Abstract
Background: While statin induces plaque regression, its effects, particularly with different doses on plaque virtual histology composition, remain unknown. Methods and Results: In this prospective, randomized, double-blinded study, 40 consecutive statin-naive patients with stable angina requiring percutaneous coronary intervention (PCI) were randomized to 2 arms (20 patients each) receiving 6 months of atorvastatin 10mg or 40mg daily. The primary end-point was (VH-IVUS) changes from baseline to 6 months, as assessed by a core laboratory. Fifty-four VH-IVUS lesions were analyzed from the 10mg group and 57 from the 40mg group. Overall, plaque volume was reduced by 4.28% (–5.10±14.93mm3, P<0.001), absolute VH-IVUS fibrous volume by 10.54% (–4.87±10.74mm3, P<0.001), and relative percentage fibrous component by 3.29±7.84% (P<0.001), while relative percentage dense calcium increased by 1.50±3.08% (P<0.001), and necrotic core by 3.19±7.82% (P<0.001). Beneficial changes were more substantial in the higher dose (40mg) group, with significantly more percentage plaque volume regression (–1.50±3.85% vs. 0.38±4.05% increase in the 10mg group, P=0.014), less relative percentage necrotic core expansion (1.68±7.57% vs. 4.78±7.82% in the 10mg group, P=0.037), and without occurrence of major adverse cardiac events (vs. 6 patients in the 10mg group, P=0.020). Conclusions: In statin-naive patients requiring PCI, 6 months of atorvastatin induced a significant percentage of plaque volume reduction and substantial modification of VH-IVUS composition. In addition, these effects appeared to vary with different doses of atorvastatin, showing significantly better limitation of relative percentage necrotic core expansion at a higher dose. (Circ J 2012; 76: 2662–2672)
