Synchrony in Cardiac Conduction: Assessing the Effects of Pacing on Cardiac Performance Through Magnetic Resonance Imaging and Advanced ECG-imaging
HARMONY
1 other identifier
interventional
88
0 countries
N/A
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
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for not_applicable heart-failure
Started Mar 2025
Typical duration for not_applicable heart-failure
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
First Submitted
Initial submission to the registry
February 2, 2025
CompletedFirst Posted
Study publicly available on registry
February 24, 2025
CompletedStudy Start
First participant enrolled
March 1, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
March 1, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
March 1, 2028
February 24, 2025
February 1, 2025
3 years
February 2, 2025
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 COMPARATORRight ventricular pacing
ACTIVE COMPARATORInterventions
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
Eligibility Criteria
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
Condition Hierarchy (Ancestors)
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