Acute Coronary Syndrome, Coronary Artery Disease
Conditions
Keywords
Coronary artery disease, CT coronary angiography, High-sensitivity cardiac troponin
Brief summary
Most patients presenting to hospital with chest pain are discharged home without further tests once a heart attack has been ruled out. Current strategies to assess patients with a suspected heart attack involve blood tests to measure troponin, a protein released into the bloodstream when the heart muscle is damaged. Despite having had a heart attack ruled-out, some patients have unrecognised coronary heart disease and are at risk of having a heart attack in the future. However, we do not know what is the best approach to identify and treat these patients. This study will use a heart scan known as computed tomography coronary angiogram (CTCA) to look for underlying coronary heart disease in patients who have had a heart attack ruled out. In an earlier study, we performed this scan in patients referred to the outpatient cardiology clinic with stable chest pain and found that this improved the diagnosis of coronary heart disease, leading to improvement in patient care that prevented many future heart attacks. Our research has also demonstrated that troponin levels below the threshold used to diagnose a heart attack identify those who are at greater risk of having a heart attack in the future. The aim of this study is to confirm whether these low levels of troponin can identify patients who have underlying coronary heart disease and may benefit from further testing and preventative treatment.
Detailed description
Using a newer, more sensitive troponin test, we now know that troponin levels even below the threshold used to diagnose a heart attack identify patients who are at risk of having a heart attack in the future. Our research in patients with stable chest pain demonstrated that computed tomography coronary angiogram (CTCA) improved the diagnosis of coronary heart disease, leading to improvement in patient care that prevented many future heart attacks. This study will build on these two major strands of research to confirm whether these low levels of troponin can identify patients who have underlying coronary heart disease and may benefit from further testing and preventative treatment. The investigators will evaluate consecutive patients presenting to hospital with suspected acute coronary syndrome and cardiac troponin concentration within the normal reference range for the presence of underlying coronary artery disease. All participants will be invited for an outpatient CTCA. Findings from this study will help inform a randomised controlled trial to evaluate the role of CTCA in patients who have a heart attack ruled out, but are identified as intermediate risk on troponin testing.
Interventions
DIAGNOSTIC_TESTComputed Tomography Coronary Angiography
In order to optimise the quality of the Computed Tomography Coronary Angiography scan images, participants might be given tablets or an injection (e.g. beta-blockers, calcium channel antagonist, ivabradine) to slow their heart rate and glyceryl trinitrate (GTN) following local protocol guidance.
Sponsors
NHS Lothian
British Heart Foundation
University of Edinburgh
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
30 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Presentation to hospital with acute chest pain or equivalent symptoms of suspected acute coronary syndrome * Maximum high-sensitivity cardiac troponin I concentration below the 99th centile (16 ng/L for women and 34 ng/L in men)
Exclusion criteria
* Diagnosis of myocardial infarction during index presentation * Clear alternative diagnosis for index presentation * Recent CT or invasive coronary angiogram (within 1 year) * Patient inability to undergo CT scanning, due to severe renal failure (estimated glomerular filtration rate \<30 mL/min) or major allergy to iodinated contrast media * Pregnancy or breast feeding * Inability to give informed consent * Further investigation for coronary artery disease would not in the patient's interest, due to limited life expectancy, quality of life or functional status
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of participants with obstructive coronary artery disease | Ideally within 4 weeks of index presentation | Proportion of participants with \>50% stenosis in the left main stem or \>70% stenosis in other coronary arteries |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of participants with moderate non-obstructive coronary artery disease | Ideally within 4 weeks of index presentation | Proportion of participants with 50-70% stenosis in one or more coronary arteries |
| Proportion of participants with mild non-obstructive coronary artery disease | Ideally within 4 weeks of index presentation | Proportion of participants with 10-50% stenosis in one or more coronary arteries |
| Proportion of participants with insignificant coronary artery disease | Ideally within 4 weeks of index presentation | Proportion of participants with 1-10% stenosis in one or more coronary arteries |
| Proportion of participants with normal coronary arteries | Ideally within 4 weeks of index presentation | Proportion of participants with no stenosis in coronary arteries |
Other
| Measure | Time frame |
|---|---|
| Leaman score for overall coronary artery disease burden | Ideally within 4 weeks of index presentation |
| Proportion of participants with adverse coronary artery plaque features | Ideally within 4 weeks of index presentation |
| Myocardial mass | Ideally within 4 weeks of index presentation |
| Proportion of participants with hemodynamically significant coronary stenosis on CT-derived fractional flow reserve (CT-FFR) | Ideally within 4 weeks of index presentation |
| Left ventricular volume | Ideally within 4 weeks of index presentation |
Countries
United Kingdom
Outcome results
None listed