Distinct gender differences in the efficacy and safety of atrial fibrillation ablation: Insights from the Kansai plus atrial fibrillation registry in Japan

Background: There are significant differences in the prevalence and prognosis of cardiovascular diseases between men and women. However, only limited data are available regarding the impact of gender difference on the clinical outcomes of catheter ablation for atrial fibrillation (AF). Methods: We conducted a large-scale, prospective, multicenter, observational study named Kansai Plus Atrial Fibrillation ablation (KPAF) registry. A total of 5013 consecutive patients who underwent an initial AF ablation in 26 centers were enrolled (64.3plusminus10.3 years, non-paroxysmal AF; 35.6%). Results: Female patients (n=1370, 27.3%) were older (women vs. men, 67.8plusminus8.7 vs. 63.0plusminus10.6 years, p<0.001), and had higher CHADS2 score, lower prevalence of non-paroxysmal AF (27.1% vs. 38.8%, p<0.001) and smaller LA dimension (38.8plusminus6.8mm vs. 40.4plusminus6.6mm, p<0.001). Procedural complications were more frequent in women (4.5%vs 3.6%, p<0.001), mainly due to higher rate of bleeding events (0.58% vs. 0.21% p=0.04). The median followup duration was 2.9 years. The 3-year cumulative incidence of AF recurrence after a single procedure was higher in women than in men (44.3% vs. 41.0%, Log rank P=0.0044). After adjustment of baseline differences, female gender remained to be an independent predictor of AF recurrence (hazard ratio; 1.21, 95% confidence interval; 1.09-1.34, p<0.001). Furthermore, the rate of AF recurrence after multiple procedures was also higher in women (26.1% vs. 20.9%, p=0.0001). Conclusion: There were distinct gender differences in the efficacy and safety of AF ablation in the Japanese patient population. Women were associated with more unfavorable short- and long-term clinical outcomes in terms of higher rates of procedural complications and AF recurrence. We should consider these gender differences in the decision making of AF ablation in the real clinical practice.