The addition of posterior wall isolation (PWI) does not improve arrhythmia outcomes compared with pulmonary vein isolation (PVI) alone in patients undergoing first time ablation for persistent atrial fibrillation (AF).
This is the concluding finding from the randomised, multicentre CAPLA study, presented for the first time during a late-breaking trial session at the European Society of Cardiology (ESC) congress (26–29 August, Barcelona, Spain) by Peter Kistler (The Alfred Heart Centre, Melbourne, Australia). Kistler told ESC delegates that the findings do not support the empiric inclusion of PWI for ablation of persistent AF.
“We are all well aware of the gap in the success of PVI alone in patients with paroxysmal, compared to persistent AF,” Kistler told the ESC audience, setting the scene for the CAPLA study, which randomised 338 patients to either PVI alone, or a combination of PVI and PWI. “We have been on a quest now for probably 20 years looking for what adjunctive therapy improves the outcome in persistent AF patients. While we see promise in non-randomised, smaller studies, once these additional strategies are subject to large multicentre randomised studies we see no additional improvement.”
CAPLA’s primary endpoint was freedom from any atrial arrhythmia greater than 30 seconds off antiarrhythmic drugs at 12 months, after a single ablation procedure. The outcome was assessed by an implantable loop recorder or single lead twice-daily electrocardiogram (ECG).
Kistler detailed that the patient population was “fairly standard for an atrial ablation series”, with a mean age of 65, predominantly male, and a median duration of continuous AF of around five months. Roughly half of the patients had hypertension, around two thirds were obese, and close to a quarter had a history of heart failure, Kistler noted.
“In keeping with the studies before it, there was no difference when posterior wall isolation was added to PVI in persistent AF patients for freedom from atrial arrhythmias off antiarrhythmic drugs at 12 months,” reported Kistler, detailing the study’s primary endpoint, which showed a rate of 52.4% freedom from AF at 12 months for PVI alone, compared to 53.9% in the PVI+PWI group for a hazard ratio (HR) of 1.01 (95% confidence interval 0.74–1.38, p=0.96).