Abstract 16064: Effect of Intensive versus Moderate Lipid-Lowering Therapy on the Progression of Coronary Lipid-Rich Plaque: A Prospective, Randomized, Serial Combined Optical Coherence Tomography and Intravascular Ultrasound Study

Abstract

Background: Despite dramatic improvements in clinical outcome, intravascular ultrasound (IVUS) trials have shown minimal improvement of atheroma volume with statin therapy. Changes in plaque composition rather than plaque volume may contribute to the marked clinical benefit. Objectives: To assess the effect of intensive versus moderate lipid-lowering therapy on fibrous cap thickness (FCT) by optical coherence tomography (OCT) and percent atheroma volume (PAV) by IVUS. Methods: The patients with ≥1 non-treated lipid-rich plaque (LRP) with moderate stenosis were randomized to receive atorvastatin 60 mg (AT60), or atorvastatin 20 mg (AT20). OCT and IVUS imaging were performed at baseline, 6 months and 12 months. The primary endpoint was the change in FCT. The secondary endpoints were the change in PAV and the percent change in normalized total atheroma volume (%NTAV). Sixty-six LRP in 46 patients defined by OCT were studied. Results: Low-density lipoprotein cholesterol (LDL-C) was reduced significantly in both groups at 6 months; however, there was no further reduction at 12 months (Fig A, C). OCT demonstrated a continuous increase in FCT over time in both groups, with greater increase in the AT60 group than the AT20 group at 6 months (139.7±160.9% vs. 68.1±83.9%, p=0.021) and 12 months (211.3±125.4% vs. 120.2±136.9%, p<0.0001) (Fig B, D). IVUS showed no significant changes in PAV and NTAV over time in two groups. The changes in PAV were similar between the two groups at 6 months (-0.48±3.4% in AT60 vs. 0.28±5.2% in AT20, p=0.50) and 12 months (-0.26±4.3% vs. 0.11±4.1%, p=0.73). %NTAV were also comparable between the two groups at 6 months and at 12 months. Conclusions: Intensive atorvastatin therapy induces more rapid and effective stabilization of coronary lipid-rich plaques by increasing FCT, as compared with moderate atorvastatin therapy. IVUS analysis did not show significant change in plaque volume over time in both groups.