Erythrocyte-bound Apolipoprotein B in Atherosclerosis and Mortality.

Background The binding of apolipoprotein (apo) B-containing lipoproteins to circulating erythrocytes (ery-apoB) is associated with a decreased prevalence of atherosclerosis. In this study, we evaluated ery-apoB as a possible prognostic factor in cardiovascular events and all-cause mortality, in a prospective cohort study. Materials and methods Ery-apoB was measured by flow cytometry in subjects with and without cardiovascular disease (CVD). The primary endpoint was the cardiovascular event rate. Secondary endpoints were allcause mortality and the combined endpoint of all-cause mortality and cardiovascular events (any event rate). A Cox regression analysis with univariate and multivariate analyses and Kaplan-Meier survival analysis was performed. Results Follow-up data were available of 384 subjects. Subjects were divided according to high (> 2.0 au, n = 60), intermediate (0.2-2.0 au, n = 274) or low (< 0.2 au, n = 50) ery-apoB. Median follow-up was 1767 days (IQR 1564-2001). In univariate analysis, low ery-apoB was associated with increased all-cause mortality [ HR 9.9 (1.2-79.0), P = 0.031] and any event rate [ HR 3.4 (95% CI 1.3-8.7), P = 0.012]. In a Cox regression analysis, only a history of CVD was significantly associated with any event rate [ HR 3.6 (1.6-8.0), P = 0.002], while low ery-apoB showed a trend [ HR 2.4 (0.9-6.4), P = 0.07]. In a subgroup analysis, in subjects with a history of CVD, ery-apoB was significantly associated with all-cause mortality (log rank P = 0.021) and any event rate (log rank P = 0.009). Conclusions Low ery-apoB is associated with increased mortality and cardiovascular risk, especially in patients with a prior history of CVD. These subjects may benefit from more aggressive secondary prevention treatment.