Heart FailureCONDUCT-AFNCT05467163
Conduction System Pacing Versus Biventricular Pacing After Atrioventricular Node Ablation
A study testing Biventricular pacemaker implantation, Conduction system pacing device implantation and AV node ablation in people with Heart Failure and Tachycardia-induced Cardiomyopathy, run by University Medical Centre Ljubljana at 10 sites in 7 countries.
Trial summary
Atrioventricular node ablation (AVNA) with biventricular (BiV) pacemaker implantation is a feasible treatment option in patients with symptomatic refractory atrial fibrillation and heart failure. Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- Heart Failure, Tachycardia-induced Cardiomyopathy, Atrial Fibrillation
- What is being tested?
- Biventricular pacemaker implantation, Conduction system pacing device implantation and AV node ablation
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 82 participants
- Where
- 10 sitesin 7 countries
- Study dates
- 18 Jul 2023to 25 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Symptomatic permanent atrial fibrillation, refractory to drug therapy or failed catheter ablation
- Left ventricular ejection fraction <50%
- Narrow intrinsic QRS ≤ 120 ms
- NT-proBNP > 600 ng/L
- Patient has provided written informed consent
- Age between 18 years and 85 years
Who cannot join
- Pre-existing permanent pacemaker, implantable cardioverter-defibrillator or cardiac resynchronization device. Patients who had devices implanted that had <5% of paced beats (i.e., backup pacing) can be enrolled.
- Life expectancy less than 12 months
- Severe concomitant non-cardiac disease
- Pregnancy
- Recent (<3 months) myocardial infarction, percutaneous or surgical myocardial revascularization
- Significant heart valve disease (severe insufficiency or stenosis)
Show all 9Show fewer
- Contraindication for oral anticoagulation
- Mechanical tricuspid valve replacement
- Unwillingness to participate or lack of availability for follow-up
Trial locations and contacts
10 sites in 7 countries.
10 sites in 7 countries
Croatia3 sites
Clinical Hospital Center Rijeka
Rijeka
University Hospital of Split
Split
University Hospital Centre Zagreb
Zagreb
Slovenia2 sites
University Medical Centre Ljubljana - Department of cardiology
Ljubljana, 1000
University Medical Centre Ljubljana - Department of cardiovascular surgery
Ljubljana, 1000
Bulgaria1 site
Acibadem City Clinic Tokuda Hospital - Department of Invasive Electrophysiology
Sofia
Hungary1 site
Central-Hospital of Northern Pest - Military Hospital
Budapest, 1134
Romania1 site
County Clinical emergency hospital of Brasov - Department of Interventional Cardiology
Brasov
About this study
Official title: CONDUCTion System Pacing Versus Biventricular Pacing After Atrioventricular Node Ablation in Heart Failure Patients With Symptomatic Atrial Fibrillation and Narrow QRS (CONDUCT-AF Trial)
Atrioventricular node ablation (AVNA) with biventricular (BiV) pacemaker implantation is a feasible treatment option in patients with symptomatic refractory atrial fibrillation and heart failure. However, conduction system pacing (CSP) modalities, including His bundle pacing and left bundle branch pacing, could offer advantages over BiV pacing by providing more physiological activation. The randomized, interventional, multicentric study will explore whether CSP is non-inferior to BiV pacing in echocardiographic and clinical outcomes in heart failure (EF <50%) patients with symptomatic AF and narrow QRS scheduled for AVNA.
