title: Changes in membrane glycoproteins of circulating platelets after coronary stent implantation.
abstract: OBJECTIVE
  To evaluate platelet function in patients with coronary stents.
  
  
  METHODS
  A non-randomised control trial in 30 patients who had immediate implantation of Palmaz-Schatz coronary stents because of a suboptimal angioplasty result. All patients received a standardised anticoagulation regimen including intravenous heparin (activated partial thromboplastin time (APTT) 80 to 120 s), oral vitamin K antagonist (target international normalised ratio (INR) of 3.5), and 100 mg aspirin twice daily. Platelet surface expression of glycoprotein IIb-IIIa, activated fibrinogen receptor, and P-selectin as well as binding of von Willebrand factor and fibrinogen were determined by flow cytometry in peripheral venous blood samples collected before the intervention and then daily for 4 days after it. The results were compared with those in 30 patients undergoing elective coronary balloon angioplasty.
  
  
  METHODS
  University hospital.
  
  
  RESULTS
  After coronary stenting surface expression of the activated fibrinogen receptor significantly increased, peaking at day 2 (P < 0.001). Similar results were found for von Willebrand factor binding and P-selectin surface expression, with a maximum at day 2 to 4 after stenting (von Willebrand factor, P < 0.001; P-selectin, P < 0.001). The changes in platelet membrane glycoproteins coincided with a significant drop in peripheral platelet count after stent placement (P < 0.01). No significant change in fibrinogen receptor activity, von Willebrand factor binding, P-selectin surface expression, or platelet count was seen in the control group.
  
  
  CONCLUSIONS
  The present study shows that current anticoagulation treatment is inefficient in suppressing platelet activation in patients with coronary stents and, therefore, might not be the best treatment for reducing the incidence of subacute stent thrombosis.
authors.affiliation: 1. Medizinische Klinik der Technischen Universität München, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Gawaz
authors.forename: F J
authors.initials: FJ
authors.lastname: Neumann
authors.forename: I
authors.initials: I
authors.lastname: Ott
authors.forename: A
authors.initials: A
authors.lastname: May
authors.forename: S
authors.initials: S
authors.lastname: Rüdiger
authors.forename: A
authors.initials: A
authors.lastname: Schömig
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary; D000911:Antibodies, Monoclonal; D001241:Aspirin / Q000627:therapeutic use; D001792:Blood Platelets / Q000378:metabolism*; D003327:Coronary Disease / Q000378:metabolism* / Q000601:surgery* / Q000628:therapy; D005260:Female; D005434:Flow Cytometry; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation; D010976:Platelet Count; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism*; D015607:Stents
chemical_list: D000911:Antibodies, Monoclonal; D010980:Platelet Membrane Glycoproteins; D006493:Heparin; D001241:Aspirin