Plasma levels of myeloperoxidase are not elevated in patients with stable coronary artery disease.

BACKGROUND: Plasma and serum levels of myeloperoxidase (MPO), a redox-active hemoprotein released by polymorphonuclear neutrophils (PMN) upon activation, is now recognized as a powerful prognostic determinant of myocardial infarction in patients suffering acute coronary syndromes. However, there is limited information on whether systemic MPO levels are also elevated and of discriminating value in patients with stable coronary artery disease (CAD) representing different ethnic groups. METHODS: Plasma levels of MPO and traditional CAD risk factors were quantified in African American and Caucasian patients (n=557) undergoing elective coronary angiography. RESULTS: MPO levels did not differ significantly between patients with or without CAD [421 pM (321, 533) vs. 412 pM (326, 500), p>0.05]. MPO levels were similar across ethnicity and gender, and correlated positively with CRP and fibrinogen levels (r=0.132, p=0.002 and r=0.106, p=0.011, respectively). CONCLUSION: In conclusion, plasma MPO levels were not elevated in patients with stable CAD, suggesting that systemic release of MPO is not a characteristic feature of asymptomatic CAD.