Left Bundle Branch Pacing vs Right Ventricular Pacing on AHRE Burden in Patients With Preserved LVEF (LBBP-AHRE)

March 10, 2026 updated by: Georgios Leventopoulos, University Hospital of Patras

Comparison of Left Bundle Branch Pacing Versus Conventional Right Ventricular Pacing on AHRE Burden in Patients With Preserved Left Ventricular Ejection Fraction and High Ventricular Pacing Dependency (LBBP-AHRE Trial): A Randomized Study

This prospective, randomized controlled trial aims to evaluate the effect of left bundle branch pacing (LBBP) compared with conventional right ventricular (RV) pacing on the cumulative duration (total time) of atrial high-rate episodes (AHREs) in patients with preserved left ventricular ejection fraction (LVEF) who are expected to require frequent ventricular pacing.

Atrial High-Rate Episodes (AHREs) are defined as episodes of atrial tachyarrhythmia that are automatically recorded by device diagnostics and detected by implanted cardiac devices. These episodes usually have an atrial rate ≥170 beats per minute and a duration ≥6 minutes. AHREs are linked to a higher risk of thromboembolic events and clinical atrial fibrillation (AF), and they may indicate subclinical AF or other atrial tachyarrhythmias.

Chronic RV pacing has been linked to mechanical and electrical dyssynchrony, which may encourage atrial remodeling and the development of AF. LBBP provides a more physiological ventricular activation and may reduce atrial tachyarrhythmia time (AHRE time).

Patients with LVEF >50% and atrioventricular (AV) conduction disorders requiring a dual-chamber pacemaker will be randomized to either conventional RV septal pacing or LBBP.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This prospective, randomized controlled trial aims to evaluate the effect of left bundle branch pacing (LBBP) compared with conventional right ventricular (RV) pacing on the cumulative duration (total time) of atrial high-rate episodes (AHREs) in patients with preserved left ventricular ejection fraction (LVEF) who are expected to require frequent ventricular pacing.

Atrial High-Rate Episodes (AHREs) are defined as episodes of atrial tachyarrhythmia that are automatically recorded by device diagnostics and detected by implanted cardiac devices. These episodes usually have an atrial rate ≥170 beats per minute and a duration ≥6 minutes. AHREs are linked to a higher risk of thromboembolic events and clinical atrial fibrillation (AF), and they may indicate subclinical AF or other atrial tachyarrhythmias.

Device Algorithm Specificity: AHREs will be validated by reviewing the stored atrial electrograms (EGMs) for a random sample of at least 20% of detected episodes to confirm atrial origin, exclude oversensing, and differentiate atrial tachycardia from atrial fibrillation-like episodes. Device model-specific detection thresholds, including refractory oversensing behavior, atrial blanking periods, and sensitivity parameters, will be documented and standardized across participants where possible.

Chronic RV pacing has been linked to mechanical and electrical dyssynchrony, which may encourage atrial remodeling and the development of AF. LBBP provides a more physiological ventricular activation and may reduce atrial tachyarrhythmia time (AHRE time).

LBBP produces a narrower paced QRS, shorter left ventricular activation time, and more synchronous ventricular contraction compared with RV pacing. These electrophysiologic differences may reduce atrial stretch, left atrial pressure, and atrial substrate remodeling, which are mechanisms believed to lower AHRE burden.

Patients with LVEF >50% and atrioventricular (AV) conduction disorders requiring a dual-chamber pacemaker will be randomized to either conventional RV septal pacing or LBBP.

Study Type

Interventional

Enrollment (Estimated)

244

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Periklis Davlouros
  • Phone Number: +306986726300
  • Email: pdav@upatras.gr

Study Locations

  • Greece
      • Pátrai, Greece
        • Recruiting
        • University General Hospital of Patras
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age ≥ 18 years
  • Scheduled implantation of a dual-chamber pacemaker for:

Permanent complete heart block Permanent second-degree AV block (Mobitz II or Mobitz I)

  • Documented preserved LVEF (≥50%)
  • Sinus rhythm at baseline
  • Ability to provide written informed consent

Exclusion Criteria:

  • History of paroxysmal, persistent, or permanent atrial fibrillation
  • Previous atrial fibrillation ablation (catheter-based or surgical)
  • LVEF < 50%
  • Sinus node disease
  • Transient AV block requiring pacemaker implantation
  • Significant structural or valvular heart disease
  • Requirement for pacemaker system upgrade during the study period
  • Requirement for antiarrhythmic therapy for causes other than atrial fibrillation
  • Existing pacemaker or other cardiac device requiring modification for study participation
  • Enrollment in another clinical trial that could interfere with study endpoints or pacing parameters
  • Contraindication to LBBP or associated lead implantation procedure
  • Life expectancy < 12 months
  • Any condition judged by the investigator to compromise participation or the integrity of study data

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Arm 1: Conventional Right Ventricular Pacing

Procedure: Standard right ventricular septal pacing

Description: Implantation of a dual-chamber pacemaker with the ventricular lead placed in the RV septum.

