Adaptive Cardiac Resynchronization Therapy in Patients With RBBB

June 30, 2023 updated by: Dr. Waddah Maskoun, Henry Ford Health System

Cardiac Resynchronization Therapy With Synchronized RV Pacing to Improve Cardiac Function in Patients With Right Bundle Branch Block and Systolic LV Dysfunction

This study will address whether acute adaptive RV pacing in sinus rhythm patients with severe LV systolic dysfunction and RBBB is superior to no ventricular pacing, and is as effective as echocardiographically optimized biventricular (BIV) pacing based on Medtronic ECG belt and cardiac performance as assessed by the echocardiographic parameters of RV and LV function.

Study Overview

Status

Terminated

Conditions

Intervention / Treatment

Detailed Description

Current guidelines state that CRT implantation is less beneficial for patients with RBBB compared to those with LBBB (2). Current evidence suggests that frequent or persistent RV-only pacing in patients with narrow QRS and LV dysfunction can be harmful due to ventricular desynchronization attributable to RV apex pacing (3-5).

Studies suggest that LV-only pacing is not inferior to BIV pacing in sinus rhythm patients with LV dysfunction and LBBB and ICD back up (6,7). A novel algorithm of CRT by delivering synchronized LV pacing with the intrinsic conduction in patients with severe LV systolic dysfunction and LBBB (adaptive CRT) has been demonstrated to show that it is at least as effective as protocol-driven echocardiographic optimization. It also has shown a significant reduction in the probability of 30-day readmission for both HF and all-cause hospitalizations, 46% reduced incidence of AF compared to conventional CRT, and prolongation of CRT device battery life (8-10). Patients who had an adaptive CRT algorithm that provided > 50% synchronized LV pacing or had normal AV conduction with the adaptive CRT algorithm had decreased risk of death or heart failure hospitalization when compared to those with <50% synchronized LV pacing or echocardiography-optimized BIV pacing respectively (11). In another acute study the LV dP/dtmax was higher with LV than BIV pacing when LV pacing was associated with ventricular fusion caused by intrinsic activation (12).

Several studies have suggested that optimization of the programmed atrioventricular delay (AVD) and interventricular delay (VVD) delays may incrementally improve the long-term outcome of BIV pacing (13-15).

The lateral LV wall contracts early in patients with RBBB when compared to LBBB so LV pacing in the CRT devices is less likely to be beneficial. . In an experimental study of 12 dogs with tachycardia-induced cardiomyopathy and RBBB (6 dogs) or LBBB (6 dogs) (16), RV-only pacing enhanced LV function and synchrony as seen by dP/dtmax measured by catheter tip placed in the LV chamber and synchrony evaluation by cardiac MRI in the RBBB group as well or better than BIV pacing. LV-only pacing worsened function in the RBBB group.

RV-only pacing was also evaluated in a prospective study of 7 patients with RBBB and RV dysfunction with most patients having congenital heart disease. LV global function was intact at baseline (17). Sequential atrioventricular RV pacing with an atrioventricular delay of 90% of the PR interval was superior to atrial-only pacing for both improvement in RV dP/dtmax and LV cardiac index as seen at cardiac catheterization. The RV dP/dtmax increased by 22% in RBBB patients with RV pacing and QRS decreased from 163 +/- 39 to 126 +/- 31 ms. The two studies together suggest that most of the benefit from BIV pacing in patients with RBBB and HF is due to the RV pacing component and the benefit might be reduced due to the LV pacing component. Better timing of RV pacing in patients with RBBB might significantly decrease desynchronization from RV pacing and maximize the benefit of RV pacing as seen in adaptive LV-pacing CRT in patients with LBBB and LV systolic dysfunction.

These studies have led to the current hypothesis that adaptive RV pacing using RV-only pacing synchronized to LV activation when intrinsic AV conduction is normal is more physiological and will improve RV and LV function by Echocardiography parameters and on Medtronic ECG belt for activation in patients with RBBB and LV dysfunction because of improved synchronization and narrowing the QRS duration.

