Posterior wall isolation for persistent atrial fibrillation catheter ablation: an updated systematic review and meta-analysis

Abstract Background The ability of catheter ablation (CA) to prevent arrhythmic recurrences in patients with persistent atrial fibrillation (PeAF) remains suboptimal. In this context, the results of studies conducted with both thermal and non-thermal technologies, that evaluated the effect of adding electrical isolation of the posterior wall of the left atrium (PWI) to isolation of the pulmonary veins alone (PVI) have provided conflicting data. Purpose To compare the efficacy and safety of an ablative strategy with the addition of PWI to PVI versus PVI alone in patients with PeAF undergoing a first ablation procedure. Methods We searched electronic databases for observational studies and randomized controlled trials (RCTs) comparing PVI+PWI versus PVI alone as first CA procedure for PeAF, regardless of the technologies used. The efficacy outcomes were recurrence of any atrial tachyarrhythmias lasting more than 30 seconds, recurrence of atrial fibrillation (AF) and atrial flutter/atrial tachycardia (AFlu/AT). The safety outcome was relevant procedural complications defined as a composite of vascular complications, pericardial effusion or tamponade, phrenic nerve palsy, stroke, atrio-esophageal fistula, and death. The procedural time was compared between the ablation strategies studied. The software RevMan 5.4 was used to estimate the risk ratio (RR) and mean difference (MD) with the relative confidence intervals (CI), using a random-effect model. Results Thirteen studies (8 RCTs and 5 observational studies) counting a total of 2994 PeAF patients (1304 treated with PVI+PWI and 1690 with PVI alone; 1847 RF, 600 cryo and 547 PFA) were included in the analysis. Mean age was 65.2±4.1 years, and 26% were female. Mean follow-up period was 14.5±4.8 years. There were no significant differences in the risk of recurrence of any atrial tachyarrhythmias (RR 0.88; 95% CI 0.68-1.14) between the ablation strategies studied. Patients treated with PWI+PVI experienced a reduced risk of recurrence of AF (RR 0.67; 95% CI 0.48-0.94; p = 0.02) balanced by a trend towards increased risk of AFlu/AT (RR 1.74; 95% CI 0.99-3.06; p = 0.06) as compared with PVI alone strategy. No statistically significant differences in the risk of relevant procedural complication were identified between the studied groups (RR 0.94; 95% CI 0.50-1.78 – Fig. 2A). Procedural time was longer in the PWI+PVI group as compared with PVI alone (MD 30.63 min; 95% CI 8.60-52.65 min; p=0.006 – Fig. 2B). Conclusions Our metanalysis shows that, in patients with PeAF treated for the first time with CA, PWI+PVI versus PVI alone was not associated with a reduction of atrial tachyarrhythmias recurrence and required longer procedural times. Nonetheless, a reduction in the risk of AF recurrence and a trend towards an increased risk of AFlu/AT were identified. No differences in the risk of relevant procedural complications were found between the ablation strategies studied.Figure 2