Left Bundle Branch vs Right Ventricular Pacing for Heart Block

Overseen By Fiorella Rafti, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

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

Disqualifiers: ICD, Mechanical valve, Pregnancy, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 12

Duration: 36 months

1300 Participants Needed

Trial Summary

What is the purpose of this trial?

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.

Will I have to stop taking my current medications?

The trial protocol does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the treatment Left bundle branch pacing lead (Select Secure 3830 lead) for heart block?

Left bundle branch pacing (LBBP) has been shown to be a safe and effective alternative to traditional pacing methods, like right ventricular pacing, especially in patients with heart failure and left bundle branch block. Studies have demonstrated that LBBP can provide synchronized heart contractions and improve heart function, potentially reducing the risk of heart failure hospitalizations. ^{1 2 3 4 5}

Is left bundle branch pacing generally safe for humans?

Left bundle branch pacing (LBBP) has been shown to be generally safe, with studies demonstrating its feasibility and safety. However, potential complications like septal perforation can occur, and long-term safety compared to traditional pacing methods still needs further study. ^{3 4 5 6 7}

How is the treatment of Left Bundle Branch Pacing different from other treatments for heart block?

Left Bundle Branch Pacing (LBBP) is unique because it directly targets the heart's natural electrical conduction system, potentially offering more natural heartbeats compared to traditional right ventricular pacing, which can lead to less synchronized heart contractions. ^{3 8 9 10 11}

Eligibility Criteria

This trial is for adults over 18 with certain types of heart block who need a lot of ventricular pacing and have an ejection fraction over 35%. It's not for those needing a defibrillator, with mechanical tricuspid valves, previous similar device attempts, pregnant women, permanent atrial fibrillation patients or those with short life expectancy.

Inclusion Criteria

I need a pacemaker and have a severe heart block.

Your heart's ejection fraction is more than 35%.

You have a specific type of heart block called third degree AV block.

Exclusion Criteria

You have a tricuspid valve that was replaced with a mechanical one.

You need an implantable device to help with heart rhythm problems.

I have permanent atrial fibrillation.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either left bundle branch pacing or standard right ventricular pacing

36 months

Echos at baseline, 12, 24, and 36 months; NTproBNPs at baseline and follow-up

Follow-up

Participants are monitored for safety and effectiveness after treatment

24 months

Treatment Details

Interventions

• Left bundle branch pacing lead (Select Secure 3830 lead)
• Right ventricular active fixation lead

Trial Overview The study compares two pacemaker leads: one that paces the left bundle branch (mimicking natural heart rhythm) versus standard right ventricular pacing. The goal is to see if the new method can reduce negative effects on heart function caused by traditional pacing.

Participant Groups

Group I: left bundle branch pacing Experimental Treatment 1 Intervention

Group II: Right ventricular pacing Active Control 1 Intervention

Left bundle branch pacing lead (Select Secure 3830 lead) is already approved in European Union, United States for the following indications:

Approved in European Union as Select Secure 3830 Lead for:

• Heart failure
• Cardiac resynchronization therapy
• Left ventricular dysfunction

Approved in United States as Select Secure 3830 Lead for:

• Heart failure
• Cardiac resynchronization therapy
• Left ventricular dysfunction

Who Is Running the Clinical Trial?

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

Lead Sponsor

Trials

476

Recruited

170,000+

Canadian Institutes of Health Research (CIHR)

Collaborator

Trials

1,417

Recruited

26,550,000+

Heart and Stroke Foundation of Canada

Collaborator

Trials

131

Recruited

72,600+

Medtronic

Industry Sponsor

Trials

627

Recruited

767,000+

Geoff Martha

Medtronic

Chief Executive Officer since 2020

Finance degree from Penn State University

Dr. Richard Kuntz

Medtronic

Chief Medical Officer since 2023

MD, MSc

Findings from Research

In a study of 94 patients over a mean follow-up of 30 weeks, left bundle branch area pacing (LBBAP) using a standard stylet-driven active fixation lead (SDL) showed a high procedural success rate of 96.8%, comparable to the lumen-less lead (LLL) success rate of 90.3%.

