title: Lp-PLA2 is associated with structural valve degeneration of bioprostheses.
abstract: OBJECTIVE
  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 (BPs) stenosis or regurgitation. We hypothesized that lipoprotein-associated phospholipase A2 (Lp-PLA2) is involved in the SVD of BPs.
  
  
  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 BPs (n = 39) were analysed by immunohistochemistry for the expression of Lp-PLA2.
  
  
  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-PLA2 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 Lp-PLA2 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 BPs had the expression of Lp-PLA2, which correlated with the density of macrophages (CD68), and ox-LDL levels in bioprosthetic tissues.
  
  
  CONCLUSIONS
  Increased blood plasma activity of Lp-PLA2 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.
authors: Laboratoire d'Études Moléculaires des Valvulopathies (LEMV), Groupe de Recherche en Valvulopathies (GRV), Department of Surgery, Quebec Heart and Lung Institute/Research Center, Laval University, Quebec, QC, Canada.
authors: Ablajan
authors: A
authors: Mahmut
authors: Haïfa
authors: H
authors: Mahjoub
authors: Marie-Chloé
authors: MC
authors: Boulanger
authors: Dominique
authors: D
authors: Fournier
authors: Jean-Pierre
authors: JP
authors: Després
authors: Philippe
authors: P
authors: Pibarot
authors: Patrick
authors: P
authors: Mathieu
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000502:physiology*; D000368:Aged; D001022:Aortic Valve Insufficiency / Q000209:etiology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000209:etiology / Q000601:surgery; D001705:Bioprosthesis; D003430:Cross-Sectional Studies; D015150:Echocardiography, Doppler; D005260:Female; D006083:Graft Occlusion, Vascular / Q000209:etiology*; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011475:Prosthesis Failure / Q000209:etiology*
chemical_list: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase
keywords: Bioprostheses; Lp-PLA2; structural valve degeneration