title: Increases in myeloperoxidase levels after exercise in myocardial perfusion scintigraphy are not induced by myocardial ischemia.
abstract: BACKGROUND
  Increased systemic levels of myeloperoxidase (MPO) have been reported in patients with acute myocardial ischemia. We studied the association between exercise-induced myocardial ischemia measured by myocardial perfusion scintigraphy (MPS) and the magnitude and time course of changes in MPO levels in humans.
  
  
  METHODS
  One hundred and twenty six patients underwent symptom limited exercise MPS. Myocardial ischemia was assessed semi-quantitatively. Plasma samples were taken before the start of exercise (baseline), at maximum exercise and every hour up to 6 h after maximum exercise.
  
  
  RESULTS
  Myocardial ischemia was present in 42 (33%) patients. MPO levels rapidly increased during exercise in patients with and without ischemia (to 131% (106-172%) and 145% (121-199%) of baseline, respectively). MPO levels and absolute changes in MPO did not differ between patients with and without ischemia at any time point. None of the patient characteristics, including presence of ischemia, was independently predictive of the absolute increase in MPO levels during exercise.
  
  
  CONCLUSIONS
  Exercise related immediate increases in MPO levels do not reflect myocardial ischemia.
authors.affiliation: Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands. p.m.vanderzee@amc.uva.nl
authors.forename: P M
authors.initials: PM
authors.lastname: van der Zee
authors.forename: M C
authors.initials: MC
authors.lastname: Meuwese
authors.forename: H J
authors.initials: HJ
authors.lastname: Verberne
authors.forename: M
authors.initials: M
authors.lastname: de Ruijter
authors.forename: J P
authors.initials: JP
authors.lastname: van Straalen
authors.forename: J C
authors.initials: JC
authors.lastname: Fischer
authors.forename: A
authors.initials: A
authors.lastname: Sturk
authors.forename: B L F
authors.initials: BL
authors.lastname: van Eck-Smit
authors.forename: E S G
authors.initials: ES
authors.lastname: Stroes
authors.forename: R J
authors.initials: RJ
authors.lastname: de Winter
mesh_terms: D000368:Aged; D003324:Coronary Artery Disease / Q000097:blood / Q000000981:diagnostic imaging* / Q000201:enzymology*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000503:physiopathology; D009195:Peroxidase / Q000097:blood*; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D009195:Peroxidase