NCT06843135

Brief Summary

Rationale Right ventricular pacing (RVP) is an established and effective therapy for patients with atrioventricular (AV) block. However, frequent RVP has been associated with left ventricular (LV) dyssynchrony and may progess heart failure. Conduction system pacing (CSP), a recently introduced alternative to RVP, aims to preserve physiological ventricular activation by engaging the heart's native conduction system. CSP includes diverse pacing approaches such as selective or non-selective His-bundle pacing, selective left bundle pacing, and LV-septal pacing, each with varying levels of fidelity in reproducing normal conduction. The mechanical impact of these distinct CSP strategies on left and right ventricular (RV) performance remains poorly understood. Cardiac magnetic resonance imaging (CMR), a non-invasive and highly accurate tool for assessing cardiac structure and function, is uniquely positioned to elucidate the effects of CSP and RVP on cardiac performance. This trial aims to evaluate the comparative mechanical effects of these pacing strategies, potentially identifying the optimal approach for improving outcomes in patients with AV block. Objective To investigate and compare the effects of CSP and RVP on cardiac performance, as assessed by CMR and electrocardiographic imaging (ECG-imaging). Main Trial Endpoints The primary endpoints are measures of LV and RV performance assessed via CMR, including: ventricular volumes, ejection fraction (EF), and myocardial strain Secondary Trial Endpoints Secondary endpoints include: Safety and Feasibility:

  • Adverse events (e.g., troponin release, lead displacement, arrhythmias, heart failure).
  • Technical feasibility (e.g., ease of device implantation, ability to maintain proper pacing). Electrophysiological Assessment:
  • Degree of selectivity in engaging the native conduction system.
  • Ventricular activation times as assessed by ECG-imaging. Trial Design This is a randomized, controlled, single blind, two-center crossover trial. Participants will undergo CSP and RVP in a randomized sequence, each for six months. CMR and ECG-imaging will be performed at 6 months (end of the first pacing phase) and 12 months (end of the second pacing phase). Trial Population The trial will enroll 88 patients with a normal of at most mildly reduced ejection fraction and an indication for ventricular pacing. Interventions Participants will undergo CMR and ECG-imaging at 6 months and 12 months. Ethical Considerations This trial is designed to advance understanding of the mechanical and clinical effects of CSP relative to RVP in patients with AV block. The anticipated benefits include improved cardiac performance and enhanced quality of life. The primary burden to participants is the requirement for an additional CMR scan, which may be perceived as inconvenient or even stressful. The trial minimizes risk by utilizing established clinical procedures and closely monitoring participants for adverse events.

Trial Health

65
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
88

participants targeted

Target at P50-P75 for not_applicable heart-failure

Timeline
23mo left

Started Mar 2025

Typical duration for not_applicable heart-failure

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress39%
Mar 2025Mar 2028

First Submitted

Initial submission to the registry

February 2, 2025

Completed
22 days until next milestone

First Posted

Study publicly available on registry

February 24, 2025

Completed
5 days until next milestone

Study Start

First participant enrolled

March 1, 2025

Completed
3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 1, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

March 1, 2028

Last Updated

February 24, 2025

Status Verified

February 1, 2025

Enrollment Period

3 years

First QC Date

February 2, 2025

Last Update Submit

February 18, 2025

Conditions

Outcome Measures

Primary Outcomes (1)

  • The primary endpoint is LV ejection fraction measured on CMR

    At 6 months after crossover

Study Arms (2)

Conduction system pacing

ACTIVE COMPARATOR
Device: Ventricular pacing

Right ventricular pacing

ACTIVE COMPARATOR
Device: Ventricular pacing

Interventions

Participants will undergo conductionsystem pacing and right ventricular pacing in a randomized sequence, each for six months. After each phase, patients will undergo a CMR scan and advanced ECG imaging

Conduction system pacingRight ventricular pacing

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • In order to be eligible to participate in this study, a subject must meet all of the following criteria:
  • Age ≥ 18 years
  • Patients with a left ventricular ejection fraction of ≥35%
  • Patients with an indication for ventricular pacing and high-degree atrioventricular block where the degree of anticipated RV pacing is \>20% including:
  • Third degree AV block
  • Symptomatic or asymptomatic second-degree AV block
  • High degree AV block
  • Pace and ablate (AV-node ablation)

You may not qualify if:

  • A potential subject who meets any of the following criteria will be excluded from participation in this study:
  • CRT indication (patients with heart failure (NYHA \>1) in sinus rhythm with left ventricular ejection fraction (LVEF) \<35%, QRS duration \>150 ms, and left bundle branch block (LBBB) QRS morphology despite optimised medical therapy)
  • Inability to undergo CMR (i.e. severe claustrophobia or MRI contraindications)
  • Life expectancy \<12 months
  • Indication for an implantable cardioverter defibrillator
  • Presence of severe valve disease or mechanical valves
  • Any prior attempt at implantation of an ICD, CRT, CSP
  • Permanent AF with rapid ventricular response, unless pace and ablate

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

Heart FailureAtrioventricular Block

Condition Hierarchy (Ancestors)

Heart DiseasesCardiovascular DiseasesHeart BlockArrhythmias, CardiacCardiac Conduction System DiseasePathologic ProcessesPathological Conditions, Signs and Symptoms

Central Study Contacts

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Purpose
TREATMENT
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Postdoctoral Research Fellow

Study Record Dates

First Submitted

February 2, 2025

First Posted

February 24, 2025

Study Start

March 1, 2025

Primary Completion (Estimated)

March 1, 2028

Study Completion (Estimated)

March 1, 2028

Last Updated

February 24, 2025

Record last verified: 2025-02