Association of lipoprotein-associated phospholipase A₂ with characteristics of vulnerable coronary atherosclerotic plaques.
OBJECTIVE
Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) is an inflammatory enzyme expressed in atherosclerotic plaques. We investigated the association of circulating Lp-PLA₂ with characteristics of vulnerable coronary atherosclerotic plaques.


METHODS
We recruited 113 patients with either unstable angina (UA, n=59) and stable angina (SA, n=54) by coronary angiography. Thirty-six healthy subjects served as controls. Intravascular ultrasound (IVUS) was used to evaluate the characteristics of coronary atherosclerotic plaque, and serum Lp-PLA₂ concentration was measured as well.


RESULTS
Lp-PLA₂ concentration was significantly higher in both UA and SA patients [(396±36) μg/L and (321±39) μg/L, respectively] compared with the controls [(127 ± 49) μg/L, p<0.01], and higher in UA than SA group. IVUS findings showed that remodeling index (RI) (0.91 ± 0.15 vs. 0.85 ± 0.11, p=0.005) and eccentricity index (EI) (0.73 ± 0.16 vs. 0.65 ± 0.22, p=0.039) were larger in UA than in SA group, and fibrous caps were thicker in SA than UA group [(0.91 ± 0.23) mm vs. (0.63 ± 0.21) mm, p=0.032]. Moreover, Lp-PLA₂ correlated positively with EI (r=0.439, p<0.01) and RI (r=0.592, p<0.05) in UA group. There was an inverse relationship between Lp-PLA₂ and fibrous cap thickness in both UA (r=-0.587, p<0.001) and SA (r=-0.318, p<0.05) groups. The independent risk factors in UA group were Lp-PLA₂ (OR=1.055, 95% CI: 1.03-1.08, p=0.013), LDL-cholesterol (OR=0.032, 95% CI: 0.00-0.05, p=0.041) and fibrous cap thickness (OR=0.008, 95% CI: 0.00-0.45, p=0.019). Lp-PLA₂ was strongly associated with both EI and fibrous cap thickness in both groups.


CONCLUSIONS
Serum level of Lp-PLA₂ is associated with both eccentricity index and fibrous cap thickness in both UA and SA groups. Elevated levels of circulating Lp-PLA₂ might to be a strong risk factor and more serious for unstable angina than stable angina.
Department of Cardiology, The Second Hospital of Shandong University, Jinan, China. yushengliu2004@yahoo.com.cn
Yu-Sheng
YS
Liu
Xiao-Bo
XB
Hu
Hong-Zhuan
HZ
Li
Wei-Dong
WD
Jiang
Xin
X
Wang
Hao
H
Lin
Ai-Qiong
AQ
Qin
Yong-Mei
YM
Wang
Tong
T
Zhao
Zhao-Qiang
ZQ
Dong
Mei
M
Zhang
Qing-Hua
QH
Lu
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000097:blood*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060050:Angina, Stable / Q000097:blood* / Q000201:enzymology / Q000473:pathology*; D000789:Angina, Unstable / Q000097:blood* / Q000201:enzymology / Q000473:pathology; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000097:blood* / Q000201:enzymology / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase