Posterior wall isolation not recommended for ablation of persistent atrial fibrillation: JAMA

The study's findings, published in the Journal of the American Medical Association (JAMA) on January 10, 2023, do not support the empirical inclusion of posterior wall isolation for the ablation of persistent atrial fibrillation.

Pulmonary vein isolation alone is less effective in persistent AF patients than paroxysmal AF. The left atrial posterior wall may contribute to the maintenance of persistent AF, and PWI is a common adjunct to pulmonary vein isolation. However, posterior wall isolation has not been subjected to randomized comparison.

Against the above background, Peter M. Kistler and a research team from Australia aimed to compare PVI with PWI vs PVI alone in patients with persistent AF undergoing first-time catheter ablation. They addressed the question, "does adding posterior wall isolation to pulmonary vein isolation improve success in patients with persistent atrial fibrillation undergoing first-time catheter ablation?

They conducted a multicenter, investigator-initiated, randomized clinical trial involving 11 centres in three countries (Canada, Australia, UK). It included symptomatic patients with persistent atrial fibrillation. They were randomized in a ratio of 1:1 to either PVI with PWI or PVI alone. Patient enrollment was done between 2018 to 2021, with the completion of 1-year follow-up in March 2022.

The PVI with PWI group comprising 170 patients underwent wide antral PVI followed by PW involving linear ablation at the roof and floor to achieve electrical isolation. The PVI-alone group comprising 168 patients experienced wide antral pulmonary vein isolation alone.

The primary endpoint was freedom from any documented atrial arrhythmia greater than 30 seconds without antiarrhythmic medication at 12 months following a single ablation procedure. The 23 secondary outcomes included freedom from symptomatic AF with/without antiarrhythmic prescription after multiple procedures, freedom from atrial arrhythmia with/without antiarrhythmic medication after numerous procedures, procedural outcomes, complications, and AF burden between study groups at 12 months.

The authors reported the following findings:

• Among 338 randomized patients (median age, 65.6 years; 76.9% men), 97.6% completed the study. After 12 months, 52.4% assigned to pulmonary vein isolation with PWI were free from recurrent atrial arrhythmia without antiarrhythmic medication following a single procedure, compared with 53.6% allocated to PVI alone (between-group difference, –1.2%; hazard ratio [HR], 0.99).
• Of the secondary endpoints, 9 showed no significant difference, including freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures (58.2% for PVI with PWI vs 60.1% for PVI alone; HR, 1.10), freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures (68.2% vs 72%; HR, 1.20) or AF burden (0% vs 0%).
• Mean procedural times (142 versus 121 minutes) and ablation times (34 vs 28 minutes) were significantly shorter for PVI alone. Six complications were seen in PVI with PWI and four for PVI alone.

The researchers conclude, "the addition of PWI to PVI alone does not remarkably improve freedom from atrial arrhythmia at 12 months versus PVI alone in patients undergoing first-time catheter ablation for persistent AF."

Reference:

Kistler PM, Chieng D, Sugumar H, et al. Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The CAPLA Randomized Clinical Trial. JAMA. 2023;329(2):127–135. doi:10.1001/jama.2022.23722