Feasibility, Safety, and Efficacy of Posterior Wall Isolation During Atrial Fibrillation Ablation

Abstract

Background: The posterior left atrium is an arrhythmogenic substrate that contributes to the initiation and maintenance of atrial fibrillation (AF); however, the feasibility, safety, and efficacy of posterior wall isolation (PWI) as an AF ablation strategy has not been widely reported. Methods: We undertook a systematic review and meta-analysis of studies performing PWI to assess (1) acute procedural success including the ability to achieve PWI and the number of procedure-related complications, (2) Long-term, clinical success including rates of arrhythmia recurrence and posterior wall reconnection, and (3) The efficacy of PWI compared with pulmonary vein isolation on preventing arrhythmia recurrence. MEDLINE, EMBASE, and Web of Science databases were searched in May 2018 to retrieve relevant studies. Results were pooled using a random effects model. Results: Seventeen studies (13 box isolation, 3 single ring isolation, and 1 debulking ablation) comprising 1643 patients (31.3% paroxysmal AF, left atrial diameter 41±3.1 mm) were included in the final analysis. In studies focusing specifically on PWI, the acute procedural success rate for achieving PWI was 94.1% (95% CI, 87.2%–99.3%). Single-procedure 12-month freedom from atrial arrhythmia was 65.3% (95% CI, 57.7%–73.9%) overall and 61.9% (54.2%–70.8%) for persistent AF. Randomized control trials comparing PWI to pulmonary vein isolation (3 studies, 444 patients) yielded conflicting results and could not confirm an incremental benefit to PWI. Fifteen major complications (0.1%), including 2 atrio-esophageal fistulas, were reported. Conclusions: PWI as an end point of AF ablation can be achieved in a large proportion of cases with good rates of 12-month freedom from atrial arrhythmia. Although the procedure-related complication rate is low, it did not eliminate the risk of atrio-esophageal fistula. Registration: URL: http://www.crd.york.ac.uk/prospero . PROSPERO registration number: CRD42018107212.

Clinical outcomes of adjunctive posterior wall isolation in persistent atrial fibrillation: A meta‐analysis

“…Another disadvantage of PWI is the risk of complications, 6 such as atrioesophageal (AE) fistula. A rise in temperature of the esophagus has been cited as a reason to abandon PWI by some operators 33 . In those instances, different approaches have been used in obtaining successful ablation of the PW, such as lowering the wattage of radiofrequency energy, or using higher power but for a shorter duration.…”

Safety and Efficacy of High Power Shorter duration Ablation for Atrial Fibrillation: A Systematic Review and Meta-Analysis.

“…Because retaining catheter stability in a constantly working heart for a long time is very difficult, and tissue edema by long duration ablation limits effective ablation 2 . Moreover, the left atrium is adjacent to the esophagus, injury depth may be excessive by long duration ablation despite a lower power setting, thus increasing the risk of esophageal thermal injury (ETI) 5 . Simultaneously, a large fluid volume infused via a catheter during ablation, which is proportional to the ablation time, can induce acute heart failure in patients with impaired left ventricular function 6 .…”

Comparison of high‐power short‐duration and low‐power long‐duration radiofrequency ablation for treating atrial fibrillation: Systematic review and meta‐analysis

“…[2][3][4][5][6] The left atrium is adjacent to the esophagus and the injury depth may be excessive from long-duration ablation, both of which increase the risk of esophageal thermal injuries (ETIs). 7 The incidence of atrio-esophageal fistula (AEF) was reported as 0.1% to 0.25%, and the incidence of ETI was 2% to 50% for the LPLD 8 .…”