Independent and Additive Predictive Value of Total Cholesterol Content of Erythrocyte Membranes with Regard to Coronary Artery Disease Clinical Presentation

Background: A new mechanism for clinical instability in coronary artery disease (CAD) has been proposed where erythrocytes could play an active role in atherosclerotic plaque growth and rupture. Clinical studies showed increased total cholesterol levels in the membrane of circulating erythrocytes (CEM) in acute coronary syndrome (ACS) patients compared to patients with chronic stable angina (CSA). We investigated the independent and incremental discriminating value of CEM along with N-terminal propeptide of BNP (NT-proBNP), high sensitivity C-reactive protein (hs CRP), myeloperoxidase (MPO) and apolipoprotein B (apoB) with regard to CAD clinical presentation.

Methods: 519 consecutive angina patients were assessed; 252 had CSA (195 men, 62 ± 9 years) and 267 had ACS (213 men, 62 ± 10 years).CEM levels and serum concentrations of NT-proBNP, hs CRP, MPO and apoB were measured upon study admission.

Results: Simple logistic regression models showed that all biomarkers could distinguish ACS, nevertheless CEM with greater potency (OR 9.26 95%CI 6.31-13.59, p<0.001). Multiple logistic regression models after adjustment for all the variables that were different between the 2 groups as well as for other biomarkers showed that CEM continued to be a significant and an independent predictor of ACS (OR 22.27 95%CI 10.63-46.67, p<0.001). An increment of the C-statistic was also shown when CEM levels were incorporated in the predictive model (including traditional vascular risk factors and new well established biomarkers i.e. hs CRP, MPO, apoB and NT-proBNP).

Conclusions: The present study showed that CEM levels are associated with clinical instability in CAD patients in an independent and incremental manner.