Plaque-Stabilizing Effect of Atorvastatin Is Stronger for Plaques Evaluated as More Unstable by Angioscopy and Intravenous Ultrasound

Background: The aim of this study was to compare the effect of atorvastatin treatment on high-grade yellow coronary plaques (grade ≥2, group H) vs. low-grade yellow plaques (grade ≤1, group L). Methods and Results: Twenty-nine hypercholesterolemic patients with coronary heart disease were treated with atorvastatin (10-20mg/day) for 80 weeks and were divided into 2 groups by baseline plaque color grade. The angioscopic plaque grade and the vessel, plaque, and luminal volumes were measured by intravascular ultrasound at baseline and in weeks 28 and 80. The plaque color grade decreased significantly from baseline to weeks 28 and 80 in group H (2.27±0.48, 1.47±0.75, and 1.55±0.86, respectively), but not significantly in group L (0.90±0.31, 0.83±0.61, and 0.89±0.56, respectively). The plaque volume of group HP was greater than that of group LP (respectively 158.0±45.8 vs. 107.5±21.9mm3 at baseline, 144.5±41.1 vs. 97.5±24.8mm3 in week 28, and 128.8±31.5 vs. 87.9±31.5mm3 in week 80 (P