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NCT Number: NCT05015660

Conduction System Pacing With Left Bundle Branch Pacing as Compared to Standard Right Ventricular Pacing

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.

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Key information

Conditions

Pacemaker Ddd Arrhythmias, Cardiac Cardiac Conduction System Disease Cardiovascular Diseases Heart Block Heart Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

McGill University Health Centre-Research Institute

Montreal, Quebec, H3Y2T6, Canada

Location status: Recruiting

About this study

We hypothesize that in patients with high degree AV block with anticipated ventricular pacing >90%, and an EF >35% patients undergoing LBBP will demonstrate a significantly lower number of the primary composite endpoint of cardiovascular death, heart failure events, and change in LVESVi as compared to standard RV pacing. Echos will be performed at baseline, 12, 24, and 36 months. NTproBNPs are performed at baseline and follow-up. There will be a core echo lab, and blinded adjudication of ECGs and events.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age ≥ 18 years
  • Patients with an ejection fraction of >35%
  • Patients with an indication for ventricular pacing and high-degree atrioventricular block where the degree of anticipated RV pacing is >90% including:
  • Third degree AV block
  • Symptomatic or asymptomatic second-degree AV block
  • First degree AV block ≥ 280ms with a narrow QRS, or ≥ 240ms with an intraventricular delay (QRS duration ≥120ms)
  • Echocardiogram within the last 3 months, with ability to have DICOM images

Exclusion criteria

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

Treatment and study plan

Left bundle branch pacing lead

Device

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

Right ventricular active fixation lead

Device

Active fixation lead (standard)

Primary outcomes

  1. Time to cardiovascular death

    Time frame: 36 months

    Clinical

  2. Time to first heart failure event

    Time frame: 36 months

    Defined as: (i) Emergency department (ED) visits or hospitalization for HF (requiring signs and symptoms consistent with congestive heart failure (CHF) that is responsive to oral or parenteral medications); (ii) intensification of therapy (intravenous diuretic therapy on an outpatient basis); or (iii) indication for device upgrade to CRT due to deteriorating LV function defined as an absolute decline in LVEF ≥ 10% from baseline and an LVEF ≤ 40%

  3. Worsening LV end systolic volume index by 2 years

    Time frame: 24 months

    Defined as a 15% increase from baseline each year up to the two-year echo

Secondary outcomes

  1. Cardiovascular mortality

    Time frame: 24 months

    CV-related

  2. New visit for Heart Failure

    Time frame: 24 months

    Heart failure visit is defined as: i) Emergency department visit or hospitalization for signs and symptoms of HF that is responsive to oral or intravenous diuretics ii) intensification of therapy defined as outpatient intravenous diuretic therapy, and iii) device upgrade to cardiac resynchronization therapy.

  3. Total mortality

    Time frame: 24 months

    Total mortality

  4. Change in left ventricular ejection fraction

    Time frame: 24 months

    Echo parameter, change from baseline to 24 months

  5. Change in NTproBNP level

    Time frame: 24 months

    From baseline to 24 months

  6. Atrial fibrillation progression

    Time frame: 24 months

    Atrial fibrillation burden as noted on pacemaker

  7. Development of new tricuspid regurgitation

    Time frame: 24 months

    More than mild TR from baseline

  8. Presence of Mitral regurgitation

    Time frame: 24 months

    Progression/Development from baseline

  9. Change in Lead parameter

    Time frame: 24 months

    stability of impedance, sensing, thresholds

  10. Quality of Life Improvement

    Time frame: Evaluated at 1, 12, and 24 months, measure as compared to baseline

    Health related quality of life score: Short Form 12

  11. Safety of procedure and long-term safety

    Time frame: 24 months

    Procedural and long-term safety of left bundle pacing

Interested in participating?

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Sponsors and collaborators

Lead sponsor

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

Other

Collaborators

  • Canadian Institutes of Health Research (CIHR)
  • Heart and Stroke Foundation of Canada

Registry information

Official study title

LEFT Bundle Pacing vs Standard Right Ventricular Pacing for Heart Failure

Important dates

Study start
2022
Primary completion
2026
Study completion
2030
First posted
Aug 20, 2021
Registry last updated
Mar 11, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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