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

A randomised, double-blind, placebo-controlled trial to evaluate the efficacy of orally administered Triiodothyronine (T3) for 24 weeks in patients with heart failure with reduced ejection (HFrEF)

Status

Recruiting

Phases

Phase 3

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN11121053

Enrollment

258

Registered

2026-05-21

Start date

2026-05-25

Completion date

Unknown

Last updated

2026-06-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Heart failure with reduced ejection fraction and low serum T3 levels Circulatory System

Interventions

Intervention: 10 mcg oral liothyronine sodium capsule taken orally twice daily for 24 weeks. Control: Matched placebo capsule, taken orally twice daily for 24 weeks. All randomised participants

Serum markers of heart failure (assessed by plasma levels of NT pro-BNP) and inflammation (assessed by high sensitivity CRP), Functional classification for HF (assessed by NYHA class)

HRQoL assessed using EQ-5D-5L, and Minnesota Living with Heart Failure

LV function measured by LVEF assessed by 2D echocardiography

Cardiac function measured by GLS and GCS, assessed by 2D echocardiography

Heart rate and new-onset atrial fibrillation (assessed by ECG)

MACE (defined as: cardiovascular mortality

AMI

hospitalisation for HF

stroke

hospitalisation for unstable angina or coronary revascularisation procedure)

Length of stay for any HF hospitalisation assessed by clinical notes review

Non-cardiovascular mortality

and Mechanism(s) affecting exercise tolerance i.e. cardiac function. Eligible participants will be randomised 1:1 using a minimisation algorithm with a random element to either active treatment (10 m

Eligibility

Sex/Gender

All

Age

18 Years to 120 Years

Inclusion criteria

Inclusion criteria: 1. Adults aged 18 years or older who are able to provide informed consent 2. Those with moderate to severe HFrEF (defined as LVEF =40% on the most recent echocardiogram) 3. Participants with chronic and stable HF (diagnosed =3 months before recruitment and no inpatient admission to hospital for HF exacerbations <1 month before recruitment) 4. Those with serum free T3 levels =4.0 pmol/L 5. Those on maximally tolerated guideline-directed medical therapies for HFrEF

Exclusion criteria

Exclusion criteria: 1. Taking medications affecting thyroid function (including levothyroxine, antithyroid drugs, amiodarone, lithium and sodium valproate) 2. Participating in another interventional trial if it is deemed to interfere with the assessment of the primary outcome by the local investigator 3. Unable to attempt the 6MWT (as it would be unethical to include a person in an intervention trial where they would not be contributing to the primary outcome) 4. Currently pregnant or are planning to become pregnant in the next 24 weeks 5. Newly diagnosed with overt hypothyroidism (serum TSH higher than the upper limit of the reference range and a low serum free T4 level) or hyperthyroidism (low TSH with normal or elevated FT4 levels) 6. Any current comorbidity expected to reduce life expectancy to =6 months

Countries

England, United Kingdom

Contacts

Public ContactGrace Young

YoungG4@cardiff.ac.uk-

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Jun 11, 2026