Skip to content

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

LEFT Bundle Pacing vs Standard Right Ventricular Pacing for Heart Failure

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05015660
Enrollment
1300
Registered
2021-08-20
Start date
2022-09-01
Completion date
2030-01-01
Last updated
2026-03-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Heart Block, Pacemaker DDD

Keywords

left bundle branch pacing

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.

Detailed description

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.

Interventions

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

Active fixation lead (standard)

Sponsors

McGill University Health Centre/Research Institute of the McGill University Health Centre
Lead SponsorOTHER
Heart and Stroke Foundation of Canada
CollaboratorOTHER
Canadian Institutes of Health Research (CIHR)
CollaboratorOTHER_GOV

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Masking description

Blinded outcome adjudication

Intervention model description

Prospective open-label randomized controlled trial (1:1) with blinded outcome adjudication

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
Time to cardiovascular death36 monthsClinical
Time to first heart failure event36 monthsDefined 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%
Worsening LV end systolic volume index by 2 years24 monthsDefined as a 15% increase from baseline each year up to the two-year echo

Secondary

MeasureTime frameDescription
Cardiovascular mortality24 monthsCV-related
New visit for Heart Failure24 monthsHeart 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.
Total mortality24 monthsTotal mortality
Change in left ventricular ejection fraction24 monthsEcho parameter, change from baseline to 24 months
Change in NTproBNP level24 monthsFrom baseline to 24 months
Atrial fibrillation progression24 monthsAtrial fibrillation burden as noted on pacemaker
Development of new tricuspid regurgitation24 monthsMore than mild TR from baseline
Presence of Mitral regurgitation24 monthsProgression/Development from baseline
Change in Lead parameter24 monthsstability of impedance, sensing, thresholds
Quality of Life ImprovementEvaluated at 1, 12, and 24 months, measure as compared to baselineHealth related quality of life score: Short Form 12
Safety of procedure and long-term safety24 monthsProcedural and long-term safety of left bundle pacing

Countries

Canada

Contacts

CONTACTJacqueline Joza, MD MSc
jacqueline.joza@gmail.com514-934-1934
CONTACTFiorella Rafti, PhD
fiorella.rafti@mail.mcgill.ca514-934-1934

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 12, 2026