Biventricular vs conduction system pacing after atrioventricular node ablation for heart failure with atrial fibrillation: the CONDUCT-AF trial.

BACKGROUND AND AIMS: Randomized evidence comparing conduction system pacing (CSP) and biventricular pacing (BVP) following atrioventricular node ablation in patients with refractory atrial fibrillation (AF) and heart failure (HF) remains limited. This study evaluated whether CSP with left bundle branch area pacing is non-inferior to BVP in patients undergoing atrioventricular node ablation. METHODS: CONDUCT-AF was an investigator-initiated, multicentre, randomized trial conducted across 10 European centres. Patients with refractory AF, HF with left ventricular ejection fraction (LVEF) < 50%, narrow QRS duration (≤120 ms), and N-terminal pro-B-type natriuretic peptide > 600 ng/L were randomized 1:1 to CSP or BVP. The primary endpoint was the change in LVEF after 6 months, assessed by an independent core laboratory. Secondary endpoints included echocardiographic, clinical, and procedural outcomes. Analyses followed the intention-to-treat principle. RESULTS: Eighty-two patients were randomized (mean age 72 ± 7 years, 46% male). At 6 months, LVEF improved similarly in CSP {from 36% [95% confidence interval (CI) 33-39] to 46% [95% CI 44-49]; P < .001} and BVP group [from 34% (95% CI 31-36) to 46% (95% CI 43-49); P < .001]. The between-group difference was .4% (95% CI -3.1-3.8; P = .002 for non-inferiority). Changes in left ventricular volumes, clinical parameters, and composite endpoint of worsening HF or cardiovascular death were comparable between groups. Paced QRS [mean difference -14 ms (95% CI -19 to -9; P < .001)] and procedural and fluoroscopy times were significantly shorter with CSP compared with BVP. CONCLUSIONS: In HF patients with refractory AF undergoing atrioventricular node ablation, CSP with left bundle branch area pacing was non-inferior to BVP for LVEF improvement at 6 months, providing comparable clinical outcomes and a favourable procedural profile.