ABC | Volume 110, Nº5, May 2018

Original Article Odozynski et al Gender and AF ablation Arq Bras Cardiol. 2018; 110(5):449-454 Table 2 – Results of the procedures: Efficacy and safety Variables Men (n = 161) Women (n = 64) p-value N°. of procedures 195 77 - Complications * 5 (3%) 2 (3%) 0.98 Length of stay 2.5 ± 0.7 days 2.1 ± 0.8 days 0.76 Recurrence 34/161 (21%) 13/64 (20%) 0.89 Values with ± indicate mean and standard deviation; * Men: 3 inguinal pseudo-aneurysms, 1 inguinal hematoma and 1 urethral trauma (bladder catheter). Women: 1 inguinal hematoma and 1 retroperitoneal hematoma; there were no deaths. Student’s t-test and χ 2 . P-value indicates a statistically significant difference at the level of 5% of men and women who underwent paroxysmal AF ablation during the study period. Regarding the mean age, women undergoing catheter ablation were older than men (57 ± 11 M x 62 ± 9 W p < 0.01) but there was no difference between groups in relation to body mass index (BMI) and left atrium anteroposterior diameter, although a smaller LV ejection fraction, possibly without clinical relevance, was observed among males (63 ± 10% M x 66 ± 6% W p < 0.05). There was also no difference between genders regarding comorbidities such as hypertension, diabetes mellitus, heart failure, coronary disease and previous history of stroke/TIA. However, womenpresenteda higher CHADS2 score (0.9±0.8M x 1.2 ± 1 W, p = 0.04) and were more symptomatic than men according to the CCS-SAF score (1.8 ± 0.8 M x 2.3 ± 0.8 W p = 0.02). Between genders, there was no difference in the proportion of the use of ACE/ARA-2 inhibitors and antiarrhythmic drugs; however, women showed greater use of statins compared to men (27% M x 40% W p = 0.03 - Table 1). Efficacy and safety of procedures Recurrence rates after single ablation procedure were similar between groups (21%Mx 20%Wp=0.52). Table 2 summarizes procedures results as well as complications by gender. Therewere 3 inguinal pseudoaneurysms, 1 inguinal hematoma and 1 urethral trauma during bladder catheterization in men; among women, 1 inguinal hematoma and 1 retroperitoneal hematoma (5 (3%) M x 2 (3%) W p = 0.98) were observed. Despite prolonging hospitalization time, none of the complications required surgical intervention to be controlled. Throughout the study, atrium‑esophageal fistulas, pericardial effusions, TIA/stroke after ablation or death were not reported. The Kaplan-Meier curve (Figure 1) shows, throughout the study, gender equity in relation to recurrence rates, which occurred more frequently in first 12 months of follow-up, regardless of patient's gender. There was no difference in patients hospitalization time (days) categorized by gender (2.5 ± 0.7 M x 2.1 ± 0.8 W p = 0.76). Discussion Gender-specific differences may influence clinical and therapeutic behaviors in women with AF assistance. In a Canadian study, Singh et al. 16 characterized safety and efficacy equivalence and homogeneity of ablative procedure between men and women with persistent AF (post-hoc MAGIC-AF Trial), 16 guaranteeing its safety. In present study, in a current patients cohort with paroxysmal AF undergoing the first catheter ablation procedure, it is suggested that recurrence rates and complications are independent of patient's gender. These findings indicate that possible clinical considerations about safety and efficacy of ablative procedures in women with AF may be the main cause of ablation underutilization in female patients. Gender-related differences in cardiac rhythm pharmacological control are well described in literature. Women are more symptomatic by the CCS-SAF score and report a lower improvement in quality of life when submitted to drug treatment, compared to men. 17 In addition, female patients have a higher toxicity and intolerability rate to antiarrhythmic drugs than men, being more prone to Torsade de Pointes and need for pacemaker implants due to drug induced bradycardia. 17,18 Therefore, catheter ablation can be considered as an early alternative for treatment of women with AF; it is a therapeutic method superior to drug therapy in maintenance of sinus rhythm 19 with low complications rates in same proportion than men. It is speculated that there are biological differences in the mechanism of AF between men and women, that, in theory, could justify different results when they undergo ablation, but such hypothesis seems unlikely. In previous studies, Walters et al. 20 demonstrated left atrium and pulmonary veins electrophysiological characteristics similarity inmen andwomen. 20 Similarly; Pfannmuller et al. 21 verified that there were no specific differences between genders due toatrial remodeling inAF through the expression of amyloid, collagen or bound junctions. 21 In our study, the hypothesis that women in advanced age with AF present greater atrium electrical and structural remodeling and, consequently, worse post-ablation outcome, was not validated. The group of women was older thanmen and yet the time of diagnosis of arrhythmia is similar in both genders. In addition, left atrial diameter, a marker for post-ablation clinical recurrence, stroke, and death, 22,23 was similar in both groups. The fact that same clinical outcomes were observed in the long term between the groups also suggests that, in our study, there were no significant biological differences between men and women undergoing AF ablation. 24 Limitations In addition of being retrospective, the sample size may not have been sufficient to show differences between groups (M x W). The existence of selection bias in our cohort should also be considered, since only female candidates 451