Read the detailed description
Atrio-ventricular node ablation (AVNA) with subsequent permanent pacemaker implantation provides definite rate control and represents an alternative therapeutic approach in patients with symptomatic atrial fibrillation (AF) and rapid ventricular rate, refractory to optimal medical treatment or catheter ablation. However, optimal pacing modality remains unclear. Previous studies have demonstrated that biventricular (BiV) pacing followed by AVNA resulted in significant reduction in mortality, heart failure (HF) hospitalizations, significant improvement in symptoms and left ventricular (LV) remodeling. Although, its benefit was much less transparent in patients with narrow QRS and LV impairment, as it still causes abnormal cardiac activation with potential worsening of electrical dyssynchrony. To avoid the detrimental effects of BiV pacing a new concept, conduction system pacing (CSP), including His bundle Pacing (HBP) and left bundle branch pacing (LBBP), was proposed as a potential alternative. Both CSP modalities offer advantages over BiV pacing by providing more physiological activation, avoiding cardiac dyssynchrony and left ventricular dysfunction. Moreover, LBBP showed some advantages over HBP. Since the lead is implanted in the region of the left bundle, which has an adequate distance from the AVNA site, this modality could minimize the risk of increase in capture threshold after AVNA. Additionally, the pacing parameters of LBBP were stable in long-term follow-up studies precluding the need for back-up pacing. Therefore compared to HBP and BiV pacing, LBBP may offer a more feasible physiologic pacing option to be adopted into clinical practice. Some observational studies have already shown positive outcomes of HBP and LBBP in symptomatic AF patients who underwent AVNA with the favorable clinical and echocardiographic improvement compared to BIV pacing, especially in HF patients with narrow baseline QRS and reduced ejection fraction (EF<50%). However, prospective randomized study evaluating the value of CSP as an alternative approach to BiV pacing in combination with AVNA is lacking.
The purpose of this study is to compare the effects of CSP and conventional BiV pacing on echocardiographic and clinical outcomes in HF patients with symptomatic AF and narrow QRS scheduled for AVNA. In this multicentric study, 82 patients will be randomized into one of two arms: a BiV pacing arm with BiV pacemaker implantation + AVNA or CSP arm with the implantation of a CSP device + AVNA. In patients randomized in CSP group, LBBP will be the preferred pacing technique. If LBBP will be unobtainable, HBP implantation will be attempted. In both arms additional defibrillator backup will be implanted at the discretion of the physician according to the ESC guidelines. In short-term analysis after 6 months, echocardiographic, laboratory and symptomatic parameters will be evaluated. Long-term analysis to assess HF hospitalization, cardiovascular mortality and pacing parameters will be performed after at least 24 months of follow-up.
Investigators hypothesize that CSP could represent a feasible and safe alternative to BiV pacing in terms of clinical and echocardiographic outcomes.
- Being tested
- Biventricular pacemaker implantation, Conduction system pacing device implantation, AV node ablation
- Keywords
- Heart failure, Atrial fibrillation, Conduction system pacing, His bundle pacing, Left bundle branch pacing, Biventricular pacing, Atrioventricular node ablation
- Medical subject headings
- Heart Failure, Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Biventricular pacemaker implantationDevice
Implantation of permanent pacemaker with biventricular stimulation with or without defibrillator lead placement using standard techniques. The right ventricle lead will be positioned in the RV apex or septum, while the left ventricle lead will be delivered to the most appropriate coronary sinus tributary, preferably posterolateral or lateral vein.
Conduction system pacing device implantationDevice
Left bundle branch pacing (LBBP) will be the preferred pacing technique. In brief, after localizing the His bundle area the LBBP lead will be positioned approximately 1-1.5 cm distal to the His bundle position in the right ventricular septum. Before screwing the lead deep into the interventricular septum, the suitable position will be confirmed by fluoroscopic signs and adequate paced QSR morphology. Given that the pacing parameters with LBBP are typically low and stable, backup RV lead will not be mandatory. If LBBP will be unobtainable, His bundle pacing (HBP) implantation will be attempted. His bundle potential mapping will be performed with the use of the electrophysiological system and under fluoroscopic guidance. Distal HB potential with a large ventricular signal and a small atrial signal will be targeted before the pacing lead will be screwed into position. Backup RV lead will be mandatory for all patients receiving HBP devices.
