Abstract 15066: Erythrocyte-Rich Thrombi Aspirated from Patients with ST-Elevation Myocardial Infarction Influence Oxidative Stress and Predict Long-Term Mortality
Background: Recent studies have demonstrated erythrocytes are a potential component in atheromatous lesions and thrombus formation in patients with ST-elevation myocardial infarction (STEMI). The aim of this study was to determine the association between the red blood cell (RBC) component of coronary thrombi and oxidative stress, angiographic outcome and long-term mortality.
Methods: Aspirated thrombi from 178 STEMI patients within 12 hours of symptom onset were investigated immunohistochemically using antibodies against platelets, RBCs, fibrin, macrophages and neutrophils [myeloperoxidase (MPO)]. The thrombi were divided into three types according to their RBC component: Low group (RBC-positive area <0.3 mm2; n=60), intermediate group (<1.7 to 0.3 mm2; n=59) and high group (≥1.7 mm2; n=59). We also measured the plasma levels of MPO and oxidized low-density lipoprotein (ox-LDL) on admission.
Results: Plasma MPO and ox-LDL levels (median [interquartile range]) were significantly higher in the high-RBC group than in the other two groups (MPO: low, 49.8 [30.1–74.3]; intermediate, 50.8 [29.6–103.9]; high, 80.6 [51.8–126.6] ng/ml, P<0.005; ox-LDL: low 0.64 [0.40–1.05]; intermediate, 1.04 [0.50–1.86]; high, 1.07 [0.58–2.12] ng/5μg LDL protein, P<0.001). Quantitative analysis demonstrated the percentage of MPO-positive neutrophils in the high-RBC group was significantly greater than that in the low-RBC group (low, 20.2±15.6% intermediate, 32.1±17.9% high, 38.6±15.6% P<0.0001). The angiographic results showed that visible distal embolizations after PCI were seen more frequently in the high-RBC group than in the low-RBC group (P<0.005). Kaplan-Meier survival analysis demonstrated the high-RBC group had significantly worse mortality (P=0.005). Moreover, multivariate analysis demonstrated that the presence of a high-RBC thrombus was an independent determinant of long-term mortality (hazard ratio, 4.67; 95% confidence interval, 1.63–13.37, P=0.004).
Conclusions: This study demonstrated that RBC-rich thrombi may play a role in generating excessive production of pro-oxidants, thereby potentially increasing mortality in patients with STEMI.
- © 2010 by American Heart Association, Inc.