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

N/ANot Yet RecruitingNCT07250529

University Hospital of Patras100 enrolled

Overview

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 burden 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 ≥170-190 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 arrhythmic 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.

This prospective, randomized trial compares left bundle branch pacing (LBBP) with conventional right ventricular (RV) pacing in patients with preserved left ventricular ejection fraction (LVEF ≥50%) who are expected to require frequent ventricular pacing. The primary goal is to evaluate the effect of LBBP versus RV pacing on atrial high-rate episode (AHRE) burden, detected by dual-chamber pacemakers. AHREs are device-recorded atrial tachyarrhythmias (atrial rate ≥170-190 bpm, duration ≥6 minutes) associated with increased risk of atrial fibrillation (AF) and thromboembolic events. Eligible patients with AV conduction disorders and sinus rhythm will be randomized 1:1 to LBBP or RV septal pacing at pacemaker implantation. All devices used are commercially available in the European Union and carry a valid CE mark. Device interrogation will occur at 3, 6, and 12 months to record AHRE burden, pacing percentage, and occurrence of AF. Permanent AF will be defined per ESC Guidelines, based on physician-patient consensus, including a rate-control strategy when rhythm restoration is not attempted. Secondary outcomes include AHRE episode duration, progression to clinical AF, development of permanent AF, device- or procedure-related complications, hospitalization due to AF, need for cardioversion, and all-cause mortality. Beta-blocker therapy for other indications is allowed and documented. This study will provide prospective, randomized evidence on whether physiological ventricular activation with LBBP reduces AHRE burden compared with conventional RV pacing in patients with preserved systolic function and high expected ventricular pacing dependency.

Interventions

Right Ventricular PacingDEVICE

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.

Left Bundle Branch PacingDEVICE

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.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Percentage of time in AHRE during the total monitored period (device-detected).

Cumulative duration of all AHREs (\>6 minutes) divided by total monitoring time, expressed as a percentage (aligning with current device-based burden metrics).