Background: Increased levels of oxidized low-density lipoprotein (ox-LDL) are related to plaque instability, so the aim of the present study was to investigate whether there is a relationship between angiographic coronary plaque morphology in patients with unstable angina pectoris (UAP) and the level of ox-LDL.
Methods and results: Plasma ox-LDL levels were measured in 149 patients with UAP and in 88 control subjects, using a highly sensitive enzyme-linked immunosorbent assay method. Angiographic morphology of the culprit lesion was classified as either simple or complex based on the Ambrose classification. Plasma ox-LDL levels in patients with Braunwald class III were significantly higher than in patients with class I (p<0.0001) or in control subjects (p<0.0001). In each of the 3 Braunwald classes, plasma ox-LDL levels in patients with a complex lesion were significantly higher than in patients with a simple lesion. Multivariate logistic regression analysis revealed that ox-LDL level and Braunwald class III were independent factors associated with angiographically detected complex lesions.
Conclusion: In each Braunwald class of UAP, elevated plasma levels of ox-LDL closely relate to the presence of angiographically detected complex and thrombotic lesion morphology.