Prognostic value of total cholesterol content of erythrocyte membranes in patients with acute coronary syndrome

Abstract

Objective: Previous cross-sectional studies suggested that elevated levels of total cholesterol content of erythrocyte membrane (CEM) could significantly increase the risk of acute coronary syndrome (ACS). The purpose of the present study was to assess the predictive value of baseline CEM levels for the risk of clinical endpoint events in patients with ACS through prospective follow-up studies. Methods: This study is a prospective follow-up study, which consisted of 859 patients with first ACS (698 patients with unstable angina pectoris and 161 patients with acute myocardial infarction), diagnosed and hospitalized in the First and Second Affiliated Hospital of Anhui Medical University. The routine blood lipid levels and CEM were measured. Patients were divided into two groups according to the median of baseline CEM: CEM≤131.56 μg/mg group (n=430) and CEM>131.56 μg/mg group (n=429). Patients were followed up at 6 months interval. The clinical endpoints were nonfatal myocardial infarction, nonfatal stroke, all-cause mortality, all-cause mortality, heart failure requiring hospitalization, and coronary artery revascularization. Kaplan-Meier curve analysis and Cox proportional hazard model were used to analyze the impact of elevated CEM on the occurrence of clinical end-point events. HR values and 95%CI of each variable were obtained. Cox regression analysis of all-cause mortality was performed according to whether patients had risk factors for coronary heart disease (hypertension, diabetes, smoking and elevated LDL-C) and whether they were treated with PCI. Results: The follow-up time was 1 640 (1 380, 2 189) days. Cox analysis after adjustment showed that an elevated baseline of CEM (>131.56 μg/mg) was associated with an increased risk of all-cause mortality (HR=1.690, 95%CI 1.041-2.742, P=0.034), but had no significant predictive effect on the other clinical endpoints. Subgroup analysis showed that elevated baseline CEM levels in ACS patients with LDL-C>1.8 mmol/L (HR=1.687, 95%CI 1.026-2.774, P=0.039), receiving in-hospital PCI (HR=2.365, 95%CI 1.054-5.307, P=0.037), or male (HR=1.794, 95%CI 1.010-3.186, P=0.046) were associated with an increased risk of all-cause mortality. Conclusion: The results showed that elevated CEM levels can increase the risk of all-cause mortality in ACS patients.