Recruiting

Left Bundle Branch Pacing vs. Right Ventricular Pacing

Sponsor:

McGill University Health Centre/Research Institute of the McGill University Health Centre

Code:

NCT05015660

Conditions

Pacemaker DDD

Heart Block

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Left bundle branch pacing lead

Right ventricular active fixation lead

Study Details

Brief summary:

High burden right ventricular (RV) pacing has been shown to increase cardiovascular mortality, incidence of heart failure (HF), worsen left ventricular (LV) function and accelerate the development of atrial fibrillation (AF). High percentage ventricular pacing and wider paced QRS in the setting of normal baseline LV ejection fractions have consistently been shown to be independent risk factors for pacing-induced cardiomyopathy. Left bundle branch pacing (LBBP) has emerged as a potential alternative pacing mechanism that may avoid LV dyssynchrony and pacing-induced LV dysfunction by mimicking native electrical conduction.

Conditions

Pacemaker DDD

Heart Block

Study ID

NCT05015660

Start date

Sep 1, 2022

Status verified date

Mar, 2026

Completion date

Jan 1, 2030

Anticipated

Primary completion date

Dec 1, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Age ≥ 18 years
2. Patients with an ejection fraction of >35%
3. Patients with an indication for ventricular pacing and high-degree atrioventricular block where the degree of anticipated RV pacing is >90% including:

1. Third degree AV block
2. Symptomatic or asymptomatic second-degree AV block
3. First degree AV block ≥ 280ms with a narrow QRS, or ≥ 240ms with an intraventricular delay (QRS duration ≥120ms)
4. Echocardiogram within the last 3 months, with ability to have DICOM images

Exclusion Criteria:

1. Indication for an implantable cardioverter defibrillator
2. Presence of a mechanical tricuspid valve
3. Any prior attempt at implantation of an ICD, CRT, HBP, or LBBP
4. Lack of capacity to consent
5. Other serious medical condition with life expectancy of <2 years
6. Pregnancy
7. Patients in whom the conduction system abnormality is expected to be transient or recover over time
8. Patients with permanent atrial fibrillation

Study Design

Enrollment

1300 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: left bundle branch pacing

active comparator: Right ventricular pacing

Interventions

Left bundle branch pacing lead

Implantation of a left bundle branch pacing lead via sheath, to perform selective or non-selective pacing

Right ventricular active fixation lead

Active fixation lead (standard)

Primary outcome measure

  • Time to cardiovascular death [ Time Frame: 36 months ]
  • Time to first heart failure event [ Time Frame: 36 months ]
  • Worsening LV end systolic volume index by 2 years [ Time Frame: 24 months ]

Central Contacts and Locations

Central contacts

Jacqueline Joza, MD MSc

514-934-1934jacqueline.joza@gmail.com

Fiorella Rafti, PhD

514-934-1934fiorella.rafti@mail.mcgill.ca

Locations

McGill University Health Centre-Research Institute

Recruiting

Montreal, Quebec, Canada, H3Y2T6

Contacts

Fiorella Rafti, PhD

514-934-1934fiorella.rafti@mail.mcgill.ca

Jacqueline Joza

514-934-1934jacqueline.joza@gmail.com

Principal Investigator:

Jacqueline Joza

More Information

Sponsor

McGill University Health Centre/Research Institute of the McGill University Health Centre

Last update posted

Mar 11, 2026

Last verified

Mar, 2026

Keywords

  • left bundle branch pacing

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by McGill University Health Centre/Research Institute of the McGill University Health Centre on 2026-03-11.