Repeat Atrial Fibrillation Ablation Research Articles

Pulmonary vein reconnection and repeat ablation characteristics following cryoballoon-compared to radiofrequency-based pulmonary vein isolation.

Despite advances in efficacy and safety of pulmonary vein isolation (PVI), atrial fibrillation (AF) recurrence after PVI remains common. PV-reconnection is the main finding during repeat PVI procedures performed to treat recurrent AF. To analyze pulmonary vein (PV) reconnection patterns during repeat ablation procedures in a large cohort of consecutive patients undergoing radio frequency or cryoballoon-based PVI. Retrospective analysis of PV-reconnection patterns and analysis of re-ablation strategies in consecutive index RF- and CB-based PVI and their respective re-ablation procedures during concomitant usage of both energy sources at a single high-volume center in Germany. A total of 610 first (06/2015-10/2022) and 133 s (01/2016-11/2022) repeat ablation procedures after 363 (60%) RF- and 247 (40%) CB-based index PVIs between 01/2015 and 12/2021 were analyzed. PV-reconnection was found in 509/610 (83%) patients at first and 74/133 (56%) patients at second repeat procedure. 465 of 968 (48%) initially via CB isolated PVs were reconnected at first re-ablation but 796 of 1422 initially RF-isolated PV (56%) were reconnected (OR: 0.73 [95% CI: 0.62-0.86]; p < .001). This was driven by fewer reconnections of the left PVs (LSPV: OR: 0.60 [95% CI: 0.42-0.86]; p = .005 and LSPV: 0.67 [0.47-0.95]; p = .026). PV-reconnection was more likely after longer, RF-based index PVI and in older females. Repeat procedures were shorter after CB-compared to after RF-PVI. Reconnection remains the most common reason for repeat AF ablation procedures after PVI. Our data suggest to preferentially use of the cryoballoon during index PVI, especially in older women.

The Impact of Gastroesophageal Reflux Disease and Proton Pump Inhibitor Use on the Risk of Repeat Catheter Ablation for Atrial Fibrillation.

Gastroesophageal reflux disease (GERD) has been associated with increased incidence/recurrence of atrial fibrillation (AF). However, the impact of GERD and proton pump inhibitor (PPI) therapy on outcomes of AF catheter ablation remains unclear. We aimed to assess the association between the presence of GERD and risk of repeat AF ablation, stratified by PPI therapy. A retrospective cohort study was conducted on patients with paroxysmal/persistent AF undergoing initial ablation in January 2011-September 2015. GERD was defined by endoscopic findings, objective reflux testing, or clinical symptoms. The association between GERD/PPI use and time to repeat ablation was evaluated by time-to-event analysis with censoring at the last clinic follow-up within 1 year. Three hundred eighty-one subjects were included. Patients with GERD (n = 80) had a higher 1-year repeat ablation rate compared with those with no GERD (25% vs 11.3%, P = 0.0034). Stratifying by PPI use, patients with untreated GERD (37.5%) more likely needed repeat ablation compared with reflux-free (11.3%, P = 0.0003) and treated GERD (16.7%, P = 0.035) subjects. On multivariable Cox regression analyses, GERD was an independent risk factor of repeat ablation (hazard ratio [HR] 3.30, confidence interval [CI] 1.79-6.08, P = 0.0001). Specifically, untreated GERD was associated with earlier repeat ablation compared with no GERD (HR 4.02, CI 1.62-12.05, P = 0.0013). However, no significant difference in repeat ablation risk was noted between reflux-free and PPI-treated GERD groups. GERD was an independent predictor for risk of repeat AF ablation within 1 year, even after controlling for major cardiovascular comorbidities and confounders. PPI therapy modulated this risk, as repeat ablation-free survival for PPI-treated GERD was noninferior to reflux-free patients.

A multicenter evaluation of repeat ablation for atrial fibrillation in patients with isolated pulmonary veins: a Netherlands Heart Registration study