The SDL group required significantly fewer lead deployments (2 vs. 4), while both groups maintained low pacing thresholds and had similar complication rates, indicating that SDL may offer a more efficient approach to LBBAP.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Zwolle experience with left bundle branch area pacing using stylet-driven active fixation leads. Daniëls, F., Adiyaman, A., Aarnink, KM., et al.[2023]

Left bundle branch pacing (LBBP) is effective for patients with heart failure and a left ventricular ejection fraction (LVEF) of 35% or less, particularly those with a widened QRS complex.

Bi-bundle pacing can correct the iatrogenic incomplete right bundle branch block (iRBBB) caused by LBBP, potentially leading to a further reduction in QRS duration and improvement in LVEF.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Permanent Bi-Bundle Pacing in a Patient With Heart Failure and Left Bundle Branch Block. Vezi, B., Akinrimisi, OP.[2023]

A right-sided approach for left bundle branch area pacing (LBBAP) was successfully performed in a heart failure patient using a modified delivery sheath, demonstrating that LBBAP can be adapted for right-sided implantation.

This case highlights the feasibility of LBBAP in patients with anatomical challenges, such as a persistent left superior vena cava, and suggests that with proper modifications, effective pacing can be achieved with stable parameters in the short term.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Right-sided approach to left bundle branch area pacing combined with atrioventricular node ablation in a patient with persistent left superior vena cava and left bundle branch block: a case report. Prolič Kalinšek, T., Žižek, D.[2022]

Left bundle branch pacing (LBBP) is a promising alternative to traditional right ventricular pacing and His bundle pacing, offering synchronized ventricular contraction and potentially overcoming limitations such as lead stability and early battery depletion.

LBBP has demonstrated safety and low threshold requirements compared to His bundle pacing, making it a viable option for patients with left ventricular dysfunction and recurrent heart failure, although further long-term studies are needed to confirm its clinical outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Left bundle branch pacing. Sundaram, S., Vijayaraman, P.[2020]

In a study involving 50 bradycardia patients, the Medtronic SelectSecure™ MRI SecureScan™ Model 3830 lead used for left bundle branch area pacing (LBBAP) required an average of 2.1 attempts and 13 rotations for successful placement, indicating that LBBAP implants are more complex than standard pacing procedures.

Bench testing showed that even under extreme simulated conditions, the 3830 lead demonstrated a predicted 10-year conductor fracture rate of only 0.02%, suggesting high reliability and safety for long-term use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical use conditions of lead deployment and simulated lead fracture rate in left bundle branch area pacing. Zou, J., Chen, K., Liu, X., et al.[2023]

Left bundle branch pacing (LBBP) has a high success rate of 96.8%, but septal perforation occurred in 14.1% of patients, which can be identified using specific unipolar impedance measurements.

When septal perforation is detected during the procedure, it can be managed effectively through reimplantation, and it does not lead to adverse outcomes, as shown by the absence of lead dislodgment in patients during a follow-up period of nearly 10 months.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Electrophysiological characteristics of septal perforation during left bundle branch pacing. Ponnusamy, SS., Basil, W., Vijayaraman, P.[2022]

Left bundle branch pacing (LBBP) is a promising new method for pacemaker implantation that allows for low and stable pacing thresholds and faster left ventricular activation, which can improve heart function.

The procedure can be safely performed in most patients needing pacemaker therapy, but further standardization and long-term studies are necessary to fully establish its efficacy and safety.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

How to implant left bundle branch pacing lead in routine clinical practice. Chen, K., Li, Y.[2020]

A visualization-enhanced technique for left bundle branch pacing (LBBP) implantation significantly reduced procedural time and fluoroscopy duration compared to the standard approach, with times of 66.76 minutes and 7.83 minutes respectively versus 85.46 minutes and 11.11 minutes.

