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

Not Applicable

Recruiting

• Conditions: Pacemaker DDD; Heart Block
• Interventions: Device: Left bundle branch pacing lead (Select Secure 3830 lead); Device: Right ventricular active fixation lead

• Registration Number: NCT05015660
• Lead Sponsor: McGill University Health Centre/Research Institute of the McGill University Health Centre

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.

Study Timeline

• Study First Submitted: 2021-08-10
• Study First Submitted QC: 2021-08-16
• Study First Posted: 2021-08-20
• Study Start: 2022-09-01
• Status Verified: 2024-03
• Last Update Submitted: 2024-03-18
• Last Update Posted: 2024-03-20
• Primary Completion: 2026-07-01
• Study Completion: 2027-07-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 1300

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

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
left bundle branch pacing	Left bundle branch pacing lead (Select Secure 3830 lead)	-
Right ventricular pacing	Right ventricular active fixation lead	-

Primary Outcome Measures

Name	Time	Method
Time to first heart failure event	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%
Time to cardiovascular death	36 months	Clinical
Worsening LV end systolic vloume index at 2 years	24 months	Defined as a 15% increase from baseline on the two-year echo

Secondary Outcome Measures

Name	Time	Method
Change in NTproBNP level	24 months	From baseline to 24 months
Development of new tricuspid regurgitation	24 months	More than mild TR from baseline
Change in Lead parameter	24 months	stability of impedance, sensing, thresholds
Cardiovascular mortality	24 months	CV-related
Atrial fibrillation progression	24 months	Atrial fibrillation burden as noted on pacemaker
New visit for Heart Failure	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.
Presence of Mitral regurgitation	24 months	Progression/Development from baseline
Quality of Life Improvement	Evaluated at 1, 12, and 24 months, measure as compared to baseline	Health related quality of life score: Short Form 12
Total mortality	24 months	Total mortality
Change in left ventricular ejection fraction	24 months	Echo parameter, change from baseline to 24 months
Safety of procedure and long-term safety	24 months	Procedural and long-term safety of left bundle pacing

Trial Locations

Locations (1)

McGill University Health Centre-Research Institute; 🇨🇦 Montreal, Quebec, Canada