Not recruitingRare disease

Study on Theophylline for Improving Exercise Capacity in Adolescents with Univentricular Heart Disease and Fontan Circulation

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of the medication Theophylline in individuals with a specific type of heart condition known as univentricular congenital heart disease that has been treated with a Fontan-type surgical palliation. The medication being tested is called Theo-Dur 200mg depottablett, which is a prolonged-release tablet taken orally. The purpose of the study is to explore the feasibility and safety of a 12-week treatment plan, which includes adjusting the dosage remotely and monitoring heart rhythm during the treatment phase.

Participants in the study will be adolescents aged 16 to 25 years who have undergone the Fontan procedure. The study will estimate the effect of 12 weeks of oral treatment with Theophylline on exercise capacity. Throughout the study, participants will be monitored for any side effects and changes in their ability to exercise. The study will also assess differences in oxygen uptake, which is a measure of how well the body uses oxygen during physical activity, before and after the treatment.

In addition to exercise capacity, the study will evaluate other health aspects such as quality of life through questionnaires, heart function using echocardiography (a type of ultrasound for the heart), and breathing capacity. Participants will also undergo a home-based sleep study to check for changes in sleep patterns. The study aims to provide valuable insights into the potential benefits and safety of Theophylline for young people with this heart condition.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

Step 1
Joining the study
Upon joining the study, you will be required to sign an informed consent form. If you are under 18, your parents or caregivers must also sign the form.
You will need to confirm that you meet the eligibility criteria, which include being between 16 and 25 years old, having a specific heart condition, and being able to perform certain tests.
Step 2
Initial assessments
Before starting the treatment, you will undergo initial assessments. These may include a heart function test using an exercise bike and imaging tests of your liver.
A pregnancy test will be conducted for female participants, and you will receive information about contraception requirements during the study.
Step 3
Treatment phase
You will begin a 12-week treatment with a medication called Theo-Dur, which contains theophylline. This is a prolonged-release tablet taken orally.
The dosage will be adjusted remotely based on your needs, and your heart rhythm will be monitored during this period.
Step 4
Monitoring and adjustments
Throughout the treatment, your response to the medication will be monitored. This includes checking for any side effects and adjusting the dosage if necessary.
You will be asked to report any new symptoms or changes in your health to the study team.
Step 5
Final assessments
At the end of the 12-week treatment, you will undergo final assessments to evaluate the effects of the medication.
These assessments will include tests similar to those conducted at the beginning of the study, such as heart function tests and questionnaires about your health and well-being.

Who can join the trial?

10 criteria

Participant must be between 16 to 25 years old at the time of signing the consent form.
Participants must have univentricular congenital heart disease with a Fontan-type palliation.
Participants must be able to perform all necessary tests during the trial, especially a cardiopulmonary exercise test on a stationary bike.
Participants must have recent liver imaging results (ultrasound or MRI) from the last 12 months.
Participants must not have signs of more than mild liver disease or severe kidney problems.
Participants must be eligible to take the medication Theo-Dur® (theophylline) as per the guidelines.
Participants must have a Body Mass Index (BMI) between 18.5 and 34.9 kg/m².
Women must use contraception according to local regulations for clinical studies.
Female participants must have a negative pregnancy test at the start and must report any pregnancy during the study.
Participants must be able to give signed informed consent. If under 18, parents or guardians must also sign.

Who cannot join the trial?

4 criteria

Patients who do not have **univentricular congenital heart disease** with a **Fontan-type surgical palliation** cannot participate. This means the study is only for those who have a specific heart condition where they have had a particular type of surgery.
Patients who are not between the ages of **16 to 25 years** cannot participate. The study is only for adolescents and young adults within this age range.
Patients who are not able to take **theophylline** cannot participate. Theophylline is a medication used in the study, and participants must be able to take it safely.
Patients who cannot undergo **remote dosage titration** and **ambulatory heart rhythm monitoring** cannot participate. This means participants must be able to have their medication dose adjusted remotely and have their heart rhythm monitored while they go about their daily activities.

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Oslo Universitetssykehus HF
Oslo, Norway

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Investigated drugs

Theophylline is a medication used in this clinical trial to help improve exercise capacity in adolescents with a specific type of heart condition known as univentricular congenital heart disease with Fontan circulation. Theophylline works by relaxing and opening up the airways in the lungs, making it easier to breathe. It also has effects on the heart and blood vessels, which may help improve blood flow and oxygen delivery during physical activity. In this trial, theophylline is taken orally, and the study aims to see how well it works and how safe it is for the participants over a 12-week period.

Theophylline

What is already known about the treatment

Theophylline – Theophylline is administered orally, typically in the form of tablets or capsules, and is used in a clinical trial to assess its effects on individuals with univentricular congenital heart disease who have undergone Fontan-type surgical palliation. Currently, theophylline is being studied for its potential to improve exercise capacity in adolescents and young adults with this condition. It works by relaxing and opening air passages in the lungs, making it easier to breathe, and may also improve heart function by increasing the strength of heart muscle contractions. Theophylline is classified as a bronchodilator, which is a type of medication that helps to open the airways in the lungs.

Investigated diseases

Univentricular congenital heart disease with a Fontan-type surgical palliation – This condition is a type of congenital heart defect where only one ventricle is functional. The Fontan procedure is a surgical technique used to direct blood flow from the veins directly to the pulmonary arteries, bypassing the heart. Over time, individuals with this condition may experience complications such as reduced exercise capacity and heart rhythm abnormalities. The heart's ability to pump blood efficiently can be compromised, leading to symptoms like fatigue and shortness of breath. As the person ages, the single ventricle may struggle to handle the body's demands, potentially affecting overall heart function. Regular monitoring and management are essential to address any arising issues.