Abstract Background Of the 25-50% atrial fibrillation (AF) ablation patients who undergo repeat ablation, approximately 15-30% have all pulmonary veins (PVs) isolated at the repeat procedure. Currently, there is limited evidence and a lack of consensus on the appropriate treatment strategy for patients with isolated PVs. Purpose Our aim was to characterize and compare the effectiveness of repeat AF ablation strategies to reduce AF recurrences in patients with isolated PVs using a real-world multicenter registry. Methods All AF patients referred for repeat AF ablation with all PVs isolated at 8 hospitals in the Netherlands were included (Netherlands Heart Registration; 2016-2019). Medical record reviews were conducted for all patients referred for repeat AF ablation to determine study eligibility, the presence of PV reconnection, ablation strategy used, and the outcome of AF recurrence. Patients referred for repeat AF ablation, with PVI only conducted during previous ablations, and all PVs isolated were eligible. Effectiveness of repeat AF ablation strategies were assessed with multivariable Cox models comparing individual ablation strategies, number of ablation strategies performed, and presence of persistent AF. Results Of 2,311 repeat AF ablations performed, 274 (11.9%) were eligible and had all PVs isolated (Figure 1). Patients with isolated PVs were a median age of 66 (IQR 58-70) years, 44.2% were women, 45.6% had persistent or long-standing persistent AF, and the median CHA2DS2-Vasc score was 2 (IQR 1-3). Ablation was not performed in 33 (12.0%) patients with isolated PVs (Figure 2a). A single ablation strategy was performed most often (41.2%; Figure 2a). Posterior box ablation was the most frequent (58.4%) ablation strategy performed, followed by antralization of the PVs (26.3%). Over a median follow-up of 2.0 (1.0-3.3) years, 147 (59.8%) patients with isolated PVs had an AF recurrence &amp;gt;3 months after repeat ablation and 30 (12.7%) patients had another repeat AF ablation within 1 year of repeat procedure. After multivariable adjustment, no difference in AF recurrences was detected between ablation strategies [p&amp;gt;0.05 for all; Figure 2b]. Further, there was no difference detected in AF recurrences for the number of ablation strategies performed (Figure 2c), the individual ablation strategy conducted, and persistent AF (p&amp;gt;0.05 for all). Among patients with isolated PVs, patients with larger left atrial size had a higher risk of AF recurrences [adjusted HR 1.03 (95% CI 1.01-1.05)]. Conclusion Among the 2,311 repeat AF ablations performed, 11.9% had all PVs isolated. Despite multiple ablation strategies performed for isolated PVs, 59.8% of patients had an AF recurrence over follow-up and no difference in the incidence of AF recurrences was detected between repeat ablation strategies. Further evidence is warranted to determine an effective treatment strategy to reduce AF recurrences in AF patients with isolated PVs.

Integrating clinical variables with magnetic resonance imaging and electroanatomic mapping parameters to predict response to first-time and repeat atrial fibrillation ablation procedures

Abstract Background The heterogeneity in patient response to atrial fibrillation ablation mandates the development of methods to predict clinical outcomes. Several clinical risk scores exist to prognosticate patients post ablation. Magnetic resonance imaging can quantify anatomical and functional atrial properties, whilst electroanatomic mapping data provides unparalleled atrial substrate characterisation. These data could be leveraged to predict ablation outcomes more accurately. Purpose To incorporate magnetic resonance imaging and electroanatomic mapping parameters with clinical variables to predict response to 1) first-time and 2) repeat atrial fibrillation ablation. Methods A retrospective analysis of 123 consecutive patients undergoing first-time atrial fibrillation ablation including pre-procedural atrial magnetic resonance imaging was performed. Data were split into training (n=68) and test (n=55) cohorts depending on data availability for clinical risk score calculation. The APPLE, DR-FLASH, FLAME, HATCH, HATCH+OSA, CHA2Ds2VASc and CAAP-AF scores were calculated for patients in the training cohort. Univariate logistic regression was used to identify variables associated with arrhythmia recurrence which were then combined into a multivariate logistic regression model. Area under the curve receiver operating characteristic (AUC-ROC) analysis was used to compare the ability of clinical risk scores and the combined model to predict arrhythmia recurrence risk after one procedure. The model's ability to predict repeat ablation response was tested in 38 patients who underwent redo procedures. The ROC optimal cut-off score was used to divide patients into two groups (high and low arrhythmia recurrence risk) for time-to-event analysis. Results In univariate analysis, weight, age, hypertension, left atrial ejection fraction and mean left atrial bipolar voltage were associated with arrhythmia recurrence after one procedure. The multivariate logistic regression model achieved an AUC of 0.7491 (95% confidence interval (CI) 0.6269-0.8712) in the training cohort and 0.7457 (95% CI 0.6137-0.8778) in the test cohort for predicting arrhythmia recurrence at 12 months (Figure 1A). Amongst clinical risk prediction tools, CAAP-AF had the highest predictive value (AUC 0.6529, 95% CI 0.5265-0.7793) (Figure 1B). In patients undergoing repeat ablations, the combined model had an AUC of 0.7585 (95% CI 0.5989-0.9182) for predicting arrhythmia recurrence (Figure 2A). The Kaplan-Meier curves showed a higher risk of arrhythmia recurrence in the ‘high recurrence risk’ group at 12 months (log-rank p=0.029) (Figure 2B). Conclusion A logistic regression model integrating clinical, anatomical, functional, and electrophysiological parameters improved the accuracy of atrial fibrillation ablation outcome prediction compared to existing clinical risk scores. The model may be used to predict response to repeat procedures offering the potential to improve the patient selection process.

Feasibility and efficacy of single-shot PFA technology for redo procedures after a previous atrial fibrillation ablation procedure

