title: Platelet collagen receptor glycoprotein VI as a possible novel indicator for the acute coronary syndrome.
abstract: BACKGROUND
  Platelet collagen receptor glycoprotein VI (GPVI) plays a critical role in acute coronary thrombosis. This prospective study examined the predictive value of GPVI for acute coronary syndromes (ACS) in a large consecutive group of patients with symptomatic coronary artery disease to identify the high-risk cohort with imminent coronary events.
  
  
  METHODS
  We evaluated 1,003 patients with symptomatic coronary artery disease, verified by coronary angiography, and determined the surface expression of GPVI using flow cytometry. In a subgroup of 471 patients, who were treated with aspirin plus clopidogrel for coronary stenting, adenosine disphosphate (20 micromol/L)-induced platelet aggregation was evaluated.
  
  
  RESULTS
  Patients with ACS (n = 485) showed a significantly enhanced GPVI expression compared to patients with stable angina pectoris (SAP; n = 518) (mean fluorescence intensity for ACS 19.8 +/- 5.9; SAP 18.7 +/- 8.5, P = .01). Patients with elevated GPVI levels on admission (GPVI cutoff value > or =18.6 mean fluorescence intensity) had a 1.4-fold relative risk for ACS. Logistic regression analysis showed that an elevated platelet GPVI level may indicate ACS independent of biomarkers of myocardial necrosis including troponin, creatine kinase, and creatine kinase-MB. Patients with increased platelet activation (GPVI expression level > or =18.6) showed significant enhanced residual platelet aggregation despite dual antiplatelet therapy compared to patients with low GPVI levels (P = .028).
  
  
  CONCLUSIONS
  Surface expression of GPVI is enhanced in patients with ACS and indicates an imminent acute coronary event before irreversible myocardial necrosis is evident. High GPVI levels are associated with increased residual platelet aggregation despite antiplatelet therapy. Therefore, GPVI is useful to identify the subgroup of patients with a high risk for coronary stent thrombosis and thromboischemic events.
authors.affiliation: Medizinische Klinik, Klinik für Kardiologie und Kreislauferkrankungen, Eberhard Karls-Universität Tübingen, Tübingen, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Bigalke
authors.forename: Tobias
authors.initials: T
authors.lastname: Geisler
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Stellos
authors.forename: Harald
authors.initials: H
authors.lastname: Langer
authors.forename: Karin
authors.initials: K
authors.lastname: Daub
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kremmer
authors.forename: Peter
authors.initials: P
authors.lastname: Seizer
authors.forename: Andreas E
authors.initials: AE
authors.lastname: May
authors.forename: Stephan
authors.initials: S
authors.lastname: Lindemann
authors.forename: Meinrad
authors.initials: M
authors.lastname: Gawaz
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D006328:Cardiac Catheterization; D015331:Cohort Studies; D017023:Coronary Angiography; D003328:Coronary Thrombosis / Q000097:blood / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000502:physiology; D010980:Platelet Membrane Glycoproteins / Q000032:analysis*; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016019:Survival Analysis
chemical_list: D015415:Biomarkers; D010980:Platelet Membrane Glycoproteins; C098341:platelet membrane glycoprotein VI