Background: Activation of leukocytes with release of myeloperoxidase (MPO) has been linked to acute coronary disease. To date, studies investigating the diagnostic and prognostic performance of circulating MPO in patients with chest pain (CP) are mainly retrospective, of low size, and lack a cut-off value for MPO. Herein, we prospectively assess the diagnostic and prognostic properties of MPO compared with sensitive troponin I (sTNI) in patients admitted to the emergency room with CP.
Methods and results: One thousand, eight hundred and eighteen consecutive patients (mean age, 61.4±13.5 years; 33.6% female) admitted for CP underwent determination of MPO, sTnI, and B-natriuretic peptide plasma levels at admission and 3 hours and 6 hours thereafter. A cut-off for MPO was defined in 5000 population-based subjects. Baseline MPO levels were elevated in patients with acute myocardial infarction compared with patients with noncoronary CP. For all time-points accuracy of MPO was inferior to sTNI for predicting AMI. The sensitivity of MPO to diagnose AMI at presentation was 73.5% compared with 90.7% for sTNI, and the specificity of MPO was 45.5% as opposed to 90.2%. B-natriuretic peptide levels also failed to demonstrate independent diagnostic information. Both MPO and B-natriuretic peptide were predictive for increased risk of adverse events at 30 days and 6 months, whereas their predictive value was weakened after covariate adjustment.
Conclusions: The data demonstrate that MPO and B-natriuretic peptide fail to provide incremental information for patients with acute onset CP when added to sensitive troponin. However, there is a potential value for both biomarkers as prognostic markers.