Abstract 2549: Natural Course of Lipid-rich Plaques Assessed with Combination of Intra-vascular Ultrasound and Optical Coherence Tomography

Abstract

Background Identification of coronary lesions with morphological characteristic of “rupture-prone plaques” is not sufficient. We examined the natural history of non-culprit lipid-rich plaques in patients with acute coronary syndrome (ACS). Methods Fifty patients with ACS who underwent percutaneous coronary intervention (PCI) were enrolled. We retrospectively assessed the extent of residual non-culprit lipid-rich plaques and these fibrous cap thickness (FCT) by use of intra-vascular ultrasound (IVUS) and optical coherence tomography (OCT), respectively, at baseline and after 9-months. Results During 9 months follow-up periods, the change in percent area volume (PAV) was 0.42±0.6% and the change in FCT was 14±12%. Percent change in PAV showed a significant positive correlation with percent LDL-C reduction (R=0.52, P<0.01). In contrast, the change in FCT demonstrated no correlation with LDL-C level, but had a significant positive correlation with percent change in high sensitive CRP (R=0.60, P<0.01). And between PAV and FCT changes, no significant correlation was observed. Furthermore, in a multivariable analysis including age, sex, diabetes mellitus, hypertension, several concomitant drugs, only statin-use was the independent predictor for changing well-stabilized plaques, which obtained both PAV reduction and FCT increase. Conclusion The change in PAV and in FCT of coronary plaques during 9-months was related to the two different independent factor (reduction rate of LDL-C and high sensitive CRP, respectively). Furthermore, lipid lowering therapy by use of statin has a potential to stabilize them by both plaque reduction and fibrous cap thickening.