Use of Intravascular Ultrasound to Compare Effects of Different Strategies of Lipid-lowering Therapy on Plaque Volume and Composition in Patients with Coronary Artery Disease

Background: We studied whether lipid-lowering therapy with atorvastatin (target LDL cholesterol [LDL-C] <100 mg/dL) compared with a moderate treatment regimen that used other lipid-lowering drugs led to a lesser progression of atherosclerosis and to different changes in plaque echogenicity in patients with coronary artery disease.

Methods And Results: This study was a 12-month, open-label, randomized, multicenter trial, which used serial 3D intracoronary ultrasound to calculate plaque volume and plaque echogenicity. After transcatheter therapy, 131 patients were randomized (atorvastatin n=65, usual care n=66). The target plaque had to be a minor lesion (ie, a diameter stenosis of <50% on angiography). After 12 months, mean LDL-C was reduced from 155 to 86 mg/dL in the atorvastatin group and from 166 to 140 mg/dL in the usual care group. Mean absolute plaque volume showed a larger increase in the usual care group compared with the atorvastatin group (usual care 9.6+/-28.1 mm(3), atorvastatin 1.2+/-30.4 mm(3); P=0.191). The hyperechogenicity index of the plaque increased to a larger extent for the atorvastatin group than for the usual care group, with a significant treatment effect for the percent change (atorvastatin 42.2%, usual care 10.1%; P=0.021).

Conclusions: One year of lipid-lowering therapy to <100 mg/dL LDL-C most likely led to a slowdown of plaque growth of minor lesions. The significantly larger increase in plaque hyperechogenicity is most likely due to a change in plaque composition.