Direct HIS/LBB Pacing as an Alternative to Biventricular Pacing in Patients With HFrEF and a Typical LBBB. (HIS-alt_2)

February 10, 2026 updated by: Michael Vinther, Rigshospitalet, Denmark

Direct HIS/LBB Pacing as an Alternative to Biventricular Pacing in Patients With Symptomatic Heart Failure Despite Optimal Medical Treatment and an ECG With a Typical Left Bundle Branch Block Pattern.

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.

Study Overview

Status

Completed

Detailed Description

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%.

Study Type

Interventional

Enrollment (Actual)

150

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Capital Region
      • Copenhagen, Capital Region, Denmark, 2100
        • Rigshospitalet

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients over 18 years of age, ischemic or non-ischemic cardiomyopathy with LVEF ≤ 35% assessed by echocardiography, NYHA class II-IV heart failure symptoms despite optimal medical treatment and

    • Either planned new implantation of a biventricular pacing system (CRT-P or CRT-D), where the ECG is with sinus rhythm and a typical left bundle branch block (see definition below)
    • Or planned upgrade of an existing pacemaker or ICD to a biventricular pacing system (CRT-P or CRT-D), where the ECG is with sinus rhythm and a typical left bundle branch block or there has been> 90% right ventricular pacing from an existing pacemaker for at least 2 months prior to enrollment
  • Signed informed consent

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:

  • Existing biventricular pacing system
  • Permanent atrial fibrillation
  • Severe renal failure with eGFR < 30 ml/min
  • AMI or CABG within the last three months
  • The patient does not want to participate

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: HIS/LBB pacing
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.
3830 lead to HIS or LBB
Active Comparator: LV 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.
LV lead in a CS branch

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Success rate of implanting a HIS-bundle lead with capture of the left bundle branch or a LBB-lead with narrowing of QRS
Time Frame: 6 months
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
6 months
Change in Left ventricular end-systolic volume
Time Frame: 6 months
Echocardiographic response after 6 months defined as decrease in left ventricular systolic volume
6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in LVEF and left ventricular chamber dimensions
Time Frame: 6 months
Echocardiographic response assessed by chamber dimensions and LVEF on a continuous scale
6 months
Change in 6-min hall-walk test
Time Frame: 6 months
Functional response after 6 months defined as an increase in 6-min walking distance of ≥ 20% of the initial value
6 months
Change in NYHA class
Time Frame: 6 months
Symptomatic response after 6 months defined as a fall in NYHA class of ≥ 1
6 months
Change in Minnesota Living with Heart Failure score
Time Frame: 6 months
Change in well-being after 6 months defined as a decrease in Minnesota Living With Heart Failure score of ≥ 15% of baseline
6 months
Shortening of QRS duration
Time Frame: 6 months
Shortening the duration of the QRS complex defined as the widest paced QRS complex rated at 12-lead ECG after 6 months
6 months
Change in NT-pro BNP value
Time Frame: 6 months
Change in NT-pro BNP value
6 months
Complications
Time Frame: 6 months
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).
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Michael Vinther, MD PhD, Rigshospitalet, Denmark

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2020

Primary Completion (Actual)

February 1, 2026

Study Completion (Actual)

February 1, 2026

Study Registration Dates

First Submitted

May 26, 2020

First Submitted That Met QC Criteria

May 26, 2020

First Posted (Actual)

June 1, 2020

Study Record Updates

Last Update Posted (Actual)

February 12, 2026

Last Update Submitted That Met QC Criteria

February 10, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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