Abstract 3200: Elevated Plasma Levels of Myeloperoxidase Are Related to Angiographic Coronary Complex Plaque Morphology in patients with Unstable Angina
Background: Myeloperoxidase (MPO) has emerged as a potential participant in the promotion and/or propagation of atherosclerosis. MPO is an abundant hemeprotein released mainly by activated neutrophils and is present in some tissue macrophages such as those in vascular lesions. We have already demonstrated that an infiltration of MPO released from activated neutrophils occurs in the culprit lesions of patients with unstable angina pectoris (UAP). The purpose of this study was to determine the relationship between angiographic coronary plaque morphology in UAP patients and plasma MPO levels.
Methods: Plasma MPO levels on admission were measured in 153 patients with UAP and in 85 control subjects using an enzyme-linked immunosorbent assay kit. Angiographic morphology of the culprit lesion was classified into 2 types, simple or complex, based on the Ambrose classification.
Results: Plasma MPO levels in patients with Braunwald class III were significantly higher than in patients with class I (P<0.05) or in control subjects (P<0.0001). Plasma MPO levels in patients with a complex lesion were significantly higher than in patients with a simple lesion (65.5±54.3 versus 32.3±23.7ng/ml, P<0.0001), whereas the number of white blood cells and neutrophils, and serum C-reactive protein levels on admission were not significantly different between the two groups. On multivariate analysis, elevated plasma MPO levels and Braunwald class III were independent factors for angiographically-detected complex lesions.
Conclusion; This study demonstrates that elevated plasma MPO levels are closely related to the presence of angiographically-documented, complex plaque morphology in patient with UAP.