Residual Inflammation and Plaque Progression Long-term Evaluation

While vascular inflammation can be detected using 18F-FDG PET, this method lacks inflammatory cell specificity and is unreliable for coronary imaging because of high background signals from the myocardium. Upregulation of somatostatin receptor subtype-2 (SST2) occurs in activated macrophages, offering a novel inflammation imaging target. 68Ga-DOTATATE, an SST2 PET tracer with low myocardial binding, shows promise for imaging coronary inflammation. Having previously demonstrated increased 68Ga-DOTATATE signals in coronary atherosclerotic lesions post-MI, we now aim to study the natural history of residual arterial inflammation in non-culprit arteries and better understand how 68Ga-DOTATATE signals relate to plaque morphology, progression and rupture. Residual infarct-related myocardial inflammation and its association with ischemic myocardial remodelling will also be examined.

Inclusion criteria

• Male or female participants >18 years old
• Able to give written, informed consent and to lie flat
• First-presentation of myocardial infarction within ~2 weeks
• At least mild non-culprit coronary artery disease on angiography, managed medically

Exclusion criteria

• Women of child bearing potential not using adequate contraception
• Contrast allergy or contrast-nephropathy
• Uncontrolled atrial fibrillation
• Chronic kidney disease (eGFR <30 mL/min/1.73 m2)
• Any medical condition, in the opinion of the investigator, that prevents the participant from lying flat during scanning, or from participating in the study
• Uncontrolled chronic inflammatory disorder
• History of recent malignancy deemed relevant to the study by the investigator
• Current use of systemic corticosteroids
• Previous coronary artery bypass grafting surgery (CABG) or percutaneous coronary intervention (PCI) before the index event
• Contraindication to coronary angiography
• Requires CABG or staged non-culprit artery PCI