Circulating microRNAs and Degenerative Abdominal Aorta Aneurysm
Condition: Abdominal Aorta Aneurysm
MeSH terms: Aneurysm; Aortic Aneurysm; Aortic Aneurysm, Abdominal
Study type: Interventional

Summary: 
      Abdominal aortic aneurysm (AAA) is an aortic dilatation superior or equal to 30 mm with an
      estimated prevalence at 8% in men over 65 year-old. It evolves with no clinical signal until
      the rupture of the aortic wall with dramatic outcomes. The pathophysiological mechanisms
      include extracellular matrix remodeling, smooth muscle cells apoptosis, aggregation and
      activation of inflammatory cells in the aortic wall and heredity. The initiating and
      regulatory processes are complex and not fully elucidated. They encompass local aortic
      environment (flux, thrombus, wall shear stress, pressure and adipose tissue) and
      patient-dependent genetic (de)regulation.

      This project follows the previous prospective ACTA study that aimed at identifying clinical
      criteria, circulating biomarkers or imaging data for thoracic aneurysm prognosis in an AAA
      population. The preliminary results showed that 1) a low wall shear stress index and the
      luminal volume are more predictive values for a rapid AAA growth and an intraluminal thrombus
      than the maximal aortic diameter 2) three thoracic aortic phenotypes (normal, dilated,
      aneurysmal) stratify the disease extent 3) the age and the female gender are associated to an
      extended disease. During this study we created a biobank in which blood samples of AAA
      patients were collected at the time of their inclusion (T1). This new ACTA-miRNA study aims
      at correlating circulating biomarkers to the anatomical and biomechanical markers previously
      highlighted for a rapid aneurysmal growth. Circulating miRNA are involved in parietal
      remodeling and constitute promising targets for estimating patients-specific aortic risk.

      From the literature, we thus selected 18 miRNA described to be involved in AAA biology:
      inflammation, remodeling, cellular homeostasis and wall shear stress. As control, we select
      non-AAA patients presenting with peripheral arterial obstructive disease (PAOD) matched in
      age, BMI, tobacco consumption, diabetes, cholesterol level and blood pressure with AAA
      patients enrolled in the ACTA study. During their follow-up, these ACTA patients are
      solicited to continue the program research and can participate to the ACTA-miRNA study. A
      third time analysis is performed for them (T3): we collect imaging data of total aorta
      required by their standard follow-up, as well as a blood sample. Differential analysis of the
      miRNA panel will be conducted between 1) AAA patients (T1) vs PAOD patients 2) fast-growing
      AAA vs slow-growing AAA 3) AAA & AAT patient group vs AAA alone and/or AAA & dilatation of
      thoracic aorta. 110 patients from the ACTA study are eligible to be included into the ACTA
      mi-RNA study. Inclusion of PAOD controls will be conducted until the number of 165 cases is
      reached (1:1.5 ratio).

      Our primary objective is to validate a circulating-miRNA signature specific for abdominal
      aortic aneurysm.
    


Intervention name(s): Tissue-library
Intervention type(s): Genetic
Intervention description(s): circulating biomarkers (miRNA panel) analysis of blood samples
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other