Abstract 11724: Increased Expression and Plasma Levels of Myeloperoxidase are Closely Related to Intracoronary Thrombi Types, Lesion Characteristics and Ventricular Remodeling in Patients with Acute Myocardial Infarction
Background: Myeloperoxidase (MPO), released from activated neutrophils and monocytes, may play a key role in plaque instability. This study investigated whether plasma MPO levels were useful for identifying intracoronary thrombi types and lesion characteristics of patients with acute myocardial infarction (AMI), as determined by coronary angioscopy and left ventricular (LV) remodeling. In addition, we investigated whether MPO-positive cells identified by immunostaining in aspirated thrombi were related to the types of intracoronary thrombi identified by angioscopy.
Methods: Patients (n=49) with ST-segment elevation AMI underwent pre-interventional angioscopy and thrombus aspiration during percutaneous coronary intervention within 24 hours of symptom onset. Plasma MPO levels were measured on admission. Thrombi were defined as coalescent red, white or mixed (white and red), and as either intraluminal superficial or protruding mass. The predominant color of the culprit lesion (yellow or white) was recorded. Aspirated thrombi from 49 AMI patients within 12 hours of symptom onset were investigated immunohistochemically using an antibody against MPO. In addition, left ventriculography was performed at the acute phase and 6 months after AMI, and left ventricular end-diastolic volume was calculated in 43 AMI patients.
Results: Plasma MPO levels were significantly higher in patients with mixed/red thrombi (n=35) than in patients with white thrombi (n=14) (P=0.024). Plasma MPO levels were also significantly higher in patients with yellow plaque (n=42) than in patients with white plaque (n=7) (P=0.01). Nine patients (21%) showed LV remodeling (≥20% increase in end-diastolic volume) 6 months after AMI. Plasma MPO levels were significantly higher in patients with than without remodeling (P=0.04). The number of the MPO-positive cells in the aspirated thrombi were significantly (P=0.024) higher in angioscopic mixed or red thrombi than in white thrombi.
Conclusions: These results demonstrate that increased expression and plasma levels of MPO are associated with angioscopic mixed or red thrombi, yellow culprit plaques and LV remodeling in AMI patients.
- © 2011 by American Heart Association, Inc.