Levothyroxine around coronary bypass for people with subclinical hypothyroidism
Official title: Thyroid Hormone Replacement After Coronary Artery Bypass Grafting for Patients With Subclinical Hypothyroidism
Run by Seoul National University Bundang Hospital · NCT07380854 · Data updated 2026-11-12
This will test whether taking levothyroxine starting before surgery reduces heart complications and improves outlook after coronary artery bypass grafting in adults with subclinical hypothyroidism.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 19 Years to 90 Years |
| Sex | All |
| Enrollment | 338 (estimated) |
| Sponsor | Seoul National University Bundang Hospital Academic / other |
| Locations | 1 site (Seongnam-si) |
| Status | Recruiting |
| Started | February 27, 2022 |
| Main results expected | February 26, 2032 |
| Study ends | February 26, 2037 |
| Registry record updated | February 2, 2026 |
| Trial ID | NCT07380854 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates are adults aged 19–90 with subclinical hypothyroidism (normal free T4 and TSH >4 μIU/mL) who are scheduled for first-time elective CABG and are not recently treated with thyroid drugs and have reasonable life expectancy.
✕Probably not a fit
Patients with normal thyroid function, treated overt hypothyroidism, emergency or repeat CABG, recent levothyroxine or antithyroid drug use, or severe comorbidities with life expectancy under one year are unlikely to benefit from this intervention.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
Adults with subclinical hypothyroidism who are scheduled for elective coronary artery bypass grafting are randomly assigned to receive levothyroxine or no thyroid hormone replacement. Participants assigned to levothyroxine start the drug one day before surgery and have thyroid function checked regularly. Investigators track major adverse cardiovascular events (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and new arrhythmias) and other outcomes during follow-up visits for up to five years. Key eligibility includes age 19–90, normal free T4 and TSH >4 μIU/mL within 31 days before surgery, with exclusions for recent thyroid drug use, repeat or emergency CABG, or severe comorbidity with life expectancy under one year.
Why it matters
Potential benefit: If successful, levothyroxine could lower rates of major cardiovascular complications and improve recovery and long-term prognosis after CABG for patients with subclinical hypothyroidism.
How similar studies have gone: Previous trials of levothyroxine for subclinical hypothyroidism have shown mixed and limited cardiovascular outcome data, so applying it in the perioperative CABG setting is relatively novel.
Who can join: the full rules
Show full inclusion / exclusion criteria
Eligibility Criteria * Adults aged 19 to 90 years. * Patients scheduled to undergo coronary artery bypass graft (CABG) surgery. * Subclinical hypothyroidism (SCH), defined as a normal free thyroxine (free T4) level and a thyroid-stimulating hormone (TSH) level greater than 4 μIU/mL, based on testing performed within 31 days prior to surgery. Exclusion Criteria: * 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)
Where it's running
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Department of Internal Medicine, Seoul National University Bundang Hospital
Seongnam-si, South Korea Recruiting
Study contacts
- Study coordinator: Min Joo Kim, Professor
- Email: chorong24@gmail.com
- Phone: +82-31-787-7855
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.