title: The structural examination of myocardial samples from patients with end-stage heart failure supported by ventricular assist devices using electron microscopy and amino acid analysis reveals low degree of reverse remodeling.
abstract: BACKGROUND
  Chronic heart failure is a multifactorial, progressive disease of many causes and is associated with complex ventricular remodeling. Deposition of extracellular matrix proteins and sarcomeric disarray of the myocytes occur in end-stage heart failure. Ventricular assist devices (VAD), implanted as bridge to transplantation, may reverse ventricular remodeling. Although successfully weaning patients from VAD support has been reported, it is not clear to what degree reversal of remodeling occurs in unloaded failing hearts. Because collagen deposition and ultrastructural disarray are hallmarks of myocardial remodeling, we analyzed the myocardial ultrastructure and collagen content of VAD-supported hearts before and after mechanical unloading.
  
  
  METHODS
  We used amino acid analysis to measure collagen content (4-hydroxyproline content) in 24 transplant candidates receiving VAD support. We used transmission electron microscopy to examine the ultrastructure in 6 patients receiving VAD support.
  
  
  RESULTS
  The 4-hydroxyproline content increased significantly at VAD implantation and was not altered by mechanical unloading. The ultrastructure showed signs of persisting cardiomyopathy.
  
  
  CONCLUSIONS
  Mechanical unloading does not alter the total collagen content of the supported, failing heart. Thus, structural reversal of the remodeling process associated with heart failure is not a general phenomenon in mechanically unloaded hearts.
authors.affiliation: Ruhr-Universität Bochum, Herz- und Diabeteszentrum NRW, Forschungslabor der Herzchirurgie, Bad Oeynhausen, Germany. hmilting@hdz-nrw.de
authors.forename: Hendrik
authors.initials: H
authors.lastname: Milting
authors.forename: Monika
authors.initials: M
authors.lastname: Jacob
authors.forename: Astrid
authors.initials: A
authors.lastname: Kassner
authors.forename: Peter
authors.initials: P
authors.lastname: Heimann
authors.forename: Hans Georg
authors.initials: HG
authors.lastname: Mannherz
authors.forename: Gabriele
authors.initials: G
authors.lastname: Becker
authors.forename: Helmut E
authors.initials: HE
authors.lastname: Meyer
authors.forename: Dietmar
authors.initials: D
authors.lastname: Böthig
authors.forename: Latif
authors.initials: L
authors.lastname: Arusoglu
authors.forename: Michel
authors.initials: M
authors.lastname: Morshuis
authors.forename: Reiner
authors.initials: R
authors.lastname: Körfer
authors.forename: Aly
authors.initials: A
authors.lastname: El Banayosy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003094:Collagen / Q000378:metabolism; D006333:Heart Failure / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D016027:Heart Transplantation; D006352:Heart Ventricles / Q000378:metabolism / Q000648:ultrastructure; D006353:Heart-Assist Devices; D006801:Humans; D006909:Hydroxyproline / Q000378:metabolism*; D008854:Microscopy, Electron; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure*; D020257:Ventricular Remodeling / Q000502:physiology*
chemical_list: D003094:Collagen; D006909:Hydroxyproline