Background: Studies have identified significant sex-based differences and disparities in the clinical presentation and treatment of atrial fibrillation (AF). Studies have shown women are less likely to be referred for catheter ablation, are older at the time of ablation, and are more likely to have recurrence after ablation. However, in most studies investigating AF ablation outcomes, the female cohorts were relatively small. The impact of gender on the outcome and safety of ablation procedures is still unclear. Objective: To investigate sex-based differences in outcomes and complications after AF catheter ablation, with a significant size female cohort Method: In this retrospective study, patients undergoing AF ablation from January 1, 2014, to March 31, 2021, were included. We investigated clinical characteristics, duration and progression of AF, number of EP appointments from diagnosis to ablation, procedural data, and procedure complications. Results: Total 1346 patients underwent first catheter ablation for AF during this period, including 896 (66.5%) male and 450 (33.4%) female patients. Female patients were older at the time of ablation (66.2y vs 62.4y; p<0.001). Women had higher CHA 2DS 2-VASc scores (3 vs 2; p<0.001) than men, expectedly, as the female sex warrants an additional point. 25.3% female patients had PersAF at the time of diagnosis vs 35.3% male patients (p<0.001). At the time of ablation, 31.8% female patients had PersAF as compared to 43.1% male patients (p<0.001), indicating progression of PAF to PersAF in both genders. Women tried more AADs than men before ablation (1.13 vs 0.98; p=0.002). Male and female patients had no statistically significant difference in (a) arrhythmia recurrence at 1-y post ablation (27.7% vs 30%; p=0.38) or (b) procedural complication rate (1.8% vs 3.1%; p=0.56). Conclusion: Female patients were older and had higher CHA 2DS 2-VASc scores compared to males at the time of AF ablation. Women tried more AADs than men prior to ablation. 1-y arrhythmia recurrence rates and procedural complications were similar in both genders. No sex- based differences were observed in safety and efficacy of ablation.

Background: Catheter ablation for atrial fibrillation (AF) is a common therapeutic strategy for patients with either paroxysmal or persistent AF, but long-term ablation success rates are imperfect. Maintenance of sinus rhythm immediately prior to ablation with anti-arrhythmic drug (AAD) therapy has been associated with improved outcomes in patients undergoing ablation. Amiodarone has superior efficacy relative to other AADs. Whether failure of amiodarone to maintain sinus rhythm prior to ablation for either paroxysmal or persistent AF is associated with poor outcomes is unknown. Methods: A total of 307 patients who received amiodarone in a one-year window before undergoing catheter ablation for AF were included. Patients were divided into amiodarone success (n=183) and amiodarone failure (n=124) groups based on the response to pre-ablation amiodarone treatment. Analysis of procedural outcomes as a function of response to amiodarone therapy was performed. Patients were followed for at least 12 months post-ablation to assess outcomes (adverse events and arrhythmia recurrence). Procedural success was defined by the absence of documented arrhythmia (>30s) without any anti-arrhythmic agents beyond a 90d blanking period. Results: Following ablation for either paroxysmal or persistent AF, freedom from any recurrent atrial arrhythmia at 1y was 57.7% for the entire cohort. One-year freedom from recurrent arrhythmia in the amiodarone success group was comparable to that in the amiodarone failure group (55.7% vs 60.5%; p=0.54). Success rates following ablation did not vary by the response to amiodarone when analyzed for paroxysmal or persistent AF subgroups. Conclusion: Failure to restore and maintain sinus rhythm with amiodarone prior to ablation for either paroxysmal or persistent AF is not a predictor of ablation procedural failure. Amiodarone failure alone should not deter practitioners from considering ablation therapy for patients with AF.

