Sequential Analysis of Myeloperoxidase for Prediction of Adverse Events After Suspected Acute Coronary Ischemia

Background Myeloperoxidase (MPO) plasma values predict major adverse cardiac events (MACE) in cases of acute coronary syndrome. The effect of serial testing in patients who are suspected for acute coronary ischemia is unclear. Hypothesis We hypothesize that sequential MPO measurement may improve prediction of MACE in patients with suspected acute coronary ischemia. Methods The present prospective observational study examined the prognostic significance of MPO in 917 patients with suspicion of acute coronary syndrome. Blood samples were taken at cardiac catheter laboratory admission and the day after coronary angiography. We recorded patients' mortality, the occurrence of cardiac ischemia, and repeated percutaneous coronary intervention through the next 6 months. Results Mortality among patients with increased MPO plasma levels the day after coronary angiography was increased significantly (P < 0.01). Patients with MPO values above 306.3 pmol/L had a significantly higher incidence of 6-month MACE (P < 0.0001) than patients with lower plasma values. Cox proportional hazards multivariate regression analyses revealed that MPO was an independent marker for MACE after suspected acute coronary ischemia (P = 0.048). However, MPO plasma levels at cardiac catheter laboratory admission showed no prognostic significance. Conclusions In patients with suspected myocardial infarction, MPO levels above 306.3 pmol/L measured 24 hours after onset of symptoms were independent predictors of 6-month mortality and MACE.