title: Changes in matrix metalloproteinase-9 levels during progression of atrial fibrillation.
abstract: OBJECTIVE
  To observe levels of matrix metalloproteinase (MMP)-9 and evaluate their significance in various stages of idiopathic atrial fibrillation (AF).
  
  
  METHODS
  Patients with idiopathic AF were recruited into this prospective study and classified into one of three groups according to stage of disease progression: paroxysmal AF; persistent AF; permanent AF. Healthy individuals were enrolled as control subjects. Serum levels of MMP-9 in all four groups were determined using a double-antibody sandwich enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Each AF group included 25 patients; 40 healthy individuals were included as controls. MMP-9 levels in the three AF groups were significantly higher than in the control group: 168.72 ± 25.970, 201.36 ± 31.26 and 253.20 ± 22.99 ng/ml for the paroxysmal, persistent and permanent AF groups respectively, versus 76.80 ± 14.90 ng/ml for the control group. MMP-9 levels increased with idiopathic AF disease progression (P < 0.05).
  
  
  CONCLUSIONS
  An elevated MMP-9 level appears to be associated with a diagnosis of AF. MMP-9 levels appear to increase in relation to the stage of idiopathic AF progression.
authors.affiliation: Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China.
authors.forename: Mingjiang
authors.initials: M
authors.lastname: Li
authors.forename: Guokang
authors.initials: G
authors.lastname: Yang
authors.forename: Bin
authors.initials: B
authors.lastname: Xie
authors.forename: Kamesh
authors.initials: K
authors.lastname: Babu
authors.forename: Congxin
authors.initials: C
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000201:enzymology*; D016022:Case-Control Studies; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D020780:Matrix Metalloproteinase 9
keywords: Atrial fibrillation; concentration; disease progression; extracellular matrix; matrix metalloproteinase-9; pathological mechanism