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NCT Number: NCT06918795

Fontan Fitness Trial

The goal of this randomized control trial is to learn about physical fitness and exercise habits in children aged 10-17 with the Fontan Circulation through a home-based, digital exercise intervention. The main questions it aims to answer are:

* Does a home-based, digital intervention increase physical activity (PA) in youth with the FC compared to enhanced usual care? * Does a home-based, digital intervention increase physical fitness in youth with the FC compared to enhanced usual care? * Do multi-level factors (medical, neurodevelopmental, sociodemographic, neighborhood) impact the effectiveness of the digital intervention?

Researchers will compare participants in the enhanced usual care arm to those in the exercise intervention arm to see if the digital intervention is effective.

All participants will wear a PA tracker for 12 months and complete testing at baseline, 6 months, and 12 months.

In addition, participants in the exercise intervention arm will complete a 6-month exercise intervention with the following components:

* aerobic exercise * resistance exercise * engagement strategies

Recruiting

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Key information

Conditions

Single-ventricle Cardiovascular Abnormalities Cardiovascular Diseases Congenital Abnormalities Congenital Heart Disease Congenital, Hereditary, and Neonatal Diseases and Abnormalities Heart Defects, Congenital Heart Diseases Univentricular Heart

Age range

10 year–17 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Children's Hospital of Philadelphia

Philadelphia, Pennsylvania, 19104, United States

Location status: Recruiting

About this study

The Fontan Circulation is associated with poor exercise performance and reduced quality of life. Current standard of care encourages physical activity (PA) in this population, but few structured interventions exist. Participants will be randomly assigned to either enhanced usual care (PA tracker and standard encouragement) or an interactive digital intervention that includes personalized aerobic and resistance exercises with behavioral engagement strategies. This study will evaluate a home-based, digital intervention delivered through a mobile health platform to promote PA and improve fitness among youth with FC.

The study will recruit up to 200 participants aged 10-17 years with FC. After initial testing and a two-week run-in period, 120 participants with peak VO2 between 45% and 80% of predicted norms will be randomized. The intervention will last 6 months, followed by a 5.5-month monitoring phase. Outcomes will include changes in PA (measured via accelerometry), peak VO2, muscle strength, body composition, and quality of life.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Fontan Circulation present
  • Girls ≥11 years of age or menstruating must have negative urine pregnancy test
  • Neurodevelopmental capacity to complete all study procedures
  • Physical capacity to complete all study procedures
  • English speaking with at least one English speaking parent/guardian
  • To enroll in the randomized control trial, percent predicted peak VO2 <80% of age-sex matched normal controls on the baseline exercise stress test (EST)

Exclusion criteria

  • Inability to complete an EST at any time (i.e. limited physical or executive function)
  • Uncontrolled lymphatic disorders
  • Uncontrolled noncardiac conditions
  • Exercise induced or uncontrolled arrhythmias
  • Pacemaker or internal cardiac defibrillator (ICD)
  • Peak VO2 <45% age-sex predicted
  • Having had or under consideration for a heart transplant
  • Pregnant or lactating females
  • Parents/guardians or subjects who, in the opinion of the investigator, may be non-compliant with study schedules or procedures

Treatment and study plan

Digital Exercise Intervention

Behavioral

Subjects randomized to the intervention arm will receive the same as the enhanced usual care arm but will be additionally exposed to: (1) personalized plans for aerobic-based PA, (2) personalized resistance exercise sessions, and (3) financial and non-financial engagement strategies. These intervention components will be delivered continuously using an advanced digital health informatics platform during the 6 months of the intervention. The intervention will be overseen and supplemented by the exercise physiologist, who will meet with participants on a weekly, then biweekly and finally monthly basis over 6 months.

Primary outcomes

  1. MIMS-units

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in total volume of physical activity (PA) operationalized as a Monitor Independent Movement Summary (MIMS) units, expressed as a percentile based on what is expected for their age and sex.

  2. Absolute peak VO2

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in absolute peak VO2, the maximum amount of oxygen the body consumes during exercise without regard to body weight (liters/minute).

  3. Percent predicted peak VO2

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in percent predicted peak VO2, the maximum amount of oxygen the body consumes during exercise expressed as a percentage of what is expected for their age and sex.

  4. Leg lean mass

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in leg lean mass presented as a z-score. Leg lean mass z-score compares an individual's leg muscle mass to the average for their age and sex, with values below -2.0 indicating lower-than-expected muscle mass.

Secondary outcomes

  1. MVPA

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in time spent in moderate to vigorous physical activity (MVPA), in terms of minutes per day.

  2. Forearm strength

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in forearm strength measured via handgrip test and presented as a z-score. Z-scores are used to standardize measurements across individuals with different demographics (i.e. age, sex, body size).

  3. Lower extremity strength

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in lower extremity strength measured via knee and ankle peak torsion and presented as a z-score.

  4. PROMIS Pediatric Profile-25 T-score

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Profile-25. This 25-item questionnaire provides a T-score based on physical function, anxiety, depression, fatigue, peer relationships and pain. Children and parents will complete a PROMIS questionnaire. Children will answer questions about themselves and parents will answer questions in regard to their child.

  5. PCQLI score

    Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.

    Change in Pediatric Cardiac Quality of Life Instrument (PCQLI) total and sub-scale scores (i.e. Disease Impact, Psychosocial Impact).The PCQLI is a cardiac-specific health-related quality-of-life instrument. Children will answer questions about themselves and parents will answer questions in regard to their child.

Interested in participating?

Recruiting

Interested in participating?

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Sponsors and collaborators

Lead sponsor

Children's Hospital of Philadelphia

Other

Collaborators

  • National Heart, Lung, and Blood Institute (NHLBI)
  • University of Pennsylvania

Registry information

Official study title

Home-based, Digital Intervention to Increase Physical Activity in Patients With the Fontan Circulation

Important dates

Study start
2025
Primary completion
2029
Study completion
2029
First posted
Apr 9, 2025
Registry last updated
Apr 13, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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