An interventional study of His-CRT implantation and BIV-CRT implantation in Right Bundle-Branch Block, Heart Failure and His-bundle Pacing, sponsored by University of Rochester. Recruiting at 14 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-09.
Sponsored by University of Rochester · Not applicable, Interventional, and Treatment
The investigators aim to prospectively evaluate the efficacy and mechanism of benefit of His-bundle pacing enhanced cardiac resynchronization therapy (His-CRT) vs. cardiac resynchronization therapy (BIV-CRT) in patients with heart failure and right bundle branch block (RBBB).
In this prospective, randomized, multi-center clinical trial, the investigators aim to prospectively evaluate the efficacy and mechanism of benefit of His-bundle pacing enhanced cardiac resynchronization therapy (His-CRT) vs. cardiac resynchronization therapy (BIV-CRT) in patients with Right Bundle Branch Block (RBBB) Electrocardiogram (ECG) Pattern by assessing the improvement in left ventricular ejection fraction (LVEF) in the His-CRT vs. BIV-CRT arm at 6 months, and by evaluating changes in ECG biomarkers, NT-pro-brain natriuretic peptide (NT-proBNP) levels, and echocardiography biomarkers (left ventricular volumes, strain contractility, and dyssynchrony), as well as temporal changes in functional status and quality of life in the His-CRT vs. BIV-CRT arm at 6, 12, and 24 months.
94 studies on the registry are indexed under Bundle-Branch Block; 30 are open to participants now.
This study's planned enrollment of 120 is above the median of 60 across 59 interventional studies indexed under Bundle-Branch Block.
Browse Bundle-Branch Block studies →University of Rochester is the lead sponsor of 729 studies on the registry; 116 are open to participants now.
Of its 56 completed or terminated interventional studies of FDA-regulated products, 44 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Class IIa or IIb guideline-based indication for CRT-D implant in RBBB patients, including one of the following:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
His-CRT implantation includes implantation of three leads, an endocardial right atrial lead, an endocardial right ventricular lead, and an endocardial His-bundle pacing leads directly pacing the intrinsic conduction system.
Procedure: His-CRT implantation
BIV-CRT implantation includes implantation of three leads, an endocardial right atrial lead, an endocardial right ventricular lead, and an epicardial left ventricular lead implanted in a branch of the coronary sinus.
Procedure: BIV-CRT implantation
The pathophysiological process is utilized in His-Bundle corrective pacing, resulting in a faster and more homogeneous activation of the heart pacing directly via the intrinsic conduction system of the heart accompanied by a right atrial endocardial lead and a right ventricular endocardial lead.
Biventricular cardiac resynchronization therapy has been shown to improve outcomes by delivering synchronized electrical stimuli to the right and left ventricles utilizing an an endocardial right atrial lead, an endocardial right ventricular lead, and an epicardial left ventricular lead implanted in a branch of the coronary sinus.
Change in Left Ventricular Ejection Fraction at 6 months with His-CRT vs. BIV-CRT, in heart failure patients with Right bundle branch block (RBBB)
The effect of His-CRT vs. BIV-CRT on left ventricular ejection fraction (as a percentage) measured during an echocardiography imaging study will be analyzed using an analysis of covariance model for changes in LVEF from pre-implantation (baseline) to post-implantation (6 months follow-up), with randomized treatment group as the factor of interest, and baseline LVEF as a covariate. A t-test will be performed using this model to compare the adjusted group means, and a confidence interval will be constructed for their difference.
Time frame: 6 month
Assess the mechanism of benefit with His-CRT vs. BIV-CRT by evaluating changes in ECG biomarkers
Secondary endpoint measured on a continuous scale of paced ventricular depolarization (QRS) duration in the His-CRT vs. BIV-CRT arm
Time frame: 6 months
Assess the mechanism of benefit with His-CRT vs. BIV-CRT by evaluating changes in echocardiographic left ventricular end-systolic volume (LVESV)
Secondary endpoint measured from echocardiography on left ventricular end-systolic volume (LVESV) in the His-CRT vs. BIV-CRT arm
Time frame: 6 months
Assess the mechanism of benefit with His-CRT vs. BIV-CRT by evaluating changes in echocardiographic left ventricular end-diastolic volume (LVEDV)
Secondary endpoint measured from echocardiography on left ventricular end-diastolic volume (LVEDV) in the His-CRT vs. BIV-CRT arm
Time frame: 6 months
Assess the mechanism of benefit with His-CRT vs. BIV-CRT by evaluating changes in NT-proBNP
Secondary endpoint of NT-proBNP in the His-CRT vs. BIV-CRT arm
Time frame: 6 months
Ascertain the mechanism of benefit on ventricular depolarization (QRS duration) over time, at 6 months, 12 months, and 24 months.
Assessing changes in QRS duration at 6, 12, 24 months in the His-CRT vs. BIV-CRT arm
Time frame: Up to 24 months
Heart failure (HF) or death events
Assess heart Failure (HF)/death rates in the His-CRT vs. BIV-CRT arm
Time frame: Up to 24 months
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