Identification of Carotid Vasa Vasorum and Correlation With Acute Coronary Events

Adventitial vasa vasorum (VV) as well as intraplaque microvessels are known to be associated
with atherosclerotic plaque vulnerability. Contrast-enhanced ultrasound has been validated
as a technique to measure the density of VV. Previous studies have demonstrated a
relationship between identification of VV and relationship to vascular events such as stroke
and myocardial infarction. No previous study has reported the utilization of
contrast-enhanced ultrasound identification of VV in the carotid bed as a means of
identifying patients at high risk for acute coronary events.

Aims: In this study, the investigators will aim to identify VV and intraplaque microvessels
along with carotid intima media thickness (CIMT), a known marker for acute coronary events.
The investigators will attempt to measure the correlation of VV with acute coronary events
independent of traditional cardiovascular disease (CVD) risk factors and CIMT.

Methods: 90 volunteers (30 low risk patients, 30 patients with established coronary artery
disease (CAD), and 30 patients with recent acute coronary syndrome (ACS)) will be enrolled.
All patients will undergo contrast-enhanced ultrasound imaging of their carotid arteries and
measurement of CIMT while obtaining baseline histories and assessment of traditional risk
factors for coronary artery disease. VV density and CIMT will be measured in all patients.
Statistical differences in VV among the three groups will be assessed and analyses will be
made to attempt to identify if VV in the carotid bed is an independent predictor of acute
coronary events after controlling for CIMT and traditional risk factors.

Study population: The study population will reflect the patient population of UPMC. No
individual will be excluded on the basis of race, gender, or ethnicity.