Abstract 3323: Quantitative Analysis Of Atherosclerotic Plaque Components After Statin Therapy Using Intracoronary Optical Coherence Tomography
[Background] Several clinical trials have suggested that aggressive lipid lowering by statins could stabilize vulnerable plaques of coronary artery and prevent acute coronary events. Fibrous cap thickness might be a major determinant of plaque vulnerability, but conventional imaging modalities were limited to identify thin cap fibroatheroma. Optical coherence tomography (OCT) has recently been proposed as a high-resolution imaging modality, and might allow us to evaluate fibrous cap thickness and lipid-core size in vivo. The purpose of this study was to assess the effect of statin treatment on fibrous cap thickness and lipid-core size in the coronary atherosclerotic plaques by OCT.
[Methods and Results] A total of 35 acute myocardial infarction patients with hyperlipidemia were divided into two groups; statin treatment group (n=20) or diet group (n=15). The tissue characteristics of non-culprit plaque in each patient (1 coronary plaque per patient) were analyzed by OCT at baseline and 9-month follow-up. The LDL-cholesterol level was similar in both groups at baseline (143 +/− 22 vs.153 +/− 41mg/dl, p=0.359), and it was significantly decreased in statin group compared with diet groups after 9-month follow-up (91 +/− 12 vs.132 +/− 18mg/dl, p<0.001). In OCT analysis at baseline, lipid arc (149 +/− 57 vs. 144 +/− 53 degree, p=0.793) and fibrous cap thickness (151 +/− 111 vs. 153 +/− 118 micrometer, p=0.959) were not different between two groups. The lipid arc was significantly diminished (147 +/− 55 vs. 124 +/− 52 degree, p<0.001) and the fibrous cap thickness was significantly increased (152 +/− 115 vs. 229 +/− 123 micrometer, p<0.001) 9-month later compared with those at baseline. At 9-month follow up, the lipid arc in the statin group was significantly smaller than that in the diet group (103 +/− 48 vs. 144 +/− 55 degree, p=0.025) and the fibrous cap thickness in the statin group was significantly thicker than that in the diet group (280 +/− 123 vs. 178 +/− 122 micrometer, p=0.020).
[Conclusions] The lipid-lowering therapy by statin for 9 months significantly reduced the lipid-core size and increased fibrous cap thickness, and OCT might be useful for the quantitative analysis of atherosclerotic plaque components in patients with coronary artery disease.