Biomarkers and predictive models for abdominal aortic aneurysm growth

Objective: Abdominal aortic aneurysms (AAA) are currently followed-up by measuring their diameter with serial ultrasound or computed tomography scanning, but evidence shows that AAA growth is mostly discontinuous and unpredictable in a given patient. A reliable predictive model of AAA growth and/or rupture risk could help individualize management. The aim of this study was to define a predictive model of short-term AAA growth with clinical, serological and anatomical data. Methods: A total of 148 consecutive asymptomatic infrarenal atherosclerotic AAA patients were included. The following details were recorded: clinical data (age, gender, cardiovascular risk factors, comorbidity, medication), baseline aortic diameter, prospective 1-year AAA growth, and the concentration of MMP-2, MMP-9, cystatin C, alpha1-antitrypsin, myeloperoxidase, MCP-1, homocysteine, D-dimer, PAP and C-reactive protein in peripheral blood at the time of baseline assessment. Predictive models were constructed for 1-year AAA growth assessed as a continuous variable (mm/year) as well as a dichotomic variable (defined as stability, if AAA growth rate was <= 2 mm/year, versus expansion, if AAA growth rate was > 2 mm/year), using simple and multiple linear and logistic regression. Results: Every increase by 1 ng/mL in the plasma concentration of D-dimer was related to a mean 1-year increase of 0.0062 mm in the AAA growth. Likewise, CRF increased the 1-year prospective AAA growth by a mean of 2.95 mm. When AAA growth was assessed as a dichotomic variable, both the increase in the peripheral concentrations of PAP and the presence of chronic renal failure (CRF) increased the risk of AAA expansion (odds ratio [OR]: 1.01 and 14,523.62; 95% confidence interval [CI]: 1.00-1.02 and 0-7.39E + 40 respectively). Conclusions: D-dimer and PAP seem to be promising biomarkers of short-term AAA activity. CRF is an important independent prognostic factor of AAA expansion. The dichotomic classification of AAA growth can be useful in the development of management models and their clinical application. (C) 2015 SEACV. Published by Elsevier Espana, S.L.U. All rights reserved.