The CONDUCT-AF trial: Rationale and design of a prospective, randomized, multicentre study comparing conduction system and biventricular pacing in patients undergoing atrioventricular node ablation for heart failure with atrial fibrillation.

AIMS There is a lack of data from randomized clinical trials comparing treatment outcomes between conduction system pacing (CSP) modalities and biventricular pacing (BVP) in symptomatic patients with refractory atrial fibrillation (AF) scheduled for atrioventricular node ablation (AVNA). The CONDUCT-AF investigates whether CSP is non-inferior to BVP in improving left ventricular ejection fraction (LVEF) and clinical outcomes in heart failure (HF) patients with symptomatic AF undergoing AVNA. METHODS This study is an investigator-initiated, prospective, randomized, multicentre clinical trial conducted across 10 European centres, enrolling 82 patients with symptomatic AF, HF with reduced LVEF, and narrow QRS. Participants will be randomized 1:1 to CSP or BVP with subsequent AVNA and followed for at least 24 months. The primary endpoint is the change in LVEF after 6 months. Secondary endpoints will include time to the first occurrence of worsening HF or cardiovascular death and its individual components, total number of HF hospitalizations, change in quality of life, N-terminal pro-B-type natriuretic peptide, 6-min walk test distance, and safety outcomes. CONCLUSIONS The CONDUCT-AF trial will provide critical insights into the optimal pacing modality for patients with HF and refractory AF undergoing AVNA. Recruitment is expected to conclude in 2025, with the first study results anticipated in 2026.