Purpose Catheter ablation has become a mainstay therapy for atrial fibrillation (AF) with rapid innovation over the past decade. Variability in ablation techniques may impact efficiency, safety, and efficacy; and the ideal strategy is unknown. Real-world evidence assessing the impact of procedural variations across multiple operators may provide insight into these questions. The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal (PAF) and Persistent (PsAF) Atrial Fibrillation registry (Real-AF) is a multicenter prospective registry that will enroll patients at high volume centers, including academic institutions and private practices, with operators performing ablations primarily with low fluoroscopy when possible. The study will also evaluate the contribution of advent in technologies and workflows to real-world clinical outcomes. Methods Patients presenting at participating centers are screened for enrollment. Data are collected at the time of procedure, 10-12 weeks, and 12 months post procedure and include patient and detailed procedural characteristics, with short and long-term outcomes. Arrhythmia recurrences are monitored through standard of care practice which includes continuous rhythm monitoring at 6 and 12 months, event monitors as needed for routine care or symptoms suggestive of recurrence, EKG performed at every visit, and interrogation of implanted device or ILR when applicable. Results Enrollment began in January 2018 with a single site. Additional sites began enrollment in October 2019. Through May 2021, 1,243 patients underwent 1,269 procedures at 13 institutions. Our goal is to enroll 4000 patients. Discussion Real-AF's multiple data sources and detailed procedural information, emphasis on high volume operators, inclusion of low fluoroscopy operators, and use of rigorous standardized follow-up methodology allow systematic documentation of clinical outcomes associated with changes in ablation workflow and technologies over time. Timely data sharing may enable real-time quality improvements in patient care and delivery. Trial registration Clinicaltrials.gov: NCT04088071

Background Active esophageal cooling is increasingly utilized as an alternative to luminal esophageal temperature (LET) monitoring for protection against thermal injury during pulmonary vein isolation (PVI) when treating atrial fibrillation (AF). Published data demonstrate the efficacy of active cooling in reducing thermal injury, but impacts on procedural efficiency are not as well characterized. LET monitoring compels pauses in ablation due to heat stacking and temperature overheating alarms that in turn delay progress of the PVI procedure, whereas active esophageal cooling allows avoidance of this phenomenon. Our objective was to measure the change in PVI procedure duration after implementation of active esophageal cooling as a protective measure against esophageal injury. Methods We performed a retrospective review under IRB approval of patients with AF undergoing PVI between January 2018 and February 2020. For each patient, we recorded age, gender, and total procedure time. We then compared procedure times before and after the implementation of active esophageal cooling as a replacement for LET monitoring. Results A total of 373 patients received PVI over the study period. LET monitoring using a multi-sensor probe was performed in 198 patients, and active esophageal cooling using a dedicated device was performed in 175 patients. Patient characteristics did not significantly differ between groups (mean age of 67 years, and gender 37.4% female). Mean procedure time was 146 ± 51 min in the LET-monitored patients, and 110 ± 39 min in the actively cooled patients, representing a reduction of 36 min, or 24.7% of total procedure time (p < .001). Median procedure time was 141 [IQR 104 to 174] min in the LET-monitored patients and 100 [IQR 84 to 122] min in the actively cooled patients, for a reduction of 41 min, or 29.1% of total procedure time (p < .001). Conclusions Implementation of active esophageal cooling for protection against esophageal injury during PVI was associated with a significantly large reduction in procedure duration.

Background: Active esophageal cooling reduces the incidence of endoscopically identified severe esophageal lesions during radiofrequency (RF) catheter ablation of the left atrium for the treatment of atrial fibrillation. No atrioesophageal fistula (AEF) has been reported to date with active esophageal cooling, and only one pericardio-esophageal fistula has been reported; however, a formal analysis of the AEF rate with active esophageal cooling has not previously been performed. Methods: Atrial fibrillation ablation procedure volumes before and after adoption of active cooling using a dedicated esophageal cooling device (ensoETM, Attune Medical) were determined across 25 hospital systems with the highest total use of esophageal cooling during RF ablation. The number of AEFs occurring in equivalent time frames before and after adoption of cooling were then determined, and AEF rates were compared using generalized estimating equations robust to cluster correlation. Results: Throughout the 25 hospital systems, which included a total of 30 separate hospitals, 14,224 patients received active esophageal cooling during RF ablation, with the earliest adoption beginning in March 2019 and the most recent beginning in March 2022. In the time frames prior to adoption of active cooling, a total of 10,962 patients received primarily luminal esophageal temperature (LET) monitoring during their RF ablations. In this pre-adoption cohort a total of 16 AEFs occurred, for an AEF rate of 0.146%, in line with other published estimates of <0.1% to 0.25%. No AEFs were found in the cohort treated after adoption of active esophageal cooling, yielding an AEF rate of 0% (P<0.0001). Conclusion: Adoption of active esophageal cooling during RF ablation of the left atrium for the treatment of atrial fibrillation was associated with a significant reduction in AEF rate.

