NCT07250529

Left Bundle Branch Pacing vs Right Ventricular Pacing on AHRE Burden in Patients With Preserved LVEF

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

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 244 (estimated)
• Sponsor: University Hospital of Patras · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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.

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.

Conditions

• Atrial Fibrillation (AF)
• Pacemaker Therapy
• Atrioventricular Block
• Preserved Ejection Fraction

Interventions

Type	Name	Description
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.
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.

Timeline

• Start date: 2026-02-05
• Primary completion: 2029-04-20
• Completion: 2029-06-20
• First posted: 2025-11-26
• Last updated: 2026-03-13

Locations

1 site across 1 country: Greece