The visualization technique also resulted in fewer lead deployment attempts and a higher success rate in recording left bundle branch potentials (79.3% vs 46.4%), indicating improved efficacy in achieving optimal lead placement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Contrast-enhanced image-guided lead deployment for left bundle branch pacing. Liu, X., Niu, HX., Gu, M., et al.[2022]

Bilateral bundle branch area pacing (BBBP) was successfully performed in 22 out of 36 patients, showing a significant reduction in QRS duration compared to left bundle branch pacing (LBBP), indicating more synchronized ventricular activation.

BBBP not only resolved right bundle branch block morphology in 18 patients but also improved right ventricular activation times, demonstrating its potential for more physiological pacing compared to LBBP.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Bilateral Bundle Branch Area Pacing to Achieve Physiological Conduction System Activation. Lin, J., Chen, K., Dai, Y., et al.[2020]

In a study of 40 patients with heart failure and left bundle branch block, left bundle branch pacing (LBBP) showed a significantly greater improvement in left ventricular ejection fraction (LVEF) compared to biventricular pacing (BiVP) after 6 months, with a mean difference of 5.6%.

LBBP also resulted in greater reductions in left ventricular end-systolic volume and NT-proBNP levels, indicating better heart function and reduced heart failure markers, while showing comparable improvements in other functional measures to BiVP.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Randomized Trial of Left Bundle Branch vs Biventricular Pacing for Cardiac Resynchronization Therapy. Wang, Y., Zhu, H., Hou, X., et al.[2022]

In a study of 21 patients with heart failure and left bundle branch block, left bundle branch pacing (LBBP) showed greater improvements in electrical and mechanical synchrony compared to biventricular pacing (BVP), including a significant reduction in QRS duration and area.

LBBP also resulted in a higher increase in hemodynamic performance, as measured by the maximum rate of left ventricular pressure rise (dP/dtmax), indicating it may be a more effective option for cardiac resynchronization therapy in these patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Left Bundle Branch Pacing Versus Biventricular Pacing for Acute Cardiac Resynchronization in Patients With Heart Failure. Liang, Y., Wang, J., Gong, X., et al.[2022]

References

1. Germany pubmed.ncbi.nlm.nih.gov

The Zwolle experience with left bundle branch area pacing using stylet-driven active fixation leads. [2023]

2. Netherlands pubmed.ncbi.nlm.nih.gov

Permanent Bi-Bundle Pacing in a Patient With Heart Failure and Left Bundle Branch Block. [2023]

3. England pubmed.ncbi.nlm.nih.gov

Right-sided approach to left bundle branch area pacing combined with atrioventricular node ablation in a patient with persistent left superior vena cava and left bundle branch block: a case report. [2022]

4. Germany pubmed.ncbi.nlm.nih.gov

Left bundle branch pacing. [2020]

5. United States pubmed.ncbi.nlm.nih.gov

Clinical use conditions of lead deployment and simulated lead fracture rate in left bundle branch area pacing. [2023]

6. United States pubmed.ncbi.nlm.nih.gov

Electrophysiological characteristics of septal perforation during left bundle branch pacing. [2022]

7. United States pubmed.ncbi.nlm.nih.gov

How to implant left bundle branch pacing lead in routine clinical practice. [2020]

8. United States pubmed.ncbi.nlm.nih.gov

Contrast-enhanced image-guided lead deployment for left bundle branch pacing. [2022]

9. United States pubmed.ncbi.nlm.nih.gov

Bilateral Bundle Branch Area Pacing to Achieve Physiological Conduction System Activation. [2020]

10. United States pubmed.ncbi.nlm.nih.gov

Randomized Trial of Left Bundle Branch vs Biventricular Pacing for Cardiac Resynchronization Therapy. [2022]

11. United States pubmed.ncbi.nlm.nih.gov

Left Bundle Branch Pacing Versus Biventricular Pacing for Acute Cardiac Resynchronization in Patients With Heart Failure. [2022]