Effects of Statin Treatments on Coronary Plaques Assessed by Volumetric Virtual Histology Intravascular Ultrasound Analysis

Objectives: We evaluated the effects of statin treatments for each component of coronary plaques. Background: Effects of statin treatments on coronary plaques have not been sufficiently evaluated. Methods: One hundred patients without significant lesion stenosis underwent baseline and 12-month follow-up virtual histology (VH) intravascular ultrasound (IVUS) studies and were treated with statin for 1 year. They were randomized to simvastatin (20 mg/day, n = 50) or rosuvastatin (10 mg/day, n = 50). With VH-IVUS, plaque was characterized as fibrotic, fibrofatty, dense calcium, and necrotic core. Results: In overall patients, necrotic core volume significantly reduced (15.7 to 13.7 mm³, p = 0.010) and fibrofatty plaque volume increased (4.3 to 5.5 mm³, p = 0.006) after statin treatments for 1 year. There were no significant differences of changes in either plaque component volume between simvastatin- and rosuvastatin-treated subgroups. In serial comparisons during 1-year follow-up, simvastatin treatment did not achieve statistically significant changes in fibrofatty plaque (4.1 to 5.1 mm³, p = 0.131) and necrotic core volume (15.8 to 14.4 mm³, p = 0.216). However, there was a significant decrease in necrotic core volume (15.5 to 13.0 mm³, p = 0.015) and an increase in fibrofatty plaque volume (4.5 to 5.9 mm³, p = 0.017) in the rosuvastatin-treated subgroup. Conclusions: Serial volumetric VH-IVUS analysis showed that statin treatments might be associated with significant changes in necrotic core and fibrofatty plaque volume in overall patients. The changes in both plaques' component volume were not statistically different between simvastatin- and rosuvastatin-treated subgroup.