Subclinical HypothyroidismRepleniSHNCT07380854
Thyroid Hormone Replacement After Coronary Artery Bypass Grafting for Patients With Subclinical Hypothyroidism
A study testing levothyroxine in people with Subclinical Hypothyroidism, run by Seoul National University Bundang Hospital at 1 site in South Korea.
Trial summary
The goal of this clinical trial is to find out whether levothyroxine reduces complications and improves the prognosis of patients with subclinical hypothyroidism (SCH) undergoing coronary artery bypass grafting (CABG). Read more about this study
- Who is it for?
- Ages 19 to 90 years
- Conditions the study is for
- Subclinical Hypothyroidism
- What is being tested?
- levothyroxine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 338 participants
- Where
- 1 siteSouth Korea
- Study dates
- 27 Feb 2022to 26 Feb 2037
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 to 90 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
None listed.
Who cannot join
- Patients who underwent repeat or emergency CABG surgery
- Use of LT4 within the previous 4 weeks
- Use of antithyroid drug use (propylthiouracil, methimazole, or carbimazole) within the previous 3 months
- Severe comorbid conditions with a life expectancy of less than 1 year (e.g. advanced malignancy)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
South Korea1 site, 1 recruiting
- Recruiting
Department of Internal Medicine, Seoul National University Bundang Hospital
Seongnam-si, 13620
Kang, +82-787-7029, hjk@snubh.org
About this study
The goal of this clinical trial is to find out whether levothyroxine reduces complications and improves the prognosis of patients with subclinical hypothyroidism (SCH) undergoing coronary artery bypass grafting (CABG).
The main questions this study aims to answer are:
Read more
- Does levothyroxine reduce major adverse cardiovascular events (MACE), including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and new arrhythmias, in SCH patients undergoing CABG? Researchers will compare patients who take levothyroxine with those who do not.
Participants will:
- Be randomly assigned to either receive levothyroxine or not
- Start the medication one day before surgery if assigned to the treatment group.
- Have regular follow-up visits to check thyroid function and cardiovascular events for up to five years after surgery.
- Conditions
- Subclinical Hypothyroidism
- Being tested
- levothyroxine
- Keywords
- subclinical hypothyroidism, coronary artery bypass grafting, thyroid hormones, levothyroxine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
levothyroxineDrug
Intervention description: Participants assigned to the LT4 group will begin receiving levothyroxine the day before CABG. The initial dose is 25 μg once daily, or 12.5 μg for participants weighing less than 60 kg. The dose will then be adjusted based on thyroid function test results to achieve target TSH levels of 0.4-2.0 μIU/mL.
| Study group | Role | What they receive |
|---|---|---|
| LT4 group | Experimental | Participants in this group will receive levothyroxine Receives: Drug: levothyroxine |
| Control group | No intervention | Participants in this group will not receive levothyroxine |
What is being measured
The primary outcome is the main question the study is designed to answer.
A composite of MACE within 4months after surgery
A composite of major adverse cardiovascular events (MACE), including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and the occurrence of new arrhythmias assessed within 4 months after CABG.
Measured: within 4months after surgery
Secondary outcomes (12)
Number of participants who experience cardiovascular death within 4 months after surgery
Number of participants who experience cardiovascular death within 4 months after CABG
Measured: within 4months after surgery
Number of participants who experience nonfatal myocardial infarction within 4 months after surgery
Number of participants who experience nonfatal myocardial infarction within 4 months after CABG
Measured: within 4months after surgery
Number of participants who experience nonfatal stroke within 4 months after surgery
Number of participants who experience nonfatal stroke within 4 months after CABG
Measured: within 4months after surgery
Number of participants who experience new arrhythmia within 4 months after surgery
Number of participants who experience new arrhythmia within 4 months after CABG
Measured: within 4months after surgery
A composite of MACE within 1 year after surgery
A composite of major adverse cardiovascular events (MACE), including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and the occurrence of new arrhythmias assessed within 1year after CABG
Measured: within 1 year after surgery
A composite of MACE within 5 year after surgery
A composite of major adverse cardiovascular events (MACE), including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and the occurrence of new arrhythmias assessed within 5 years after CABG
Measured: within 5 years after surgery
All-cause mortality within 5 years after surgery
All-cause mortality within 5 years after surgery
Measured: within 5 years after surgery
Change in LVEF from baseline to 1 year after surgery
Left ventricular ejection fraction (LVEF) will be measured using transthoracic echocardiography at baseline (pre-operative) and at 1 year post-operatively. The outcome will be reported as the mean change in LVEF (%) from baseline to 1 year.
Measured: From baseline to 1 year after surgery
Change in LV EDD from baseline to 1 year after surgery
Left ventricular end-diastolic diameter (LVEDD) will be measured using transthoracic echocardiography at baseline (pre-operative) and at 1 year post-operatively. The outcome will be reported as the mean change in LVEDD (%) from baseline to 1 year.
Measured: From baseline to 1 year after surgery
Change in LV ESD from baseline to 1 year after surgery
Left ventricular end-systolic diameter (LV ESD) will be measured using transthoracic echocardiography at baseline (pre-operative) and at 1 year post-operatively. The outcome will be reported as the mean change in LV ESD (%) from baseline to 1 year.