Abstract Introduction Despite significant technological advancements and a better understanding of atrial tachyarrhythmia pathophysiology, a non-negligible percentage of atrial fibrillation (AF) patients undergoing catheter ablation experiences arrhythmia relapse. Repeat procedures have been traditionally performed via thermal energy systems, which carry a certain risk of collateral damage to adjacent tissues. Pulsed Field Ablation (PFA) has emerged as an alternative non-thermal energy source for cardiac ablation. The main advantage is its selectivity to cardiac tissue. FarapulseTM is the first PFA technology to have received regulatory approval and includes a pentaspline PFA catheter. Although designed for pulmonary vein isolation, its use for extrapulmonary vein site ablation has been previously documented. Purpose To evaluate the feasibility and efficacy of the pentaspline FarawaveTM for redo procedures. Methods Patients referred for a redo procedure using FarapulseTM system were enrolled in 3 high-volume European centers. A workflow (Figure 1.A) was established based on rhythm at presentation (Group 1: sinus rhythm; Group 2: AFL; Group 3: AF). Results A total of 117 patients were included (64 in Group 1, 18 in Group 2, and 35 in Group 3). The mean number of previous procedures was 1.26, and 23 patients (19.66%) had already undergone ≥2 procedures. Previous ablation targets included PVI, either alone (46.15%) or in combination with other targets, including posterior mitral line (39.32%), posterior wall (6.84%), or anterior mitral line (2.56%). Electroanatomical mapping (EAM) was adopted in 15.38% of the cases. Specifically, in 27.78% (n=5) of group 2, 15.63% (n=10) of group 1 and 8.57% (n= 3) of group 3 cases. Additional focal radiofrequency ablation was required in 4 patients for CTI line ablation. Lesion sets are depicted in Figure 2. Mean procedural and LA dwelling time were 95.2 ± 38.0 and 50.7 ± 36.7 minutes, respectively. There was a total of one major complication (intracranial haemorrhage) and 5 minor complications (two vascular site related, and three reversible ST segment changes, related to applications on the mitral annulus area). A total of 100 patients completed at least 3 months of follow-up (FU), with a median FU time was 7.55 months (IQR 5.18 – 11.85). The total number of recurrences was 20, including 2 during the blanking period. Survival function (excluding blanking period) was 88.6 (95% CI 79.7 – 93.8) at 6 months and 80.0% (95% CI 67.3 – 88.3) 12 months. Atrial arrhythmia free-survival was higher in patients presenting in sinus rhythm, compared to the other two groups (p = 0.0135), as displayed in Figure 1.B. Conclusion The proposed stepwise approach to repeat AF ablation procedures based on the use of the single-shot PFA system (with or without EAM) was feasible, safe, fast and effective at one year follow-up.Flow chart and Kaplan Meier curveLesion sets

Multicenter retrospective evaluation of a patient-tailored electrogram-based ablation strategy using an artificial intelligence software in repeat atrial fibrillation ablation procedures

Abstract Background While pulmonary vein isolation (PVI) is the gold standard approach of treatment of atrial fibrillation (AF), the optimal strategy in case of AF recurrences for redo patients is not well established. Several studies described the usefulness of ablating in atrial regions exhibiting abnormal electrograms, i.e. spatio-temporal dispersion, during AF and an artificial intelligence (AI) electrograms (EGMs)-based software solution has been developed and validated to obtain real-time adjudications of multipolar electrograms in de novo patients. Purpose This study sought to evaluate the novel AI-EGMs-based software approach for redo-AF ablation procedures. Methods This study was a retrospective, multicentric, nonrandomized study. Patients with recurrent symptomatic AF were enrolled in 7 European centers. Redo ablation procedures were performed using the AI software and acute and long-term outcomes after ablation were evaluated. Results A total of 117 patients with refractory symptomatic AF admitted for redo procedure were included with 30% paroxysmal, 42% short-standing persistent and 28% long-standing persistent AF at the time of the redo procedure. During the index procedures, a previous PVI ablation was performed in all patients while additional ablation such as lines and EGM-based ablation was performed in 64 patients (55%). Out of 117 patients, 30 (26%) presented with structural heart disease, 61 (52%) with hypertension, 31 (26%) with a BMI &amp;gt;30, 16 (14%) a sleep apnea syndrome and 24 (20%) had an antiarrhythmic treatment at the time of the procedure. The average AF history was 6.54 ± 4.15 years with an average sustained duration equal to 25 ± 62 months. AI-EGMs-based AF ablation was performed in all patients and easily integrated in the physicians’ workflow during redo procedures. AF termination, i.e. AF regularization or sinus rhythm conversion, occurred in 82/117 patients (71%) with sinus rhythm conversion by ablation in 79/117 patients (68%). After a mean follow-up of 11 ± 5 months, 81% of patients were free from documented AF, with or without antiarrhythmic drugs (AADs) after one redo procedure and 60% of patients were free from any documented atrial arrhythmia, with or without AADs, after one redo procedure per patient. Furthermore, we observed that 77%, 84% and 82% of patients were free from documented AF with or without AADs in paroxysmal, short-standing and long-standing persistent AF patients respectively, and that 71%, 59% and 49% of patients were free from any documented atrial arrhythmia with or without AADs in paroxysmal, short-standing and long-standing persistent AF patients respectively. Conclusions This retrospective study reports that patient-tailored spatiotemporal dispersion ablation is a relevant and standardized approach for repeat AF ablation. This was obtained with an AI-EGMs-based software solution, which may be added to the operative workflow of redo AF procedures.

