Gender-related Difference in Clinical Outcome of the Patient with Atrial Fibrillation after Radiofrequency Catheter Ablation

Background and Objectives: Previous studies provided controversial result about gender differences in the clinical outcome after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). We assessed pure difference after adjustment of referral bias. Methods: The clinical outcomes including freedom from AF/atrial tachycardia (AT) recurrence after RFCA were compared between women and men in 1:1 confounding factor matching with age, AF type, periods since diagnosis (${\pm}12months$), and procedure era (${\pm}12months$). Subgroup analysis was performed in categories defined by AF type and age of 55 (mean menopausal age of Asian women). Results: Total 1,875 patients with AF underwent 2,307 RFCA between January 1998 and May 2014 in a single center. Total 367 women (19.6%, $59{\pm}10years$) who had undergone first ablation were included. Women had larger left atrial diameter index ($26{\pm}4$ vs. $23{\pm}4mm/m^2$; p<0.001) and higher peri-procedural complications (9.2% vs. 4.9%; p=0.030) compared to men. The freedom from AF/AT recurrence after RFCA was not different between both groups (71% vs. 76%; log-rank p=0.131, mean follow-up of 55 months). Women with non-paroxysmal AF (PAF) had significantly worse outcome (54% vs. 69%; p=0.014), especially in subgroup with age ${\leq}55$ (48% vs. 71%; p=0.010). In multivariate analysis, female gender was an independent predictor of recurrence in subgroup with non-PAF and age ${\leq}55$ (hazard ratio [HR], 2.539; 95% confidence interval [CI], 1.112-5.801; p=0.027). Conclusions: The clinical outcome after RFCA was not different between both genders regardless of referral bias. However, the gender difference became evident in patients under 55 years with non-PAF.