Abstract 13940: Increased Circulating Level of Lp-PLA2 Activity is Associated With Bioprosthetic Valve Degeneration
Objectives: In this study, we sought to determine the blood lipid markers associated with SVD.
Background: Structural valve degeneration (SVD) is the major cause of bioprosthetic valve failure leading to bioprostheses (BPs) stenosis or regurgitation. Lipoprotein-associated phospholipase A2 (Lp-PLA2) could be associated with the SVD of BPs.
Methods: We studied 197 patients who underwent aortic valve replacement with a bioprosthetic valve and had echocardiographic follow-up to evaluate valve function. In addition, explanted BPs (n=39) were analyzed by immunohistochemistry for the expression of Lp-PLA2.
Results: Forty-one patients (21%) were identified as developing SVD. Patients with SVD had significantly higher plasma level of Lp-PLA2 (133.2 ng/ml vs 151.8 ng/ml, p=0.03) and activity (25.01 nmol/min/ml vs 27.63 nmol/min/ml, p=0.005). Multivariate linear regression analysis revealed that Lp-PLA2 activity (odds ratio [OR]: 1.10, p=0.04) was the strongest independent predictor of SVD. Immunohistochemistry studies showed that 77% of explanted BPs had the expression of Lp-PLA2, which correlated with the density of macrophages (CD68), and ox-LDL levels.
Conclusions: In this study, we identified for the first time that blood plasma activity of Lp-PLA2 is independently associated with SVD of BPs. Hence, blood plasma activity of Lp-PLA2 could be considered as a potential novel biomarker to identify patients at risk of SVD. Also, it may open new research avenues aiming at the prevention of SVD through the pharmacological inhibition of Lp-PLA2.
- © 2013 by American Heart Association, Inc.