Venous Compression in Fontan

NCT07220226 | Not Yet Recruiting FDA Device

• 1 other identifier: STU20250885
• Study Type: interventional
• Target: 20
• Locations: 0 countries
• Sites: N/A

Brief Summary

The aim of this study is to investigate whether venous compression garments increase exercise stroke volume in patients with Fontan circulation. To address this aim, we will test the following hypotheses:

• Undergo submaximal exercise testing in MRI to measure venous return and exercise stroke volume with and without the wearing of compression garments
• Undergo submaximal exercise testing on a seated upright exercise ergometer with concurrent measurement of stroke volume with and without the wearing of compression garments
• A subset of participants will repeat both testing visits after wearing compression garments for 2-weeks during waking hours. Participants will:
• Undergo submaximal exercise testing in MRI to measure venous return and exercise stroke volume with and without the wearing of compression garments
• Undergo submaximal exercise testing on a seated upright exercise ergometer with concurrent measurement of stroke volume with and without the wearing of compression garments
• A subset of participants will repeat both testing visits after wearing compression garments for 2-weeks during waking hours.

Conditions

Single-ventricle; Fontan Circulation

Keywords

Venous Compression; Exercise Testing; Cardiac Reserve; Fontan Circulation; Magnetic Resonance Imaging; vascular function

Outcome Measures

Primary Outcomes (5)

• Change in Stroke Volume with Exercise

  The change in single ventricular stroke volume from rest to moderate intensity exercise with compression garments during baseline testing

  Rest (20 minutes), Exercise (10 minutes)

• Change in Stroke Volume with Exercise

  The change in single ventricular stroke volume from rest to moderate intensity exercise without compression garments during baseline testing

  Rest (20 minutes), Exercise (10 minutes)

• Change in Stroke Volume with Exercise

  The change in single ventricular stroke volume from rest to moderate intensity exercise following 2 weeks of wearing compression garments.

  Rest (20 minutes), Exercise (10 minutes) at 2-weeks follow-up testing

• The Acute Effect of Compression Garments on Stroke Volume during Exercise

  The difference in the change in single ventricular stroke volume during moderate intensity exercise between baseline testing with (outcome #1) and without (outcome #2) garments

  Rest (20 minutes) and Exercise (10 minutes) repeated during baseline testing

• The Chronic Effect of Compression Garments on Stroke Volume during exercise

  The difference in the change in single ventricular stroke volume during moderate intensity exercise between baseline testing without garments (outcome #2) and following 2 weeks of wearing compression garments (outcome #3) in patients with Fontan Circulation.

  Rest (20 minutes) and Exercise (10 minutes) completed during baseline and during follow-up testing

Secondary Outcomes (5)

• Change in Venous Return with Exercise

  Rest (10 minutes) and Exercise (5 minutes)

• Change in Venous Return with Exercise

  Rest (10 minutes) and Exercise (5 minutes)

• Change in Venous Return with Exercise

  Rest (10 minutes) and Exercise (5 minutes)

• The Acute Effect of Compression Garments on Changes in Venous Return with Exercise

  Rest (10 minutes) and Exercise (5 minutes) repeated during baseline testing

• The Chronic Effect of Compression Garments on Changes in Venous Return with Exercise

  Rest (10 minutes) and Exercise (5 minutes) completed during baseline and during follow-up testing

Study Arms (2)

Fontan circulation Arm

EXPERIMENTAL

Fontan circulation participants will undergo Rest +Submax exercise with and without wearing venous compression garments. A subset of patients with Fontan circulation will undergo repeat testing 2-weeks later.

Device: Lower extremity compression garments; Other: Without compression garments

Healthy controls

EXPERIMENTAL

Healthy group participants will undergo Rest +Submax exercise with and without wearing venous compression garments.

Device: Lower extremity compression garments; Other: Without compression garments

Interventions

Lower extremity compression garments DEVICE

Acute and 2-week effects of compression garments

Fontan circulation Arm; Healthy controls

Without compression garments OTHER

Acute effects without compression garments

Fontan circulation Arm; Healthy controls

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Patients at UTSW aged 18-45 years old with a Fontan circulation.

You may not qualify if:

• NYHA Class 4
• Severe AV valve regurgitation
• Severe ventricular dysfunction
• Large ascites
• Significant varicosities
• Atrio-pulmonary (AP) Fontan
• Known Fontan thrombus
• Poorly controlled arrythmia
• Unplanned cardiac admission in the last 6 months
• Cyanosis (resting O2 saturation \<85%)
• Pregnant
• Common femoral vein obstruction \>50% to be performed following completion of informed consent.
• Healthy Controls:
• Healthy control participants will be recruited on the basis of having no known chronic diseases and not currently taking any cardiovascular medications.

Sponsors & Collaborators

• University of Texas Southwestern Medical Center: lead

MeSH Terms

Conditions

Univentricular Heart

Condition Hierarchy (Ancestors)

Heart Defects, Congenital; Cardiovascular Abnormalities; Cardiovascular Diseases; Heart Diseases; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

• Keri Shafer, MD

  University of Texas Southwestern Medical Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Keri Shafer, MD

CONTACT

2146451165; keri.shafer@utsouthwestern.edu

Denis J Wakeham, PhD

CONTACT

2146451165; denis.wakeham@utsouthwestern.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor of Medicine

Study Record Dates

• First Submitted: September 25, 2025
• First Posted: October 23, 2025
• Study Start (Estimated): May 10, 2026
• Primary Completion (Estimated): November 1, 2027
• Study Completion (Estimated): November 1, 2027
• Last Updated: April 22, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share