title: Associations between N-terminal procollagen type III, fibrosis and echocardiographic indices in dogs that died due to myxomatous mitral valve disease.
abstract: OBJECTIVE
  To evaluate associations between N-terminal procollagen type III (PIIINP), a serum biomarker of collagen biosynthesis, and myocardial fibrosis in dogs with naturally-occurring myxomatous mitral valve disease (MMVD).
  
  
  METHODS
  Twenty-two dogs with echocardiographically-confirmed MMVD were prospectively recruited from a hospital population. All died as a result of MMVD and their hearts were available for post mortem examination.
  
  
  METHODS
  Echocardiographic measurements and serum PIIINP concentrations were obtained from all dogs prior to death or euthanasia. Serum PIIINP concentrations (μg/mL) were measured using a validated commercially available radioimmunoassay. Myocardial tissue samples were collected post mortem and myocardial fibrosis was scored. The average fibrosis score for all cardiac sites in the heart was designated the global fibrosis score (GFS). The average fibrosis score for all papillary muscle sites was designated the papillary fibrosis score (PFS). Univariate and multivariate linear regression analyses were used separately to evaluate associations between GFS and PFS, respectively, and PIIINP and echocardiographic variables.
  
  
  RESULTS
  Left ventricular end-diastolic diameter normalized for body weight (LVEDDN) and PIIINP were weakly independently positively associated with both GFS and PFS. LVEDDN and PIIINP were weakly negatively correlated.
  
  
  CONCLUSIONS
  Both LVEDDN and serum PIIINP increase with increasing fibrosis score, although these relationships were not strong enough to be clinically useful. Although LVEDDN and PIIINP were positively correlated with fibrosis, PIIINP decreased with increasing LVEDDN, suggesting a complex interplay between fibrosis and remodeling in MMVD.
authors.affiliation: Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, United Kingdom. Electronic address: mhezzell@vet.upenn.edu.
authors.forename: Melanie J
authors.initials: MJ
authors.lastname: Hezzell
authors.affiliation: The Department of Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Fredriksberg, Denmark.
authors.forename: Torkel
authors.initials: T
authors.lastname: Falk
authors.affiliation: The Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Fredriksberg, Denmark.
authors.forename: Lisbeth Høier
authors.initials: LH
authors.lastname: Olsen
authors.affiliation: Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, United Kingdom.
authors.forename: Adrian
authors.initials: A
authors.lastname: Boswood
authors.affiliation: Department of Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 0TU, United Kingdom.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Elliott
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000378:metabolism / Q000473:pathology*; D004285:Dogs; D004452:Echocardiography; D005260:Female; D005355:Fibrosis / Q000473:pathology / Q000662:veterinary*; D016014:Linear Models; D008297:Male; D008945:Mitral Valve Prolapse / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D011347:Procollagen / Q000235:genetics / Q000378:metabolism*; D016277:Ventricular Function, Left
chemical_list: D010446:Peptide Fragments; D011347:Procollagen; C041876:procollagen Type III-N-terminal peptide
keywords: Degenerative mitral valve disease; Left ventricular end-diastolic diameter; Mitral regurgitation; Myocardial fibrosis