Adjunctive Left Atrial Posterior Wall Isolation in Treating Atrial Fibrillation: Insight From a Large Secondary Analysis.

Abstract

This study evaluated the role of adjunctive left atrium posterior wall isolation (PWI) in preventing atrial fibrillation (AF) recurrence. The left atrium posterior wall is an arrhythmogenic substrate that contributes to the development of AF. This was an updated pooled analysis that included clinical data regarding PWI plus pulmonary vein isolation (PVI) in treating AF. The primary outcome was recurrence of atrial tachyarrhythmias. A total of 26 studies with 3,287 patients with AF (age 61.7 ± 10.8 years) were included. Mean follow-up was 15.2± 8.4months. Procedural success to achieve PWI was 92.8%. In paroxysmal AF, adjunctive PWI did not reduce the recurrence of all atrial arrhythmias (P=0.21) or AF (P=0.37); however, in persistent AF, adjunctive PWI was associated with substantially lower recurrence of all atrial arrhythmias (risk ratio: 0.74; P< 0.001) and AF (risk ratio: 0.67; P=0.01), particularly when randomized data were included. Subgroup analyses based on meta-regression demonstrated that patients with older age, a larger left atrial diameter, and persistent AF benefited more significantly from the adjunctive PWI. Adjunctive PWI using either radiofrequency or a cryoballoon reduced AF recurrence, whereas using radiofrequency seemed to be associated with higher recurrence rate of atrial tachycardias and/or atrial flutter. Non-BOX adjunctive PWI rather than BOX PWI was associated with significantly lower recurrence of AF. The incidence of procedural adverse events between the PVI+PWI (3.2%) and PVI (2.8%) groups was low and similar. PVI+PWI needed longer ablation and/or procedural time but had similar fluoroscopy time. Adjunctive PWI can be achieved in most patients without compromising safety. Patients with persistent AF appear to benefit from this approach. The ablation technology and/or approach may affect the clinical outcome of PWI.