Atrial Fibrillation Ablation Versus Atrioventricular Nodal Ablation With Conduction System Pacing in Heart Failure (ABACUS)

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University Hospitals (UH)


Not yet enrolling


Atrial Fibrillation, Persistent
Heart Failure


Procedure: Atrioventricular nodal ablation
Procedure: Atrial fibrillation ablation
Device: Conduction system pacing

Study type


Funder types




Details and patient eligibility


The goal of this clinical trial is to evaluate two treatment strategies in patients with chronic atrial fibrillation and heart failure, who are eligible for atrial fibrillation ablation. Patients will be randomized to either atrial fibrillation ablation or to implantation of a pacemaker with conduction system pacing followed by atrioventricular node ablation. The effect of treatment allocation on total mortality, cardiovascular hospitalization and heart failure hospitalization will be compared.

Full description

Aim To compare clinical outcome with a strategy of conduction system pacing and atrioventricular nodal ablation (CSP+AVNA), versus atrial fibrillation (AF) ablation by pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF) and heart failure (HF), to guide future management of these patients. Hypotheses CSP+AVNA is superior to AF ablation in patients with persistent AF and HF for reducing mortality and cardiovascular hospitalization. CSP+AVNA is non-inferior to AF ablation in patients with persistent AF for reducing mortality and heart failure hospitalization. Design Investigator-initiated, prospective randomized, controlled, open-label, multicentre study conducted in ~ 30 centres from 14 countries in Europe with expertise in CSP and AF ablation. Sample size 220 patients Study duration 4 years


220 estimated patients




60+ years old


No Healthy Volunteers

Inclusion criteria

(i) Persistent AF with symptomatic HF despite medical therapy, considered to be suitable for AF ablation, with at most one previous PVI procedure.

(ii) At least one prior hospital admission, or emergency room / HF clinic visit for HF in the past 2 years, with NT-pro-BNP > 1000 pg/ml or BNP > 250 pg/ml measured at any timepoint during this interval.

(iii) Previous or current rate or rhythm control drug therapy. (iv) Age > 60 years

Exclusion criteria

(i) NYHA Class IV and systolic blood pressure ≤80 mmHg despite optimized therapy.

(ii) Life expectancy < 2 years. (iii) Need for major surgical intervention. (iv) Myocardial infarction, stroke or PCI within the previous 3 months. (v) Previously implanted or planned implantation of CRT device or pacemaker. Implantable cardioverter defibrillator (ICD) implantation without a pacing indication is acceptable.

(vi) Participation in another controlled trial. (vii) Inability to sign and informed consent form.

Trial design

Primary purpose




Interventional model

Parallel Assignment


Single Blind

220 participants in 2 patient groups

Atrial fibrillation ablation
Other group
Catheter ablation of atrial fibrillation using technique at the investigator's discretion but including pulmonary vein isolation as an endpoint.
Procedure: Atrial fibrillation ablation
Conduction system pacing + atrioventricular nodal ablation
Active Comparator group
Conduction system pacing (either His bundle pacing or left bundle branch area pacing) with catheter ablation of the atrioventricular node.
Device: Conduction system pacing
Procedure: Atrioventricular nodal ablation

Trial contacts and locations



Central trial contact

Haran Burri; Nikola Kozhuharov

Data sourced from

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