AV node ablationProcedure or surgery
Atrioventricular node ablation (AVNA) will be performed following pacemaker implantation (preferably during the same hospitalization). After femoral vein access will be obtained, the ablation catheter will be positioned to the presumed area of the AV node in the mid-septum under fluoroscopy. The location will be optimized according to the intracardiac electrograms. Ablation will be performed in a temperature-controlled mode. Successful AVNA will be recognized with an abrupt drop of heart rate to 40 bpm and will continue for 60 seconds thereafter.
| Study group | Role | What they receive |
|---|---|---|
| Biventricular pacing + AV node ablation | Active comparator | Implantation of biventricular pacemaker with or without defibrillator lead placement followed by AV node ablation. Optimal guidelines-based heart failure treatment. Receives: Device: Biventricular pacemaker implantation; Procedure: AV node ablation |
| Conduction system pacing + AV node ablation | Experimental | Implantation of permanent pacemaker with conduction system pacing (preferably left bundle branch) with or without defibrillator lead placement followed by AV node ablation. Optimal guidelines-based heart failure treatment. Receives: Device: Conduction system pacing device implantation; Procedure: AV node ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in left ventricular ejection fraction.
Simpson's method assessed with echo.
Measured: baseline and 6 months
Secondary outcomes (16)
Time to the first occurrence of worsening heart failure or cardiovascular death.
An episode of heart failure that requires unplanned medical attention with increase of diuretic dose / intravenous diuretic therapy or death due to cardiovascular causes.
Measured: at least 24 months
Time to the first occurrence of worsening heart failure.
An episode of heart failure that requires unplanned medical attention with increase of diuretic dose or intravenous diuretic therapy.
Measured: at least 24 months
Time to cardiovascular death.
Death due to cardiovascular causes.
Measured: at least 24 months
Number of heart failure hospitalizations.
Episodes of heart failure that require unplanned medical attention with increase of diuretic dose or intravenous diuretic therapy.
Measured: at least 24 months
Change in LV end-diastolic and end-systolic volume index.
LV volumes indexed for body surface area - assessed by echo.
Measured: baseline and 6 months
Change in clinical parameters
Quality of life measured by New York Heart Association (NYHA) classification.
Measured: baseline and 6 months
Change in clinical parameters
Quality of life measured by Kansas City Cardiomyopathy Questionnaire (KCCQ).
Measured: baseline and 6 months
Improvement in clinical parameters
Quality of life measured by European Heart Rhythm Association score of atrial fibrillation (EHRA AF).
Measured: baseline and 6 months
Change in 6-Minute walk test.
Standard measurement.
Measured: baseline and 6 months
Laboratory parameters.
NT-proB-type Natriuretic Peptide (BNP)
Measured: baseline and 6 months
Procedural-related characteristics.
Total procedure and fluoroscopy time.
Measured: peri-procedural
Procedure-associated adverse events.
Lead dislocations, device infection, bleeding, pneumotorax, etc.
Measured: peri-procedural, 30 days after the procedure
Need for procedural reintervention.
Unplanned reintervention due to lead dysfunction or dislocation, device infection etc.
Measured: at least 24 months
ECG parameters.
QRS duration and morphology.
Measured: before and after the procedure
Pacing parameters.
Capture threshold measurement.
Measured: peri-procedural, at least 24 months
Number of detected sustained VT/VF.
Detected sustained ventricular tachycardia or ventricular fibrillation on pacemaker telemetry.
Measured: at least 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jul 2022
- Study start18 Jul 2023
- Primary completion25 Dec 2025
- Study completion25 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (12)Papers the sponsor has linked to this study.
- Other trials for Heart FailureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 82 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Medical Centre Ljubljana
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David Žižek, MD, PhD, University Medical Centre Ljubljana
- Investigators
- Andrej Pernat, MD, PhD, Study director, UMC LjubljanaDavid Zizek, MD, PhD, Principal investigator, UMC Ljubljana
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05467163
- Sponsor's protocol ID
- CONDUCT-AF trial
- Acronym
- CONDUCT-AF
- Status last verified
- Apr 2026
- First submitted
- 17 Jul 2022
- Last updated
- 29 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: It is not yet known if there will be a plan to make IPD available.
