OxLDL as a prognostic biomarker of plaque instability in patients qualified for carotid endarterectomy

Abstract

Atherosclerotic plaque instability increases the risk of stroke. As such, determining the nature of an instability atherosclerotic plaque may speed up qualification for carotid endarterectomy (CEA), thus reducing the risk of acute vascular events. The aim of the study was to determine the diagnostic value of oxidized LDL cholesterol (ox-LDL), matrix metalloproteinase 9 (MMP-9) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in serum as a prognostic markers of instability atherosclerotic plaques. Serum was collected from 67 patients who underwent CEA in accordance with the qualification criteria. The levels of ox-LDL, MMP-9 and 8-OHdG were assessed by ELISA. The predictive value of the markers was determined based on an ROC curve, and the cut-off points with the highest sensitivity and specificity were determined. Patients with unstable atherosclerotic plaque had significantly higher serum ox-LDL, MMP-9 and 8-OHdG values. It was found that in patients before CEA, ox-LDL >31.4 ng/mL was associated with an 82.5% probability of unstable atherosclerotic plaque, MMP-9 >113.1 ng/mL with 78.6%, and 8-OHdG >2.15 ng/mL with 64.7%. Multivariate regression analysis found ox-LDL to be an independent factor associated with plaque instability. Patients with unstable plaques tend to have higher serum levels of ox-LDL, MMP-9 and 8-OHdG compared to those with stable plaques. The optimal cut-off point for ox-LDL (AUC 0.86, p <0.0001) was 31.14 ng/mL, with 91.18% sensitivity and 78.79% specificity. The high sensitivity and specificity of ox-LDL suggests that it can be used as an independent marker of plaque instability.