An interventional study of HIS/LBB pacing and LV pacing in Heart Failure and Left Bundle-Branch Block, sponsored by Rigshospitalet, Denmark. Completed at 1 site in Denmark. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-12.
Sponsored by Rigshospitalet, Denmark · Not applicable, Interventional, and Treatment
The study will investigate the feasibility of using direct HIS pacing or left bundle branch pacing (LBB pacing) as an alternative to biventricular pacing in patients with symptomatic heart failure and an ECG with a typical left bundle branch block pattern.
Biventricular pacing has for more than a decade been standard of care for patients with HFrEF, LVEF \< 35%, NYHA II-IV despite optimal medical treatment and an ECG with left bundle branch block (LBBB). However, it is not always ideal because of several drawbacks such as phrenic nerve capture, inability to reach late activated areas and many more. Direct HIS pacing can in many cases capture the left bundle and provide normal electrical activation of the left ventricle but sometimes with high pacing thresholds. Recently direct left bundle branch pacing has shown promise with synchronous activation of the left ventricle at low pacing thresholds.
In the present study we randomize 150 patients in two centres to either conventional CRT (50 patients) or HIS/LBB pacing (100 patients). In the HIS/LBB arm, direct HIS-pacing is attempted first but if its not possible or the pacing threshold for capturing the left bundle branch is > 2.5 V at 1 ms we switch to placing a LBB-lead.
Power calculation for non-inferiority: With the 50 patients in the first His Alternative study (25 Biv-CRT og 25 His-CRT) we observed a fall in systolic volumes of 34% and 46% with a standard deviation of 13-16%. Using these numbers it would take at least 108 patients to be 90% sure that the lower limit of a one-sided 97.5% confidence interval (equal to a 95% two-sided confidence interval) would be over the non-inferiority limit of -10%.
6,331 studies on the registry are indexed under Heart Failure; 1,396 are open to participants now.
This study's enrollment of 150 is above the median of 76 across 4,049 interventional studies indexed under Heart Failure.
Browse Heart Failure studies →Rigshospitalet, Denmark is the lead sponsor of 1,007 studies on the registry; 175 are open to participants now.
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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.
Patients over 18 years of age, ischemic or non-ischemic cardiomyopathy with ≤ 35% assessed by echocardiography, class II-IV heart failure symptoms despite optimal medical treatment and
Typical left bundle branch block:
QRS width > 130 msec for women and > 140 msec for men QS or rS pattern in leads V1 and V2, and mid-QRS plateau phase with or without extras in at least 2 of leads V1, V2, V5, V6, I, and aVL
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 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.
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.
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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
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.
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.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
In this arm a right ventricular (RV) lead or implantable cardioverter defibrillator (ICD) lead is placed first and then implantation of a HIS-pacing lead is attempted. If it is not possible to find and pace HIS, to correct the LBBB or the threshold for correcting the LBBB is \> 2.5 V at 1 ms, implantation of a LBB-pacing lead is attempted instead. If that is not possible either, a left ventricular (LV) lead is implanted.
Device: HIS/LBB pacing
In this arm an RV-lead or ICD-lead is placed first and then implantation of a LV-pacing lead is attempted. If this is not possible due to anatomical difficulties (no coronary sinus (CS) access, no available branches other than v cordis anterior or v cordis media) or electrical difficulties (no capture below 4 V at 1.0 msec or phrenic nerve stimulation \< 2x pacing threshold), implantation of a HIS-pacing lead is attempted instead. If that is not possible or the threshold for correcting the LBBB is \> 2.5 V at 1 ms, implantation of a LBB-pacing lead is attempted instead.
Device: LV pacing
3830 lead to HIS or LBB
LV lead in a CS branch
Change in Left ventricular end-systolic volume
Echocardiographic response after 6 months defined as decrease in left ventricular systolic volume
Time frame: 6 months
Success rate of implanting a HIS-bundle lead with capture of the left bundle branch or a LBB-lead with narrowing of QRS
The success rate of implanting a pacing lead to the HIS-bundle with capture of the left bundle at a threshold \< 2.5 V at 1 ms or implantation of a LBB lead with narrowing of the QRS duration and maintaining this effect at 6 month follow-up
Time frame: 6 months
Change in LVEF and left ventricular chamber dimensions
Echocardiographic response assessed by chamber dimensions and LVEF on a continuous scale
Time frame: 6 months
Change in 6-min hall-walk test
Functional response after 6 months defined as an increase in 6-min walking distance of ≥ 20% of the initial value
Time frame: 6 months
Change in NYHA class
Symptomatic response after 6 months defined as a fall in NYHA class of ≥ 1
Time frame: 6 months
Change in Minnesota Living with Heart Failure score
Change in well-being after 6 months defined as a decrease in Minnesota Living With Heart Failure score of ≥ 15% of baseline
Time frame: 6 months
Shortening of QRS duration
Shortening the duration of the QRS complex defined as the widest paced QRS complex rated at 12-lead ECG after 6 months
Time frame: 6 months
Change in NT-pro BNP value
Change in NT-pro BNP value
Time frame: 6 months
Complications
Device-related complications (periprocedural: electrode reoperation, pneumothorax, hemothorax, pericardial bleeding/tamponade and later (after 30 days post implantation): LV/HIS electrode reoperation, change of device due to battery depletion and infection requiring extraction).
Time frame: 6 months
Plan to share: Undecided
Ran from Jun 2020 to primary completion in Feb 2026, 68 months.
Of 1,118 non-industry interventional studies with no phase under Heart Failure, half reached primary completion within 29 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 50. This study's 68 months is above that.
Counting every sponsor, half of 1,354 studies reached it within 31 months; a quarter within 16 and three quarters within 52.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.
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