Background: The aim of this study was to elucidate the time course of atorvastatin-induced changes in vulnerable plaque using angioscopy and intravascular ultrasound (IVUS).
Methods and results: Fifty-seven hypercholesterolemic patients with coronary artery disease (CAD) were treated with atorvastatin (10-20 mg/day) for 80 weeks and then coronary plaques were evaluated with angioscopy and IVUS. Angioscopic images were classified into 6 grades (0-5) based on yellow color intensity. A 20-mm segment containing angioscopically-identified yellow plaque was also examined by IVUS to measure atheroma volume. The mean angioscopic grade of 58 yellow plaques significantly decreased from 1.5 (95% confidence interval [CI] 1.2 to 1.8) to 1.1 (95%CI 0.9 to 1.3, P=0.012) at week 28 and 1.2 (95%CI 0.9 to 1.4, P=0.024) at week 80. Mean volume of 30 lesions, including the 58 yellow plaques, significantly reduced -8.3% (95%CI -11.5 to -5.2) at week 28 (P<0.001 for baseline vs week 28) and -17.8% (95%CI -23.9 to -11.8) at week 80 (P<0.001 for baseline vs week 80).
Conclusions: In patients with CAD treated with atorvastatin, serial analysis with angioscopy demonstrated early loss of yellow color in plaques, and IVUS volumetric analysis showed subsequent plaque regression. Both changes possibly indicate reduction of plaque vulnerability in an additive manner.