Recruiting

HFpEF

Sponsor:

University of Texas Southwestern Medical Center

Code:

NCT05723679

Conditions

Heart Failure With Preserved Ejection Fraction

Obesity

Eligibility Criteria

Sex: All

Age: 55 - 70+

Healthy Volunteers: Accepted

Interventions

HeO2 gas mixture

Room air gas mixture

Study Details

Brief summary:

The overall purpose of this study is to investigate whether pulmonary limitations that increase the oxygen (O2) cost of breathing impact dyspnea on exertion (DOE) and peak exercise capacity in patients with HFpEF and obesity. As per investigator's hypothesis, obesity is likely a significant contributor to DOE and exercise intolerance in patients with HFpEF.

Conditions

Heart Failure With Preserved Ejection Fraction

Obesity

Study ID

NCT05723679

Start date

Jul 1, 2023

Status verified date

May, 2026

Completion date

Jun 30, 2029

Anticipated

Primary completion date

Jun 30, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 55 - 70+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • signs and symptoms of heart failure
  • an ejection fraction > 0.50;
  • objective evidence of diastolic dysfunction. elevated biomarkers (NT-proBNP >300 ng/dl) or HF hospitalization
  • healthy volunteers

Exclusion Criteria:

  • age < 55 years
  • BMI > 50 kg/m2
  • Atrial fibrillation with poorly controlled heart rate
  • phosphodiesterase type 5 (PDE5) inhibitor use
  • severe valvular disease
  • severe Chronic obstructive pulmonary disease (COPD)
  • Chronic kidney disease (CKD) 4 or higher
  • any restriction of ambulation and mobility.

Study Design

Enrollment

78 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: HeO2 gas mixture, then Room air gas mixture

Participant will be randomized to each intervention on separate days (Study visit 3 and 4) in this cross-over trial. Participants that receive HeO2 first will then receive the room air gas mixture. At least 24 hours will separate each visit.

experimental: Room air gas mixture, then HeO2 gas mixture

Participant will be randomized to each intervention on separate days (Study visit 3 and 4) in this cross-over trial. Participants that receive Room air first will then receive the HeO2 mixture. At least 24 hours will separate each visit.

Interventions

HeO2 gas mixture

Low-density helium-oxygen gas mixture (HeO2: 21% O2 and 79% He). Participant will be breathing this gas mixture.

Room air gas mixture

Normal room air

Primary outcome measure

  • O2 cost of breathing (Objective 1) [ Time Frame: Day 2 ]
  • Change in DOE during HeO2 breathing (Objective 2) [ Time Frame: Day 3 or 4 ]
  • Change in peak exercise capacity during HeO2 breathing (Objective 2) [ Time Frame: Day 3 or 4 ]

Central Contacts and Locations

Central contacts

Raksa B Moran, RN

214-345-6574raksamoran@texashealth.org

Jessica N Alcala, RN

214-345-6574jessicaalcala@texashealth.org

Locations

UT Southwestern Medical Center

Recruiting

Dallas, Texas, United States, 75390

Contacts

Raksa B Moran, RN

2143456574raksamoran@texashealth.org

Jessica N Alcala, RN

2143456574jessicaalcala@texashealth.org

More Information

Sponsor

University of Texas Southwestern Medical Center

Last update posted

May 7, 2026

Last verified

May, 2026

Keywords

  • exertional dyspnea
  • exercise intolerance
  • HFpEF
  • breathing limitations
  • cardiopulmonary physiology

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Texas Southwestern Medical Center on 2026-05-07.