Overview

Coronary artery disease, caused by the furring up of the heart arteries by atherosclerosis, is a major cause of death in the UK. Despite existing therapies, adverse cardiovascular events remains high, especially in patients who have already had a heart attack, as some of these patients have aggressive atherosclerotic disease. If we could identify these vulnerable patients, then in wider clinical practice in the future we might be able to treat them better with new therapies that can otherwise be expensive or come with a risk of side-effects. Traditionally, the assessment of atherosclerotic disease and the identification of the plaques that will cause heart attacks is performed using invasive imaging - imaging taken by passing a wire into the arteries of the heart that has a camera on its tip. Invasive imaging, however, can be used only in patients with symptoms and has risks. Photon counting (PC) CT is a new CT system that has image quality comparable to invasive imaging and can be used in the community to examine individuals with stable angina symptoms. In this study we aim to compare how well PC-CT detects high-risk plaques compared with invasive imaging and in due course develop a platform that will expedite the analysis of CT images to allow its broad use in the clinical practice.

Eligibility

Inclusion Criteria:

• Able and willing to give informed consent
• Between ages 18-79
• Patients with a stable coronary syndrome that had recent PC-CTA showing at least one lesion requiring further evaluation with intravascular imaging or fractional flow reserve and is considered suitable for PCI under IVUS guidance

Exclusion Criteria:

• Unable to or unwilling to give informed consent
• Age \>80 years
• Recent acute coronary syndrome within \< 3 months
• Renal failure (eGFR \<60ml/min/1.73m²)
• History of previous coronary artery bypass surgery
• Decompensated heart failure, or left ventricular ejection fraction ≤30%
• Previous heart transplantation
• Intravenous contrast allergy
• Unable to receive treatment with aspirin, heparin, or thienopyridines
• Anticipated life expectancy \<1 year
• Pregnancy
• Patient that requires surgical revascularisation
• Extensive coronary artery disease (i.e. multiple chronic total occlusions) or tortuous coronary anatomy that does not allow assessment of the coronary arteries with NIRS-IVUS imaging