Abstract 683: Serum Myeloperoxidase/Paraoxonase 1 Ratio Predicts Recurrent Coronary Artery Disease

Abstract

Objective: Myeloperoxidase (MPO) is known as major leukocyte enzyme that oxidizes lipoproteins. High density lipoprotein (HDL) contains paraoxonase 1 (PON1), which hydrolyzes oxidized phospholipids. HDL requires PON1 to attenuate accumulation of lipid peroxides in LDL. We recently reported that serum MPO/PON1 ratio could be used as a useful marker for dysfunctional HDL and showed elevated ratios in patients undergoing recurrent percutaneous coronary intervention (PCI). However, it remains obscure whether serum MPO/PON1 ratio can predict relapsing coronary atherosclerotic lesions after PCI.

Methods and Results: Total 111 patients who had a history of successful PCI were enrolled. Their serum MPO mass and PON1 activities were measured at the time point of enrollment, and they had angiographical follow-up evaluation. Fourteen patients needed repeat-PCI due to restenosis and/or de novo lesions during the follow up period (143±730 days). With the established cut off value of 1.59 based on our previous work, Kaplan-Meier analysis showed significantly higher recurrence rate of coronary lesions which required PCI treatment in patients with higher MPO/PON1 ratio at enrollment than that in patients with lower MPO/PON1 ratio (66.7% vs. 6.0%, p<0.001). High MPO/PON1 ratio was independently associated with recurrent coronary atherosclerotic lesions in multivariate Cox regression analysis after adjusting for age, gender, hypertension, diabetes mellitus, dyslipidemia, and smoking (Hazard ratio 15.8, 95% CI 4.20-59.07, p <0.001), while conventional lipid profiles failed to show any statistical relationships to disease recurrence. In addition, C-index of MPO/PON1 ratio was significantly larger than that of MPO alone, indicating that combination of MPO and PON1 provides greater improvement than single application of MPO in predicting coronary lesions (0.787 vs. 0.719, p<0.05).

Conclusions: This study demonstrated that higher MPO/PON1 ratio (>1.59) could predict future recurrence of coronary lesions after PCI. This ratio could be useful marker for secondary prevention of coronary artery disease.