title: Intra-individual changes of active matrix metalloproteinase-9 are associated with clinical in-stent restenosis of bare metal stents.
abstract: OBJECTIVE
  Increased chronic postprocedural levels of active matrix metalloproteinase-9 (MMP-9) have been associated retrospectively with a history of in-stent restenosis (ISR). This study aimed to determine whether index or post-percutaneous coronary intervention (PCI) plasma levels of active MMP-9 are a predictor of subsequent clinical ISR, in a standard population of patients treated with bare metal coronary stents.
  
  
  METHODS
  Four hundred thirty-two patients were prospectively recruited and sampled at index and 3 and 6 months after PCI. Those who developed symptomatic angiographically confirmed ISR were compared to randomly selected, asymptomatic controls, stratified by index presentation in a nested case-control design. Plasma samples were analyzed for the active form of MMP-9.
  
  
  RESULTS
  In all, 35 patients (8.1%) developed ISR, and these were compared to 98 controls. The increase in active MMP-9 over 3 months was significantly greater in the ISR group (p = 0.030) and independent of the established risk factors. Index clinical presentation was not associated with acute changes in active MMP-9; however, patients with ST-elevation myocardial infarction had greater increases in active MMP-9 at 3 months.
  
  
  CONCLUSIONS
  The change in active MMP-9 over 3 months after bare metal coronary stent placement appears to be independently associated with the development of ISR in a standard PCI population.
authors.affiliation: Department of Surgical Sciences, University of Otago, Dunedin, New Zealand.
authors.forename: G P
authors.initials: GP
authors.lastname: Tarr
authors.forename: M J A
authors.initials: MJ
authors.lastname: Williams
authors.forename: G T
authors.initials: GT
authors.lastname: Wilkins
authors.forename: V H T
authors.initials: VH
authors.lastname: Chen
authors.forename: L V
authors.initials: LV
authors.lastname: Phillips
authors.forename: A M
authors.initials: AM
authors.lastname: van Rij
authors.forename: G T
authors.initials: GT
authors.lastname: Jones
mesh_terms: D023903:Coronary Restenosis / Q000209:etiology* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000628:therapy; D062645:Percutaneous Coronary Intervention; D012307:Risk Factors; D015607:Stents
chemical_list: D020780:Matrix Metalloproteinase 9