Publications
Tan ES, Rienstra M, Wiesfeld AC, Schoonderwoerd BA, Hobbel HH, Van Gelder IC. Long-term outcome of the atrioventricular node ablation and pacemaker implantation for symptomatic refractory atrial fibrillation. Europace. 2008 Apr;10(4):412-8. doi: 10.1093/europace/eun020. Epub 2008 Feb 12.
PubMed 18272509Orlov MV, Gardin JM, Slawsky M, Bess RL, Cohen G, Bailey W, Plumb V, Flathmann H, de Metz K. Biventricular pacing improves cardiac function and prevents further left atrial remodeling in patients with symptomatic atrial fibrillation after atrioventricular node ablation. Am Heart J. 2010 Feb;159(2):264-70. doi: 10.1016/j.ahj.2009.11.012.
PubMed 20152225Chatterjee NA, Upadhyay GA, Ellenbogen KA, Hayes DL, Singh JP. Atrioventricular nodal ablation in atrial fibrillation: a meta-analysis of biventricular vs. right ventricular pacing mode. Eur J Heart Fail. 2012 Jun;14(6):661-7. doi: 10.1093/eurjhf/hfs036. Epub 2012 Mar 21.
PubMed 22436544Brignole M, Pentimalli F, Palmisano P, Landolina M, Quartieri F, Occhetta E, Calo L, Mascia G, Mont L, Vernooy K, van Dijk V, Allaart C, Fauchier L, Gasparini M, Parati G, Soranna D, Rienstra M, Van Gelder IC; APAF-CRT Trial Investigators. AV junction ablation and cardiac resynchronization for patients with permanent atrial fibrillation and narrow QRS: the APAF-CRT mortality trial. Eur Heart J. 2021 Dec 7;42(46):4731-4739. doi: 10.1093/eurheartj/ehab569.
PubMed 34453840Muthumala A, Vijayaraman P. His-Purkinje conduction system pacing and atrioventricular node ablation. Herzschrittmacherther Elektrophysiol. 2020 Jun;31(2):117-123. doi: 10.1007/s00399-020-00679-7. Epub 2020 May 6.
PubMed 32377902Wang S, Wu S, Xu L, Xiao F, Whinnett ZI, Vijayaraman P, Su L, Huang W. Feasibility and Efficacy of His Bundle Pacing or Left Bundle Pacing Combined With Atrioventricular Node Ablation in Patients With Persistent Atrial Fibrillation and Implantable Cardioverter-Defibrillator Therapy. J Am Heart Assoc. 2019 Dec 17;8(24):e014253. doi: 10.1161/JAHA.119.014253. Epub 2019 Dec 13.
PubMed 31830874Su L, Cai M, Wu S, Wang S, Xu T, Vijayaraman P, Huang W. Long-term performance and risk factors analysis after permanent His-bundle pacing and atrioventricular node ablation in patients with atrial fibrillation and heart failure. Europace. 2020 Dec 26;22(Suppl_2):ii19-ii26. doi: 10.1093/europace/euaa306.
PubMed 33370800Huang W, Su L, Wu S, Xu L, Xiao F, Zhou X, Ellenbogen KA. Benefits of Permanent His Bundle Pacing Combined With Atrioventricular Node Ablation in Atrial Fibrillation Patients With Heart Failure With Both Preserved and Reduced Left Ventricular Ejection Fraction. J Am Heart Assoc. 2017 Apr 1;6(4):e005309. doi: 10.1161/JAHA.116.005309.
PubMed 28365568Zizek D, Antolic B, Meznar AZ, Zavrl-Dzananovic D, Jan M, Stublar J, Pernat A. Biventricular versus His bundle pacing after atrioventricular node ablation in heart failure patients with narrow QRS. Acta Cardiol. 2022 May;77(3):222-230. doi: 10.1080/00015385.2021.1903196. Epub 2021 Jun 2.
PubMed 34078244Ivanovski M, Mrak M, Meznar AZ, Zizek D. Biventricular versus Conduction System Pacing after Atrioventricular Node Ablation in Heart Failure Patients with Atrial Fibrillation. J Cardiovasc Dev Dis. 2022 Jul 1;9(7):209. doi: 10.3390/jcdd9070209.
