Plasma lipoprotein-associated phospholipase A2(Lp-PLA2) activity is related to plaque stability and the potential biomarker for ACS: Lp-PLA2 as a biomarker for ACS

Abstract

Plasma Lipoprotein-associated phospholipase A2 (Lp-PLA2), an enzyme expressed in atherosclerotic plaques, is bound to LDL in the circulation. Plasma Lp-PLA2 activity reflects the plaque burden, is associated with vulnerable plaque rupture, and is upregulated in acute coronary syndrome(ACS). We investigated the predictive value of Lp-PLA2 activity and it might be the potential biomarker for ACS. We classified 226 participants into three groups by their clinical presentation: coronary artery without significant stenotic lesion(control); stable angina(SA); and ACS which included unstable angina and myocardial infarction. Plasma Lp-PLA2 activity and hs-CRP levels were significantly greater in the ACS groups than in SA(p=0.044 and p=0.029, respectively) and greater(but not significantly so) than in controls. Multivariate logistic regression analysis revealed that plasma Lp-PLA2 activity was significantly associated with ACS (odds ratio=1.047, p=0.013). The addition of Lp-PLA2 to the ACS model significantly increased the global χ2 value over traditional risk factors(from 28.14 to 35.602, p=0.006). Areas under the ROC curve for Lp-PLA2 was 0.624(p=0.004). The addition of plasma Lp-PLA2 activity to serum hs-CRP concentration yielded an integrated discrimination improvement(IDI) of 0.0368(p=0.0093, SE 0.0142) and net reclassification improvement(NRI) of 0.0854(p=0.2046, SE 0.0673). The addition of plasma Lp-PLA2 activity to serum hs-CRP concentration improved the ability to predict ACS, therefore which the addition of plasma Lp-PLA2 activity to serum hs-CRP improved the ability to predict ACS.In conclusion, plasma Lp-PLA2 activity is related to plaque stability and might be a predictive biomarker for vulnerable plaques in patients with ACS.