The Primary Objective is to determine if a new nuclear tracer (named 18F-Florbetaben) used with nuclear imaging (PET imaging) can detect inflamed plaque in patients with recent ACS or stroke/TIA.

The Primary Objective is to determine the feasibility of using 18F-Florbetaben PET in patients with recent ACS or stroke/TIA to detect inflammatory plaque.

Exploratory Objectives will define relationships of calcification imaging to other biomarkers and comparisons between high and low plaque burden regions and between patients with and without recent vascular events.

Patients with a recent ACS (i.e. STEMI or NSTEMI), stroke or transient ischemic attack (TIA) will be recruited will be recruited to the FERMATA study. A control population of patients with known vascular disease but without recent ACS, stroke/TIA will also be recruited.

FERMATA is a pilot, single- centerre, imaging study. We will evaluate the ability of the amyloid tracer, 18F-Florbetaben, to detect active atherosclerotic plaque in patients with recent ACS, or recent TIA/stroke. We plan to enroll 24 patients with ACS or patients with stroke/TIA and 6 control patients without recent ACS or stroke/TIA. Primary endpoint is the difference in Florbetaben uptake between the culprit artery (of either the ACS or TIA/stroke, respectively), and the non-culprit arteries. Parameters of interest are the maximal and total standard uptake values (SUVs) and tissue-to- background ratios (TBRs) of the coronary and carotid arteries as well as aorta.

Exploratory endpoints include a correlation analysis (Pearson correlation) to evaluate the relationship of inflammation on Florbetaben PET/CT to the histopathological levels of inflammation. In addition, we will look to see if Florbetaben uptake on PET correlates with lesion levels of B-amyloid. Comparisons will also be made between regions of high plaque burden vs lower plaque burden and between patients with recent vascular events vs those who have not had recent events.

Inclusion Criteria:

1. suffered a recent cardiovascular event (30-120 days post ACS (i.e. STEMI or NSTEMI) or TIA/stroke with ipsilateral large vessel atherosclerotic disease confirmed on US, CT or MRI;
2. stable symptoms and hemodynamics;
3. age >/= 18 years;
4. given informed consent.

Exclusion Criteria:

1. a recent CV event likely to have been embolic in the opinion of the neurologist or cardiologist;
2. severe LV dysfunction (EF<30%);
3. severe valve disease requiring intervention;
4. decompensated heart failure;
5. pregnancy (all women of child bearing potential will have a negative BHCG test;
6. breastfeeding;
7. women of childbearing potential who refuse to use two forms of contraception (this includes at least one form of highly effective and one effective method of contraception) throughout the study OR men capable of fathering a child who refuse to use contraception;.
8. unable to give informed consent;.
9. Florbetaben allergy;
10. glomerular filtration rate (GFR) <50 ml/min/1.72m2

Exclusion for CTA portion of the protocol: Patients with dye allergy, or those with GFR <60, will not undergo CTA but will have PET/CT.

Patients with a recent ACS (i.e. STEMI or NSTEMI), stroke or transient ischemic attack (TIA) will be recruited. Standard definitions will be used for STEMI, NSTEMI including chest pain, EKG changes and troponin rise; likewise for ischemic stroke confirmed by CT or MRI imaging and TIA confirmed as a definite by a neurologist.