PubMed 35877570Pillai A, Kolominsky J, Koneru JN, Kron J, Shepard RK, Kalahasty G, Huang W, Verma A, Ellenbogen KA. Atrioventricular junction ablation in patients with conduction system pacing leads: A comparison of His-bundle vs left bundle branch area pacing leads. Heart Rhythm. 2022 Jul;19(7):1116-1123. doi: 10.1016/j.hrthm.2022.03.1222. Epub 2022 Mar 26.
PubMed 35351624Brugada J, Katritsis DG, Arbelo E, Arribas F, Bax JJ, Blomstrom-Lundqvist C, Calkins H, Corrado D, Deftereos SG, Diller GP, Gomez-Doblas JJ, Gorenek B, Grace A, Ho SY, Kaski JC, Kuck KH, Lambiase PD, Sacher F, Sarquella-Brugada G, Suwalski P, Zaza A; ESC Scientific Document Group. 2019 ESC Guidelines for the management of patients with supraventricular tachycardiaThe Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). Eur Heart J. 2020 Feb 1;41(5):655-720. doi: 10.1093/eurheartj/ehz467. No abstract available.
PubMed 31504425
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- CONDUCTion System Pacing Versus Biventricular Pacing After Atrioventricular Node Ablation in Heart Failure Patients With Symptomatic Atrial Fibrillation and Narrow QRS (CONDUCT-AF Trial)
- ClinicalTrials.gov ID
- NCT05467163
- Acronym / sponsor ID
- CONDUCT-AF / CONDUCT-AF trial
- Keywords
- Heart failure, Atrial fibrillation, Conduction system pacing, His bundle pacing, Left bundle branch pacing, Biventricular pacing, Atrioventricular node ablation
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 82 participants (estimated)
- Lead sponsor
- University Medical Centre LjubljanaUniversity, hospital or other
- Study start
- 18 Jul 2023 (actual)
- Primary completion
- 25 Dec 2025 (actual)
- Study completion
- 25 Dec 2026 (estimated)
- First posted
- 20 Jul 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Atrioventricular node ablation (AVNA) with biventricular (BiV) pacemaker implantation is a feasible treatment option in patients with symptomatic refractory atrial fibrillation and heart failure. However, conduction system pacing (CSP) modalities, including His bundle pacing and left bundle branch pacing, could offer advantages over BiV pacing by providing more physiological activation. The randomized, interventional, multicentric study will explore whether CSP is non-inferior to BiV pacing in echocardiographic and clinical outcomes in heart failure (EF <50%) patients with symptomatic AF and narrow QRS scheduled for AVNA.
Detailed description
Atrio-ventricular node ablation (AVNA) with subsequent permanent pacemaker implantation provides definite rate control and represents an alternative therapeutic approach in patients with symptomatic atrial fibrillation (AF) and rapid ventricular rate, refractory to optimal medical treatment or catheter ablation. However, optimal pacing modality remains unclear. Previous studies have demonstrated that biventricular (BiV) pacing followed by AVNA resulted in significant reduction in mortality, heart failure (HF) hospitalizations, significant improvement in symptoms and left ventricular (LV) remodeling. Although, its benefit was much less transparent in patients with narrow QRS and LV impairment, as it still causes abnormal cardiac activation with potential worsening of electrical dyssynchrony. To avoid the detrimental effects of BiV pacing a new concept, conduction system pacing (CSP), including His bundle Pacing (HBP) and left bundle branch pacing (LBBP), was proposed as a potential alternative. Both CSP modalities offer advantages over BiV pacing by providing more physiological activation, avoiding cardiac dyssynchrony and left ventricular dysfunction. Moreover, LBBP showed some advantages over HBP. Since the lead is implanted in the region of the left bundle, which has an adequate distance from the AVNA site, this modality could minimize the risk of increase in capture threshold after AVNA. Additionally, the pacing parameters of LBBP were stable in long-term follow-up studies precluding the need for back-up pacing. Therefore compared to HBP and BiV pacing, LBBP may offer a more feasible physiologic pacing option to be adopted into clinical practice. Some observational studies have already shown positive outcomes of HBP and LBBP in symptomatic AF patients who underwent AVNA with the favorable clinical and echocardiographic improvement compared to BIV pacing, especially in HF patients with narrow baseline QRS and reduced ejection fraction (EF<50%). However, prospective randomized study evaluating the value of CSP as an alternative approach to BiV pacing in combination with AVNA is lacking.
