ABC | Volume 110, Nº5, May 2018

Original Article Odozynski et al Gender and AF ablation Arq Bras Cardiol. 2018; 110(5):449-454 Procedures All patients underwent circumferential isolation of pulmonary veins (PVs) through irrigated catheter ablation with a 3.5 mm tip without contact forcemeasurement, using radiofrequency energy applications up to 35 Watts and 43°C per 10-45 seconds and demonstration of entrance and exit electrical blockade of PVs in relation to left atrium at the insulation end. All procedures were performed under general anesthesia, orotracheal intubation and invasive blood pressure monitoring by radial or left femoral puncture by the anesthesiologist. Transseptal punctures were performed with the help of intracardiac Eco, which was maintained throughout the procedure. Applications to left atrium posterior wall were monitored by an oesophageal thermometer with multiple covered sensors (Circa) and stopped whenever there was a change in esophageal temperature above 38°C. During all procedures, performed with an electro-anatomical mapping system based on thoracic impedance (EnSite Navx - Abbott), IV heparin bolus of 100mg / kg was performed followed by continuous infusion to maintain coagulation time activated between 350 and 450 sec. After the procedure, patients remained on antiarrhythmic drugs (propafenone, sotalol or amiodarone depending on preference of attending physician) for 1 month and anticoagulant for a 3 months minimum period regardless CHA2DS2-VASc. It was done clinical follow-up 1, 3, 6 and 12 months after the procedure, performing ECG and at least two Holters throughout all the clinical follow-up. At the 10th week after ablation, patients were encouraged to perform continuous electrocardiographic monitoring (Holter) for 5 days. Any atrial arrhythmia greater than 30 seconds documented duration after 1 month of blanking period indicated arrhythmia recurrence. 14 Symptoms severity before ablation and during eventual recurrences was characterized by the Canadian Cardiovascular Society Severity of Atrial Fibrillation score (CCS-SAF). 15 Statistical analysis Clinical characteristics and procedures were compared between genders (M x W). Recurrence rates after a single procedure, as well as complications were also compared between groups. A convenience sample (non-probabilistic) was adopted during the study time, respecting the inclusion/ exclusion criteria and follow-up time. Continuous variables were described as mean and standard deviation and compared using unpaired Student's t-test (two‑tailed), respecting the criteria of normality by the Shapiro-Wilk test. Categorical variables were described by absolute number and percentages in relation to total sample, and were compared using the χ ² test or Fisher's exact test. Level of statistical significance adopted was 5%. Kaplan‑Meier curve was used to evidence recurrence rates on the follow-up time and the Log-Rank test to evaluate difference between groups (M x W). Statistical analysis was performed using IBM SPSS Statistics Editor software, version 22.0. Results Patients 225 patients undergoing AF ablation were included in the study: 161 (71%) men and 64 (29%) women. Regarding follow-up time, there was no difference between men and women. Table 1 summarizes clinical characteristics Table 1 – Clinical characteristics of patients undergoing AF ablation, categorization by gender Variables Men (n = 161) Women (n = 64) p-value Age (years) 57 ± 11 62 ± 9 0.001* BMI 27 ± 3.7 27 ± 5 0.64 Ejection Fraction (%) 63 ± 10 66 ± 6 0.02* LA Diameter (mm) 38 ± 5 38 ± 5 0.93 CHADS2 0.9 ± 0.8 1.2 ± 1 0.04* CHF 12 (7%) 4 (6%) 0.73 SAH 85 (52%) 43 (67%) 0.06 Diabetes Mellitus 17 (10%) 11 (17%) 0.18 Coronary Artery Disease 25 (15%) 12 (19%) 0.44 Prior Stroke/TIA 6 (4% ) 5 (8%) 0.06 CCS SAF score 1.8 ± 0.8 2.3 ± 0.8 0.02* Statin Use 44 (27%) 26 (40%) 0.03 ACE/ARA-2 Inhib 66 (41%) 30 (46%) 0.25 Previous / current use of AA 134 (83%) 58 (90%) 0.21 Diagnostic time (months) 11 ± 12 14 ± 10 0.87 Follow-up time (months) 34 ± 17 (12 – 66) 33 ± 14 (13 – 64) 0.87 Values with ± indicate mean and standard deviation; CCS SAF: Canadian Cardiovascular Society Severity ofAtrial Fibrillation scale;ACE: angiotensin converting enzyme; ARA-2: Angiotensin 2 receptor antagonist; Student t test and χ 2 for independent samples. * p-value indicates a statistically significant difference at the level of 5%. 450