Measured: From baseline to 1 year after surgery
Change in LVMI from baseline to 1 year after surgery
Left ventricular mass index (LVMI) will be measured using transthoracic echocardiography at baseline (pre-operative) and at 1 year post-operatively. The outcome will be reported as the mean change in LVMI (%) from baseline to 1 year.
Measured: From baseline to 1 year after surgery
Change in LAMI from baseline to 1 year after surgery
Left atrial volume index (LAMI) will be measured using transthoracic echocardiography at baseline (pre-operative) and at 1 year post-operatively. The outcome will be reported as the mean change in LAMI (%) from baseline to 1 year.
Measured: From baseline to 1 year after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Feb 2026
- Study start27 Feb 2022
- Primary completion26 Feb 2032 (estimated)
- Study completion26 Feb 2037 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Subclinical HypothyroidismStudies of the same condition, open and under way.
- More trials run by Seoul National University Bundang HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 338 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Seoul National University Bundang Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Min Joo Kim, Seoul National University Bundang Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07380854
- Sponsor's protocol ID
- IRB-B-2110-717-003
- Acronym
- RepleniSH
- Status last verified
- Dec 2025
- First submitted
- 15 Jan 2026
- Last updated
- 2 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Thyroid Hormone Replacement After Coronary Artery Bypass Grafting for Patients With Subclinical Hypothyroidism
- ClinicalTrials.gov ID
- NCT07380854
- Acronym / sponsor ID
- RepleniSH / IRB-B-2110-717-003
- Conditions
- Subclinical Hypothyroidism
- Keywords
- subclinical hypothyroidism, coronary artery bypass grafting, thyroid hormones, levothyroxine
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 338 participants (estimated)
- Lead sponsor
- Seoul National University Bundang HospitalUniversity, hospital or other
- Study start
- 27 Feb 2022 (actual)
- Primary completion
- 26 Feb 2032 (estimated)
- Study completion
- 26 Feb 2037 (estimated)
- First posted
- 2 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to find out whether levothyroxine reduces complications and improves the prognosis of patients with subclinical hypothyroidism (SCH) undergoing coronary artery bypass grafting (CABG).
The main questions this study aims to answer are:
- Does levothyroxine reduce major adverse cardiovascular events (MACE), including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and new arrhythmias, in SCH patients undergoing CABG? Researchers will compare patients who take levothyroxine with those who do not.
Participants will:
- Be randomly assigned to either receive levothyroxine or not
- Start the medication one day before surgery if assigned to the treatment group.
- Have regular follow-up visits to check thyroid function and cardiovascular events for up to five years after surgery.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| LT4 group | Experimental | Drug: levothyroxineParticipants in this group will receive levothyroxine |
| Control group | No intervention | –Participants in this group will not receive levothyroxine |
Who may qualify
- Ages
- 19 to 90 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (0 listed)
Key exclusion criteria (4 listed)
- Patients who underwent repeat or emergency CABG surgery
- Use of LT4 within the previous 4 weeks
- Use of antithyroid drug use (propylthiouracil, methimazole, or carbimazole) within the previous 3 months
- Severe comorbid conditions with a life expectancy of less than 1 year (e.g. advanced malignancy)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| levothyroxineIntervention description: Participants assigned to the LT4 group will begin receiving levothyroxine the day before CABG. The initial dose is 25 μg once daily, or 12.5 μg for participants weighing less than 60 kg. The dose will then be adjusted based on thyroid function test results to achieve target TSH levels of 0.4-2.0 μIU/mL. | Drug | LT4 group |
Primary outcome
A composite of MACE within 4months after surgery
Time frame: within 4months after surgery
A composite of major adverse cardiovascular events (MACE), including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and the occurrence of new arrhythmias assessed within 4 months after CABG.
12 secondary outcomes
Number of participants who experience cardiovascular death within 4 months after surgery
Time frame: within 4months after surgery
Number of participants who experience nonfatal myocardial infarction within 4 months after surgery
Time frame: within 4months after surgery
Number of participants who experience nonfatal stroke within 4 months after surgery
Time frame: within 4months after surgery
Number of participants who experience new arrhythmia within 4 months after surgery
Time frame: within 4months after surgery
A composite of MACE within 1 year after surgery
Time frame: within 1 year after surgery
A composite of MACE within 5 year after surgery
Time frame: within 5 years after surgery
All-cause mortality within 5 years after surgery
Time frame: within 5 years after surgery
Change in LVEF from baseline to 1 year after surgery
Time frame: From baseline to 1 year after surgery
Change in LV EDD from baseline to 1 year after surgery
Time frame: From baseline to 1 year after surgery
Change in LV ESD from baseline to 1 year after surgery
Time frame: From baseline to 1 year after surgery
Change in LVMI from baseline to 1 year after surgery
Time frame: From baseline to 1 year after surgery
Change in LAMI from baseline to 1 year after surgery
Time frame: From baseline to 1 year after surgery
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Feb 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing levothyroxine in people with Subclinical Hypothyroidism, run by Seoul National University Bundang Hospital at 1 site in South Korea.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 0 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Min Joo Kim, Professor (+82-31-787-7855, chorong24@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
A composite of MACE within 4months after surgery (time frame: within 4months after surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Feb 2026.