Re-Energize Fontan

June 17, 2026 updated by: Seda Tierney, Stanford University

RE-ENERGIZE FONTAN: A RandomizEd Exercise INtERvention DesiGned to MaximIZE Fitness in Pediatric FONTAN Patients

Survival of children with single ventricles ("half a heart") beyond the neonatal period has increased dramatically with the staged Fontan palliation. Yet, long-term morbidity remains high. By the age of 40, 50% of Fontan patients will have died or undergone heart transplantation. With >1,000 Fontan palliations performed in the US annually, there is a burgeoning population of Fontan patients at risk for progressive heart failure and death. Factors that contribute to onset and progression of heart failure in Fontan patients remain incompletely understood. However, it is established that Fontan patients have poor exercise capacity, associated with a greater risk of morbidity and mortality, in addition to decreased muscle mass, abnormal muscle function, and endothelial dysfunction contributing to disease progression. In adult patients with two ventricles and heart failure, reduced exercise capacity, muscle mass, and muscle strength are powerful predictors of poor outcomes, and exercise interventions can not only improve exercise capacity and muscle mass, but also reverse endothelial dysfunction. Limited exercise interventions in children with congenital heart disease have demonstrated that exercise is safe and effective; however, these studies have been conducted in small, heterogeneous groups, and most had few Fontan patients. Furthermore, none of these interventions have studied the impact of exercise on muscle mass or mitochondrial function, or endothelial function. The investigators propose a milestone-driven, randomized controlled trial in pediatric Fontan patients to test the hypothesis that a live-video-supervised exercise (aerobic + resistance) intervention will improve cardiac and physical capacity; muscle mass, strength and function; and endothelial function. The investigators' ultimate goal is the translation of this model to clinical application as an "exercise prescription" to intervene early in pediatric Fontan patients and decrease long-term morbidity and mortality.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
150

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • California
      • Palo Alto, California, United States, 94304
        • Stanford University, Lucile Packard Children Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

8 years to 19 years (Child, Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 8-19 years of age
  • Fontan palliation
  • Ability to fast overnight
  • Cardiac clearance to exercise by primary cardiologist
  • Presence of an adult at home during exercise sessions for patients <14 years old
  • English-speaking patient.

Exclusion Criteria:

  • NYHA Class IV (severe heart failure)
  • Acute illness within the past three months
  • Active protein losing enteropathy (albumin <2.5 mg/dL)
  • Implanted pacemaker
  • Cognitive delay deemed severe enough to inhibit the ability to follow the exercise

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Live Video-Supervised Exercise Intervention Arm
Patients randomized to exercise intervention at baseline will participate in live-video-supervised exercise sessions x3/week for 3 months, and then will follow a maintenance regimen for 6 months. During maintenance, patients will continue live-video-supervised exercise sessions, only x1/week, and will be instructed to exercise on their own x2/week following an individualized prescribed exercise program and use their heart rate monitor as an activity tracker.
Other: Live-Video-Supervised Exercise Intervention
The live-video-supervised exercise intervention includes exercise sessions x3/week for 3 months, and then maintenance regimen for 6 months. Maintenance includes live-video-supervised exercise sessions, only x1/week, and self-exercise x2/week following an individualized prescribed exercise program and use their heart rate monitor as an activity tracker.
Experimental: Live-Video-Supervised Exercise Control Arm
Patients randomized to usual care at baseline will receive usual care for 9 months and will then start the 3-month exercise intervention of live-video-supervised exercise sessions x3/week for 3 months.
Other: Usual Care then Live-Video Supervised Exercise Intervention
Patients randomized to usual care at baseline will receive usual care for 9 months and will then start the live-video-supervised exercise intervention that includes exercise sessions x3/week for 3 months.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in volume of Oxygen Consumed at Maximal Exertion
Time Frame: Baseline, 3 months, 9 months, 12 months
In Fontan patients, peak VO2 is a powerful predictor of poor outcomes. The subjects will undergo progressive cardiopulmonary exercise testing with continuous monitoring by 12-lead EKG and gas exchange by measuring breath-to-breath ventilation. Exercise capacity will be measured by a cardiopulmonary exercise test to obtain the peak VO2
Baseline, 3 months, 9 months, 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Stanford University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Heart, Lung, and Blood Institute (NHLBI)
The Methodist Hospital Research Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 6, 2020

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 27, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 6, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 9, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 11, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 22, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 46606
  • R33HL146775 (U.S. NIH Grant/Contract)
  • 1R61HL146775-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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