Recurrence of Atrial Fibrillation After Cryoballoon Ablation in Women Is Less Pulmonary Vein Mediated as Compared to Men: Lessons From Repeat Ablation Procedures.

Background: Data on sex-related outcomes of pulmonary vein isolation (PVI) of cryoballoon ablation (CBA) in atrial fibrillation (AF) are sparse.

Aim: To compare sex-differences in PV reconnection, strategy and outcome of repeat ablations after CBA.

Methods: Repeat procedures were performed using radiofrequency ablation guided by 3D mapping. PV reconnection characteristics were compared in 229 patients (77 (33.6%) females). In durable PVI patients, we compared left atrial voltage maps, ablation strategy and 1-year outcome. Clinical success was defined as freedom of documented AF or atrial tachycardia (AT) > 30 s.

Results: Female patients had a lower overall number of PV reconnections (0.8 ± 0.9 vs 1.2 ± 1.0, p < 0.001) driven by less reconnected left PVs: 13/77 (16.9%) vs 51/152 (33,6%), p = 0.008 and 7/77 (9.1%) vs 39/152 (25.7%), p = 0.003 for LSPV and LIPV, respectively. Durable PVI was more frequent in women (34/77 (44.1%) vs 37/152 (24.4%), p = 0.001). Female sex was the only independent predictor for durable PVI (HR = 2.003; 95% CI 1.090-3.682; p = 0.025). In durable PVI patients, substrate ablation was more frequently performed in women (21/35 (60%) vs 13/35 (37.1%), p = 0.044), mainly targeting the higher prevalent atrial low-voltage zones (21/35 (60.0%) vs 12/36 (33.3%), p = 0.017). At 1 year, recurrence of AF/AT did not differ between sexes: 6/35 (17.1%) versus 8/35 (22.9%), p = 0.591.

Conclusions: The higher persistence of durable PVI in women points to a sex difference in AF recurrence driver after CBA. In durable PVI patients, a higher prevalence of low-voltage regions results in more substrate ablation in women. Despite sex differences in ablation strategy, 1-year outcome was similar.