Abstract 684: Intensive Statin Therapy Decreases Lipid-Rich Coronary Plaques as Detected by 64-Slice Computed Tomographic Angiography
Computed tomography (CT) densities within coronary plaques measured by multislice CT have been shown to reflect plaque components. We evaluated an effect of statin therapies on characteristics of non-calcified coronary atherosclerotic lesions (NCALs) defined by CT density. We studied 92 consecutive stable patients (67 men, age 67 ± 9 years) with at least one NCAL detected by 64-slice CT angiography (CTA). We excluded patients with previous coronary revascularization procedures. Each NCAL (size >1-mm2, density <120HU) was evaluated with the minimum CT density (ROI = 1-mm2). NCALs with <40HU were considered as lipid-rich based on our previous report. We examined drug uses (intensive statins [IS; atorvastatin or rosuvastatin], non-intensive statins [NS; pravastatin or simvastatin], ACE inhibitors or ARB, and aspirin) continuing for >6-months before CTA in each patient. There were no significant differences in the patient’s characteristics and drug uses except for statin among the three groups classified by statin use (IS: n = 21, NS: n = 23, and no statin: n = 48). Serum LDL-cholesterol level (90 ± 18 vs. 115 ± 30 vs. 122 ± 34 mg/dl, p = 0.0005) and LDL/HDL-cholesterol ratio (1.6 ± 0.5 vs. 2.3 ± 0.7 vs. 2.5 ± 1.1, p = 0.002) were lower in the IS group than the others. A total of 191 NCALs (lipid-rich; 91 lesions) were detected by CTA. The number of all NCALs per patient was similar among the three groups (2.0 ± 0.9 vs. 2.1 ± 1.2 vs. 2.1 ± 1.0), while that of lipid-rich NCALs per patient was lower in the IS group than the others (0.5 ± 0.6 vs. 1.2 ± 0.9 vs. 1.1 ± 0.9, p = 0.01). On multivariate analysis regarding age, gender, coronary risk factors, and drug uses, the IS use was only significant predictor for decreasing lipid-rich NCALs (coefficient value −0.46, 95% CI −0.78– −0.14, p = 0.006). Otherwise, among the three groups classified by the number of lipid-rich NCALs per patient (absence: n = 26, one: n = 46, and ≥2: n = 20), the difference of LDL/HDL-cholesterol ratio was most significant (1.9 ± 0.6 vs. 2.1 ± 0.9 vs. 2.9 ± 1.1, p = 0.0004). Our CT findings support the concept that intensive statin therapy stabilizes lipid-rich coronary plaques. LDL/HDL-cholesterol ratio is most strongly related to lipid-rich NCALs on CTA.