Abstract 12791: Soluble Lectin-Like Oxidized LDL Receptor-1 (LOX-1) and LOX Index Are Useful Biomarkers for Vulnerable Plaques
Backgrounds: Soluble LOX-1 (sLOX-1) is elevated in peripheral blood of patients with acute coronary syndrome (ACS). LOX index is a novel predictive biochemical marker for coronary heart disease, determined as multiplying sLOX-1 by LOX-1 ligands containing apolipoprotein B (LAB) [LOX index = sLOX-1 × LAB]. However, sLOX-1 in coronary circulation has not been examined. Furthermore, significance of LOX index in ACS has not been defined.
Aim: We investigated the values of sLOX-1 and LOX index in systemic circulation and coronary circulation.
Methods: This study enrolled 67 patients with ischemic heart disease (IHD) including 27 patients with ACS and 40 patients with effort angina pectoris (EAP) who underwent percutaneous coronary intervention (PCI). We measured the levels of sLOX-1 and LAB in blood samples from aorta (Ao) and coronary sinus (CS) at the same time just prior to PCI by newly established ELISA systems.
Results: Both Ao and CS sLOX-1 were significantly higher in ACS than in EAP as well as Ao and CS LOX index were significantly higher in ACS than in EAP, but not LAB. The values of sLOX-1 and LOX index of CS were significantly higher than those of Ao in both ACS and EAP. The difference of sLOX-1 and LOX index between CS and Ao (CS-Ao) were greater in ACS than in EAP. These findings suggested that elevated sLOX-1 and LOX index were derived from coronary circulation. ROC curve showed that both Ao and CS sLOX-1 and LOX index can significantly discriminate ACS from EAP among patients with IHD, with no significant difference in AUC between Ao and CS values. Correlation between sLOX-1 and CK-MB, Troponin-I or CRP in ACS was not significant, probably because sLOX-1 of ACS appeared to be increased earlier after onset compared to other markers.
Conclusions: The present study showed that systemic increased sLOX-1 originated from coronary circulation, suggesting that sLOX-1 was a specific biomarker of vulnerable plaque in ACS as well as LOX index.
- © 2010 by American Heart Association, Inc.