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

What is HFpEF? In heart failure with preserved ejection fraction (HFpEF), the heart pumps well but struggles to relax and fill with blood between beats. This raises the pressure inside the heart, especially during physical activity, causing symptoms like shortness of breath and fatigue - even with light activities like walking or climbing stairs. What is this study about? Recent research suggests that a higher heart rate may help lower this elevated pressure. Many HFpEF patients already have a pacemaker. This study investigates whether simply increasing the pacemaker rate during light exercise can reduce the pressure in the heart. How does the study work? We wille measure heart pressures in 20 patients in rest and while cycling using a heart catheter and monitor their breathing. Throughout these measurements, we will gradually increase the pacemaker rate step by step. Why does this matter? If a higher pacemaker rate successfully lowers heart pressure, this could offer a simple, drug-free way to improve daily functioning and comfort for thousands of patients with HFpEF, 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 PCWP at each pacing frequency (+20 bpm, +40 bpm, +60 bpm) with its corresponding optimal AV-delay at rest, compared to baseline PCWP. The change in PCWP at each pacing frequency (+10 bpm, +30 bpm, +50 bpm) using dynamic AV-delay programming, while avoiding truncation, compared to baseline PCWP during exercise (cycle ergometry at 25 W) Baseline PCWP is calculated as the average of the measurements before and after each accelerated pacing-on step, using the intrinsic HR or baseline atrial pacing rate as the reference HR, as applicable

  Intraprocedural

Secondary Outcomes (4)

• 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

• Stroke volume

  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 resting and one exercise protocol (25 Watts). During each protocol, the pacemaker rate will be gradually increased in three stages: +20, +40, +60 bpm at rest and +10, +30, +50 bpm during exercise. At each stage, intracardiac pressures and shear-wave velocity will be measured. In a final fourth stage, the pacemaker rate returns to the level associated with the lowest filling pressure, after which blood oxygen levels and oxygen uptake are assessed to calculate cardiac output.

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
• Hartcentrum 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): March 1, 2027
• Study Completion (Estimated): March 1, 2027
• Last Updated: June 5, 2026

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

BE (2)