About this trial
We now have very sensitive blood tests that can pick up damage to the heart and find patients who have had a heart attack. However, whilst this is welcome, it does not identify what causes the heart attack and can sometimes pick up other conditions that cause a strain on the heart.
The classic cause of a heart attack is when a blood clot forms on fatty deposits within the heart arteries. This leads to treating patients with blood thinning medication, and this is very effective and saves lives. However, many apparent heart attacks are not caused by blood clots and some may be caused by blood clots but pass unrecognised.
In this proposal, we will test an exciting new imaging test that can 'see' from outside the body whether there is a blood clot in the heart arteries. This could provide a major new way of assessing patients to ensure they get the right diagnosis and the right treatment. This could ultimately improve the outcomes of or patients with heart attacks.
We will recruit 80 patients in total who have recently been diagnosed with a heart attack from the cardiology department at the Royal Infirmary of Edinburgh. The research team will review patient's medical records to determine eligibility for the study.
The research study involves participants undertaking the following research procedures and assessments:
1. A combined Positron Emission Tomography and Computed Tomography (PET-CT) scan of the heart 2. Ultrasound scan of the heart (Echocardiogram) 3. MRI scan of the heart 4. A blood test - a total of up to four tablespoons (60 mL) of blood will be taken for immediate testing and the remaining blood will be stored for future ethically approved studies 5. A follow up questionnaire 6 -12 months following the heart attack
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Males and females ≥ 18 years of age
Clinical presentation of chest pain, ST-segment deviation within a coronary artery territory on the electrocardiogram, raised cardiac troponin and non-obstructive coronary arteries on invasive coronary angiography as per international societal diagnostic criteria
Disqualifiers
<18 years of age
Takatsubo cardiomyopathy
Myocarditis
Renal failure (estimated glomerular filtration rate <30 mL/min/1.73 m2)
Trial population
We will recruit two patient populations after invasive coronary angiography has been completed. We have established comparator control populations including 50 patients with stable coronary artery disease (no angina or recent myocardial infarction) and valvular heart disease who underwent 18F-GP1 cardiac PET-CT as part of a concurrent study (NCT04073875). Cohort 1: Patients with myocardial infarction with non-obstructive coronary arteries We will recruit 50 patients with myocardial infarction and non-obstructive coronary arteries on coronary angiography Cohort 2: Patients with coronary causes of type 2 myocardial infarction We will recruit 10 patients with coronary artery thromboembolism and 10 patients with spontaneous coronary artery dissection. Finally, we will include 10 subjects who have had iatrogenic coronary artery dissection or intramural haematoma as a complication of their percutaneous coronary intervention.
Trial design
Case-control
Prospective
Treatments tested in this trial
Hybrid 18F-GP1 positron emission tomography and coronary computed tomography coronary angiography
Radiation18F-GP1 will be synthesized by our radiochemistry facility, the Edinburgh Imaging Facility Radiochemistry (EIFR), which is co-located within our Edinburgh Imaging Facility, Queens Medical Research Institute (EIF QMRI) using our well-established protocols. Each patient will undergo 18F-GP1 PET/CT coronary angiography imaging on our hybrid scanner (Biograph mCT, Siemens) as soon as practical after their index event and within a maximum of 7 days from symptom onset. Patients will initially be injected with 250 MBq 18F-GP1, before resting in a quiet environment for 60 min. A low-dose attenuation correction CT scan (120 kV, 50 mAs, 5/3 mm) will be followed by acquisition of PET data in list mode using a two 20-min bed position centred on the thoracic aorta and heart. A contrast-enhanced CT coronary angiogram will then be performed.
Treatment groups
Trial outcomes
Primary outcomes
The primary endpoint will be the degree and location of platelet activation as determined by the target to background ratio of 18F-GP1
Secondary outcomes
The secondary endpoints will include measuring the presence of platelet activation in acute myocardial infarction with non-obstructive coronary arteries and identifying the presence and site of platelet activation in thrombosis-related coronary causes of
Sponsors and contacts
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