專題討論5:急性冠心症之處置─現今在台灣之挑戰
Management of Acute Coronary Syndrome - Current Challenge in Taiwan

S5-4
Biomarkers for Acute Coronary Syndrome
Jaw-Wen Chen MD
Institute of Pharmacology, Institute of Critical Care Medicine, and Cardiovascular Research Center, National Yang-Ming University School of Medicine, and Taipei Veterans General Hospital, Taipei, Taiwan, ROC

It has been suggested that inflammatory process is not only a major initiator of atherogenesis but also a major contributor to the rupture of atheroma plaque during the onset of critical cardiovascular events including sudden death, acute myocardial infarction, and acute coronary syndrome (ACS). Thus, ACS is an emergent clinical condition of coronary artery disease with the presence of ruptured or vulnerable plaque with or without the formation of thrombosis in coronary trees.

A number of potential risk markers could be proposed as providing prognostic information for patients with ACS. In addition to the traditional risk factors, myocardial injury markers such as CK CK-MB, troponin-I have been used for the risk stratification during the onset of ACS. Besides, elevation in plasma inflammatory biomarkers such as CRP or high sensitivity CRP could not only be related to future cardiovascular events in patients with stable coronary artery disease but also indicate the on-going status of the adverse events in patients with ACS. Recently, BNP and pro-BNP, originally used to identify patients with heart failure, were also used in clinical practice to recognize ACS patients at major risk, providing incremental information respect to the traditional markers.
On the other hand, several markers of platelet aggregation, endothelial dysfunction and vascular thrombosis have been evaluated for ACS. However, it is not clear whether each of the proposed markers may provide incremental predictive information in addition to the traditional and the inflammatory markers mentioned above.

Accordingly, it is still critical to find more laboratory markers with potential clinical and prognostic power to identify the presence of ruptured and more importantly the vulnerable plaque in patients with ACS. Together with the different laboratory indexes that could be easily available, it would be possible to identify those patients at high risk immediately and precisely. Aggravated interventional strategy could then be applied to improve the outcome of these patients.

Current and potential biomarkers for ACS

Current markers
Trponin for severe stenosis and embolization
CRP and IL for complex lesion and vulnerable plaques
BNP and pro-BNP for diffuse coronary atherosclerosis

Potential markers
CD40L, P-SELECTIN for platelet aggregationand thrombosis
MMPs, MPO for myocardial fibrosis and injury, macrophage activation
tPA, PAI-1 for endothelial activation and inflammation