The purpose of this study is to compare the effects of CSP and conventional BiV pacing on echocardiographic and clinical outcomes in HF patients with symptomatic AF and narrow QRS scheduled for AVNA. In this multicentric study, 82 patients will be randomized into one of two arms: a BiV pacing arm with BiV pacemaker implantation + AVNA or CSP arm with the implantation of a CSP device + AVNA. In patients randomized in CSP group, LBBP will be the preferred pacing technique. If LBBP will be unobtainable, HBP implantation will be attempted. In both arms additional defibrillator backup will be implanted at the discretion of the physician according to the ESC guidelines. In short-term analysis after 6 months, echocardiographic, laboratory and symptomatic parameters will be evaluated. Long-term analysis to assess HF hospitalization, cardiovascular mortality and pacing parameters will be performed after at least 24 months of follow-up.
Investigators hypothesize that CSP could represent a feasible and safe alternative to BiV pacing in terms of clinical and echocardiographic outcomes.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Biventricular pacing + AV node ablation | Active comparator | Device: Biventricular pacemaker implantation, Procedure: AV node ablationImplantation of biventricular pacemaker with or without defibrillator lead placement followed by AV node ablation. Optimal guidelines-based heart failure treatment. |
| Conduction system pacing + AV node ablation | Experimental | Device: Conduction system pacing device implantation, Procedure: AV node ablationImplantation of permanent pacemaker with conduction system pacing (preferably left bundle branch) with or without defibrillator lead placement followed by AV node ablation. Optimal guidelines-based heart failure treatment. |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Symptomatic permanent atrial fibrillation, refractory to drug therapy or failed catheter ablation
- Left ventricular ejection fraction <50%
- Narrow intrinsic QRS ≤ 120 ms
- NT-proBNP > 600 ng/L
- Patient has provided written informed consent
Key exclusion criteria (9 listed)
- Pre-existing permanent pacemaker, implantable cardioverter-defibrillator or cardiac resynchronization device. Patients who had devices implanted that had <5% of paced beats (i.e., backup pacing) can be enrolled.
- Life expectancy less than 12 months
- Severe concomitant non-cardiac disease
- Pregnancy
- Recent (<3 months) myocardial infarction, percutaneous or surgical myocardial revascularization
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Biventricular pacemaker implantationImplantation of permanent pacemaker with biventricular stimulation with or without defibrillator lead placement using standard techniques. The right ventricle lead will be positioned in the RV apex or septum, while the left ventricle lead will be delivered to the most appropriate coronary sinus tributary, preferably posterolateral or lateral vein. | Device | Biventricular pacing + AV node ablation |
| Conduction system pacing device implantationLeft bundle branch pacing (LBBP) will be the preferred pacing technique. In brief, after localizing the His bundle area the LBBP lead will be positioned approximately 1-1.5 cm distal to the His bundle position in the right ventricular septum. Before screwing the lead deep into the interventricular septum, the suitable position will be confirmed by fluoroscopic signs and adequate paced QSR morphology. Given that the pacing parameters with LBBP are typically low and stable, backup RV lead will not be mandatory. If LBBP will be unobtainable, His bundle pacing (HBP) implantation will be attempted. His bundle potential mapping will be performed with the use of the electrophysiological system and under fluoroscopic guidance. Distal HB potential with a large ventricular signal and a small atrial signal will be targeted before the pacing lead will be screwed into position. Backup RV lead will be mandatory for all patients receiving HBP devices. | Device | Conduction system pacing + AV node ablation |
| AV node ablationAtrioventricular node ablation (AVNA) will be performed following pacemaker implantation (preferably during the same hospitalization). After femoral vein access will be obtained, the ablation catheter will be positioned to the presumed area of the AV node in the mid-septum under fluoroscopy. The location will be optimized according to the intracardiac electrograms. Ablation will be performed in a temperature-controlled mode. Successful AVNA will be recognized with an abrupt drop of heart rate to 40 bpm and will continue for 60 seconds thereafter. | Procedure or surgery | Biventricular pacing + AV node ablation, Conduction system pacing + AV node ablation |
Primary outcome
Change in left ventricular ejection fraction.
