PURPOSE: 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. MATERIALS AND 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) microg/L and (321+/-39) microg/L, respectively] compared with the controls [(127+/-49) microg/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. CONCLUSION: 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.
1-Alkyl-2-acetylglycerophosphocholine Esterase/*blood ; Adult ; Aged ; Aged, 80 and over ; Angina, Stable/*blood/enzymology/*pathology ; Angina, Unstable/*blood/enzymology/pathology ; Coronary Angiography ; Coronary Artery Disease/*blood/enzymology/*pathology ; Female ; Humans ; Male ; Middle Aged

OBJECTIVETo observe and compare perioperative myocardial enzyme changes in 107 patients with congenital (CHD, n = 53), rheumatic (RHD, n = 40) and coronary artery (CAD, n = 14) diseases, and to find whether different diseases can affect the release and recovery of myocardial enzymes after heart operations.

METHODSOn the day before operation and the 1st, 3rd, 5th and the 8th day after operation, the venous blood was taken to measure the release of myocardial enzymes: aspartate aminotransferase (AST), creatine kinase (CK), MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) and LDH-1.

RESULTSAll the enzymes measured before operation in three groups were in the normal range; their release increased abruptly on the 1st day postoperatively to 2 - 15 times of those before operation; on the 3rd day, they recovered to some degrees, and on the 8th day they recovered to normal in all groups except LDH and LDH-1 in rh and CAD groups. Because the aortic cross-clamp time (CCT) had a good positive correlation to the release of myocardial enzymes, those patients whose CCT was over 60 minutes in three groups were compared revealing that the CCT was not different between three groups (P < 0.05). The release of CK, CK-MB and AST was significantly higher in CHD60 group than those in CHD60 and CAD60 groups, they recovered afterwards; while the release of DH and LDH-1 was higher in CAD60 group than those in CAD60 and in CHD60 groups from the 1st day to the 8th day postoperatively.

CONCLUSIONSThe release of all the 5 enzymes measured before operation was in normal range in selected CHD, RHD and CAD patients. The release peak and the recovery order of all enzymes were the same in three groups. The release of CK, CK-MB and AST was higher in CHD60 group than those in RHD60 and CAD60 groups on the 1st day. The release of LDH and LDH-1 was higher in RHD60 group than those in CHD60 and CAD60 groups from the 1st day to the 8th day postoperatively. The shorter the CCT is, the less the release of myocardial enzymes. Using the release of LDH and LDH-1 to evaluate the recovery of myocardial injury after open-heart operations was recommended.

Adolescent ; Adult ; Aspartate Aminotransferases ; blood ; Child ; Coronary Artery Bypass ; Coronary Artery Disease ; blood ; enzymology ; surgery ; Creatine Kinase ; blood ; Creatine Kinase, MB Form ; blood ; Female ; Heart Defects, Congenital ; blood ; enzymology ; surgery ; Humans ; Intraoperative Period ; Isoenzymes ; blood ; L-Lactate Dehydrogenase ; blood ; Male ; Middle Aged ; Myocardium ; enzymology ; pathology ; Rheumatic Heart Disease ; blood ; enzymology ; surgery ; Time Factors