Background Transesophageal echocardiography (TEE) is variably performed before atrial fibrillation (AF) ablation to evaluate left atrial appendage (LAA) thrombus. We describe our experience with transitioning to the pre-ablation cardiac computed tomography (CT) approach for the assessment of LAA thrombus during the COVID-19 pandemic. Methods We studied consecutive patients undergoing AF ablation at our center. The study cohort was divided into pre- vs. post-COVID groups. The pre-COVID cohort included ablations performed during 1 year before the COVID-19 pandemic; pre-ablation TEE was used routinely to evaluate LAA thrombus in high-risk patients. Post-COVID cohort included ablations performed during the 1 year after the COVID-19 pandemic; pre-ablation CT was performed in all patients, with TEE performed only in patients with LAA thrombus by CT imaging. The demographics, clinical history, imaging, and ablation characteristics, and peri-procedural cerebrovascular events (CVE) were recorded. Results A total of 637 patients (pre-COVID n=424, post-COVID n=213) were studied. The mean age was 65.6  10.1 years in the total cohort, and the majority were men. There was a significant increase in pre-ablation CT imaging from pre to post-COVID cohort (74.8 vs. 93.9%, p=<0.01), with a significant reduction in TEEs (34.6 vs. 3.7%, p=<0.01). One patient in the post-COVID cohort developed CVE following negative pre-ablation CT. However, the incidence of peri-procedural CVE between both cohorts remained statistically unchanged (0 vs. 0.4%, p=0.33). Conclusion Implementation of pre ablation CT-only imaging strategy with selective use of TEE for LAA thrombus evaluation is not associated with increased CVE risk during the COVID- 19 pandemic.

Catheter Ablation of Accessory Pathways: Can We Do Better by Using Dual Chamber Mapping ?

Background: Data related to electrophysiologic characteristics of atypical atrial flutter (AFL) following atrial fibrillation (AF) ablation and its prognostic value on repeat ablation success are limited. Methods: We studied consecutive patients undergoing a repeat LA ablation for either recurrent AF or atypical AFL, following 3 months after index AF ablation, between January 2012 and July 2019. The demographics, procedural data, complications, and 1-year arrhythmia-free survival rates were recorded for each subject after the first repeat ablation. Results: Of the total 336 included patients, 102 underwent a repeat ablation for atypical AFL and 234 for recurrent AF. The mean age was 63.7  10.7 years, and 72.6 % of patients were male. The atypical AFL cohort had significantly higher LA diameters (4.6 vs. 4.4 cm, p=0.04) and LA volume indices (LAVi; 85.1 vs. 75.4 ml/m2, p=0.03) compared to AF patients at repeat ablation. Atypical AFLs were roof-dependent in 35.6% and peri-mitral in 23.8% of cases. Major complications at repeat ablation occurred in 0.9 % of the total cohort. Arrhythmia-free survival at one year was significantly higher in the recurrent atypical AFL than the recurrent AF cohort (75.5 vs. 65.0 %, p=0.04). Conclusion: In our series, roof-dependent flutter is the most common form of atypical atrial flutter post AF ablation. Patients developing atypical AFL after index AF ablation have greater LA dimensions than patients with recurrent AF. The success rate of first repeat ablation is significantly higher among patients with recurrent atypical AFL compared to recurrent AF after index AF ablation.

Introduction: There are limited data describing the experience of index radiofrequency (RF) vs. cryoballoon (CB) ablation for atrial fibrillation (AF) among elderly patients in the United States. Methods: We conducted a retrospective analysis of patients > 75 years of age undergoing index AF ablation between January 2010 and March 2019 at our center. Major complications and efficacy, defined as freedom from any atrial tachyarrhythmia (ATA) lasting ≥30 seconds after one year of follow-up, were assessed in patients with index RF vs. CB ablation. Predictors of ATA recurrence at 1 year follow-up were also evaluated. Results: In our cohort of 194 patients, the mean age was 78 ± 3.1 years, 58.2% were men, and 39.4% had persistent AF. The mean left atrial (LA) diameter was 4.5 ± 0.7, while the mean CHA2DS2-VASc score was 3.5 ± 1.2. The majority (n=149, 76.8%) underwent RF ablation. The incidence of complications was similar in the two sub-groups (RF: 1.3% vs. CB: 2.2%, p=0.67). No significant difference in success rate at 1-year follow-up was found between patients receiving RF vs. CB ablation (59.7% vs. 66.7%, p=0.68). In a multivariable model adjusting for the relevant covariates only LA size [HR=1.64, CI: 1.15-2.34, p<0.01] was independently associated with ATA recurrence at 1year follow-up. Conclusion: In our cohort of elderly patients undergoing index CA for AF, RF ablation was the predominant modality with similar safety and efficacy relative to CB ablation. LA size was a significant predictor of ATA recurrence at 1year independent of index ablation modality.