iNav-based, Automated Coronary Magnetic Resonance Angiography for the Detection of Coronary Artery Stenosis (iNav-AUTO CMRA)

Ischaemic Heart Disease (IHD) is the worlds leading cause of death. IHD is often caused by a narrowing of the coronary arteries, which prevents blood from flowing to the heart muscle, causing pain and damage to the heart. If an individual has a myocardial infarction (MI), parts of the heart that are damaged cannot be repaired. Therefore, it is important to identify and treat the narrowing of the arteries before an MI occurs.

At present there are 2 main methods of identifying narrowing of the arteries. The first is an invasive procedure, the other using a CT scan. Whilst both methods are effective, they entail risk. The invasive procedure can damage the coronary arteries, whilst the CT scan exposes patients to radiation and contrast, which can increase the risk of cancer and allergic reactions.

Magnetic Resonance (MR) scanning is an alternative to these methods, but it has been limited in use in the past due, in part, to the high technical knowledge required to obtain images. In addition, there is a degree of subjectivity in the selection of the mid-diastolic rest period, potentially affecting consistency of results. This means it is difficult to use in a day-to-day hospital environment. However, recent technological developments using artificial intelligence mean that images can be acquired in a more automated and consistent fashion. This new scan has yet to be tested in a clinical trial.

Therefore, the objective of the clinical study is to test this new scan to determine its efficacy. 230 patients at 5 sites at risk of coronary artery disease, who have been referred for invasive coronary angiography, will undergo both their angiography and the new MR scan. The MR scan will then be compared to CCTA for diagnostic accuracy and image quality.

The investigators hypothesise that the new MR scan will have the same diagnostic accuracy as invasive coronary angiography, with no differences in interpretation of the images across the 5 different hospitals.

If proven effective, this would demonstrate that MR scanning of the coronary arteries could prove a safe, clinically useful alternative to both CT scanning and invasive assessment of coronary artery narrowing. In addition, if there is no difference across different locations, it would demonstrate that these scans can be performed consistently, facilitating implementation on a healthcare-system wide basis.