Effect of pitavastatin treatment on changes of plaque volume and composition according to the reduction of high-sensitivity C-reactive protein levels

Background: There are few data regarding the effect of statins on regression and compositional changes of plaque according to the reduction in high-sensitivity C-reactive protein (hs-CRP) levels in acute myocardial infarction (AMI) patients. Methods: We used serial virtual histology-intravascular ultrasound to assess the efficacy of pitavastatin (dosage: 2. mg/day) on plaque regression and compositional changes according to the degree of reduction in hs-CRP levels from baseline to follow-up [≥1. mg/dl (n= 62) vs. <1. mg/dl (n= 32)] in non-intervened non-infarct related artery in AMI patients who were enrolled in the Livalo in acute myocardial infarction study (LAMIS). Results: Total atheroma and percent atheroma volumes decreased more significantly in patients with reduction in hs-CRP ≥1mg/dl compared with those with reduction in hs-CRP <1mg/dl (-1.7±12.4mm³ vs. +2.7±7.8mm³, p<0.015, and -0.4±3.4% vs. +0.4±4.8%, p<0.001, respectively). Absolute and %necrotic core volumes decreased more significantly in patients with reduction in hs-CRP ≥1mg/dl compared with those with reduction in hs-CRP <1mg/dl (-0.4±3.5mm³ vs. +1.9±3.4mm³, p=0.038, and -1.1±4.9% vs. +2.7±4.7%, p=0.016, respectively). Reduction in hs-CRP ≥1mg/dl at follow-up was the independent predictor of reduction of percent atheroma volume and %necrotic core volume at follow-up [odds ratio (OR), 2.228; 95% confidence interval (CI), 1.390-2.977, p=0.016, and OR, 2.204; 95% CI, 1.512-2.916, p=0.020, respectively]. Conclusions: Reduction in hs-CRP levels in AMI patients plays an important role in the beneficial effects of statins on the regression and compositional change of coronary plaque.