Utility of myeloperoxidase in the differential diagnosis of acute coronary syndrome.

OBJECTIVES To determine the usefulness of myeloperoxidase in discriminating between patients with acute coronary syndrome and patients with chest pain by other causes. METHODS The study included all patients over 18 years of age who come consecutively to the emergency department from September 2015 to December 2015 with chest pain of non-traumatic origin. The initial patient evaluation was performed according to the study protocol for patients with suspected acute coronary syndrome (ACS) in our Emergency Department. This included the serial measurement of troponin, and in this case myeloperoxidase, with serialization on admission and at 6h. For the determination of myeloperoxidase (MPO), a single step sandwich enzyme immunoassay by Siemens, automated on a Dimension analyser, was used. RESULTS Statistically significant differences were observed in the concentration of myeloperoxidase at time 0 among patients diagnosed with ACS: 505 (413)pmol/L, and non-ACS patients: 388 (195)pmol/L (p<.001), as well as at 6h (p<.001). An area under the curve ROC of 0.824 was obtained at 6h for ACS patients, with a confidence interval of 95% from 0.715 to 0.933 and a level of significance of p<.001. Statistically significant differences were also found in the concentration of myeloperoxidase at time 0 and at 6h among patients with ACS and patients with heart disease other than coronary artery disease. CONCLUSIONS The concentration of MPO helps to differentiate between ACS and non-ACS patients, as well as between ACS patients and patients with heart diseases other than coronary artery disease.