Impact of Malondialdehyde-Modified Low-Density Lipoprotein on Tissue Characteristics in Patients With Stable Coronary Artery Disease　– Integrated Backscatter-Intravascular Ultrasound Study –

Abstract

Background:Malondialdehyde-modified low-density lipoprotein (MDA-LDL) is considered to play an essential role in plaque destabilization. We aimed to investigate the association between the tissue characteristics of culprit plaque assessed by integrated backscatter (IB)-intravascular ultrasound (IVUS) and the serum MDA-LDL levels in patients with stable coronary artery disease.

Methods and Results:The study group consisted of 179 patients undergoing IB-IVUS during elective percutaneous coronary intervention. Patients were classified into 2 groups based on serum MDA-LDL level: low MDA-LDL group (<102 U/L, n=88) and high MDA-LDL group (≥102 U/L, n=91). Plaques in the high MDA-LDL group had higher %lipid (45.2±12.5% vs. 54.9±14.5%, P<0.001) and lower %fibrosis (43.0±9.1% vs. 36.4±11.4%, P<0.001) than did plaques in the low MDA-LDL group. Lipid-rich plaque (%lipid >60% or %fibrosis <30%) was significantly more frequently found in the high MDA-LDL group than in the low MDA-LDL group (14.3% vs. 39.8%, P<0.001). The incidence of MACE (cardiac death, myocardial infarction and/or hospitalization for heart failure) during 3 years was significantly higher in the high MDA-LDL group than in the low MDA-LDL group (6.6% vs. 15.9%, P=0.02).

Conclusions:Higher MDA-LDL might be associated with greater lipid and lower fibrous content, contributing to coronary plaque vulnerability.