At follow-up, the ventricular pacing percentage and pacing configuration will be noted.
Device: Right Ventricular Pacing

Implantation of a dual-chamber pacemaker with the ventricular lead placed in the RV septum.

At follow-up, the ventricular pacing percentage and pacing configuration will be noted.

All devices used in this study are commercially available in the European Union and carry a valid CE mark.
Active Comparator: Arm 2: Left Bundle Branch Pacing (LBBP)

Procedure: Left bundle branch pacing lead implantation

Description: Implantation of a dual-chamber pacemaker with the ventricular lead placed at the left bundle branch area.

Physiological pacing will be programmed into the devices and, at follow-up, the percentage of spontaneous pacing will be noted.
Device: Left Bundle Branch Pacing

Implantation of a dual-chamber pacemaker with the ventricular lead placed at the left bundle branch area.

Physiological pacing will be programmed into the devices and, at follow-up, the percentage of spontaneous pacing will be noted.

All devices used in this study are commercially available in the European Union and carry a valid CE mark.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Total cumulative AHRE time for device-detected episodes lasting >6 minutes
Time Frame: From pacemaker implantation (or randomization) to 24 months (primary endpoint)
Sum of the durations of all device-detected AHREs with individual episode duration >6 minutes (atrial rate threshold per device diagnostics, typically ≥170 bpm), expressed as total time (minutes/hours). Total analyzable monitoring time will be defined as the interval from implantation to the last successful device interrogation/remote transmission, excluding periods of missing device data.
From pacemaker implantation (or randomization) to 24 months (primary endpoint)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Total cumulative time in AHRE episodes with individual episode duration 6 minutes to 6 hours.
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Total cumulative time in AHRE episodes with individual episode duration 6 hours to 24 hours.
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Total cumulative time in AHRE episodes with individual episode duration >24 hours.
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Time to event - for AHRE episodes > 6 min
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Incidence of progression to clinically documented atrial fibrillation (paroxysmal or persistent, symptomatic or asymptomatic, confirmed by ECG, Holter, or wearable monitoring).
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Development of permanent atrial fibrillation.
Time Frame: From pacemaker implantation (or randomization) to 24 months
Atrial fibrillation (AF) will be evaluated using routine interrogation of implanted pacemakers, which provide device-recorded atrial arrhythmia data, including AF burden and episode duration. Permanent atrial fibrillation will be defined according to the ESC Guidelines for Atrial Fibrillation and will require a consensus decision between the treating physician and the patient that the arrhythmia is ongoing. This consensus will also include an agreement to pursue a rate-control strategy with no further attempts to restore or maintain sinus rhythm.
From pacemaker implantation (or randomization) to 24 months
Device- or procedure-related complications (e.g., cardiac perforation, pericardial tamponade, pneumothorax, hemothorax, infection requiring antibiotics or system removal, generator or lead malfunction, hematoma).
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
All-cause mortality.
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Hospitalization due to AF
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Need for cardioversion.
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Total cumulative time in AHRE episodes with individual episode duration 0 to 6 minutes.
Time Frame: From pacemaker implantation (or randomization) to 24 months (primary endpoint)
From pacemaker implantation (or randomization) to 24 months (primary endpoint)
Time to first clinically documented atrial fibrillation.
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Time to progression to permanent atrial fibrillation.
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Hospitalization due to HF
Time Frame: From pacemaker implantation (or randomization) to 24 months
From pacemaker implantation (or randomization) to 24 months
Development of pacing-induced cardiomyopathy (PICM)
Time Frame: From pacemaker implantation (or randomization) to 24 months
Defined as a drop in LVEF of at least 10 percentage points resulting in LVEF <50%, or a relative reduction in global longitudinal strain of at least 15%
From pacemaker implantation (or randomization) to 24 months
Changes in biomarkers associated with myocardial stress, inflammation, or injury
Time Frame: At baseline and at 12 and 24 months, where available.
NT-proBNP, hsCRP, and troponin
At baseline and at 12 and 24 months, where available.
Changes in structured echocardiographic parameters
Time Frame: At baseline and at 12 and 24 months, where available.
Including left atrial strain, left atrial volume index, interventricular mechanical delay, left ventricular mechanical delay, and global longitudinal strain, in participants with available echocardiographic studies from centers able to perform these measurements.
At baseline and at 12 and 24 months, where available.
Quality-of-life change assessed using a validated questionnaire during follow-up.
Time Frame: At baseline and at 3,6,12,18 and 24 months
Minnesota living with heart-failure questionnaire
At baseline and at 3,6,12,18 and 24 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital of Patras

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 5, 2026

Primary Completion (Estimated)

April 20, 2029

Study Completion (Estimated)

June 20, 2029

Study Registration Dates

First Submitted

November 14, 2025

First Submitted That Met QC Criteria

November 22, 2025

First Posted (Actual)

November 26, 2025

Study Record Updates

Last Update Posted (Actual)

March 13, 2026

Last Update Submitted That Met QC Criteria

March 10, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UHP-LBBP-AHRE-2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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