The Importance of Age and Statin Therapy in the Interpretation of Lp-PLA2 in ACS Patients, and Relation to CRP

Abstract

C-reactive protein (CRP) is a marker of arterial inflammation while lipoprotein-associated phospholipase A2 (Lp-PLA2) is related to plaque instability. The aim of this study was to evaluate the correlation between the risk of unstable plaque presenting as acute coronary syndrome (ACS) and Lp-PLA2, and to assess the influence of statins on interpretation of Lp-PLA2. A total of 362 consecutive patients presenting to the emergency department (ED) with acute chest pain suggestive of ACS were evaluated by cardiologists as STEMI, NSTEMI, or unstable angina, and non-ACS. Serum biomarkers measured on admission: troponin I, C-reactive protein (Abbott), and Lp-PLA2 (DiaDexus). Four groups were defined according to the final diagnosis and history of statin medication: ACS/statin−; ACS/statin+; non-ACS/statin−; non-ACS/statin+. Lp-PLA2 was highest in ACS/statin− group; statins decreased Lp-PLA2 both in ACS and non-ACS of about 20 %. Lp-PLA2 was higher in ACS patients in comparison with non-ACS patients group without respect to statin therapy (p<0.001). Lp-PLA2 predicted worse outcome (in terms of acute coronary syndrome) effectively in patients up to 62 years; limited prediction was found in older patients. C-reactive protein (CRP) failed to discriminate four groups of patients. Statin therapy and age should be taken into consideration while interpreting Lp-PLA2 concentrations and lower cut-off values should be used for statin-treated persons.