Lipoprotein-associated Phospholipase A2, Lp-PLA2, and Age, are Predictors for Future Cardiovascular Events in Acute Coronary Syndrome Patients

Aims: We investigated whether Lp-PLA2 activity of blood samples collected 24 h after hospital admission could serve as a predictor of future cardiovascular events in Vietnamese patients with acute coronary syndrome (ACS). In addition, we correlated Lp-PLA2 with common risk factors of ACS, such as age, HDL, diabetes, BMI, etc. and compared Lp-PLA2 levels of ACS patients with those of a control group.

Methods and Results: Lp-PLA2 activity was measured in serum collected in fasting state within 24 h of hospitalization in 293 ACS patients. The mean [SD] of Lp-PLA2 activity (nmol/min/mL) was higher in ACS patients than in controls (212.7[57.8] versus 182.5[58], p<0.001), the mean difference was 14.2% of mean in ACS group. Both non-ST elevated myocardial infarction (NSTEMI) and STEMI had higher Lp-PLA2 compared to unstable angina (UA) (p<0.017). The 3rd tertile of Lp-PLA2 had a strong correlation with MI (NSTEMI/STEMI) showing ORs of 3.65 and 3.98 in logistic regression analysis compared to the 2 lower tertiles. There were only two factors, Lp-PLA2 and age, serving as best independent predictors for future CV events in multivariate HR analysis. However their effects strongly began to start around 50 days after acute phase of ACS. The future CV event rates had an increasing trend from 1st to 3rd tertile (ptrend=0.011). The HR between 2nd to 1st tertile was 1.71 (p=0.075). The 3rd tertile had nearly a double of adjusted hazard ratio (HR) as 1.92 compared to the 1st tertile (p=0.029). There was weak association of Lp-PLA2 activity with risk factors of CV diseases.

Conclusion: Lp-PLA2 in acute phase of ACS was different between 3 groups of ACS. Both Lp-PLA2 and age were independent predictors for future cardiovascular events in ACS patients.