L p‐ PLA 2 is associated with structural valve degeneration of bioprostheses

Objectives In this study, we sought to determine the metabolic markers associated with structural valve degeneration ( SVD ). Background Structural valve degeneration ( SVD ) is the major cause of bioprosthetic valve failure leading to bioprostheses ( BP s) stenosis or regurgitation. We hypothesized that lipoprotein‐associated phospholipase A 2 ( L p‐ PLA 2) is involved in the SVD of BP s. Methods We included 197 patients who underwent aortic valve replacement with a bioprosthetic valve and had echocardiographic follow‐up to evaluate valve function. Moreover, explanted BP s ( n  = 39) were analysed by immunohistochemistry for the expression of L p‐ PLA 2. Results After a mean follow‐up of 7·9 ±0·2 years, forty‐one patients (21%) were identified as developing SVD . Patients with SVD had significantly higher plasma level of Lp‐ PLA 2 mass (151·8 ± 9·2 ng/mL vs. 133·2 ± 3·4 ng/mL, P  = 0·03) and activity (27·6 ± 0·9 nmol/min/mL vs. 25·0 ± 0·4 nmol/min/mL, P  = 0·005). Multivariate analysis revealed that L p‐ PLA 2 activity ( OR : 1·09, 95% CI: 1·01–1·18; P  = 0·03) was the strongest independent predictor of SVD . Immunohistochemistry studies of explanted BP showed that 77% of explanted BP s had the expression of L p‐ PLA 2, which correlated with the density of macrophages ( CD 68), and ox‐ LDL levels in bioprosthetic tissues. Conclusions Increased blood plasma activity of Lp‐ PLA 2 is associated with higher prevalence of SVD . These findings open new avenues for the identification of patients at risk for SVD and for the development of pharmacotherapy aiming at the prevention of SVD .