablation in women have not been well established. Purpose To evaluate the acute efficiency, safety, and long-term outcomes of AF ablation in female-only patients using the Farapulse PFA system versus thermal-based technologies. Methods We conducted a retrospective study on consecutive female patients undergoing AF ablation and enrolled in the ATHENA-CHARISMA registries. Thermal ablation systems (radiofrequency ablation - RF - or cryoablation - Cryo -) were compared to all initial cases approached with the Farapulse PFA system. The ablation approach followed standard clinical practice, with additional lesions performed at the operator’s discretion. Results A total of 1402 female patients (mean age 64±10 years, mean LVEF 59.5±7%, 1058 (75.5%) with paroxysmal AF, 344 (24.5%) with persistent AF) were included: 682 (48.0%) underwent RF ablation, 429 (30.2%) Cryo ablation, and 291 (20.5%) PFA. The PFA group had significantly shorter procedural times (60 [54-80] min) compared to both RF (120 [90-150] min, p<0.001) and Cryo (90 [60-100] min, p<0.001). Fluoroscopy time was lower in the RF group (13.1 [8.4-20] min) compared to both PFA (15 [11-20] min, p=0.0014) and Cryo (15.7 [11-20] min, p=0.0001). Time to PVI was similar between PFA (19 [13-25] min) and RF (18 [11-26] min, p=0.834), but higher in Cryo (22 [16-31] min, p=0.001 vs RF, p<0.001 vs PFA) cases. Overall complication rates were significantly higher with thermal ablation: 1.4% (n=6) with PFA, 4.4% (n=30) with RF (p=0.021 vs PFA), and 5.1% (n=22) with Cryo (p=0.0076 vs PFA). Complete follow-up information was available for 995 (71.0%) patients. During a median follow-up of 406 [349-571] days, 211 (21.1%) patients experienced AF recurrence (median time to recurrence 224 [143-342] days). The Kaplan-Meier estimated freedom from AF was 81.2% with PFA, 80.4% with Cryo, and 77.0% with RF (log-rank p-value: 0.411). Persistent AF patients had a higher AF recurrence rate than paroxysmal AF patients (28.9% vs 18.6%, p=0.0009; HR=1.72, 95% CI: 1.2 to 2.4, p=0.0002). No significant differences were observed among energy sources when separately analyzing paroxysmal and persistent AF patients. Conclusion In female patients undergoing AF ablation, pulsed field ablation resulted in significantly shorter procedural times and a lower rate of complications compared to conventional thermal ablation systems. Follow-up data showed similar rates of AF freedom across all ablation methods.