Time frame: baseline and 6 months
Simpson's method assessed with echo.
16 secondary outcomes
Time to the first occurrence of worsening heart failure or cardiovascular death.
Time frame: at least 24 months
Time to the first occurrence of worsening heart failure.
Time frame: at least 24 months
Time to cardiovascular death.
Time frame: at least 24 months
Number of heart failure hospitalizations.
Time frame: at least 24 months
Change in LV end-diastolic and end-systolic volume index.
Time frame: baseline and 6 months
Change in clinical parameters
Time frame: baseline and 6 months
Change in clinical parameters
Time frame: baseline and 6 months
Improvement in clinical parameters
Time frame: baseline and 6 months
Change in 6-Minute walk test.
Time frame: baseline and 6 months
Laboratory parameters.
Time frame: baseline and 6 months
Procedural-related characteristics.
Time frame: peri-procedural
Procedure-associated adverse events.
Time frame: peri-procedural, 30 days after the procedure
Need for procedural reintervention.
Time frame: at least 24 months
ECG parameters.
Time frame: before and after the procedure
Pacing parameters.
Time frame: peri-procedural, at least 24 months
Number of detected sustained VT/VF.
Time frame: at least 24 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Apr 2026.
- Background: PubMed 18272509Tan ES, Rienstra M, Wiesfeld AC, Schoonderwoerd BA, Hobbel HH, Van Gelder IC. Long-term outcome of the atrioventricular node ablation and pacemaker implantation for symptomatic refractory atrial fibrillation. Europace. 2008 Apr;10(4):412-8. doi: 10.1093/europace/eun020. Epub 2008 Feb 12.
- Background: PubMed 20152225Orlov MV, Gardin JM, Slawsky M, Bess RL, Cohen G, Bailey W, Plumb V, Flathmann H, de Metz K. Biventricular pacing improves cardiac function and prevents further left atrial remodeling in patients with symptomatic atrial fibrillation after atrioventricular node ablation. Am Heart J. 2010 Feb;159(2):264-70. doi: 10.1016/j.ahj.2009.11.012.
- Background: PubMed 22436544Chatterjee NA, Upadhyay GA, Ellenbogen KA, Hayes DL, Singh JP. Atrioventricular nodal ablation in atrial fibrillation: a meta-analysis of biventricular vs. right ventricular pacing mode. Eur J Heart Fail. 2012 Jun;14(6):661-7. doi: 10.1093/eurjhf/hfs036. Epub 2012 Mar 21.
- Background: PubMed 34453840Brignole M, Pentimalli F, Palmisano P, Landolina M, Quartieri F, Occhetta E, Calo L, Mascia G, Mont L, Vernooy K, van Dijk V, Allaart C, Fauchier L, Gasparini M, Parati G, Soranna D, Rienstra M, Van Gelder IC; APAF-CRT Trial Investigators. AV junction ablation and cardiac resynchronization for patients with permanent atrial fibrillation and narrow QRS: the APAF-CRT mortality trial. Eur Heart J. 2021 Dec 7;42(46):4731-4739. doi: 10.1093/eurheartj/ehab569.
- Background: PubMed 32377902Muthumala A, Vijayaraman P. His-Purkinje conduction system pacing and atrioventricular node ablation. Herzschrittmacherther Elektrophysiol. 2020 Jun;31(2):117-123. doi: 10.1007/s00399-020-00679-7. Epub 2020 May 6.
