Project Summary

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.

What is the research about?

In a healthy heart, an electrical signal causes the heart to beat. In some patients with heart failure, the lower heart chambers don’t beat together like they should. When this occurs, the heart can’t pump enough blood to the body, which can cause shortness of breath, fluid retention, and sudden death. Patients with this type of heart failure need treatment to help the heart beat as it should. In pacing treatment, a doctor implants a small device in the chest. The device sends electrical signals to the heart that tell it to beat. 

In this study, the research team is comparing two pacing treatments for heart failure:

  • Biventricular pacing, or BiVP. BiVP uses three wires that go to the heart’s right chambers and the left lower chamber to help the chambers beat together. BiVP doesn’t use the heart’s normal electrical signal path. BiVP is the standard of care for patients with this type of heart failure. But BiVP doesn’t work for 30 to 40 percent of patients who get it.
  • His bundle pacing or left bundle branch pacing, or His/LBBP. His/LBBP uses two wires that go to the heart’s right upper chamber and right lower chamber to help the chambers beat together. His/LBBP uses the heart’s normal electrical signal path. 

The research team is looking to see how well each pacing treatment prevents hospital visits and death among patients with heart failure.

Who can this research help?

Results may help doctors and patients when considering pacing treatments for heart failure.

What is the research team doing?

The research team is enrolling 2,136 patients with heart failure caused by the lower heart chambers not beating together. The team is assigning patients by chance to receive BiVP or His/LBBP. 

For up to five and a half years after treatment, the research team is following patients to see if they go to the hospital for or die from heart failure. Before and after pacing treatment, the team is also surveying patients about their quality of life and physical activity. The team wants to learn if patient traits, such as race or sex, predict how well each treatment works. Finally, the team is comparing how often patients have adverse events such as an infection after treatment.

Patients with heart failure, patients with a pacemaker, caregivers, patient advocacy groups, and health insurers helped design and conduct this study.

Research methods at a glance

Design ElementDescription
DesignRandomized controlled trial
Population2,136 adults ≥18 years with a left ventricular ejection fraction ≤50% and wide QRS complex or advanced conduction disease
  • BiVP
  • His/LBBP

Primary: composite measure of all-cause mortality and hospitalization for heart failure

Secondary: quality of life, composite measure of all-cause mortality, first hospitalization for heart failure, and echocardiography on left ventricular end-systolic volume; all-cause mortality; mortality from any cardiovascular cause; hospitalization for heart failure; cardiovascular hospitalization; stage of heart failure; walking ability

Timeframe  Timeframe Length of follow-up for collecting data on primary outcomes. View Glossary Up to 5.5-year follow-up for primary outcome

Project Information

Mihail G. Chelu, MD, PhD
Kenneth A. Ellenbogen, MD
Baylor College of Medicine
Cardiac Resynchronization Therapy Using His/Left Bundle Pacing vs. Left Ventricular Epicardial Pacing in Patients with Heart Failure

Key Dates

July 2022
June 2029


Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: January 24, 2024