Abstract 2058: Soluble Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1 Level is a Sensitive Indicator of Left Ventricular Structural Derangement in Dilated Cardiomyopathy
[Background] Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is highly expressed in the vascular endotherial cells and also in failing cardiomyocytes. Cell-surface LOX-1 is proteolytically cleaved to release soluble form of LOX-1 (sLOX-1), and Elevated sLOX-1 was reported in acute coronary syndrome. However, sLOX-1 in failing heart, such as dilated cardiomyopathy (DCM), has not been investigated. The aim of this study was to examine the hypothesis that sLOX-1 is closely related to the severity of DCM designated by left ventricular enlargement and recent occurrence of heart failure.
[Subjects and Methods] Thirty-seven clinically and pathologically diagnosed DCM patients (28 males, 9 females; age 57.5 ± 2.6) and 24 controls (15 males, 9 females; age 51.0 ± 3.1) were enrolled. Blood samples for sLOX-1 were obtained from ascending aorta during cardiac catheterizations. Laboratory and echocardiographic data were collected within two days of sLOX-1 sampling. sLOX-1 was measured by a sandwich ELISA method with blind manners.
[Results] Serum levels of sLOX-1 in DCM patients were significantly higher than those in control subjects (133.1 ± 27.5 vs 74.4 ± 12.4 pg/ml, respectively, p<0.0001). In DCM, serum levels of sLOX-1 correlated significantly with left ventricular diastolic dimension (r2=0.278, p<0.001), but not in controls (r2=0.046, p=0.33). Furthermore, sLOX-1 levels of 21 DCM patients with recent occurrence (within one month) of heart failure were significantly greater than those of the remaining 16 DCM patients (185.1 ± 45.2 vs 65.0 ± 8.6 pg/ml, respectively, p<0.05). On the other hand, serum levels of B-type natriuretic peptide did not show significant correlation with left ventricular diastolic dimension either in DCM or controls. Nevertheless B-type natriuretic peptide levels of 21 DCM patients who had recent occurrence of heart failure were significantly higher than those of 16 DCM patients without recent heart failure (1002 ± 358 vs 274 ± 75 pg/ml, respectively, p<0.001).
[Conclusion] These results suggest that sLOX-1 appears to be a better marker than B-type natriuretic peptide for identifying the structural derangement of left ventricle, but not better for assessing the incident of heart failure in DCM.