Increases in myeloperoxidase levels after exercise in myocardial perfusion scintigraphy are not induced by myocardial ischemia.
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.
van der Zee
P M
PM
Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands. p.m.vanderzee@amc.uva.nl
Meuwese
M C
MC
Verberne
H J
HJ
de Ruijter
M
M
van Straalen
J P
JP
Fischer
J C
JC
Sturk
A
A
van Eck-Smit
B L F
BL
Stroes
E S G
ES
de Winter
R J
RJ
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
D009195:Peroxidase