Metabolic Mapping and Cardiac Resynchronization

Study Overview
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Brief Summary
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The purpose of this study is to gather information on the safety and effectiveness of cardiac resynchronization therapy (CRT) in patients who have mild heart failure (HF) and left bundle branch block (LBBB).

Official Title
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Metabolic Mapping and Cardiac Resynchronization (Aim 1)

Conditions
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Heart Failure

Intervention / Treatment
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* Device: Cardiac resynchronization therapy pacemaker (CRT-P)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: LVEF 35%-50% NYHA class I-II QRS duration of ≥120ms Left bundle branch block (LBBB) Patient is able to receive a transvenous pectoral CRT implant Patient is able to sign informed consent Two echocardiograms are required to confirm a stable reduced LVEF Patient is on optimal and stable medical therapy (ACE inhibitor or AT1 blocker, beta blocker, etc. over the last 6 months) Exclusion Criteria: Advanced comorbid conditions with life expectancy <1 year Patient is <18 of years of age Patient has a CRT device Female patients who is pregnant or not on a reliable form of birth control. Women of childbearing potential are required to have negative pregnancy test within the 7 days prior to device implant Unwilling or unable to return for required follow-up visits Patient decides study participation is cost-prohibited

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Single-center, randomized cross-over study
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CRT-On first, then CRT-Off<br>Subjects will be randomized to have the cardiac resynchronization therapy pacemaker (CRT-P) programmed on in the first intervention period, and after six months the CRT function will be turned off in the second intervention period. | Device: Cardiac resynchronization therapy pacemaker (CRT-P)<br>* A pacemaker is an implantable, battery-powered minicomputer that sends electrical pulses to the heart whenever it detects a slow heartbeat or no heartbeat at all. When it senses a slow heartbeat or lack of heartbeat, it sends electrical impulses to restore a normal rhythm. Cardiac resynchronization therapy pacemakers, or CRT-Ps, treat heart failure by resynchronizing electrical impulses in the heart's four chambers, improving the heart's ability to pump blood to the body effectively and efficiently.<br>* Other names: BIOTRONIK Evia HF-T;|
| Experimental: CRT-Off first, then CRT-On<br>Subjects will be randomized to have the cardiac resynchronization therapy pacemaker (CRT-P) programmed off in the first intervention period, and after six months the CRT function will be turned on in the second intervention period. | Device: Cardiac resynchronization therapy pacemaker (CRT-P)<br>* A pacemaker is an implantable, battery-powered minicomputer that sends electrical pulses to the heart whenever it detects a slow heartbeat or no heartbeat at all. When it senses a slow heartbeat or lack of heartbeat, it sends electrical impulses to restore a normal rhythm. Cardiac resynchronization therapy pacemakers, or CRT-Ps, treat heart failure by resynchronizing electrical impulses in the heart's four chambers, improving the heart's ability to pump blood to the body effectively and efficiently.<br>* Other names: BIOTRONIK Evia HF-T;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Left Ventricle End-Systolic Volume Index (LVESVI) | LVESVI is the volume of blood in the left ventricle at the end of contraction, or systole, and the beginning of filling, or diastole. | baseline, approximately 12 months | 
| Number of Subjects Not Experiencing Any System-Related Complications | This is a composite endpoint; system-related complications could include any of the following: device pocket hematoma, pneumothorax, myocardial perforation, lead dislodgement, lead revision and device-related infection. | baseline, approximately 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Subjects Admitted to the Hospital for Heart Failure |  | Approximately 12 months | 
| Number of Subjects Whose N-Terminal Pro B-Type Natriuretic Peptide (NT-proBNP) Increases by 30% | The NT-proBNP is a substance that is produced in the heart and released when the heart is stretched and working hard to pump blood. | Approximately 12 months | 
| Number of Subjects Who Experience Sustained Ventricular Tachycardia or Fibrillation Greater than 30 Seconds | In ventricular tachycardia, abnormal electrical signals in the ventricles cause the heart to beat faster than normal, usually 100 or more beats a minute, out of sync with the upper chambers. Ventricular fibrillation is the most serious cardiac rhythm disturbance. The lower chambers quiver and the heart can't pump any blood, causing cardiac arrest. | Approximately 12 months | 
| Number of Subjects Who Experience a Decrease in Left Ventricular Ejection Fraction (LVEF) to ≤35% | LVEF refers to how well your left ventricle (or right ventricle) pumps blood with each heart beat. Most times, EF refers to the amount of blood being pumped out of the left ventricle each time it contracts. The left ventricle is the heart's main pumping chamber. | Approximately 12 months | 
| Number of Subjects Who Die in One Year |  | Approximately 12 months |