Low-Density Lipoprotein and Noncalcified Coronary Plaque Composition in Patients With Newly Diagnosed Coronary Artery Disease on Computed Tomographic Angiography

We sought to determine significant relations between atherogenic lipoproteins and the contribution of calcified plaque (CP), mixed plaque (MP), and noncalcified plaque (NCP) to the total plaque (TP) burden in patients without previous coronary artery disease. From 823 adult patients without previously established coronary artery disease (52% receiving statin therapy, 34% asymptomatic) but with visible coronary plaque on coronary computed tomographic angiography, we obtained segmental CP, MP, NCP, and TP counts from contrast-enhanced, electrocardiographic-gated computed tomography. Multivariate linear regression analysis was used to determine the associations of clinical factors and lipoprotein levels to CP, MP, and NCP counts and CP/TP, MP/TP, and NCP/TP count ratios. Age, male gender, diabetes, smoking, and statin therapy were significantly associated with the CP count (p <0.001, p <0.001, p = 0.049, p = 0.016, and p = 0.003, respectively). Low-density lipoprotein (LDL) cholesterol was significantly associated with MP and NCP counts (all p values ≤0.002). LDL cholesterol was also the only variable to demonstrate significant concurrent relations with CP/TP, MP/TP, and NCP/TP ratios, including an inverse association with CP/TP (p = 0.008) and a positive association with MP/TP (p = 0.032). Analyses using non-high-density lipoprotein cholesterol in place of LDL cholesterol yielded similar results. In conclusion, among the traditional clinical factors used to estimate cardiovascular event risk, LDL cholesterol is associated with an increased MP and NCP burden and is the sole variable that independently predicted relative predominance of CP, MP, and NCP, suggesting a potentially important role for lipoprotein levels in modulating the type of detectable coronary arterial plaque.