Abstract 10924: Soluble Amyloid Precursor Protein 770 is a Novel Marker for Diagnosis of Acute Coronary Syndrome
Background: Developing biomarker to facilitate diagnosis of acute coronary syndrome (ACS) is desired in clinical practice. ACS is a prevalent syndrome, which is caused by endothelial injury, plaque disruption, platelet activation, and thrombus formation. It has been reported that soluble Amyloid Precursor Protein (APP) 770 is expressed in vascular endothelial cells and is produced rapidly by the degranulation from the activated platelets. However, it is unclear whether sAPP770 is useful to identify patients with ACS.
Methods and Results: We performed kinetic analysis in rat myocardial infarction (MI) model. MI was created by ligation of the left coronary artery. Rats with sham surgery were served as control. Blood samples were collected from MI and sham rats at 0, 1, 2, and 3 hours after surgery, and levels of plasma sAPP770, cardiac troponin-I and creatine kinase were measured. At one hour after coronary ligation, we observed about 4-fold increase of plasma sAPP770 as compared with that in sham rats. Moreover increase of plasma sAPP770 was earlier than increases of cardiac troponin-I and creatine kinase. Since sAPP770 is released from activated platelets, increase of plasma sAPP770 preceded myocardial injury. We then moved to clinical study. In this study, 52 patients with ACS, 105 patients with stable angina pectoris (SAP) and 23 age-matched control subjects were enrolled. We measured circulating levels of sAPP770 in the peripheral blood samples. Levels of plasma sAPP770 were significantly higher in ACS group than in other groups (ACS 160.3 ± 68.4 ng/ml vs. SAP 135.2 ± 76.3, P<0.05, and control 99.7 ± 56.4, P<0.01).
Conclusions: SAPP770 can be a novel marker for diagnosis of ACS.
- © 2012 by American Heart Association, Inc.