Effects of Glucagon-Like Peptide-1 Receptor Agonists on Atrial Fibrillation Recurrence After Catheter Ablation

BackgroundRelationship between glucagon-like peptide-1 receptor agonist (GLP-1 RA) use prior to atrial fibrillation (AF) ablation and subsequent AF recurrence is not well-understood. ObjectivesThis study investigated the effects of GLP-1 RA use within 1 year before ablation and its association with AF recurrence and associated outcomes. MethodsThe TriNetX research database was used to identify patients aged ≥18 years undergoing AF ablation (2014-2023). Patients were categorized into 2 groups, and propensity score matching (1:1) between preablation GLP-1 RA users and nonusers was performed based on demographics, comorbidities, body mass index, laboratory tests, AF subtype, and medications. Primary outcome was composite of cardioversion, new antiarrhythmic drug therapy, or repeat AF ablation after a 3-month blanking period following the index ablation. Additional outcomes included ischemic stroke, all-cause hospitalization, and mortality during 12-month follow-up period. ResultsAfter 1:1 propensity score matching, the study cohort comprised 1,625 GLP-1 RA users and 1,625 matched GLP-1 RA nonusers. Preablation GLP-1 RA therapy was not associated with a lower risk of cardioversion, new AAD therapy, and repeat AF ablation after the index procedure (HR: 1.04 [95% CI: 0.92-1.19]; log-rank P = 0.51). Furthermore, the risk of ischemic stroke, all-cause hospitalization, and mortality during the 12-month follow-up period did not differ between the 2 groups. ConclusionsThese findings suggest that preprocedural use of GLP-1 RAs is not associated with a reduced risk of AF recurrence or associated adverse outcomes following ablation, and underscore the need for future research to determine whether these agents improve outcome in AF patients.

Rates of pulmonary vein reconnection at repeat ablation for recurrent atrial fibrillation and its impact on outcomes among females and males.

Several studies have demonstrated that females have a higher risk of arrhythmia recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF). There are limited data on sex-based differences in PV reconnection rates at repeat ablation. We aimed to investigate sex-based differences in electrophysiological findings and atrial arrhythmia recurrence after repeat AF ablation METHODS: We conducted a retrospective study of 161 consecutive patients (32% female, age 65±10 years) who underwent repeat AF ablation after index PV isolation between 2010 and 2022. Demographics, procedural characteristics and follow-up data were collected. Recurrent atrial tachycardia (AT)/AF was defined as any atrial arrhythmia ≥30 s in duration. Compared to males, females tended to be older and had a significantly higher prevalence of prior valve surgery (10vs. 2%; P=.03). At repeat ablation, PV reconnection was found in 119 (74%) patients. Males were more likely to have PV reconnection at repeat ablation compared to females (81vs. 59%; P=.004). Excluding repeat PV isolation, there were no significant differences in adjunctive ablation strategies performed at repeat ablation between females and males. During follow-up, there were no significant differences in freedom from AT/AF recurrence between females and males after repeat ablation (63vs. 59% at 2 years, respectively; P=.48). After initial PV isolation, significantly fewer females have evidence of PV reconnection at the time of repeat ablation for recurrent AF. Despite this difference, long-term freedom from AT/AF was similar between females and males after repeat ablation.

Comparison of Long-Term Clinical Outcomes Between Segmental and Circumferential Pulmonary Vein Isolation in Patients Undergoing Repeat Atrial Fibrillation Ablation.

Circumferential pulmonary vein isolation (CPVI) has supplanted segmental PVI (SPVI) as standard procedure for atrial fibrillation (AF). However, there is limited evidence examining the efficacy of these strategies in redo ablations. In this study, we investigated the difference in recurrence rates between SPVI and CPVI in redo ablations for PV reconnection.Methods and Results: This study retrospectively enrolled 543 patients who had undergone AF ablation between 2015 and 2017. Among them, 167 patients (30.8%, including 128 male patients and 100 patients with paroxysmal AF) underwent redo ablation for recurrent AF. Excluding 26 patients without PV reconnection, 141 patients [90 patients of SPVI (Group 1) and 51 patients of CPVI (Group 2)] were included. The AF-free survival rates were 53.3% and 56.9% in Group 1 and Group 2, respectively (P=0.700). The atrial flutter (AFL)-free survival rates were 90% and 100% in Group 1 and Group 2, respectively (P=0.036). The ablation time was similar between groups, and there no major complications were observed. For redo AF ablation procedures, SPVI and CPVI showed similar outcomes, except for a higher AFL recurrence rate for SPVI after long-term follow-up (>2 years). This may be due to a higher probability of residual PV gaps causing reentrant AFL.

Abstract 12390: Differences in the Impact of Use of Contact Force Sensing Catheters on Subsequent Rates of Pulmonary Vein Reconnection Detected Between Men and Women During Repeat Ablation of Atrial Fibrillation

Background: Radiofrequency catheter ablation (CA) is an effective treatment for atrial fibrillation (AF). Contact force (CF) sensing catheters permit tissue contact monitoring that may lead to durable pulmonary vein (PV) isolation. Objective: To assess the impact of CF-sensing catheters on PV reconnection rates at repeat AF ablation and whether there are sex-based differences. Methods: We conducted a retrospective study of patients who underwent repeat AF ablation after index PV isolation between 2010 and 2022. Patients were divided into 2 groups: Group 1 (non-CF sensing catheters) and Group 2 (CF-sensing catheters). Results: One hundred sixty-one patients were included in the study (76 in Group 1 and 85 in Group 2, 32% female, 70 ± 10 years old). Initial use of CF-sensing catheters at index ablation was associated with a lower PV reconnection rate at repeat ablation (60% for Group 2 vs 87% for Group 1; P = 0.001). There were no significant differences in locations of PV reconnection between Group 1 and Group 2. When stratified by sex, there were significantly lower rates of PV reconnection in male patients with use of CF-sensing catheters (92% for Group 1 vs 67% for Group 2; p=0.001) but not for female patients (71% for Group 1 vs 50% for Group 2; p=0.23). On multivariable logistic regression analysis, use of CF-sensing catheters at index ablation (adjusted odds ratio [aOR]: 0.28, 95% CI: 0.12 to 0.65; p=0.003) and female sex (aOR: 0.38, 95% CI: 0.17 to 0.86; p=0.02) were associated with significantly lower rates of PV reconnection found at repeat ablation. Conclusion: Use of CF sensing catheters reduced PV reconnection rate found at repeat AF ablation. Females have lower rates of PV reconnection identified at repeat ablation which suggest that non-PV triggers may be a more common cause of recurrent AF, thereby blunting the impact of CF-sensing catheters on reducing recurrent AF in females.

