title: Natural and prosthetic heart valve calcification: morphology and chemical composition characterization.
abstract: Calcification is the most common cause of damage and subsequent failure of heart valves. Although it is a common phenomenon, little is known about it, and less about the inorganic phase obtained from this type of calcification. This article describes the scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy and Ca K-edge X-ray absorption near edge structure (XANES) characterization performed in natural and bioprosthetic heart valves calcified in vivo (in comparison to in vitro-calcified valves). SEM micrographs indicated the presence of deposits of similar morphology, and XANES results indicate, at a molecular level, that the calcification mechanism of both types of valves are probably similar, resulting in formation of poorly crystalline hydroxyapatite deposits, with Ca/P ratios that increase with time, depending on the maturation state. These findings may contribute to the search for long-term efficient anticalcification treatments.
authors.affiliation: School of Chemical Engineering, University of Campinas, UNICAMP, Campinas, SP, Brazil.
authors.forename: Raquel F
authors.initials: RF
authors.lastname: Weska
authors.forename: Cassiano G
authors.initials: CG
authors.lastname: Aimoli
authors.forename: Grínia M
authors.initials: GM
authors.lastname: Nogueira
authors.forename: Adolfo A
authors.initials: AA
authors.lastname: Leirner
authors.forename: Marina J S
authors.initials: MJ
authors.lastname: Maizato
authors.forename: Olga Z
authors.initials: OZ
authors.lastname: Higa
authors.forename: Bronislaw
authors.initials: B
authors.lastname: Polakievicz
authors.forename: Ronaldo N M
authors.initials: RN
authors.lastname: Pitombo
authors.forename: Marisa M
authors.initials: MM
authors.lastname: Beppu
mesh_terms: D002114:Calcinosis / Q000473:pathology*; D009202:Cardiomyopathies / Q000473:pathology*; D006350:Heart Valve Prosthesis; D006351:Heart Valves / Q000473:pathology*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011475:Prosthesis Failure; D013052:Spectrometry, X-Ray Emission