Does Energy Matter when Performing Posterior Wall Isolation in Addition to Pulmonary Vein Isolation at Atrial Fibrillation Ablation: a Meta-Analysis

Abstract Background Pulmonary vein isolation (PVI) remains the cornerstone of atrial fibrillation (AF) ablation. Posterior wall isolation (PWI) has been proposed as an adjunct to PVI to improve outcomes. Small series have reported conflicting outcomes. We conducted a meta-analysis of available data to assess the incremental impact of PWI based on whether patients were ablated using a cryoballoon (CB) or radiofrequency (RF) energy. Objective To evaluate whether PVI + PWI ablation is a more effective approach for treatment of AF than PVI alone when comparing different ablation energies. Methods The online databases (Pubmed, Medline, Embase) were searched using the terms "pulmonary vein isolation", "posterior wall isolation", or "posterior wall ablation". Out of 1917 studies, 11 met our strict criteria (Table). Specifically, patients were undergoing de novo ablation for treatment of AF using either CB or RF energy. Patients had PVI +/- PWI; studies that included additional ablations (except for cavotricuspid isthmus ablation) were excluded. The primary outcome was long-term freedom from recurrence of any atrial tachyarrhythmia (AT). Results The cohort consisted of 1905 patients (65 ± 18 years, 74% male); 910 (48%) pts ablated with CB energy and 995 (52%) pts ablated with RF energy (Table). In the CB group, AT recurrence was significantly higher in patients who underwent PVI alone as compared to those who also had PWI (OR 2.47, 95% CI [1.85, 3.31], P < 0.0001, Figure). In contrast, in the RF group, outcome was similar in patients who did and did not undergo PWI in addition to PVI (OR 1.22, 95% CI [0.80, 1.86], P = 0.36, Figure). Conclusions PWI in addition to PVI improved outcomes for patients ablated with CB energy. Conversely there was no benefit for patients in whom RF energy was used. Additional randomized studies are needed to determine the role of energy selection for patients undergoing PWI in conjunction with PVI for management of AF.