Background: Virtual histology intravascular ultrasound (VH-IVUS) is used to diagnose coronary plaques and evaluate statin therapy. However, in most cases, quantitative changes in plaques have been evaluated in the chronic stage. We evaluated the quantitative and qualitative early effects of 2 statins on coronary lesions using VH-IVUS.
Methods and results: Patients with acute coronary syndrome who underwent emergency percutaneous coronary intervention (PCI) were randomly assigned to receive pitavastatin (n=80; 2 mg/day) or atorvastatin (n=80; 10 mg/day) immediately after PCI. All patients underwent a blood lipid test and VH-IVUS evaluation of non-PCI lesions at admission and after 2-3 weeks of statin administration. After treatment, total cholesterol and low-density lipoprotein-cholesterol (LDL-C) showed significant decreases to similar levels in each group (P<0.001). In the pitavastatin group, the plaque volume index and fibrofatty volume index (FFVI) also decreased significantly. In patients from the pitavastatin group with a dense calcium ratio of < or =10% (n=61), the percentage changes in FFVI and LDL-C were correlated positively (r=0.305, P=0.017), whereas no significant changes were found after treatment in the atorvastatin group.
Conclusions: Fibrofatty composition and plaque volume decreased significantly following treatment with pitavastatin, which suggests that pitavastatin might have a higher affinity for fibrofat compared with atorvastatin.