Catheter ablation of atrial fibrillation in patients with and without hypertrophic cardiomyopathy: systematic review and meta-analysis.

Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM). There is limited data regarding the outcomes of AF catheter ablation in HCM patients. In this study, we aimed to synthesize all available evidence on the effectiveness of ablation of AF in patients with HCM compared to those without HCM. We systematically reviewed bibliographic databases to identify studies published through February 2023. We included cohort studies with available quantitative information on rates of recurrent atrial arrhythmias, anti-arrhythmic drug (AAD) therapy, and repeat ablation procedures after initial AF ablation in patients with vs without HCM. Estimates were combined using random-effects meta-analysis models and reported as risk ratios (RR) and 95% confidence intervals (CI). Eight studies were included in quantitative synthesis (262 HCM and 642 non-HCM patients). During median follow-up 13-54 months across studies, AF recurrence rates ranged from 13.3% to 92.9% in HCM and 7.6% to 58.8% in non-HCM patients. The pooled RR for recurrent atrial arrhythmia after the first AF ablation in HCM patients compared to non-HCM controls was 1.498 (95% CI = 1.305-1.720; P < 0.001). During follow-up, HCM patients more often required AAD therapy (RR = 2.844; 95% CI = 1.713-4.856; P < 0.001) and repeat AF ablation (RR = 1.544; 95% CI = 1.070-2.228; P = 0.02). The pooled RR for recurrent atrial arrhythmias after the last AF ablation was higher in patients with HCM than those without HCM (RR = 1.607; 95% CI = 1.235-2.090; P < 0.001). Compared to non-HCM patients, those with HCM had higher rates of recurrent atrial arrhythmias, AAD use, and need for repeat AF ablation after initial ablation of AF.

Thawing plateau time indicating the duration of phase transition from ice to water is the strongest predictor for long-term durable pulmonary vein isolation after cryoballoon ablation for atrial fibrillation-Data from the index and repeat procedures.

This study aimed to clarify the relationship between the durability of pulmonary vein (PV) isolation and the time of phase transition from ice to water indicated by thawing plateau time in a cryoballoon ablation for atrial fibrillation (AF). In this retrospective study, 241 PVs from 71 patients who underwent a repeat AF ablation 526 (IQR: 412, 675) days after a cryoballoon ablation were analyzed. Reconnection was observed in 101 (41.9%) PVs of 53 patients (74.6%). Thawing plateau time (TimeTP) was defined as the time from 0°C to 10°C inside the balloon in the thawing period. Durable PV isolation was associated with significantly longer TimeTP compared with PV reconnection (26.0 vs. 11.0 s, P < 0.001). The proportion of durable PV isolations increased with TimeTP in a dose-proportional manner. The cut point for PV reconnection was TimeTP <15 s with a positive predictive value of 82.1% (sensitivity = 63.4%, specificity = 90.0%) while for durable PV isolation the cut point was TimeTP >25 s with a positive predictive value of 84.6% (sensitivity = 55.0%, specificity = 86.1%). In the analysis of multivariable logistic regression, location of PV reconnection (P < 0.01), TimeTP (P < 0.05) and thawing plateau integral (P < 0.01) were shown as independent predictors for durable PV isolation. TimeTP is an independent predictor for the durability of PV isolation, and it presents in a dose-proportional manner. TimeTP <15 s predicts long-term reconnection while TimeTP >25 s predicts durable PV isolation.

Reverse structural left atrial remodeling and atrial tachycardia in patients with repeat ablation for atrial fibrillation.