- Background: PubMed 31830874Wang S, Wu S, Xu L, Xiao F, Whinnett ZI, Vijayaraman P, Su L, Huang W. Feasibility and Efficacy of His Bundle Pacing or Left Bundle Pacing Combined With Atrioventricular Node Ablation in Patients With Persistent Atrial Fibrillation and Implantable Cardioverter-Defibrillator Therapy. J Am Heart Assoc. 2019 Dec 17;8(24):e014253. doi: 10.1161/JAHA.119.014253. Epub 2019 Dec 13.
- Background: PubMed 33370800Su L, Cai M, Wu S, Wang S, Xu T, Vijayaraman P, Huang W. Long-term performance and risk factors analysis after permanent His-bundle pacing and atrioventricular node ablation in patients with atrial fibrillation and heart failure. Europace. 2020 Dec 26;22(Suppl_2):ii19-ii26. doi: 10.1093/europace/euaa306.
- Background: PubMed 28365568Huang W, Su L, Wu S, Xu L, Xiao F, Zhou X, Ellenbogen KA. Benefits of Permanent His Bundle Pacing Combined With Atrioventricular Node Ablation in Atrial Fibrillation Patients With Heart Failure With Both Preserved and Reduced Left Ventricular Ejection Fraction. J Am Heart Assoc. 2017 Apr 1;6(4):e005309. doi: 10.1161/JAHA.116.005309.
- Background: PubMed 34078244Zizek D, Antolic B, Meznar AZ, Zavrl-Dzananovic D, Jan M, Stublar J, Pernat A. Biventricular versus His bundle pacing after atrioventricular node ablation in heart failure patients with narrow QRS. Acta Cardiol. 2022 May;77(3):222-230. doi: 10.1080/00015385.2021.1903196. Epub 2021 Jun 2.
- Background: PubMed 35877570Ivanovski M, Mrak M, Meznar AZ, Zizek D. Biventricular versus Conduction System Pacing after Atrioventricular Node Ablation in Heart Failure Patients with Atrial Fibrillation. J Cardiovasc Dev Dis. 2022 Jul 1;9(7):209. doi: 10.3390/jcdd9070209.
- Background: PubMed 35351624Pillai A, Kolominsky J, Koneru JN, Kron J, Shepard RK, Kalahasty G, Huang W, Verma A, Ellenbogen KA. Atrioventricular junction ablation in patients with conduction system pacing leads: A comparison of His-bundle vs left bundle branch area pacing leads. Heart Rhythm. 2022 Jul;19(7):1116-1123. doi: 10.1016/j.hrthm.2022.03.1222. Epub 2022 Mar 26.
- Background: PubMed 31504425Brugada J, Katritsis DG, Arbelo E, Arribas F, Bax JJ, Blomstrom-Lundqvist C, Calkins H, Corrado D, Deftereos SG, Diller GP, Gomez-Doblas JJ, Gorenek B, Grace A, Ho SY, Kaski JC, Kuck KH, Lambiase PD, Sacher F, Sarquella-Brugada G, Suwalski P, Zaza A; ESC Scientific Document Group. 2019 ESC Guidelines for the management of patients with supraventricular tachycardiaThe Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). Eur Heart J. 2020 Feb 1;41(5):655-720. doi: 10.1093/eurheartj/ehz467. No abstract available.
- Individual participant dataSharing planned: No. It is not yet known if there will be a plan to make IPD available.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Andrej Pernat, MD, PhD study director
UMC Ljubljana
David Zizek, MD, PhD principal investigator
UMC Ljubljana
10 sites in 7 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Biventricular pacemaker implantation, Conduction system pacing device implantation and AV node ablation in people with Heart Failure and Tachycardia-induced Cardiomyopathy, run by University Medical Centre Ljubljana at 10 sites in 7 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 29 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 10 sites in Croatia, Slovenia, Austria, Belgium, Bulgaria and 2 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in left ventricular ejection fraction. (time frame: baseline and 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05467163, which also lists 12 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Apr 2026.