Functional Outcomes in CondUction System Pacing and Right Ventricular Synchrony (FOCUS-Right)

Not Applicable

Recruiting

• Conditions: Left Branch Bundle Block; RV - Right Ventricular Abnormality
• Interventions: Other: Cardiopulmonary Exercise Test (CPET) and Exercise Stress Cardiac Magnetic Resonance (ExeCMR; Other: Continuous pacemaker telemetry (CPT)

• Registration Number: NCT06601322
• Lead Sponsor: Virginia Commonwealth University

Brief Summary

The goal of this prospective single center clinical trial is to evaluate the safety and feasibility of performing simultaneous exercise stress cardiac magnetic resonance (CPET-CMR) and cardiopulmonary exercise testing in patients with pre-existing left bundle branch area pacemakers (LBBAP) programmed to an atrial sensing mode. Measurements of right ventricular, left ventricular function, and exercise capacity will be obtained at various LBBAP programming parameters at rest and during low intensity exercise. The main aims of the study are:

* Demonstrate the safety and feasibility of performing CPET-CMR in patients with pre-existing LBBAP programmed to P-synchronous ventricular pacing mode.

* Generate preliminary data evaluating differences in RV function, LV function, and exercise capacity during various pacemaker programming settings.

Detailed Description

Conduction system pacing, namely left bundle branch area pacing (LBBAP) represents an important pacing modality introduced to avoid the deleterious effects of non-physiologic ventricular activation during chronic right ventricular pacing and /or left bundle branch block (LBBBP). Previous studies have demonstrated that LBBAP exhibits similar or superior left ventricular resynchronization compared to conventional treatment modalities, the impact of this novel pacing strategy on the right ventricle has not yet been addressed. This study aims to demonstrate the safety and feasibility of assessing LBBAP performance with a focus on right ventricular function in a novel way utilizing Cardiopulmonary Exercise Testing and Exercise Stress Cardiac Magnetic Resonance.

The investigators plan a 1-day prospective non-randomized controlled pilot study in which up to 20 subjects with left bundle branch area pacemakers with evidence of output dependent anodal capture will undergo low intensity exercise CPET-CMR at three different LBBAP settings (underlying rhythm, non-selective left bundle pacing, non-selective left bundle pacing with anodal stimulation).

Study Timeline

• Study First Submitted: 2024-07-09
• Study Start: 2024-08-23
• Study First Submitted QC: 2024-09-13
• Study First Posted: 2024-09-19
• Status Verified: 2024-10
• Last Update Submitted: 2024-10-29
• Last Update Posted: 2024-10-30
• Primary Completion: 2025-09
• Study Completion: 2025-09

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• presence of dual chamber LBBAP implantation
• presence of anodal capture with bipolar pacing configuration as determined at pacing implant.

Exclusion Criteria

• Known history of chronotropic incompetence
• high degree or complete heart block
• inability to tolerate NVP during initial device interrogation
• pregnancy
• inability to undergo MRI or exercise utilizing supine bicycle at target work-load
• presence of MRI unsafe pacemaker components.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
No Ventricular Pacing (NVP)	Cardiopulmonary Exercise Test (CPET) and Exercise Stress Cardiac Magnetic Resonance (ExeCMR	Assessment 1 (No Ventricular Pacing) will be performed with no ventricular pacing to assess baseline right and left ventricular function at rest and during exercise.
No Ventricular Pacing (NVP)	Continuous pacemaker telemetry (CPT)	Assessment 1 (No Ventricular Pacing) will be performed with no ventricular pacing to assess baseline right and left ventricular function at rest and during exercise.
Non-selective or Selective Left Bundle Branch Area Pacing (nsLBBAP)	Cardiopulmonary Exercise Test (CPET) and Exercise Stress Cardiac Magnetic Resonance (ExeCMR	Phase 2 (non-selective or selective Left Bundle Branch Area Pacing or ns/sLBBAP) will assess right and left ventricular function at rest and during exercise with non-selective or selective left bundle branch area pacing
Non-selective or Selective Left Bundle Branch Area Pacing (nsLBBAP)	Continuous pacemaker telemetry (CPT)	Phase 2 (non-selective or selective Left Bundle Branch Area Pacing or ns/sLBBAP) will assess right and left ventricular function at rest and during exercise with non-selective or selective left bundle branch area pacing
Left Bundle Branch Area Pacing with Anodal Capture (aLBBAP)	Cardiopulmonary Exercise Test (CPET) and Exercise Stress Cardiac Magnetic Resonance (ExeCMR	Phase 3 (Left Bundle Branch Area Pacing with Anodal Capture or aLBBAP) will assess right and left ventricular function at rest and during exercise with left bundle branch area pacing with anodal capture.
Left Bundle Branch Area Pacing with Anodal Capture (aLBBAP)	Continuous pacemaker telemetry (CPT)	Phase 3 (Left Bundle Branch Area Pacing with Anodal Capture or aLBBAP) will assess right and left ventricular function at rest and during exercise with left bundle branch area pacing with anodal capture.

Primary Outcome Measures

Name	Time	Method
Incidence of Pacemaker Atrial (P Wave) Over-Sensed Events	Day 1: From beginning of CPET-CMR imaging procedure to end of CPET-CMR imaging procedure on study day.	Incidence of pacemaker atrial (P Wave) over sensing as derived from continuous pacemaker telemetry at optimal programmed atrial sensitivity.

Secondary Outcome Measures

Name	Time	Method
Incidence of Pacemaker Atrial (P Wave) Under-Sensed Events	Day 1: From beginning of CPET-CMR imaging procedure to end of CPET-CMR imaging procedure on study day.	Incidence of pacemaker atrial (P Wave) under sensing as derived from continuous pacemaker telemetry at optimal programmed atrial sensitivity.
Left Ventricular Ejection Fraction (%)	Day 1: From beginning of CPET-CMR imaging procedure to end of CPET-CMR imaging procedure on study day.	Left ventricular ejection fraction (%) as measured by cardiac magnetic resonance imaging.
Right Ventricular Ejection Fraction (%)	Day 1: From beginning of CPET-CMR imaging procedure to end of CPET-CMR imaging procedure on study day.	Right ventricular ejection fraction (%) as measured by cardiac magnetic resonance imaging.

Trial Locations

Locations (1)

Virginia Commonwealth University; 🇺🇸 Richmond, Virginia, United States