Catheter ablation has been evolved to a cornerstone in the therapy of atrial fibrillation (AF); however, atrial tachycardias (AT) after AF ablation are still an important issue. Besides the electrical recurrence of atrial tachyarrhythmia after ablation, left atrial (LA) remodeling has received attention as a consequence of AF. The aim of this study is to evaluate predictors for AT recurrence and LA remodeling in patients with repeat AF ablation procedures. One hundred thirteen patients who underwent repeat AF ablation with 3D electro-anatomical mapping system were evaluated. Mean age was 63.1 ± 9.3 years, and 2.3 ± 0.5 ablation procedures were performed during a time period of 22 [IQR 7;48] months. Reverse structural LA remodeling (LA volume decreased more than 15%) was observed in 25 (22.1%) patients. LA volume index (LAVI) during first procedure was the only predictor for positive reverse structural LA remodeling (hazard ratio (HR): 1.03, 95% CI: 1.00-1.07, p = .036) in multivariate analysis. Fifty-nine (52.2%) patients experienced only AF and 54 (47.8%) patients AT after first procedure. Female gender (HR: 5.21, 95% CI: 1.66-18.08, p = .006), LAVI (HR: 1.06, 95% CI: 1.02-1.11, p = .008) and LA scar percentage (HR: 1.08, 95% CI: 1.02-1.17, p = .019) were independent significant predictors for AT recurrence in multivariate analysis. Reverse structural LA remodeling occurred in a quarter of patients with repeat ablation procedures for AF. Only larger LAVI during first procedure predicted reverse structural LA remodeling. Half of the patients experienced AT between first and last ablation procedure. Female gender, larger LAVI and larger scar area were significant predictors for AT after catheter ablation for AF.

Abstract 13787: Characteristics and Occupational Trends of Military Tactical Athletes With Repeat Atrial Fibrillation Catheter Ablations

Introduction: Atrial fibrillation (AF) ablation for military personnel aims to provide therapeutic endpoints, recognizing that a subset of personnel require repeat ablation. Objective: This study aims to identify differences in characteristics and occupations of military members who received single versus repeat AF ablation. Further, we aim to understand the rates retention and deployment in those with single versus repeat AF ablation. Hypothesis: We hypothesize that there are increased rates of AF repeat ablations in personnel with risk factors for AF recurrence. Methods: Military personnel who underwent elective AF ablation between 2004 to 2019 were reviewed. Characteristics and military dispositions of personnel with repeated AF ablations were compared to those without. Results: 27 of 104 (26%) personnel received repeat AF catheter ablations on average 16.1±31 months after first ablation. There were no differences between age (34.5+9.5 vs 37.6+9.8 years, P=0.13), BMI (28.1±3.9 vs 28.7±3.4 kg/m2, P=0.48), presence of diastolic dysfunction (11.7% vs 7.4%, P=0.53), left atrial appendage emptying velocities (58.4+22 vs 59.7+23 cm/s, P=0.82), left atrial volume index (29.4+9.9 vs 29.6+8.8 ml/m2, P=0.87), left ventricular ejection fraction (60.4+6% vs 58.5+13%, P=0.31), CHA2DS2-VASc scores (0.37+0.6 vs 0.44+0.7, P=0.60) between those who received a single versus repeated AF ablation. Aviators (40%, 4/10) and healthcare workers (35%, 12/34) underwent repeated ablation at significantly increased rates when compared to 22% of administrators (4/18) and 10% of industrial workers (2/20), (P=0.032). Military retention rates were preserved in those requiring repeated ablation compared to those with single AF ablation (70%, 19/27 vs 78%, 60/77; P=0.60). Deployment rates were statistically similar between those requiring repeated AF ablation compared to single ablation (37%, 10/27 vs 43%, 33/77; P=0.43). Conclusions: Repeat AF catheter ablation rates in military tactical athletes may be driven by specific and individual occupational demands without increased traditional risk factors for AF recurrence. Military retention and deployment rates are preserved for those requiring repeated AF ablation compared to those with single ablation.

Abstract 12297: Kissing Left Atrial Appendage Closure Devices for Peri-Device Leak

Introduction: Left atrial appendage closure (LAAC) therapy is approved for stroke prevention in nonvalvular atrial fibrillation (AF) for patients intolerant in long term oral anticoagulation (OAC). Peri-device leak (PDL) is the achilles heel to optimal LAAC and increases stroke risk. Here, we describe the novel use of a second LAAC device for closure of a large PDL in a bilobar appendage. Case: A 66-year-old male with a history of nonvalvular AF with recurrent bleeding on OAC with Watchman 2.5 implant six years prior, presented to our facility for a repeat AF ablation. Pre-procedural imaging showed a PDL of 12 mm with an uncovered posterior lobe, with the Watchman 2.5 covering only the anterior lobe of the appendage. The PDL was closed with a 20 mm Amulet device delivered through a steerable sheath abutting the existing Watchman 2.5 device. The steerability of the sheath allowed for optimal placement of the Amulet device to allow for complete closure. Patient was discharged home on six weeks of dual antiplatelet therapy. Discussion: In our case, a second LAAC device was chosen due to the large size of the PDL. Smaller leaks can be closed using endovascular coils and/or occluder plugs. Larger leaks require additional consideration for closure strategies such as a second LAAC device Conclusions: Our case is the first reported case utilizing a second LAAC device for PDL closure alongside the first device. Steerability of the new Amulet sheath allowed for optimal device placement for complete closure. Additional research is needed on how PDL’s should be addressed for optimal LAAC. Figure 1: Imaging showing PDL into uncovered posterior lobe Figure 2: Complete LAAC with kissing Watchman 2.5 and Amulet

Combined contact force and local impedance dynamics during repeat atrial fibrillation catheter ablation.

