The Value of Adjunctive Left Atrial Posterior Wall Isolation on Clinical Outcomes in Atrial Fibrillation Patients: a systematic review and meta-analysis

Abstract Background Although pulmonary vein isolation (PVI) remains the cornerstone of atrial fibrillation (AF) ablation. The left atrium posterior wall is an arrhythmogenic substrate that contributes to the development of AF. It remains unclear whether additional left atrial posterior wall isolation (LAPWI) beyond PVI is beneficial in AF patients. This study evaluated the impact of PWI on clinical outcomes of AF patients. Methods PubMed, EMBASE, and Cochrane Library databases were searched for studies comparing the outcomes of AF with and without PWI. The efficacy outcomes were recurrence of all atrial arrhythmia (AA), atrial fibrillation (AF), and atrial flutter (AFL)/atrial tachycardia (AT). The safety outcomes were mainly focused on procedural adverse events. Results A total of 16 studies (7 RCTs, 3 prospective study and 6 retrospective analysis) with 3340 patients with AF were included (1550 patients in PVI with PWI group and 1790 in PVI alone group). 12 studies included persistent atrial fibrillation patients, 3 studies with paroxysmal AF patients and 1 study with paroxysmal AF and persistent AF concurrently. Mean follow-up was 16.56months. In AF patients, adjunctive PWI obviously reduced the recurrence of all atrial arrhythmias (RR 0.78 [95% CI 0.64–0.95], I²=79%, P=0.01) and the recurrence of AF (RR 0.68 [95% CI 0.53–0.88], I²=75%, P=0.004); Meanwhile, adjunctive PWI was not associated with substantially lower recurrence of atrial flutter (AFL)/atrial tachycardia (AT) (RR 1.23 [95% CI 0.94–1.60], I²=49%, P=0.12) .The incidence of procedural adverse events between the PVI only and PWI+PVI was similar (RR 1.19 [95% CI 0.80–1.79], I²=0%, P=0.39). In subgroup analyses, the benefit of adjunctive PWI compared with PVI only was more significant in persistent AF group and cryoballoon ablation group. Notably, adjunctive PWI with radiofrequency ablation may induce a slight increase of recurrent AFL/AT compared with PVI only (RR 1.56 [95% CI 1.02–2.39], I²=30%, P=0.04). Conclusions In patients with AF, adjunctive PWI was associated with decreased recurrence of AF and atrial arrhythmias compared with PVI alone without an increased risk of procedural adverse events, especially in persistent AF patients. Cryoballoon ablation seemed more suitable for PWI compared with radiofrequency ablation. More RCTs are needed to verify the conclusion.