Abstract 21108: Impaired HDL Metabolism and Remodeling is Associated with More Vulnerable Coronary Plaque Phenotype as Assessed by Quantitative Contrast-Enhanced CT Coronary Angiography
Background:. HDL particles are protective against atherosclerosis. Adequate maturation of smaller HDL particles to larger, cholesterol-rich HDL particles is critical for reverse cholesterol transport to counteract atherosclerosis. The correlation between HDL-subclass profile and plaque volume and composition by coronary CTA is unknown.
Methods: 57 patients (mean age: 61±7; 58% men) prospectively underwent coronary CTA on a 32×2 system with helical acquisition using retrospective gating and 0.6 mm collimation. Plaque volume, and % of calcified plaque (%CAP; >150 HU), low-density non-calcified plaque (%LD-NCP; −100 to 30 HU) and high-density non-calcified plaque (%HD-NCP; 30–150 HU) were measured. LD-NCP is presumed most lipid-rich. HDL-C was measured by standard enzymatic methods, apolipoprotein A-I by immuno -turbidometry and HDL subclasses by two-dimensional native gel electrophoresis, immunoblotting, and image analysis (2dPAGE). Relationship between lipoproteins and plaque parameters were assessed by linear correlation.
Results: Correlation between lipoproteins and plaque parameters are shown in the Table. Higher HDL-C levels were associated with lower %LD-NCP on lesion analysis by CTA. The larger, more mature HDL particles (α-1 and α-2) were associated with lower %LD-NCP. Smaller, less mature HDL particles (α-3 and α-4) were associated with a higher %LD-NCP (Figure). Preβ2-HDL was associated with less calcified volume and less stenosis.
Conclusions: This is the first demonstration using quantitative CTA analysis and 2dPAGE that impaired HDL metabolism is associated with a higher %LD-NCP, presumably the lipid-rich component.
- © 2010 by American Heart Association, Inc.