Level and significance of plasma myeloperoxidase and the neutrophil to lymphocyte ratio in patients with coronary artery disease

Inflammation plays a pivotal role in the etiology of coronary artery disease (CAD). Myeloperoxidase (MPO) is a potent inflammatory factor and a critical modulator of coronary inflammation and oxidative stress. The goal of this study was to determine the impact of the plasma MPO (pMPO) level and neutrophil/lymphocyte ratio on the clinical characteristics and outcomes of patients with CAD. Blood samples were collected from 210 patients with underlying chest pain or recent myocardial infarction (MI) prior to coronary angiography in order to measure pMPO levels. The pMPO levels and neutrophil/lymphocyte ratio were correlated with clinical characteristics and outcomes following catheterization. The pMPO level and neutrophil/lymphocyte ratio were higher in patients with recent MI than in patients with CAD (coronary occlusion ≥50%) or without CAD (coronary occlusion <50%). Patients with ST segment elevated MI (STEMI) had a higher neutrophil/lymphocyte ratio relative to patients with non-STEMI. The pMPO level was identified to correlate with the neutrophil/lymphocyte ratio and the need for coronary artery reperfusion by coronary artery bypass surgery or percutaneous coronary intervention. Patients who were taking aspirin had lower pMPO levels and neutrophil/lymphocyte ratio compared with those who were not taking aspirin. The plasma neutrophil/lymphocyte ratio was negatively associated with the left ventricular ejection fraction at baseline and the 30-day follow-up, whereas pMPO showed no correlation. Multivariate analysis indicated that the pMPO level was positively associated with MI, the neutrophil/lymphocyte ratio and coronary intervention. The preoperative use of aspirin was associated with a lower pMPO level and neutrophil/lymphocyte ratio. In conclusion, pMPO is positively associated with MI, the neutrophil/lymphocyte ratio and coronary intervention. The preoperative use of aspirin is associated with a lower pMPO level and neutrophil/lymphocyte ratio. pMPO may serve as a predictor of coronary intervention and as a potential therapeutic target for the reduction of inflammation in patients with CAD.