title: [Effect of early high-loading-dose tirofiban on platelet activity in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention].
abstract: OBJECTIVE
  To investigate the effect of early high-loading-dose tirofiban on platelet activity for patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention.
  
  
  METHODS
  A total of 120 acute STEMI patients were treated with 300 mg aspirin and 600 mg loading dose clopidogrel and randomized to high-dose tirofiban (25 µg/kg bolus followed by 0.15 µg×kg(-1)×min(-1) infusion for 36 hours, n = 40), standard-dose tirofiban (10 µg/kg bolus followed by 0.15 µg×kg(-1)×min(-1) infusion for 36 hours, n = 40) or control (no tirofiban, n = 40) before angiography. Inhibition of platelet aggregation (IPA) was assessed before angiography, at 10 min and 24 hours after tirofiban infusion, and at 12 and 24 hours after stopping tirofiban infusion by the thrombelastography assay.
  
  
  RESULTS
  There was no significant difference in baseline of IPA between the 3 groups (P > 0.05). IPA was significantly higher in high-dose tirofiban group compared with standard-dose tirofiban and no tirofiban group at 10 minutes after tirofiban infusion [(84.2 ± 12.0)% vs. (67.8 ± 26.8)% and (31.5 ± 21.9)%, all P < 0.01]. At 24 hours after tirofiban infusion, the IPA of high-dose and standard-dose tirofiban was similar [(93.0 ± 9.8)% vs. (88.5 ± 18.1)%, P > 0.05] and was significantly higher than no tirofiban group [(40.4 ± 22.8)%, all P < 0.01]. IPA was similar at 12 and 24 hours after stopping tirofiban use among the 3 groups (all P > 0.05). The maximum amplitude of high-dose tirofiban and standard-dose tirofiban groups at different time points was similar (all P > 0.05), and maximum amplitude in both tirofiban groups was significantly lower than in no tirofiban group at 10 min [(47.2 ± 7.6) mm and (50.0 ± 9.8) mm vs. (57.7 ± 6.5) mm, all P < 0.01] and at 24 hours after stopping tirofiban infusion [(54.6 ± 5.6) mm and (54.3 ± 9.0) mm vs. (59.6 ± 4.0) mm, all P < 0.01].
  
  
  CONCLUSIONS
  Early use of high-loading-dose of tirofiban on top of 600 mg loading dose clopidogrel is more efficient on inhibiting platelet activity than standard dose of tirofiban in patients with acute STEMI undergoing primary primary percutaneous coronary intervention.
authors.affiliation: Capital Medical University, Beijing, China.
authors.forename: Xiao-nan
authors.initials: XN
authors.lastname: Ren
authors.forename: Le-feng
authors.initials: LF
authors.lastname: Wang
authors.forename: Ming-sheng
authors.initials: MS
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Xu
mesh_terms: D000368:Aged; D001792:Blood Platelets; D004638:Emergency Treatment; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology*; D062645:Percutaneous Coronary Intervention; D015539:Platelet Activation; D010974:Platelet Aggregation; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D000077466:Tirofiban; D016896:Treatment Outcome; D014443:Tyrosine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D010975:Platelet Aggregation Inhibitors; D014443:Tyrosine; D000077466:Tirofiban