This research is Trending!
October 6, 2026
Biventricular vs conduction system pacing after atrioventricular node ablation for heart failure with atrial fibrillation: the CONDUCT-AF trial.
Key result
Conduction system pacing matches biventricular pacing for 6-month LVEF improvement after AV node ablation.
- MD 0.4
- 95% CI -3.1-3.8
- P=0.002 for non-inferiority
- n=82
Why the study?
Randomized evidence comparing conduction system pacing and biventricular pacing after atrioventricular node ablation in patients with refractory atrial fibrillation and heart failure is limited.
Does conduction system pacing with left bundle branch area pacing improve LVEF non-inferiorly to biventricular pacing in patients with refractory atrial fibrillation and heart failure undergoing atrioventricular node ablation?
Key Points
- To evaluate whether conduction system pacing with left bundle branch area pacing is non-inferior to biventricular pacing in improving left ventricular ejection fraction in patients with heart failure and refractory atrial fibrillation undergoing atrioventricular node ablation.
- Multicentre, randomized 1:1 trial across 10 European centres enrolling 82 patients with refractory atrial fibrillation, heart failure with LVEF < 50%, QRS duration ≤ 120 ms, and NT-proBNP > 600 ng/L.
- Patients were assigned to conduction system pacing (CSP) or biventricular pacing (BVP), with the primary outcome of change in LVEF evaluated by an independent core laboratory at 6 months.
- LVEF increased from 36% (95% CI 33–39) to 46% (95% CI 44–49) with CSP and from 34% (95% CI 31–36) to 46% (95% CI 43–49) with BVP (between-group difference 0.4%, 95% CI -3.1 to 3.8; P = .002 for non-inferiority).
- Paced QRS duration was shorter with CSP compared to BVP (mean difference -14 ms, 95% CI -19 to -9; P < .001), alongside significantly reduced procedural and fluoroscopy times.
- Ventricular volumes, clinical measures, and the composite rate of worsening heart failure or cardiovascular death were comparable between treatment arms.
Study Design
Type
RCT (n=82)
Randomization
1:1
Multicenter
Yes
Structured PICO
Does conduction system pacing with left bundle branch area pacing improve LVEF non-inferiorly to biventricular pacing in patients with refractory atrial fibrillation and heart failure undergoing atrioventricular node ablation?
P
Population
82 patients (mean age 72, 54% female) with refractory AF and heart failure (LVEF < 50%) undergoing atrioventricular node ablation, followed for 6 months.
I
Intervention
Conduction system pacing (CSP) with left bundle branch area pacing following atrioventricular node ablation.
C
Comparator
Biventricular pacing (BVP) following atrioventricular node ablation.
O
Outcome
Change in left ventricular ejection fraction (LVEF) after 6 months, assessed by an independent core laboratory.surrogate
Main Result
Mean Difference: 0.4 (95% CI -3.1–3.8)
Absolute Event Rate: 46% vs 46%
p-value: p=0.002 for non-inferiority
Conduction system pacing with left bundle branch area pacing is non-inferior to biventricular pacing for improving LVEF at 6 months in patients with heart failure and refractory atrial fibrillation undergoing AV node ablation, with shorter procedural times and narrower paced QRS.
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“LVEF improved by about 10% through 6 months of follow-up with either pacing modality, with the 0.4% between-group difference (95% CI -3.1% to 3.8%) meeting criteria for the noninferiority of LBBAP at a 5% margin (P = 0.002).”
“In terms of noninferiority, the study seems to have been powered correctly, seems to have been carried out appropriately, and, therefore, I think we have solid evidence that when we're focusing on preservation or improvement of LV ejection fraction, CSP in this case, provided it's done well, is a reasonable alternative to biventricular pacing.”
Implication
CSP noninferior to BVP for LVEF improvement post-AVNA; supports conduction system pacing as alternative in narrow-QRS HF with refractory AF.
Abstract
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.
CONDUCT-AF · randomized trial. After AV node ablation, conduction system pacing matches biventricular pacing on LVEF. Biventricular vs conduction system pacing after atrioventricular node ablation for heart failure with atrial fibrillation: the CONDUCT-AF trial. 82 patients: Refractory AF, HF with LVEF < 50%, narrow QRS. Both after AV node ablation: Conduction system pacing vs Biventricular pacing. 0.4% Between-group LVEF difference. MD 0.4 (95% CI -3.1–3.8), P=0.002 for non-inferiority. Non-inferior LVEF gain at 6 months. CSP was quicker with narrower QRS: Shorter paced QRS, Shorter procedure, Less fluoroscopy, Similar clinical outcomes. Dr. Klaus Witte (Cardiologist · University of Leeds and Leeds Teaching Hospitals NHS Trust, England): “CSP in this case, provided it's done well, is a reasonable alternative to biventricular pacing.” From their public comments on the paper Bottom line: In narrow-QRS HF with refractory AF, CSP is an alternative to BVP.
Coverage & sources
Journal, society, and media accounts. Useful signal, not independent expert judgment.
Discussion
No takes yet. Share an insight, caveat, or question.
Cite This Study
Žižek et al. (2026) conducted an RCT in Refractory atrial fibrillation and heart failure (n=82). Conduction system pacing (CSP) with left bundle branch area pacing vs. Biventricular pacing (BVP) was evaluated on change in LVEF after 6 months (MD 0.4, 95% CI -3.1-3.8, p=0.002 for non-inferiority). Conduction system pacing was non-inferior to biventricular pacing for 6-month LVEF improvement in patients with refractory AF and HF undergoing AV node ablation (between-group diff 0.4%; P=0.002).