Accelerated Pacing and Cardiac Filling Pressures During Exercise in Patients With Heart Failure With Preserved Ejection Fraction

NCT07270536 | Recruiting

• 1 other identifier: S70922
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 2

Brief Summary

Heart failure with preserved ejection fraction (HFpEF) is a condition where the heart pumps strongly enough, but has trouble relaxing and filling with blood properly. This causes the pressure on the left side of the heart to rise, especially during activity, which can lead to symptoms like shortness of breath and fatigue. Even light activities such as walking or climbing stairs can be difficult, limiting daily life. Recent research suggests that increasing the heart rate in people with HFpEF may help lower this elevated pressure in the heart. Because patients usually experience their symptoms during exercise, this study aims to see whether, during light activity, increasing the heart rate in patients who already have a pacemaker by adjusting its settings, can reduce this elevated pressure in the heart. Furthermore, we will look at how increasing the heart rate affects the amount of blood the heart pumps each minute, another key factor in a person's ability to perform physical activity. The investigators will examine 20 patients using a heart catheter to measure pressures, along with breathing analyses. During the measurements, all patients will perform light-intensity cycling. If increasing the pacemaker rate lowers the pressure in the heart, this simple, non-drug-based intervention could improve daily functioning and comfort for thousands of patients with heart failure, justifying further long-term studies to evaluate effects beyond the immediate changes in heart pressures.

Conditions

HFpEF

Keywords

Heart Failure with Preserved Ejection Fraction; Accelerated pacing; Chronotropic response; Hemodynamics

Outcome Measures

Primary Outcomes (1)

• Pulmonary capillary wedge pressure (PCWP), measured using a Swan-Ganz catheter (pulmonary artery catheter).

  The change in pulmonary capillary wedge pressure at each pacing step compared to the pulmonary capillary wedge pressure at the intrinsic heart rate at rest and during exercise (cycling at 10 Watts and 25 Watts). The PCWP at the intrinsic heart rate is defined as the average of the PCWP at the intrinsic heart rate heart rate before and after each pacing step.

  Intraprocedural

Secondary Outcomes (3)

• Cardiac output, measured using the direct Fick principle

  Intraprocedural

• Shear wave velocity, measured via echocardiographically obtained myocardial shear waves following mitral valve closure

  Intraprocedural

• Peripheral oxygen extraction

  Intraprocedural

Study Arms (1)

All patients

EXPERIMENTAL

Other: Accelerated pacing with AV-delay optimization during rest and light intensity cycling

Interventions

Accelerated pacing with AV-delay optimization during rest and light intensity cycling OTHER

Patients will undergo one protocol at rest and two exercise protocols (10 Watts followed by 25 Watts). During each protocol, the pacemaker rate will be gradually increased in three stages. At each stage, intracardiac pressures and shear-wave velocity will be measured. In a final fourth stage, the pacemaker rate will return to the level associated with the lowest heart pressure, blood oxygen levels and oxygen uptake will be assessed.

All patients

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Contraindication to central venous access
• Severe coagulopathy (e.g., spontaneous INR \> 2, thrombocytopenia \< 50,000/µL)
• Local infection or skin infection at the insertion site
• Thrombosis or anatomical abnormalities of the right jugular vein
• Pneumothorax or contralateral lung pathology
• Inability to properly position the patient
• Contraindication to arterial access
• Thrombosis or occlusion of the target artery
• Raynaud's phenomenon or other vasospastic disorders
• Active infection at the intended insertion site
• Severe coagulopathy (e.g., spontaneous INR \> 2, thrombocytopenia \< 50,000/µL)
• Insufficient collateral circulation (e.g., inadequate perfusion in an Allen test)
• Contraindications to CPET
• ECG signifying myocardial injury
• ECG signifying current or potentially lethal arrhythmias

Sponsors & Collaborators

• Universitaire Ziekenhuizen KU Leuven: lead
• Jessa Ziekenhuis Hasselt: collaborator

Study Sites (2)

Jessa Ziekenhuis Hasselt

Hasselt, 3500, Belgium

RECRUITING

University Hospitals Leuven

Leuven, 3000, Belgium

RECRUITING

Central Study Contacts

Margot Vermeiren, MD

CONTACT

+3216332211; margot.vermeiren@kuleuven.be

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 14, 2025
• First Posted: December 8, 2025
• Study Start: December 10, 2025
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2027
• Last Updated: January 8, 2026

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

BE (2)