Thyroxine in acute myocardial infarction

ThyrAMI: Multi-centre double-blinded placebo-controlled RCT (cTIMP) of sub-clinical hypothyroid individuals post acute myocardial infarction

Status

Active, not recruiting

Phases

Phase 4

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN52505169

Enrollment

100

Registered

2015-01-09

Start date

2014-12-08

Completion date

Unknown

Last updated

2020-08-03

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

Conditions

Topic: Metabolic and endocrine disorders

Interventions

There are two arms on the study. One arm is the active study drug Levothyroxine and the second arm is the placebo control. Randomisation is 1:1.

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Males and females aged between 18-75 yrs 2. Serum TSH between 4.01 -10.00 mU/L with normal free thyroxine levels (9 – 25 pmol/L) on two occasions (on day of admission for AMI and 7-10 days after AMI) 3. Acute myocardial infarction diagnosed on admission to hospital (chest pain with dynamic ECG changes or increase troponin enzymes (at least a fourfold increase above normal range)

Exclusion criteria

Exclusion criteria: 1. Patients on medications affecting thyroid function (levothyroxine, carbimazole, propylthiouracil, amiodarone, lithium) 2. Patients who are unable to provide written informed consent 3. Patients with advanced malignancy (who, in the opinion of the investigator, is unlikely to survive for more than 6 months) 4. Patients with sustained ventricular tachycardia requiring treatment which occurs >24hrs after myocardial re-perfusion/revascularisation 5. Patients who have contra-indications to MR scanning (cardiac pacemaker, metallic heart valves, cochlear implants, coronary artery stents incompatible with MR scanning, etc.) 6. Patients who are unlikely or unwilling, in the opinion of the investigator, to attend for study specific visits 7. Participants whose serum TSH is >10.0 or <4.0 on either occasion 8. Patients who are already participating in another interventional study

Design outcomes

Primary

Measure	Time frame
The primary outcome measure will be change in left ventricular ejection fraction as assessed by magnetic resonance imaging. Cardiac magnetic resonance (MR) is considered the gold standard for evaluating cardiac volumes and function. Gradient echo sequences provide a naturally high level of contrast between intra-cavitary blood and myocardium, thus allowing an accurate and reproducible determination of LV volumes, mass and calculation of stroke volume and ejection fraction. In this context, additional information can also be drawn from application of the more recent cardiac MR tagging analysis, which represents a non-invasive highly accurate method for direct quantification of regional systolic function. Cardiac MR imaging will be performed at the dedicated 3T MRI centre in Newcastle University.	—

Measure

Time frame

The primary outcome measure will be change in left ventricular ejection fraction as assessed by magnetic resonance imaging. Cardiac magnetic resonance (MR) is considered the gold standard for evaluating cardiac volumes and function. Gradient echo sequences provide a naturally high level of contrast between intra-cavitary blood and myocardium, thus allowing an accurate and reproducible determination of LV volumes, mass and calculation of stroke volume and ejection fraction. In this context, additional information can also be drawn from application of the more recent cardiac MR tagging analysis, which represents a non-invasive highly accurate method for direct quantification of regional systolic function. Cardiac MR imaging will be performed at the dedicated 3T MRI centre in Newcastle University.

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Secondary

Measure	Time frame
1. Left ventricular systolic and end diastolic volumes and myocardial viability: Cardiac MR parameters of both global and segmental LV function measurements will be obtained as per standardised protocols already in place in the Newcastle MR centre using a steady state free precession or fast gradient echo technique. In addition, further scans will be obtained 15-20 minutes after intra-venous gadolinium-chelate administration (delayed enhancement MRI). Regions of non-viable myocardial tissue will be identified as areas of increased enhancement (hyper enhancement) whereas viable tissue will have null (black) on the acquired images. 2. Thrombus burden: The Badimon chamber is a highly reproducible clinical ex vivo model of thrombosis that mimics flow conditions within the coronary circulation of man. The device incorporates two chambers with internal flow channels of different diameters, one simulating high-shear flow of 1690 ml/s and the other simulating low-shear flow. The internal flow channels are lined with porcine aortic tunica media - the thrombogenic substrate. After perfusion with venous blood from the patient, flowing at 10 mL min -1 for 5 min, aortic segments are fixed in 10% formalin for 72 h. Total thrombus burden is measured using a validated computer-assisted planimetry using IMAGE-PRO PLUS software (Media Cybernetics, Inc., Bethesda, MD, USA). The results are the mean of the analyzed sections (µm2 .mm-1). The measurements will be performed at the Clinical Research Facility (CRF), where they have considerable experience of using this technique in other high vascular risk groups. 3. Thromboelastography (TEG®): This is a non-invasive measure of evaluating efficiency and quality of ex vivo thrombus formation. Quantitative measures include clotting time parameters, clot strength and clot lysis. These parameters have been validated as highly correlated with longer term cardiac outcomes in several conditions of risk. TEG® will	—

Measure

Time frame

1. Left ventricular systolic and end diastolic volumes and myocardial viability: Cardiac MR parameters of both global and segmental LV function measurements will be obtained as per standardised protocols already in place in the Newcastle MR centre using a steady state free precession or fast gradient echo technique. In addition, further scans will be obtained 15-20 minutes after intra-venous gadolinium-chelate administration (delayed enhancement MRI). Regions of non-viable myocardial tissue will be identified as areas of increased enhancement (hyper enhancement) whereas viable tissue will have null (black) on the acquired images. 2. Thrombus burden: The Badimon chamber is a highly reproducible clinical ex vivo model of thrombosis that mimics flow conditions within the coronary circulation of man. The device incorporates two chambers with internal flow channels of different diameters, one simulating high-shear flow of 1690 ml/s and the other simulating low-shear flow. The internal flow channels are lined with porcine aortic tunica media - the thrombogenic substrate. After perfusion with venous blood from the patient, flowing at 10 mL min -1 for 5 min, aortic segments are fixed in 10% formalin for 72 h. Total thrombus burden is measured using a validated computer-assisted planimetry using IMAGE-PRO PLUS software (Media Cybernetics, Inc., Bethesda, MD, USA). The results are the mean of the analyzed sections (µm2 .mm-1). The measurements will be performed at the Clinical Research Facility (CRF), where they have considerable experience of using this technique in other high vascular risk groups. 3. Thromboelastography (TEG®): This is a non-invasive measure of evaluating efficiency and quality of ex vivo thrombus formation. Quantitative measures include clotting time parameters, clot strength and clot lysis. These parameters have been validated as highly correlated with longer term cardiac outcomes in several conditions of risk. TEG® will

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Countries

United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Mar 5, 2026