Leg Heat Therapy in Heart Failure With Preserved Ejection Fraction

NCT06388226 | Recruiting FDA Device

• 1 other identifier: IRB # 16143
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 2

Brief Summary

The objective of this pilot study is to establish evidence to support the validity of HT in improving skeletal muscle function and physical capacity of patients with HFpEF. Our central hypothesis is that HT treatment will lead to improvements in skeletal muscle and microvascular function compared to a control intervention. As a result, we anticipate that patients treated with HT will demonstrate improved skeletal muscle microvascular blood flow and oxygenation resulting in enhanced exercise tolerance. To explore this hypothesis, we propose the following specific aim: Explore the effects of home-based HT on exercise tolerance in patients with HFpEF.

Conditions

Heart Failure With Preserved Ejection Fraction

Outcome Measures

Primary Outcomes (1)

• Change in time to exhaustion during treadmill exercise

  The investigators will determine whether daily leg heat therapy for 90 min using water-circulating trousers perfused with water heated to 42ºC improves the time to exhaustion during treadmill exercise testing at 2-month follow-up compared to a sham treatment.

  Baseline to 2-month follow-up

Secondary Outcomes (10)

• Change in maximal pulmonary oxygen uptake during treadmill exercise

  Baseline to 2-month follow-up

• Change in triceps surae microvascular oxygenation during treadmill exercise

  Baseline to 2-month follow-up

• Change in systolic blood pressure

  Baseline to 2-month follow-up

• Change in diastolic blood pressure

  Baseline to 2-month follow-up

• Change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) score

  Baseline to 2-month follow-up

Study Arms (2)

Heat therapy

EXPERIMENTAL

Patients will be provided with water-circulating trousers, a water heater, and a water tank coupled to a water pump. The heater will be adjusted to warm up the water to 42ºC. Participants will be asked to apply the therapy daily for 90 min while in the supine position.

Device: Leg heat therapy

Sham control

SHAM COMPARATOR

Patients will be provided with water-circulating trousers, a water heater, and a water tank coupled to a water pump. The heater will be adjusted to warm up the water to 33ºC. Participants will be asked to apply the therapy daily for 90 min while seated or in the supine position.

Device: Leg sham therapy

Interventions

Leg heat therapy DEVICE

A sous vide heating immersion circulator heats up the water inside the water tank to 42ºC. A water pump circulates temperature-regulated water through the trousers.

Heat therapy

Leg sham therapy DEVICE

A sous vide heating immersion circulator heats up the water inside the water tank to 33ºC. A water pump circulates temperature-regulated water through the trousers.

Sham control

Eligibility Criteria

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

You may qualify if:

• Men and women older than 18 years
• Established diagnosis of heart failure with preserved ejection fraction (HFpEF) including left ventricular ejection fraction (LVEF) ≥50% as evidenced by Doppler echocardiography and/or ratio of the early mitral inflow velocity (E) to septal tissue Doppler velocity (e') \>8 and at least 1 other sign of chronically elevated filling pressures, including an enlarged left atrium (left atrial volume index \>34 mL/m2), an elevated N-terminal pro-brain natriuretic peptide (NT-pro-BNP) level within the past year, long-term loop diuretic use for control of symptoms, or elevated filling pressures (mean pulmonary capillary wedge pressure \>12 mmHg) on prior cardiac catheterization
• Stable medical treatment

You may not qualify if:

• Recent hospitalization (within the previous 1 month)
• Unstable angina and/or uncontrolled cardiac arrhythmia causing symptoms or hemodynamic compromise (including severe bradycardia or tachycardia, sick sinus syndrome, or multifocal premature ventricular contractions)
• Presence of any clinical condition that makes the patient unsuitable to participate in the trial, e.g., significant ischemic or valvular heart disease, cor pulmonale, unstable coronary artery disease, primary renal (e.g., estimated glomerular filtration rate (eGFR) \<25 mL/min/1.73 m2) or hepatic disease (e.g., aspartate aminotransferase and alanine aminotransferase levels \>3.0 times the upper limit of the normal range), pulmonary, neuromuscular, orthopedic disorders, among others
• Inability to exercise on the treadmill
• Inability to provide informed consent
• Concern for inability of the patient to comply with study procedures and/or follow up (e.g., alcohol or drug abuse)
• Any contraindication to heat therapy and/or inability to fit into water-circulating trousers
• Impaired thermal sensation in the leg

Sponsors & Collaborators

• Indiana University: lead
• Purdue University: collaborator

Study Sites (2)

IU Health Methodist

Indianapolis, Indiana, 46202, United States

RECRUITING

IU Health University Hospital

Indianapolis, Indiana, 46202, United States

RECRUITING

Central Study Contacts

Doris Muriathiri, MPH, CCRP

CONTACT

317-274-0903; dmuriath@iu.edu

Daniel Hirai, PhD

CONTACT

765-494-7113; dhirai@purdue.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor of Clinical Medicine

Study Record Dates

• First Submitted: April 24, 2024
• First Posted: April 29, 2024
• Study Start: August 15, 2024
• Primary Completion (Estimated): August 20, 2026
• Study Completion (Estimated): August 31, 2026
• Last Updated: November 17, 2025

Record last verified: 2025-11

Locations

US (2)