Plasma lipoprotein-associated phospholipase A2 mass is elevated in STEMI compared to non-STEMI patients but does not discriminate between myocardial infarction and non-cardiac chest pain

Abstract

Background: Plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) mass predicts future cardiovascular events in the non-acute setting. We tested the extent to which Lp-PLA2 is elevated in patients with acute coronary syndrome.

Methods: A total of 231 consecutive patients referred for acute chest pain participated. Of this number, 144 were diagnosed with myocardial infarction (MI; 100 were classified as MI with ST-elevation (STEMI) and 44 as MI without ST-elevation (non-STEMI)). Eighty-seven patients had non-cardiac chest pain. Plasma Lp-PLA2 mass was measured using turbidimetric immunoassay.

Results: Lp-PLA2 mass was not different between MI patients and patients with non-cardiac chest pain (231±72 μg/l vs.243±88 μg/l, p=0.29), and did not relate to MI in age- and sex-adjusted logistic regression analysis (odds ratio per SD increment, 0.92 (95% CI, 0.69-1.23), p=0.58). However, Lp-PLA2 mass was elevated in STEMI compared to non-STEMI patients (246±73 vs. 198±58 ng/ml, p<0.001), and independently predicted STEMI (odds ratio, 2.35 (95% CI, 1.46-3.79), p<0.001). Among MI patients maximal creatine kinase was correlated positively with Lp-PLA2 (r=0.183, p=0.034).

Conclusions: In the acute setting, plasma Lp-PLA2 mass is not elevated in MI patients, although Lp-PLA2 mass appears to relate to the severity of myocardial damage.

Keywords: Acute coronary syndrome; Atypical chest pain; Lipoprotein-associated phospholipase A(2); Non-STEMI; STEMI.