Trans-vessel gradient of myeloperoxidase in coronary artery disease

Background: Coronary artery disease (CAD) may reflect generalized inflammation. We evaluated leucocyte activation in subjects with and without CAD in different vascular compartments.

Materials and methods: Patients were divided in two groups; subjects without CAD (controls; n = 25) and with stable CAD (n = 52) based on coronary angiography. After blood sampling from vessels, cardiovascular risk factors and leucocyte activation markers CD11b, CD66b and cytoplasmatic myeloperoxidase (MPO) were determined by flow cytometry.

Results: Myeloperoxidase (MPO) was higher in patients with CAD at all sites compared with controls (188 ± 7 vs. 210 ± 12 au for venous (P < 0.05), 178 ± 7 vs. 212 ± 12 au for femoral artery (P = 0.08), 166 ± 7 vs. 195 ± 12 au for abdominal artery (P < 0.05), 166 ± 6 vs. 189 ± 14 au for left coronary (P = 0.08) and 163 ± 6 vs. 193 ± 12 au for the right coronary artery (P < 0.05)). Other markers did not differ between the groups. A gradient of inflammation from peripheral vessels to the coronaries was found by differences in MPO in both groups; from 210 ± 12 au in the venous compartments towards 189 ± 14 and 193 ± 12 au, in the left and right coronaries, respectively, for the controls (P = 0.001), and from 188 ± 7 au in the venous compartment towards 166 ± 6 and 163 ± 6 au in the left and right coronaries, respectively, for the patients (P = 0.007). Other leucocyte activation markers did not show such a gradient.

Conclusions: There is a generalized inflammatory neutrophil gradient for MPO from peripheral vessels towards the coronaries in both patients with CAD and controls. However, patients with CAD show a higher degree of inflammation, mostly in the coronaries. These data strengthen the role of activated neutrophils in CAD.