Decrease in LDL-C is associated with decrease in all components of noncalcified plaque on coronary CTA

LDL-C reduction has been associated with a decrease in noncalcified plaque (NCP) by serial quantitative coronary CT angiography (CTA). We evaluated the effect of LDL-C reduction on specific components of noncalcified plaque (NCP).

We analyzed 154 patients undergoing serial CTAs (118 men, 60 ± 10 years, interval 4 ± 2 years) with baseline LDL-C≥70 mg/dl. Semi-automated software was used for quantifying plaque components based on CT attenuation in Hounsfield units (HU): 30-75, low attenuation plaque (LAP); 76-130, medium-low attenuation plaque (MLAP); 131-350, medium attenuation plaque (MAP); >350, calcified plaque (CP). Decrease in LDL-C was defined as a reduction >10% of baseline LDL-C. Plaque volume changes were compared between patients with (n = 85) and without (n = 69) LDL-C decrease.

There was interval reduction in total plaque, LAP, MLAP, and MAP volumes in patients with LDL-C decrease vs. patients without LDL-C decrease before and after adjusting for differences between the two groups (all p ≤ 0.001). An increase in CP volume occurred in both groups (p = 0.42).

Decrease in LDL-C was associated with reduction in all components of NCP measured by quantitative CTA. Change in total NCP volume may be the optimal measurement for assessing changes over time of coronary plaque on CTA.