Abstract 2996: Comparison of Lipid Parameters for Detection of Atherosclerotic Burden in the Proximal Thoracic Aorta
BACKGROUND: Current lipid lowering guidelines recommend that therapy be targeted primarily at low-density lipoprotein (LDL) cholesterol, and that other lipid parameters be used as secondary or supplementary targets. Emerging data have suggested that measures such as high-density lipoprotein (HDL) cholesterol or apolipoprotein (apo) B/A-I ratio may be more predictive of atherosclerotic burden than LDL cholesterol. We conducted a cross-sectional analysis in a population based sample to directly compare the strengths of the associations among various lipid parameters and atherosclerotic plaque (AP) in the proximal thoracic aorta.
METHODS: As part of the NINDS-funded Aortic Plaques and Risk of Ischemic Stroke (APRIS) study, 464 subjects were studied (mean age 69.1 +/- 8.7 with 251 males and 213 females), including 255 patients with first ischemic stroke and 209 stroke-free controls. Presence and thickness of AP were assessed by transesophageal echocardiography. Measured lipid parameters included total cholesterol, triglyceride (TG), LDL, HDL, HDL subfractions (HDL2, 3), lipoprotein A, apoB and apoA-I levels.
RESULTS: Overall, AP was detected in 326 subjects (70%) and 37% of these subjects (n=174) had AP thicker than 4mm. After adjusting for other significant predictors of atherosclerosis including age, gender, hypertension, smoking and alcohol consumption, apoB/AI ratio emerged as the strongest determinant of AP (odds ratio [OR] 16.0 per 1 mg/dl increment, p=0.001), followed by HDL cholesterol (OR 0.96 per 1 mg/dl increment, p=0.003) and TG level (OR 1.01 per 1 mg/dl increment, p=0.001). Neither LDL cholesterol nor lipoprotein lp(a) levels were significantly associated with AP. Only apoB/A-I and HDL cholesterol level were significant for predicting AP thicker than 4mm, which carry higher stroke risk. Parallel analyses comparing quartile extremes and separate analyses in subgroups of stroke patients or healthy controls revealed similar findings.
CONCLUSIONS: These observations add to the published data suggesting that the cholesterol balance determined as the ApoB/A-I ratio and HDL is strongly associated with degree of proximal aortic atherosclerosis. and may be better targets of lipid-lowering treatment strategies than LDL cholesterol.