Sex differences in escalation to atrioventricular node ablation following catheter ablation for atrial fibrillation

BACKGROUND: Sex-based differences in atrial fibrillation (AF) symptom burden and response to rhythm control strategies are recognised. Whether female and male patients differ in escalation to atrioventricular (AV) node ablation after AF catheter ablation remains uncertain. OBJECTIVE: To evaluate sex differences in AV node ablation following AF ablation in a large real-world cohort. METHODS: Adults undergoing first-time AF ablation between 2015 and 2024 were identified from a global federated research network. Patients with prior AV node ablation or cardiac implantable electronic devices were excluded. Female and male patients were compared before and after 1:1 propensity score matching for demographics, AF type, heart failure phenotype, co-morbidities, medication use and prior cardioversion. The primary outcome was AV node ablation within 5 years. Secondary outcomes included repeat AF ablation, electrical cardioversion and all-cause mortality. Pre-specified falsification endpoints (pneumonia and intestinal obstruction) were assessed to evaluate residual confounding. RESULTS: Before matching (28,004 female; 52,137 male), AV node ablation occurred in 2.5% of female and 1.1% of male patients (risk ratio [RR] 2.31, 95% CI 2.07-2.58). After matching (24,377 female and 24,377 male), baseline characteristics were well balanced, yet AV node ablation remained more frequent in female than male patients (2.3% vs. 1.2%; RR 1.94, 95% CI 1.68-2.23). Female patients were also more likely to undergo repeat AF ablation (14.7% vs. 14.1%; RR 1.04, 95% CI 1.01-1.08), whilst mortality was modestly lower (4.5% vs. 4.9%; RR 0.91, 95% CI 0.84-0.99; p = 0.027). Falsification endpoints did not differ between groups after matching. CONCLUSION: Female patients were more likely than male patients to undergo AV node ablation following AF ablation despite robust adjustment, suggesting important sex-based differences in downstream AF management.