Sex differences in the efficacy of atrial fibrillation ablation according to the age: insights from a large-scale multicenter registry

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: We previously showed that females were associated with a higher risk of arrhythmia recurrence after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Whether age influences sex differences in terms of recurrence after CA of AF still remains unknown. OBJECTIVE: We sought to investigate the sex differences in the efficacy of RFCA of AF according to an advanced age. METHODS: We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry), enrolling 5010 consecutive patients who underwent an initial RFCA of AF at 26 centers (64±10 years; females, 27.3%; non-paroxysmal AF, 35.7%). The median follow-up duration was 2.9 years. RESULTS: The entire cohort was divided into either an age≥75 (n=790; females, 40.3%) and age < 75 years (n=4220; females, 24.9%). In the age≥75 group, the 3-year cumulative incidence of AF recurrences was identical between the sexes both after a single procedure (female vs. male, 38.1% vs. 40.7%, Log-rank P=0.39) and multiple procedures (22.3% vs. 21.6%, Log-rank P=0.96). On the other hand, in the age <75 group, females more frequently experienced AF recurrence than males both after a single procedure (female vs. male, 44.9% vs. 38.8%, Log-rank P=0.0003) and multiple procedures (24.7% vs. 19.3%, Log-rank P <0.0001). CONCLUSION: While the incidence of an arrhythmia recurrence after radiofrequency catheter ablation of AF was similar between the sexes in patients with an age≥75, females had a higher incidence of recurrence than males in patients with an age <75. [Figure: see text] [Figure: see text]