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

Study Overview
=================
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.

Official Title
-----------------
LEFT Bundle Pacing vs Standard Right Ventricular Pacing for Heart Failure

Conditions
-----------------
Pacemaker DDD, Heart Block

Intervention / Treatment
-----------------
* Device: Left bundle branch pacing lead (Select Secure 3830 lead)
* Device: Right ventricular active fixation lead


Participation Criteria
=================
Eligibility Criteria
-----------------
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

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Prospective open-label randomized controlled trial (1:1) with blinded outcome adjudication
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: left bundle branch pacing<br> | Device: Left bundle branch pacing lead (Select Secure 3830 lead)<br>* Implantation of a left bundle branch pacing lead via sheath, to perform selective or non-selective pacing<br>|
| Active Comparator: Right ventricular pacing<br> | Device: Right ventricular active fixation lead<br>* Active fixation lead (standard)<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to cardiovascular death | Clinical | 36 months | 
| Time to first heart failure event | 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 ≤ 50% | 36 months | 
| Worsening LV end systolic vloume index at 2 years | Defined as a 15% increase from baseline on the two-year echo | 24 months | 

Secondary Outcome Measures

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

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
left bundle branch pacing