The goal of this mechanistic clinical trial is to assess whether lowering the low-density lipoprotein cholesterol (LDL-C) levels in the blood with the injections of the medication evolocumab will have any effect on the tissue or cells of patients with abdominal aortic aneurysm (AAA). Researchers will compare participants receiving evolocumab injections to participants receiving placebo injections to see how the tissue and cells of the aorta are affected by changes in LDL-C levels.
After being informed about the study and its potential risks, all patients giving informed consent will undergo a baseline visit and be randomized to received either evolocumab 140mg subcutaneously or placebo. This baseline visit includes a vital signs assessment, laboratory tests, medical history and medication review, a pregnancy test (if applicable), and training on how to perform drug injections. Participants will receive 3 doses/autoinjectors of study drug or placebo and be instructed to perform injections every 14 days starting 5 weeks prior to their scheduled AAA repair. If the baseline assessment occurs 5 weeks prior to their scheduled AAA, the first injection will be performed during this visit. Participants will have the option of coming back to the site for injections 2 and 3 or perform these injections at home under telehealth supervision. At the time of open AAA repair, participants will repeat laboratory tests and have a sample of aneurysm tissue taken. Participants will then have a follow up phone call 4 weeks after AAA repair to assess for any adverse events. At the conclusion of the study investigators will examine gene expression and protein levels in the aortic tissue to determine the impact of LDL-C lowering with evolocumab.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
QUADRUPLE
Enrollment
44
See arm description.
See arm description.
Interleukin (IL)-6 in myeloid derived monocytes/macrophages from in AAA tissue
IL-6 expression will be measured in myeloid cells in the aortic tissue specimens using single nucleus RNA sequencing and confirmed by whole tissue ELISA.
Time frame: AAA Repair (Week 5)
Matrix metalloproteinase (MMP)-9 in myeloid derived monocytes/macrophages from in AAA tissue
MMP-9 expression will be measured in myeloid cells in the aortic tissue specimens using single nucleus RNA sequencing and confirmed by whole tissue ELISA and immunofluorescence activity assays.
Time frame: AAA Repair (Week 5)
Infiltrating immune cell composition and their activation/inflammatory states in AAA tissue
Relative numbers of infiltrating immune cell type and their activation/inflammatory state as measured by a combination of bulk and single nuclear RNA sequencing
Time frame: AAA Repair (Week 5)
Smooth muscle composition of AAA tissue
The relative numbers of smooth muscle cells and their contractile/proliferative state as measured by a combination of bulk and single nucleus RNA sequencing
Time frame: AAA Repair (Week 5)
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