Predictive Value Of Total Cholesterol Content Of Erythrocyte Membranes For Acute Coronary Syndrome

Objective: To study the changes of total cholesterol content from erythrocyte membranes in patients with coronary artery disease(CAD) and its predictive value for acute coronary syndrome..Background: Plaque rupture in ACS depends at least partly on the volume of the necrotic lipid core. Histopathologic studies have suggested that cholesterol transported by erythrocytes and deposited into the necrotic core of atheromatous plaques contributes to lipid core growth.Methods: Total 70 patients were chosen from Sep 2007 to Feb 2008.Noncoronary artery disease group was patients with paroxysmal supraventricular tachycardia(n=25),15 patients had stable angina and 30 patients had acute coronary sydrome.Rugular biochemical measurements such as red blood cell(RBC),serum lipid and C-reactive protein were abtained. Total cholesterol content in erythrocyte membranes(CEM) was measured using an enzymatic assay, and protein content was assessed by the Bradford method. The SPSS 13.0 ststistical software package was used for all calculations, A p value﹤0.05 was considered to indicate statistical significance. The 2-tailed unpaired Student t test or the Mann-Whitney U test were used to evaluate difference in continuous variables between the 2 groups. Simple and logistic regression analysis wes used to assess univariate association between biochemical measuremens and CAD status.Multiple logistic regression analysis was used to assess the independent adjusted relationship between CEM levels and CAD status, with independent variables being those with p﹤0.05 on univariate analysis. Correlation analysis between CEM levels and serum TC,TG,LDL and HDL levels was carried out by Spearman's correlation coefficient. The CEM levels in the subgroup of patients receiving statin treatment were compared with those in patients not receiving lipid-lowering treatments. Results: 1.The CEM levels did not differ in the non-CAD group( 54.5 mmol/mg,25～81 mmol/mg)compared with those in stable CAD patients(55.3 mmol/mg,34～82mmol/mg)(p=0.06). while the CEM was significantly higher in the ACS patient group(142.4mmol/mg,96～188mmol/mg)compared with patents with non-CAD and stable .2. The results of simple regression analysis showed that increased CEM measurements and CRP levels were predictive of ACS, whereas beta blocker,aspirin use were negatively associated with ACS. Of interest, the CEM levels was a stronger predictor of ACS than CRP. Multiple logistic regression analysis showed that high CEM levels continued to have an independent significant association with ACS.3. Correlation analysis showed no linear association between CEM and serum TC,TG,LDL-C,HDL-C. the Linear correlation analysis in a subgroup of patients who were not receiving statin treatment appeared the same result. In the subgroup of patients receiving statin treatment,CEM levels(n=17,89.06 mmol/mg,34～126 mmol/mg) were lowerer than those in the patients not receiving statin treatment(n=28,128.10 mmol/mg,38～188 mmol/mg)(p=0.006).Conclusions: 1.The normal range of CEM in non-CAD and stable CAD patients is 29.25～81.85mmol/mg,in the ACS patients the CEM is significantly higher.2. The CEM levels has no correlation association with serum TC and was independent of TC.3. The CEM levels is a new predictive marker of atheromatous vulnerable plaque and ACS.4. The use of statins is associated with lower CEM values in CAD patients.