Funding Acknowledgements Type of funding sources: None. Background As the burden of atrial fibrillation continues to rise with an aging population, there have been contrasting positions on the efficacy of left atrial ablation. While ablation techniques have continued to improve over the past decades, arrhythmia recurrence rates must be further reduced given the burden of ablation on patients. Since continuity of lesion sets has been associated with greater lesion durability, it has been theorized that the use of active esophageal cooling may facilitate greater freedom from arrhythmia. Purpose In order to investigate the association between use of active esophageal cooling and arrhythmia recurrence, we performed a multicenter retrospective study of arrhythmia recurrence rates in patients that received active cooling and compared them to those that received luminal esophageal temperature (LET) monitoring. Methods In this study, follow up data were collected from patients that underwent pulmonary vein isolation (PVI) at three separate large medical centers. Data were contained in a prospective hospital registry, a prospective physician registry, or the electronic health record, depending on the center. For each patient included, we recorded whether their ablation utilized LET monitoring or active esophageal cooling, along with their rhythm status at 1-year follow up. Rhythm status at follow-up was determined by either electrocardiogram, Holter monitor, or wearable heart rate monitor. Kaplan-Meier (KM) curves were created for freedom-from-arrhythmia at one year comparing those in the LET monitoring group to those in the active cooling group. Results Follow up data were collected from 1035 patients. There were 560 patients that received LET monitoring during their original ablation, and 475 patients that underwent active esophageal cooling. KM estimates for freedom-from-arrhythmia at one year were 42% in the LET monitored group and 65% in the actively cooled group (P&lt;.001). Conclusion In this large multicenter study, there is a significant increase in freedom-from-arrhythmia at one year follow-up among patients that received active esophageal cooling as compared to those that underwent LET monitoring.

Background Various factors influence successful freedom from atrial arrhythmia after pulmonary vein isolation (PVI) with radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF). Lesion transmurality and continuity (as measured by the Continuity Index) are two important factors, and these can be worsened by pauses in RF energy application due to esophageal overheating. Proactive esophageal cooling precludes the need for premature cessation of power, avoiding partially-formed lesions and the need to “hop-scotch” in the left atrium. The resulting improvement in lesion continuity may improve long-term freedom from atrial arrhythmia after PVI, particularly in patients with persistent AF, where more posterior wall ablation is often necessary. Purpose Determine differences in freedom from arrhythmia at one year between patients receiving LET monitoring and those receiving esophageal cooling during PVI for persistent AF. Methods We reviewed data from two healthcare systems for patient rhythm status at one-year follow up after PVI for the treatment of persistent or long-standing persistent AF. We then determined Kaplan-Meier estimates of freedom from arrhythmia (AF, atrial flutter, and atrial tachycardia), and compared these between patients receiving esophageal cooling and those treated with traditional LET monitoring. Results A total of 252 patients received PVI for persistent or long-standing persistent AF and had data available for review. Of these, 148 received LET monitoring (with either a single or multi-sensor temperature probe), and 104 received active cooling with a dedicated esophageal cooling device. Mean age and gender for each group was similar (67.2, range 21 to 88 years, 36% female for LET monitoring, and 67.8, range 32 to 89 years, 30% female for esophageal cooling). KM estimates for freedom from AF at the one-year follow-up were 44.2% for LET monitored patients and 79.3% for actively cooled patients (P=0.01). Conclusions Freedom from atrial arrhythmia at one-year after PVI for persistent AF is associated with significant improvement when using active esophageal cooling rather than LET monitoring. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Attune Medical