A Comparison of Left Bundle Branch Optimized Cardiac Resynchronization Therapy vs Left Bundle Branch Area Pacing Alone (LOT or NOT)

September 21, 2026 updated by: PD Dr. Guram Imnadze

Left bundle branch area pacing (LBBAP) has emerged as a promising physiological pacing strategy and may offer advantages over conventional biventricular pacing (BVP), including improved clinical outcomes. However, its effectiveness may be limited in patients with distal conduction system disease, significant endocardial and/or myocardial damage, as well as when direct left bundle branch capture is not achieved. Conventional CRT remains an effective therapy but is associated with procedural challenges and a significant non-responder rate. Current guidelines support the use of LBBAP and BVP either individually or in combination as Left Bundle Branch Optimized CRT (LOT-CRT). Recent data suggest that LOT-CRT may provide superior electrical and hemodynamic resynchronization compared with both LBBAP and BVP. However, there is a lack of randomized trials comparing LBBAP and LOT-CRT in patients with CRT-P indication. The aim of this study is to compare the LOT-CRTP to LBBAP alone.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
124

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Germany
    • Brandenburg
      • Neuruppin, Brandenburg, Germany, 16816
        • University Hospital Ruppin-Brandenburg
        • Contact:
          • Guram Imnadze, MD, PhD
          • Phone Number: +493391393111
          • Email: imnadze@web.de

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

Age ≥ 18 years Clinical indication for CRTP implantation according to the current ESC guidelines De novo implantation LBBB (QRS duration ≥130 ms) NYHA II-IV

Exclusion Criteria:

Severe mitral or aortic valvular disease History of VT/VF Failed implantation of any component of the LOT-CRTP system/ incompleteness of the system to be implanted Pregnancy Life expectancy < 1 year Inability to give written consent

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: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: LOT group

LOT group: Implanted with LOT-CRT-P device and programmed with maximum RV-LV synchronization with narrowest QRS complex on the 12-lead ECG.
Device: LOT-CRT-P (Programming: LOT-CRT-P)

Device: LOT-CRT-P (Programming: LOT-CRT-P) All patients will receive implantation of LOT-CRT-P system consisting of a CRT-P device, CSP lead placed in the LBBAP position in the right ventricle (instead of conventional RV lead), LV lead placed in the coronary sinus, and right atrial lead.

Device programming:

LOT group: Pacing with maximum RV-LV synchronization with narrowest QRS complex on the 12-lead ECG.

After 12 months and study end, each patient receives a personalised and optimally tailored adjustment.
Other: NOT group (LBBAP)

NOT group: Implanted with LOT-CRT-P device and programmed with LBBAP only along with the backup pacing of LV lead with RV-LV delay of 80-100ms.
Device: LOT-CRT-P (Programming: LBBAP)

All patients will receive implantation of LOT-CRT-P system consisting of a CRT-P device, CSP lead placed in the LBBAP position in the right ventricle (instead of conventional RV lead), LV lead placed in the coronary sinus, and right atrial lead.

Device programming:

NOT group: Synchronized with LBBAP only along with the backup pacing of LV lead with RV-LV delay of 80-100ms.

After 12 months and study end, each patient receives a personalised and optimally tailored adjustment.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Clinical Status
Time Frame: From enrollment to 12 month follow up

Hierarchical clinical composite score: 1. Patients who died for a cardiovascular cause, received a heart transplantation or had an unplanned emergency department visit or hospitalization for heart failure are 'unchanged/worsened'.

2. Patients who receive a modification of the implanted CRTP system for reasons of presumed inefficacy of the randomized system are 'unchanged/worsened'.

3. Patients to whom the above does not apply and who have >20% absolute increase in LVEF at 12 months or earlier are 'markedly improved', and patients who have <5% absolute increase in LVEF at 12 months are 'unchanged/worsened' 4. Patients to whom the above does not apply the KCCQ-12 overall summary score will be assessed. Those who have ≥ 5 points increase in KCCQ-12 overall summary score are 'markedly improved', and patients who have ≥5 points decrease are 'unchanged/worsened'.

5. Patients for whom none of the conditions above apply, are 'moderately improved'.
From enrollment to 12 month follow up

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Electrocardiographic characteristics
Time Frame: enrollment to 12 month follow up

ECG: QRS duration, assessment of LV lateral wall activation time and LV lateral wall to RV septal activation time.
enrollment to 12 month follow up
Echocardiographic characteristics
Time Frame: enrollment to 12 month follow up

left ventricular ejection fraction (LVEF), left ventricular end-systolic/ end-diastolic volume (LVESV/LVEDV), LV EDD, LV ESD.
enrollment to 12 month follow up
NYHA class
Time Frame: enrollment to 12 month follow up
enrollment to 12 month follow up
NT-ProBNP
Time Frame: enrollment to 12 month follow up
enrollment to 12 month follow up
6 minutes walking test
Time Frame: enrollment to 12 month follow up
enrollment to 12 month follow up
Quality of Life Questionaire
Time Frame: enrollment to 12 month follow up

KCCQ-12
enrollment to 12 month follow up
Worsened heart failure
Time Frame: enrollment to 12 month follow up
enrollment to 12 month follow up
Arrhythmic events
Time Frame: enrollment to 12 month follow up

VT/VF/AF occurrence
enrollment to 12 month follow up
Mortality
Time Frame: enrollment to 12 month follow up
enrollment to 12 month follow up

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
PD Dr. Guram Imnadze

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2027

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 21, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 21, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 25, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 25, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 21, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • FF109

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

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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