RecruitingPhase IIIInterventional

Effect of triiodothyronine (T3) in heart failure with reduced ejection (HFrEF)

This study investigates if a T3 hormone supplement, called liothyronine sodium, can help adults in the UK with heart failure and low T3 levels. About one million people in the UK have heart failure, and some also have low levels of a hormone called T3, which helps the heart pump. Earlier small studies suggested T3 supplements might be safe and could help the heart pump better. This larger study aims to compare T3 supplements with a dummy capsule (placebo) over 24 weeks. We will measure improvements in exercise ability, quality of life, and heart function to see if T3 is beneficial for this group of patients.

At a glance

Status

Recruiting

Phase

Phase III

Sponsor

Newcastle upon Tyne Hospitals NHS Foundation Trust

Enrolment target

258

Start

25 May 2026

Estimated completion

30 Apr 2027

Heart failure with reduced ejection fraction and low serum T3 levels

What is this study about?

Heart failure affects about one million people in the UK, making everyday tasks difficult. The thyroid gland in your neck produces hormones, including one called Triiodothyronine (T3), which plays an important role in how well your heart pumps blood around your body. Interestingly, some people with heart failure have lower levels of T3 than they should.

Previous smaller studies have shown that giving T3 supplements to people with heart failure seems safe and might even help their hearts pump more effectively after about six weeks. This study is a larger research project, called a Phase III trial, which means we're looking to confirm these promising results on a bigger scale. Our main goal is to find out if T3 supplements can improve how far people can walk in a set time (their exercise capacity), how they feel in their daily lives, and how well their heart is working over a 24-week period, compared to a dummy capsule.

We're particularly interested in patients who have heart failure with a reduced 'ejection fraction' (meaning their heart doesn't pump out as much blood as it should) and who also have low levels of T3 in their blood. If this study shows that T3 helps these patients, it could lead to better treatments for heart failure in the future.

Key takeaways

This study aims to see if T3 hormone supplements help people with heart failure.
It focuses on patients with heart failure and low natural T3 levels.
Participants will take either a T3 supplement or a dummy pill for 24 weeks.
We'll measure exercise ability, quality of life, and heart function.
The study runs from May 2026 to April 2028.

Who may be eligible?

This study is looking for adults aged 18 or over who have had heart failure for at least three months, with their heart not pumping blood as strongly as it should (known as 'reduced ejection fraction'). They also need to have low levels of T3 hormone in their blood.

To be considered, participants must already be on the best possible usual treatments for their heart failure. They cannot be taking certain medications that affect thyroid function, such as amiodarone or lithium, or be currently pregnant or planning to become pregnant during the study period. You also can't be in another clinical trial that might affect the results of this one.

This study is not suitable for people who have been recently diagnosed with an overactive or underactive thyroid, or for those with other serious health conditions that might unfortunately limit their life expectancy to six months or less.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you 18 years old or older?
Do you have moderate to severe heart failure where your heart doesn't pump blood strongly (reduced ejection fraction)?
Are your natural T3 hormone levels in your blood low?
Are you NOT pregnant or planning to get pregnant in the next 6 months?
Are you NOT taking medications like amiodarone or lithium that affect your thyroid?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll first have a screening visit where a blood test will check your T3 levels. If your T3 levels are low and you meet the other study criteria, you'll be randomly assigned to either receive a 10mcg liothyronine sodium tablet (the T3 supplement) or a matching dummy capsule (placebo). You'll have an equal 50/50 chance of getting either one, and neither you nor the research team will know which you are taking until the study ends. You'll take your assigned tablet twice a day for 24 weeks (about 6 months) in addition to your usual heart failure medications.

During this time, you'll have a few study visits. There will be an initial visit, another one at 10 weeks, and a final visit at 24 weeks. At these visits, you'll be asked to complete questionnaires about your quality of life and heart failure symptoms, and you'll do a 6-minute walking test to measure your exercise ability. Your heart function will also be checked using an ultrasound scan of your heart (echocardiogram). Blood samples will be taken by trained healthcare professionals at the screening, initial, and final visits. This process is similar to a routine blood test you might have at your GP surgery or hospital.

Potential risks and benefits

Taking part might mean some benefits, such as contributing valuable information that could help others with heart failure in the future. You will also receive regular monitoring related to your heart failure. However, there are no guaranteed personal benefits to you. Possible risks include the minor discomfort and potential bruising from blood tests, similar to any routine blood draw. We will carefully monitor the amount of blood taken to ensure it doesn't cause any problems. You'll need to remember to take your study medication daily for six months and attend the scheduled study visits. A committee will oversee the study to ensure your safety and can stop the trial if any unexpected issues arise. You are free to withdraw from the study at any time without affecting your usual medical care.

Locations (8)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

The Newcastle upon Tyne Hospitals NHS Foundation Trust
Unverified
Newcastle upon Tyne, England
Gateshead Health NHS Foundation Trust
Unverified
Gateshead, England
North Tees and Hartlepool NHS Foundation Trust
Unverified
Hartlepool, England
Liverpool Heart & Chest Hospital
Unverified
Liverpool, England
Hull University Teaching Hospitals NHS Trust
Unverified
Hull, England
Leeds Teaching Hospitals NHS Trust
Unverified
Leeds, England
Northumbria Healthcare NHS Foundation Trust (headquarters)
Unverified
North Shields, England
South Tees Hospitals NHS Foundation Trust
Unverified
Middlesbrough, England

Common questions

What is T3?

T3 is a hormone produced by your thyroid gland that helps your heart pump normally.

What is heart failure with reduced ejection fraction?

This means your heart is not pumping out as much blood as it should with each beat.

Why will some people get a 'dummy capsule'?

Comparing the T3 supplement to a dummy capsule (placebo) helps us know if any improvements are genuinely due to the T3 or other factors.

How long will the study last for me?

If you're eligible for treatment, you'll take the study medication for 24 weeks (about 6 months) and have follow-up visits during this time.

Who is paying for this research?

The study is funded by the National Institute for Health and Care Research (NIHR) in the UK.

How to find out more

Grace Young

YoungG4@cardiff.ac.uk - Official trial record

Always speak to your GP or specialist before deciding to take part in a study.