Recruiting

Exercise Lower-body Negative Pressure

Sponsor:

University of British Columbia

Code:

NCT05582044

Conditions

Heart Failure With Preserved Ejection Fraction

Eligibility Criteria

Sex: All

Age: 40+

Healthy Volunteers: Accepted

Interventions

Lower-body Negative Pressure (-25 mmHg)

Lower-body Negative Pressure (-15 mmHg)

Lower-body Neutral Pressure (0 mmHg)

Study Details

Brief summary:

The heart is a pump that must both fill and empty effectively to move blood; if it cannot move enough, heart failure may ensue. Approximately half of all adults living with heart failure have a form where the heart stiffens, which impairs its ability to fill. This form of heart failure particularly affects females and older adults. When people exercise, extra blood returns to the heart. The healthy heart can easily fill and move this extra blood to the muscles. However, when the heart's ability to fill is impaired, the extra blood can back up and pool in the lungs. Blood pooling in the lungs makes people feel breathless, although the investigators do not fully understand why, and this form of heart failure has a high risk of hospitalization and death, but few effective treatments are available. Exercise is one of the few treatments that works well if enough exercise is performed regularly. However, many people with this form of heart failure can only tolerate a small amount before stopping due to severe breathlessness, which can put them off from exercising regularly.

The study's goal is to help these people perform more exercise. The investigators will use a novel form of stationary cycling with a plastic chamber around the lower body that seals at the waist. The chamber can apply suction to the lower body during exercise which will reduce how much extra blood returns and prevent the heart and lungs from being overloaded. Participants will attend 5 visits, including 3 where they will perform a submaximal exercise test for as many minutes as possible with or without light suction. In each of these tests, the investigators will record how long they exercise and ask them to rate how breathless they feel. The investigators will also study their breathing pattern, using a mouthpiece and pressure sensor, and heart function, using ultrasound imaging.

This work will help adults living with heart failure exercise more and improve their health, and help researchers understand what causes breathlessness and develop new treatments.

Conditions

Heart Failure With Preserved Ejection Fraction

Study ID

NCT05582044

Start date

Jan 25, 2023

Status verified date

Apr, 2025

Completion date

Jan, 2026

Anticipated

Primary completion date

Jan, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 40+

Healthy Volunteers: Accepted

Inclusion Criteria for the HFpEF Group:

  • Adults with a clinical diagnosis of HFpEF (LV ejection fraction ≥50%) measured in the year prior to Visit 1 (and confirmed at Visit 1), who are New York Heart Association Functional Class II-III (mild-moderate symptoms), ambulatory, receiving guideline-directed medical therapy unchanged for ≥2 months, and clinically stable for ≥3 months.
  • Symptom(s) of heart failure requiring treatment within the year prior to Visit 1
  • NT-proBNP >50 pmol/L (sinus rhythm) or >150 pmol/L (atrial fibrillation in year prior)
  • Diastolic dysfunction based on at least one of the following echocardiographic findings:

  • Left atrial enlargement (diameter >4 cm or volume index >28 mL/m2); or
  • e' <10 cm/s (lateral) or <8 cm/s (septal), or
  • E/e' >10 (lateral), or >15 (septal)

Inclusion Criteria for the Healthy Control Group:

- Healthy sedentary or recreationally active adults from the community

Exclusion Criteria for the HFpEF Group:

  • Any prior measurement demonstrated LV ejection fraction ≤40%
  • Primary pulmonary, metabolic, renal, hepatic, neuromuscular, or malignant disease
  • Primary pulmonary vascular, complex congenital, or > mild valvular heart disease
  • Documented infiltrative cardiomyopathy
  • Documented valvular or coronary disease requiring intervention
  • Myocarditis, pericardial effusion, acute coronary syndrome, or revascularization in the last 3 months
  • Resting seated systolic blood pressure >160 mmHg or <100 mmHg
  • Jugular venous pressure >12 cm
  • Inferior vena cava >2 cm with no inspiratory collapse, or severe right ventricular dysfunction by echo
  • Ambulatory supplemental oxygen
  • Current or recent participation in >150 min. per week of moderate intensity exercise
  • Current or recent (within the past 6 months) smoking
  • Body mass index >35 kg/m2
  • Contraindication to exercise or otherwise unable to perform cycle ergometry
  • Poor echocardiographic imaging windows

Exclusion Criteria for the Healthy Control Group

  • Current or recent participation in >150 min. per week of moderate intensity exercise
  • History of any cardiovascular condition or cardioactive drug use
  • History of any respiratory condition including asthma
  • History of any metabolic condition including diabetes
  • Non-sinus rhythm
  • Echocardiographic evidence of significant left ventricular hypertrophy, valvular abnormalities, left ventricular ejection fraction <50%, or diastolic dysfunction as described in HFpEF inclusion criteria.
  • Seated blood pressure ≥140/90 mmHg
  • Any other chronic systemic illness
  • Current or recent (within the past 6 months) smoking
  • Body mass index >35 kg/m2
  • Contraindication to exercise or otherwise unable to perform cycle ergometry
  • Poor echocardiographic imaging windows

Study Design

Enrollment

60 participants

Anticipated

Allocation

Non randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Heart Failure with Preserved Ejection Fraction (40 Participants)

Lower-body negative pressure (-15 and -25 mmHg) and neutral pressure (0 mmHg)

active comparator: Healthy Controls (20 Participants)

Lower-body negative pressure (-15 and -25 mmHg) and neutral pressure (0 mmHg)

Interventions

Lower-body Negative Pressure (-25 mmHg)

The LBNP chamber will be sealed at the waist prior to Control measures, and the vacuum system will be activated to coincide with the onset of exercise, applying -25mmHg LBNP.

Lower-body Negative Pressure (-15 mmHg)

The LBNP chamber will be sealed at the waist prior to Control measures, and the vacuum system will be activated to coincide with the onset of exercise, applying -15mmHg LBNP.

Lower-body Neutral Pressure (0 mmHg)

In this placebo trial, the LBNP chamber will be sealed at the waist prior to Control measures, and the vacuum system will be activated to coincide with the onset of exercise, but the chamber will be vented to atmosphere.

Primary outcome measure

  • Time to exercise limitation (Tlim) [ Time Frame: Within 30 minutes of exercise onset ]

Central Contacts and Locations

Central contacts

Stephen P Wright, PhD

(250) 807-8860stephen.wright@ubc.ca

Locations

University of British Columbia

Recruiting

Kelowna, British Columbia, Canada, V1V1V7

Contacts

Stephen Wright, PhD

250-807-9676stephen.wright@ubc.ca

More Information

Sponsor

University of British Columbia

Last update posted

Apr 4, 2025

Last verified

Apr, 2025

Keywords

  • Heart Failure
  • Diastolic Dysfunction
  • Exercise Intolerance
  • Dyspnea
  • Pulmonary Congestion
  • Pulmonary Hemodynamics

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of British Columbia on 2025-04-04.