As a secondary goal, battery life with BIV pacing will be compared to adaptive RV pacing assuming at least 50% of RV-only pacing will be achieved with adaptive CRT for RBBB.

Study Type

Interventional

Enrollment (Actual)

5

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

  • United States
    • Arkansas
      • Little Rock, Arkansas, United States, 72205
        • Central Arkansas Veterans Healthare System
    • Michigan
      • Detroit, Michigan, United States, 48202
        • Henry Ford Hospital

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria: Included patients will have:

  • sinus rhythm or isolated atrial pacing
  • LV systolic dysfunction (EF <35% at time of device implant)
  • AV conduction <250 ms, RBBB, and
  • have an implanted CRT device based on the ACC/AHA/HRS guidelines (2, 18) or will have a CRT device implanted during the study enrollment per ACC/AHA/HRS guidelines (2).

Exclusion Criteria:

  • atrial fibrillation
  • atrial flutter
  • atrial tachycardia
  • AV delay > 250 ms
  • sinus tachycardia with resting heart rate at time of the study 100 bpm
  • frequent APCs (> 25% of the total beats/min) or PVCs (>20% of the total beats/min), or
  • patients with EF > 40% at time of enrollment (if LV systolic function was found to be improved from time of implant).

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: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: CRT Optimization
Each patient will have atrial pacing 10% higher than the sinus rate or atrial pacing at a rate of 60 bpm if significant sinus bradycardia is present. Each patient will have six ECGs and echocardiographic sequences performed in the same session. In addition six electrical activation evaluations by the Medtronic ECG belt will be done as well. The first study will always be with no ventricular pacing. One study will be echocardiography-optimized BIV pacing and four studies for echocardiography-optimized (?) adaptive RV-only pacing with different AV intervals. A random-sequence will be performed to determine the order for the rest of the studies.
Diagnostic test: Optimization of CRT Device
Each patient will have atrial pacing 10% higher than the sinus rate or atrial pacing at a rate of 60 bpm if significant sinus bradycardia is present. Each patient will have six ECGs and echocardiographic sequences performed in the same session. In addition six electrical activation evaluations by the Medtronic ECG belt will be done as well. The first study will always be with no ventricular pacing. One study will be echocardiography-optimized BIV pacing and four studies for echocardiography-optimized (?) adaptive RV-only pacing with different AV intervals. A random-sequence will be performed to determine the order for the rest of the studies.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Effectiveness of adaptive Right Ventricular (RV) pacing
Time Frame: 1 hour

Echocardiographic parameters to measure cardiac function, including:

  1. Left Ventricular Outflow Tract velocity time interval(LVOT VTI),
  2. dP/dt of Left Ventricle (LV) and RV,
  3. Myocardial Performance Index (MPI),
  4. Right Ventricular Outflow Tractvelocity time interval (RVOT VTI); and
  5. 3D derived Systolic Dyssynchrony Index (SDI).
1 hour

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Battery/device longevity
Time Frame: 1 hour
Calculations of current drain and pacing percentages for RV-only pacing versus BIV pacing. Measured by microjoule current consumption.
1 hour

Collaborators and Investigators

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

Sponsor

Henry Ford Health System

Collaborators

Central Arkansas Veterans Healthcare System

Investigators

  • Principal Investigator: Waddah Maskoun, MD, Henry Ford

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

September 15, 2017

Primary Completion (Actual)

March 31, 2021

Study Completion (Actual)

March 31, 2021

Study Registration Dates

First Submitted

August 7, 2019

First Submitted That Met QC Criteria

June 30, 2023

First Posted (Actual)

July 7, 2023

Study Record Updates

Last Update Posted (Actual)

July 7, 2023

Last Update Submitted That Met QC Criteria

June 30, 2023

Last Verified

June 1, 2023

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • E17154

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

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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