Yonsei Med J.  2014 Nov;55(6):1507-1515. 10.3349/ymj.2014.55.6.1507.

Lipoprotein-Associated Phospholipase A2 Is Related to Plaque Stability and Is a Potential Biomarker for Acute Coronary Syndrome

• Chung H
• Kwon HM
• Kim JY
• Yoon YW
• Rhee J
• Choi EY
• Min PK
• Hong BK
• Rim SJ
• Yoon JH
• Lee SJ
• Park JK
• Kim MH
• Jo M
• Yang JH
• Lee BK

• KMID: 2070197
• DOI: http://doi.org/10.3349/ymj.2014.55.6.1507

Abstract

PURPOSE
Plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) binds to low-density lipoprotein. The levels of Lp-PLA2 reflect the plaque burden, and are upregulated in acute coronary syndrome (ACS). We investigated the diagnostic value of Lp-PLA2 levels and found that it might be a potential biomarker for ACS.
MATERIALS AND METHODS
We classified 226 study participants into three groups: patients without significant stenosis (control group), patients with significant stenosis with stable angina (SA group), and patients with ACS (ACS group).
RESULTS
Lp-PLA2 and high-sensitivity C-reactive protein (hs-CRP) levels were significantly greater in the ACS group than in the SA group (p=0.044 and p=0.029, respectively). Multivariate logistic regression analysis revealed that Lp-PLA2 levels are significantly associated with ACS (odds ratio=1.047, p=0.013). The addition of Lp-PLA2 to the ACS model significantly increased the global chi2 value over traditional risk factors (28.14 to 35.602, p=0.006). The area under the receiver operating characteristic curve for Lp-PLA2 was 0.624 (p=0.004). The addition of Lp-PLA2 level to serum hs-CRP concentration yielded an integrated discrimination improvement of 0.0368 (p=0.0093, standard error: 0.0142) and improved the ability to diagnose ACS.
CONCLUSION
Lp-PLA2 levels are related to plaque stability and might be a diagnostic biomarker for ACS.

Keyword

Lp-PLA2; acute coronary syndrome; biomarker; coronary atherosclerotic plaque instability

MeSH Terms

1-Alkyl-2-acetylglycerophosphocholine Esterase/*blood
Acute Coronary Syndrome/*blood/physiopathology
Aged
Aged, 80 and over
Angina Pectoris
Biological Markers/blood
C-Reactive Protein/*metabolism
Coronary Angiography
Female
Humans
Lipoproteins, LDL/*blood
Logistic Models
Male
Middle Aged
Multivariate Analysis
Plaque, Atherosclerotic/blood
ROC Curve
Risk Factors
1-Alkyl-2-acetylglycerophosphocholine Esterase
Biological Markers
Lipoproteins, LDL
C-Reactive Protein

Figure

• 

  Fig. 1 Lp-PLA2 and hs-CRP levels in each group. (A) Levels of Lp-PLA2 and CRP in control, SA, and ACS groups. In Lp-PLA2, p=0.040, compared with SA group. In CRP, p=0.044, compared with control group. (B) Levels of Lp-PLA2 and CRP in ACS group including UA and AMI groups. Lp-PLA2, lipoprotein-associated phospholipase A2; SA, stable angina; ACS, acute coronary syndrome; hs-CRP, high-sensitivity C-reactive protein; UA, unstable; AMI, acute myocardial infarction.

• 

  Fig. 2 Bar chart comparing global χ2 values with three models for diagnosis of ACS. CRP had incremental value over traditional risk factors (Model I vs. Model II: 18.413 vs. 28.14, incremental global χ2 value: 9.727, p=0.002), and Lp-PLA2 level had incremental value over traditional risk factors and CRP (Model II vs. Model III: 28.14 vs. 35.602, incremental global χ2 value: 7.462, p=0.006). ACS, acute coronary syndrome; CRP, C-reactive protein; Lp-PLA2, lipoprotein-associated phospholipase A2.

• 

  Fig. 3 Receiver operating characteristic (ROC) curves. ROC curve for Lp-PLA2. (A) Area under the ROC curve for Lp-PLA2 was 0.624 [95% confidence interval (CI): 0.542-0.706, p=0.004]. ROC curve for hs-CRP. (B) Area under the ROC curve for hs-CRP was 0.673 (95% CI: 0.594-0.752, p=0.000). (C) ROC curves for Lp-PLA2 (green line), hs-CRP (red line), and Lp-PLA2+hs-CRP (blue line). Area under the ROC curve for Lp-PLA2+hs-CRP was 0.695 (95% CI: 0.618-0.772). Lp-PLA2, lipoprotein-associated phospholipase A2; hs-CRP, high-sensitivity C-reactive protein.

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