Apoprotein B, Small‐Dense LDL and Impaired HDL Remodeling Is Associated With Larger Plaque Burden and More Noncalcified Plaque as Assessed by Coronary CT Angiography and Intravascular Ultrasound With Radiofrequency Backscatter: Results From the ATLANTA I Study

Abstract

BACKGROUND: Apoprotein B-containing lipoproteins are atherogenic, but atheroprotective functions of apoprotein A-containing high-density lipoprotein (HDL) particles are poorly understood. The association between lipoproteins and plaque components by coronary computed tomography angiography (CTA) and intravascular ultrasound with radiofrequency backscatter (IVUS/VH) has not been evaluated. METHODS AND RESULTS: Quantitative, 3-dimensional plaque measurements were performed in 60 patients with CTA and IVUS/VH. Apoproteins, lipids, and HDL subpopulations were measured with 2-dimensional (2D) gel electrophoresis, and correlation was assessed with univariate and multivariable models. ApoB particles were associated with a higher proportion of noncalcified plaque (NCP) and a lower proportion of calcified plaque (small, dense low-density lipoprotein cholesterol and high-density NCP: r=0.3, P=0.03; triglycerides and low-density NCP: r=0.34, P=0.01). Smaller, dense, lipid-poor HDL particles were associated with a shift from calcified plaque to NCP on CTA (α3-HDL% and low-density NCP: r=0.32, P=0.02) and with larger plaque volume on IVUS/VH (α4-HDL%: r=0.41, P=0.01; α3-HDL%: r=0.37, P=0.03), because of larger dense calcium (α4-HDL%: r=0.37, P=0.03), larger fibrous tissue (α4-HDL%: r=0.34, P=0.04), and larger necrotic core (α4-HDL%: r=0.46, P<0.01; α3-HDL%: r=0.37, P=0.03). Larger lipid-rich HDL particles were associated with less low-density NCP on CTA (α2-HDL%: r=-0.34, P=0.02; α1-HDL%: r=-0.28, P=0.05), with smaller plaque volume on IVUS/VH (pre-α2-HDL: r=-0.33, P=0.05; α1-HDL%: r=-0.41, P=0.01; pre-α2-HDL: r=-0.33, P=0.05) and with less necrotic core (α1-HDL: r=-0.42, P<0.01; pre-α2-HDL: r=-0.38, P=0.02; α2-HDL: r=-0.35, P=0.03; pre-α1-HDL: r=-0.34, P=0.04). Pre-β2-HDL was associated with less calcification and less stenosis by both modalities. CONCLUSIONS: ApoB and small HDL particles are associated with larger plaque burden and more noncalcified plaque, whereas larger HDL and pre-β2-HDL particles are associated with plaque burden and less noncalcified plaque by both CTA and IVUS/VH.