Imaging and Biomarkers of Atherosclerosis in Patients With Stable or Unstable Coronary Artery Disease

Acute complications of coronary and cerebrovascular atherosclerosis -i.e., acute coronary syndromes (ACS) and strokes - remain the principal cause of death worldwide. Identification of patients at high risk of developing such complications is therefore of utmost importance. Post-MORTEM studies suggest that vulnerable coronary atherosclerotic plaques are characterized by a large, metabolically active, necrotic core, covered by a thin fibrous cap, which may rupture, leading to acute thrombosis, myocardial infarction and, potentially, sudden death. These anatomic features of plaque vulnerability are not visible on standard coronary imaging, such as coronary angiography, but might be recognized using more recent imaging modalities. In addition, new circulating biomarkers of atherosclerosis, particularly biomarkers involved in plaque destabilization, can be measured in peripheral blood and may be used to appreciate overall patient vulnerability.

Design and Methods- In the present study, 2 groups of 44 patients with moderate-to-high risk non-ST elevation ACS or stable coronary artery disease (CAD) will be compared. All the patients will undergo percutaneous coronary intervention of culprit vessels after imaging of the entire coronary tree (culprit and non-culprit lesions) using intravascular ultrasound with radiofrequency data analysis (IVUS-VH). Before discharge, fluorodeoxyglucose positron emission tomography combined with multidetector computed tomography (FDG PET-MDCT) of the carotid arteries and the thoracic aorta, along with MDCT coronary angiography, will be performed and a blood sample will be obtained for subsequent measurements of emerging or new biomarkers.

Objectives -

• The primary objective is to compare plaque phenotypes between patients with ACS vs stable CAD. For each imaging modality (coronary IVUS-VH, MDCT coronary angiography, AORTO-carotid FDG PET-CT) comparisons will be performed on a per-lesion and per-patient basis.
• Secondary objectives include: i) An evaluation of the accuracy of each plaque imaging modality and biomarkers for diagnosis of unstable CAD; ii) A comparison of the diagnostic performance of each plaque imaging modality and biomarkers for diagnosis of unstable CAD; iii) A comparison of coronary plaque phenotype between culprit and non-culprit lesions (using IVUS-VH and MDCT coronary angiography); and iv) An exploratory feasibility study of PET-CT imaging of coronary artery atherosclerotic plaques.

It's important to underline that this study must be considered as an interventional study. Indeed, in this study patients have many imaging modality : coronary IVUS-VH, MDCT coronary angiography and AORTO-carotid FDG PET-CT while in common practice patients have only FDG PET-CT which is the routinely technique used.

Inclusion criteria

First group: Non ST-elevation acute coronary syndrome

• Symptoms compatible with acute myocardial ischaemia
• Presence of either significant ST-T changes without persistent ST elevation or positive troponin I
• And successful stenting of culprit, de novo coronary stenosis located on native coronary arteries

Second group: Stable coronary artery disease

• Stable angina or silent myocardial ischaemia (documented by a positive stress test)
• And successful stenting of culprit, de novo coronary stenosis located on native coronary arteries

Exclusion criteria

In both groups

• Absence of percutaneous coronary angioplasty
• IVUS imaging not feasible
• Heart failure (≥NYHA class 2)
• Severe, persistent arrhythmia
• Renal failure (GFR < 60 ml/min using MDRD formula)
• History of autoimmune or inflammatory disease, recent sepsis (< 1 month), neoplasm
• Females without contraception (if at childbearing age)
• Pregnant of child feeding females
• Homeless
• Patients with no health coverage
• Refusal to sing informed consent
• Allergy to FDG or iodinated contrast media

In stable group:

• History of acute coronary syndrome
• History of stroke