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Noncalcified Plaque Decreases with LDL-C Reduction

In patients undergoing serial coronary CT angiography (CTA), decrease in low-density lipoprotein cholesterol (LDL-C) was associated with reduction in all components of noncalcified plaque (NCP) measured by quantitative CTA. The study included 154 patients (118 men, age 60±10 years) undergoing serial CTA with baseline LDL-C ≥170 mg/dL. 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. Among the findings:

  • There was interval reduction in total plaque, low attenuation plaque (LAP), medium-low attenuation plaque (MLAP), and medium attenuation plaque (MAP) volumes in patients with LDL-C decrease vs patients without LDL-C decrease, before and after adjusting for differences between the 2 groups.
  • An increase in calcified plaque (CP) volume occurred in both groups.
  • NCP volume change may be optimal to assess efficacy of statin.

Citation:

Otaki Y, Tamarappoo B, Cadet SJ, et al. Decrease in LDL-C is associated with decrease in all components of noncalcified plaque on coronary CTA. [Published online ahead of print April 9, 2019]. Atherosclerosis. doi:10.1016/j.atherosclerosis.2019.04.201.

Commentary:

Coronary CT angiography (CTA) can identify two types of atherosclerotic plaques. Noncalcified plaques (NCP) tend to be lipid laden plaques that are prone to inflammation and rupture causing acute coronary syndromes. Calcified plaques (CP) are plaques that have healed with a stronger fibrous cap and are less prone to rupture. This study performed serial CTA studies on patients with atherosclerotic plaques and those individuals that had a decrease in LDL-C to an average of 67 mg/dL had a significant reduction in the volume of NCP compared to those with no LDL-C change (average LDL-C 107 mg/dL). Patients with a decrease in LDL-C were more likely to be treated with statins. Both groups showed an increase in calcified plaques suggesting that volume changes in NCP may be a better method of determining statin efficacy than a change in calcium score. Statins may modify plaques in part by reducing the volume of the lipid pool in NCP. —Matthew Sorrentino, MD