Increased Presence of Oxidized Low-density Lipoprotein in the Left Ventricular Blood of Subjects with Cardiovascular Disease

OxidizedLDL(Ox-LDL) and oxidative stress have been implicated in both atherosclerosis and congestive heart failure (HF) development. Here, we tested whether Ox-LDLlevels in left ventricular blood (LVB) might differ from those of venous peripheral blood (PB), and whether the level might depend on cardiac function. We also tested whether theLDLmolecule is likely to have a longer residence time in the left ventricle ofHFsubjects with low ejection fraction (EF). The aim of this study was to determine Ox-LDLlevels, paraoxonase 1 (PON1) activity, and cholesterol efflux capacity (CEC) ofPBandLVB, and correlate these values withLVEF Sixty-oneHFpatients underwent preoperative transthoracic echocardiographic assessment of ventricular function.LVEFs were determined using Simpson's biplane technique.LVBandPBlevels of Ox-LDLwere determined, andPON1 activity and plasma cholesterol efflux capacity were measured. A significant increase in the levels of Ox-LDLinLVBwas noted as compared to levels inPB, even whenEFwas near normal. However, as ejection fraction decreased, the level of Ox-LDLinPBapproached that of theLVBPON1 activity and cholesterol efflux studies indicated increased oxidative stress inLVBand a decreased ability to promote cholesterol efflux from lipid-enriched macrophages. The results suggest thatLVBis more oxidatively stressed compared toPB, and thereforeLVtissue might be affected differently than peripheral tissues. We recently reported that brain natriuretic peptide (BNP), a marker forHF, is induced by Ox-LDL, so it is possible localized factors within theLVcould profoundly affect markers ofHF.