Background: Optimal lesion formation during catheter-based radiofrequency current (RFC) ablation depends on electro-mechanical tip-tissue coupling measurable via contact force (CF) and local impedance (LI) monitoring. We aimed to investigate CF and LI dynamics in patients with previous atrial fibrillation (AF) ablation who frequently present with heterogenous arrhythmia substrate. Methods: Data from consecutive patients presenting for repeat AF or atrial tachycardia ablation using a novel open-irrigated single-tip ablation catheter were studied. RFC applications were investigated regarding CF, LI and the maximum LI drop (∆LI) for evaluation of ablation efficacy. ∆LI > 20 Ω was defined as a successful RFC application. Results: A total of 730 RFC applications in 20 patients were analyzed. Baseline CF was not associated with baseline LI (R = 0.06, p = 0.17). A mean CF < 8 g during ablation resulted in lower ∆LI (<8 g: 13 Ω vs. ≥ 8 g: 16 Ω, p < 0.001). Baseline LI showed a better correlation with ∆LI (R = 0.35, p < 0.001) compared to mean CF (R = 0.17, p < 0.001). Mean CF correlated better with ∆LI in regions of low (R = 0.31, p < 0.001) compared to high (R = 0.21, p = 0.02) and intermediate voltage (R = 0.17, p = 0.004). Combined CF and baseline LI predicted ∆LI > 20 Ω (area under the receiver operating characteristic curve (AUC) 0.75) better compared to baseline LI (AUC 0.72), mean CF (AUC 0.60), force-time integral (AUC 0.59) and local bipolar voltage (0.55). Conclusion: Combination of CF and LI may aid monitoring real-time catheter-tissue electro-mechanical coupling and lesion formation within heterogenous atrial arrhythmia substrate in patients with repeat AF or atrial tachycardia ablation.

Empirical superior vena cava isolation in patients undergoing repeat catheter ablation procedure after recurrence of atrial fibrillation.

Although the ectopic foci responsible for initiating atrial fibrillation (AF) are usually located in the pulmonary veins (PVs), non-PV sources may initiate AF in approximately 11% of unselected patients with paroxysmal or persistent AF. The superior vena cava (SVC) is one of the most frequent non-PV origins for initiating AF. This study aims to investigate the effect of empirical SVC isolation in redo AF ablation procedures. Consecutive patients undergoing redo AF ablation procedures using a high-power short-duration protocol (HPSD) (50W; ablation index guided; target AI 350 for posterior wall ablation, AI 450 for anterior wall ablation; CARTO 3 mapping system) were included. Patients with SVC isolation were compared to patients without SVC isolation. Periprocedural parameters and complications were recorded and analyzed. Short-term endpoints included intrahospital AF recurrence, midterm endpoint AF freedom after 3months, and long-term endpoint AF freedom after 12months. A total of 276 patients underwent repeat ablation for recurrent AF (67 ± 10years; 57% male; 31.5% paroxysmal AF). The patients were divided into two groups: redo procedures with SVC isolation vs redo procedure without SVC isolation. Additional LA substrate modification was done based on intraprocedural voltage maps. Baseline characteristics did not differ significantly between the two groups. Median procedure time was 85.4 ± 27.1min with ablation times of 14.0 ± 8.5min. Intrahospital AF recurrence occurred in 32 patients (12%) with no difference among both groups: 17 patients (13%) SVC vs 15 patients (10%) No-SVC; p = 0.416. At 3-month follow-up, 47 (17%) presented an AF recurrence during the blanking period: 25 patients (19%) SVC vs 22 patients (15%) No-SVC; p = 0.304). After 12months, 202 (73%) of all patients were in stable sinus rhythm with no significant difference between the two groups: 93 patients (73%) SVC vs 109 patients (74%) No-SVC; p = 0.853). No significant differences were noted when dividing the patients in paroxysmal or persistent AF with and without SVC isolation. In our series of repeat AF ablation procedures, the addition of empirical SVC isolation to Re-PVI and LA substrate modification did not influence AF recurrence rates. This strategy can however be safe and useful in patients in whom SVC is identified as a trigger of AF.

Longitudinal risk of death, hospitalizations for atrial fibrillation, and cardiovascular events following catheter ablation of atrial fibrillation: a cohort study.

Population studies reporting contemporary long-term outcomes following catheter ablation of atrial fibrillation (AF) are sparse.We evaluated long-term clinical outcomes following AF ablation and examined variation in outcomes by age, sex, and the presence of heart failure. We identified 30601 unique patients (mean age 62.7±11.8 years, 30.0% female) undergoing AF ablation from 2008 to 2017 in Australia and New Zealand using nationwide hospitalization data. The primary outcomes were all-cause mortality and rehospitalizations for AF or flutter, repeat AF ablation, and cardioversion. Secondary outcomes were rehospitalizations for other cardiovascular events. During 124858.7 person-years of follow-up, 1900 patients died (incidence rate 1.5/100 person-years) with a survival probability of 93.0% (95% confidence interval (CI) 92.6-93.4%) by 5 years and 84.0% (95% CI 82.4-85.5%) by 10 years. Rehospitalizations for AF or flutter (13.3/100 person-years), repeat ablation (5.9/100 person-years), and cardioversion (4.5/100 person-years) were common, with respective cumulative incidence of 49.4% (95% CI 48.4-50.4%), 28.1% (95% CI 27.2-29.0%), and 24.4% (95% CI 21.5-27.5%) at 10 years post-ablation. Rehospitalizations for stroke (0.7/100 person-years), heart failure (1.1/100 person-years), acute myocardial infarction (0.4/100 person-years), syncope (0.6/100 person-years), other arrhythmias (2.5/100 person-years), and new cardiac device implantation (2.0/100 person-years) occurred less frequently. Elderly patients and those with comorbid heart failure had worse survival but were less likely to undergo repeat ablation, while long-term outcomes were comparable between the sexes. Patients undergoing AF ablations had good long-term survival, a low incidence of rehospitalizations for stroke or heart failure, and about half remained free of rehospitalizations for AF or flutter, including for repeat AF ablation, or cardioversion.

