Adjunctive Left Atrial Posterior Wall Isolation in Treating Non-Paroxysmal Atrial Fibrillation: An Updated Meta-Analysis of Randomized Clinical Trials.

Background: The clinical outcomes of adjunctive posterior wall isolation (PWI) beyond pulmonary vein isolation (PVI) for non-paroxysmal atrial fibrillation (AF) remain unclear. This meta-analysis was conducted to evaluate the role of PWI in non-paroxysmal AF by pooled analysis of most updated randomized controlled trials (RCTs).

Methods: A literature search in PubMed, Embase, and the Cochrane Library was performed to identify RCTs comparing the outcomes of PVI with and without PWI in non-paroxysmal AF patients. The primary outcomes were recurrence rates of all atrial arrhythmias, AF, and atrial tachycardia/flutter (AT/AFL). The secondary outcomes included total procedure time, ablation time, fluoroscopy time and procedure-related complications. Estimated risk ratios (RRs) and 95% confidence intervals (CIs) were evaluated.

Results: Nine RCTs with a total of 1,243 non-paroxysmal AF patients were included in our analysis. There were no significant differences in all atrial arrhythmias recurrence (RR: 0.86, 95% CI: 0.66-1.11, p = 0.24, I2 = 49%) and AF recurrence (RR: 0.74, 95% CI: 0.51-1.08, p = 0.12, I2 = 62%) between stand-alone PVI group and PVI plus PWI group. Adjunctive PWI increased the AT/AFL recurrence rate (RR: 1.62 95% CI: 1.08-2.42, p = 0.02, I2 = 0%). In the subgroup analysis, PWI using cryoballoon ablation was associated with a significantly lower recurrence rate of all atrial arrhythmias (p = 0.01) and AF (p = 0.02) recurrence and similar recurrence rate of AT/AFL (p = 0.15). Additional PWI was associated with an increased AT/AFL recurrence (p = 0.03) in patients with left atrial diameter (LAD) <44 mm. Adjunctive PWI needed longer ablation time, fluoroscopy time, and total procedure time. The incidence of procedural adverse events was low and similar between both groups.

Conclusions: Adjunctive PWI beyond PVI did not improve the freedom from all atrial arrhythmias and AF with an increased recurrence rate of AT/AFL in non-paroxysmal AF patients. The ablation energy and LAD might affect the clinical outcome of PWI. However, larger more RCTs were needed to verify our findings.