ClinicalAtrial FibrillationDurability of posterior wall isolation after catheter ablation among patients with recurrent atrial fibrillation
Introduction
Catheter ablation of atrial fibrillation (AF) is an effective strategy for treatment of paroxysmal and persistent AF. Pulmonary vein isolation (PVI) is the foundation of all AF ablation strategies, although recurrence of AF after PVI alone remains frequent, particularly with persistent AF.1 Nonpulmonary vein triggers arising from the posterior wall of the left atrium (LA), which may be particularly prone to conduction delay due to fibrosis and complex tissue architecture, frequently initiate AF.2,3 Thus, posterior wall isolation (PWI) is of theoretical benefit to prevent recurrent AF in addition to PVI. However, results regarding the efficacy of routine PWI are conflicting, as is the evidence that it may impair LA function or predispose to the development of LA flutter.4, 5, 6
Beyond determining the ideal patient population that would benefit from PWI, there are technical challenges in performing successful PWI. The posterior wall is a thin-walled structure in immediate proximity to the esophagus, and aggressive lesion creation may increase the risk of atrioesophageal fistula formation. Limited in part by this concern as well as by frequent direct epicardial connections, PWI can be challenging with endocardial ablation, and epicardial connections may be overlooked or only transiently interrupted.7,8 Incomplete PWI, either at the time of the procedure or with subsequent reconnection as edema resolves, may provide the substrate for atypical LA flutters.8
Reconnection across ablation lesions from PVI is a common reason for AF recurrence after ablation, and reconnection after PWI may also be a cause of recurrence or proarrhythmia.9,10 Given the growing interest in PWI as an ablation strategy for AF, we aimed to investigate its durability among patients with recurrent AF after a single index PVI and PWI, who were undergoing redo ablation.
Section snippets
Methods
We performed a retrospective cohort study at the Hospital of the University of Pennsylvania. All patients provided written informed consent for both their ablation procedure and use of their anonymized medical information for research. This research was approved by the Institutional Review Board. All patients referred to the Hospital of the University of Pennsylvania for catheter ablation of AF between 2009 and 2018 were eligible for inclusion. Reports from ablation procedures were screened to
Results
From among 8944 catheter ablation procedures for AF between 2009 and 2018, we identified 50 patients who underwent repeat catheter ablation for AF after a single index PVI and PWI at our institution (Table 1). At the time of the repeat ablation, patient age was 67 ± 10 years old, 19 (38%) had paroxysmal AF, and mean CHA2DS2-VASc score was 3.0 ± 1.8. All patients were taking oral anticoagulation at the time of ablation. The index PVI and PWI had been performed a mean of 1.4 ± 1.6 years before
Discussion
Although the role of electrical isolation of the posterior wall of the LA and the optimal patient population have not yet been definitively established, PWI is increasingly used to treat medically refractory AF. The most common technique for PWI is the creation of roof and floor lines connecting bilateral isolated superior and inferior pulmonary veins, respectively. Alternative strategies to achieve PWI have been suggested, and the scattered technique is increasingly advocated. With this
Conclusion
Posterior wall reconnection is present in 2 of every 5 patients at the time of redo ablation after previous PWI. The roof of the LA is the most common site of posterior wall reconnection, although multiple areas of connection, including epicardial connections, can be observed. It is critical not only that the role of PWI in patients with AF be clarified but also that the durability of isolation and significance of posterior wall reconnection be further evaluated.
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2023, JACC: Clinical ElectrophysiologyHybrid epicardial-endocardial ablation for long-standing persistent atrial fibrillation: A subanalysis of the CONVERGE Trial
2023, Heart Rhythm O2Citation Excerpt :Endocardial posterior wall isolation is not a routine procedure and may pose additional safety risks, which should be weighed against mixed clinical outcomes reported in the clinical literature.16 Posterior wall reconnection rates have been reported to be approximately 40% after endocardial posterior wall isolation with RF,17,18 and endocardial cryoballoon posterior wall isolation often requires adjunctive RF for completion.19 A recent retrospective observational study reported a propensity score-matched comparison of Catheter Ablation versus Hybrid Convergent ablation for LSPAF, with mean duration of AF from 2.5 to 3 years.20
Dr Nazarian is a consultant to Siemens, CardioSolv, and Circle Software; has given lectures for Circle Software; and has been a principal investigator for research funding to the University of Pennsylvania from Biosense Webster, Siemens, Imricor, and the National Institutes of Health. Dr Callans is a consultant to Biosense Webster and Abbott. All other authors have reported that they have no conflicts relevant to the contents of this paper to disclose.