Molecular Imaging of the Underlying Mechanism of Vessel Wall Inflammation Using Positron Emission Tomography (PET/CT)

Abdominal aortic aneurysm (AAA) is a life-threatening condition in which progressive dilatation of the infrarenal aorta leads to rupture. With \~2.3 million prevalent cases, AAA afflicts \~4% of the U.S. population ≥ 65 years of age and is responsible for \~41,000 deaths annually 4,5. No pharmacologic therapies exist that prevent AAA development, growth, rupture, or aneurysm-related deaths. No diagnostic approaches exist to predict which AAAs will grow and eventually rupture.

The study will use the radiotracer 64Cu-DOTA-ECL1i to assess the aortic wall in individuals with AAA and repeat these exams approximately 6-8 weeks after baseline to evaluate longitudinal biological variation in uptake and the impact of any clinical changes or treatment effects on tracer uptake. These data will provide insight into molecular imaging of AAA.

• 64Cu-DOTA-ECL1i (Drug): The radiotracer 64Cu-DOTA-ECL1i will be used to assess the aortic wall in individuals with AAA and age-matched participants without a diagnosis of AAA as a control group.

Primary outcomes

• • Measure uptake of 64Cu-DOTA-ECL1 [3 months]: • Measure uptake of 64Cu-DOTA-ECL1i in patients with abdominal aortic aneurysm at two time points to evaluate intra-individual variability of radiotracer uptake

Secondary outcomes

• Comparing 64Cu-DOTA-ECL1i uptake [3 months]: • Compare 64Cu-DOTA-ECL1i uptake between AAA and control individuals.

Other outcomes

• Correlate uptake of 64Cu-DOTA-ECL1i [3 months]: Correlate uptake of 64Cu-DOTA-ECL1i in the aortic wall with morphologic features on CTA.

Sex: All, ages: 18 Years to any, accepts healthy volunteers

Inclusion Criteria:

1. Participants will be at least 18 years of age
2. Have an established diagnosis of abdominal aortic aneurysm based on standard clinical criteria or are an age matched control with absence of known AAA.
3. Participants must be informed of the investigational nature of this study and be willing to provide written informed consent and participate in this study in accordance with institutional and federal guidelines prior to study-specific procedures.

Exclusion Criteria:

1. Females who are pregnant or breast feeding at the time of the PET/CT scan will not be eligible for this study; a urine pregnancy test will be performed in women of child-bearing potential before the injection of radiotracer.
2. Inability to tolerate imaging procedures in the opinion of an investigator or treating physician
3. Patients with chronic renal disease whose GFR is less than 40 mL/min/1.73m² at the time of enrollment.
4. Documented allergy to iodinated contrast
5. Any current medical condition, illness, or disorder as assessed by medical record review and/or self-reported that is considered by a physician investigator to be a condition that could compromise participant safety or successful participation in the study
6. Less than 6 months life expectancy as deemed by the treating physician at the time of initial enrollment.

• Scott M Damrauer, MD, Principal investigator, Penn Medicine Division of Vascular Surgery