Strategies for repeat ablation for atrial fibrillation: a multicentre comparison of non-pulmonary vein versus pulmonary vein target ablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Approximately 18% of patients with atrial fibrillation (AF) undergo a repeat ablation within 12 months after their index ablation. Despite the high prevalence, comparative studies on non-pulmonary vein (PV) target strategies in repeat AF ablation are scarce. Purpose: This study aims to describe 12 months efficacy of non-PV and PV target ablations as a repeat ablation strategy. Methods A multicentre retrospective, descriptive study was conducted with data of 280 patients who underwent repeat AF ablation. Ablation strategy for repeat ablation was at the operators’ discretion. Non-PV target ablation (n=140) included posterior wall isolation, mitral line, roofline and/or complex fractionated atrial electrogram ablation. PV target ablation (n=140), included re-isolation and/or wide atrium circumferential ablation. Patients’ demographics and rhythm outcomes during 12-months follow-up were analysed. Results: Overall, the mean age was 63 ± 9 years, 64% were male, and body mass index was 27.1 ± 4.2. Patients undergoing non-PV target ablation had more frequently persistent AF (47.9% vs 14.3%, p &amp;lt; 0.001), and had a higher CHA2DS2 VASc (2.0 vs 1.3, p &amp;lt; 0.001). At 12 months, more atrial tachyarrhythmias were observed in the non-PV target group (48.6%) compared to the PV target group (29.3%, p=0.001). Similarly, a significantly higher AF and atrial tachycardia (AT) recurrence rate was observed after non-PV target ablation compared to PV target ablation (36.4% versus 22.1% and 22.9% versus 10.7%). After adjusting for several associated covariates, a significantly higher AT recurrence risk remained in the non-PV target group (adjusted OR 2.19 95% CI 1.18 – 4.42, p = 0.023) (Figure 1C). Sensitivity analysis was performed with inverse propensity weighting to assess the robustness of the multivariate model and demonstrated comparable outcomes. Both groups significantly de-escalated anti-arrhythmic drug use, de-escalation was more profound after PV target ablation. Patients with isolated PVs during non-PV target ablation had a significantly higher risk for AF recurrence than those with reconnected PVs (Figure 1B). Conclusion: Compared to PV target ablation, non-PV target repeat ablation did not improve outcomes after 12 months and was independently associated with a higher risk for AT recurrences.

Thawing plateau time indicating the duration of phase transition from ice to water is the strongest predictor for long-term durable pulmonary vein isolation after cryoablation for atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Helse Vest, Norway (LBS), and the Research Council of Norway (SYC). Background Cryoballoon ablation is an important method for pulmonary vein (PV) isolation in treatment of atrial fibrillation (AF). Previous studies have shown that thawing time, but not freezing time or temperature, impacts PV reconnection during long-term follow-up. However, it is unknown whether the entire or only part of the thawing stage plays a critical role. Purposes This study aimed to clarify the relationship between the durability of PV isolation and the time of phase transition from ice to water indicated by thawing plateau (TP) time during a cryoballoon ablation. Methods In this retrospective study, 241 PVs from 71 patients who underwent a repeat AF ablation 526 (IQR: 412, 675) days after a cryoballoon ablation were analyzed. The predictive value of procedural parameters for the durability of PV isolation were evaluated. Definitions of different phases of the temperature-time curve are shown in Figure 1. TP Time is defined as the time from 0 to 10°C inside the balloon in the thawing period (the plateau on the curve). Results Reconnection was observed in 101 (41.9%) PVs of 53 patients (74.6%). Durable PV isolation was associated with significantly longer TP Time compared with PV reconnection (26.0 vs. 11.0 s, P&amp;lt;0.001). The proportion of durable PV isolations increased with TP Time in a dose-proportional manner (Figure 2). The cut point for PV reconnection was TP Time &amp;lt;15 s with a positive predictive value of 82.1% (sensitivity=63.4%, specificity=90.0%) while for durable PV isolation the cut point was TP Time &amp;gt;25 s with a positive predictive value of 84.6% (sensitivity=55.0%, specificity=86.1%). After the analysis of multivariable logistic regression, location of PV (P&amp;lt;0.01), and TP Time (P&amp;lt;0.05) were shown as independent predictors for durable PV isolation. None of nadir temperature, initial cooling time, effective freezing time, initial thawing time, or late warming time was independent predictor. Accumulated TP Time for all PVs showed a positive linear correlation with the plasma level of troponin T (ρ=0.624, P&amp;lt;0.01). Conclusions TP Time is an independent predictor for the durability of PV isolation, and it presents in a dose-proportional manner. TP Time &amp;lt;15 s predicts long-term reconnection while TP Time &amp;gt;25 s predicts durable PV isolation.