title: A randomised study comparing the antiplatelet and antiinflammatory effect of clopidogrel 150 mg/day versus 75 mg/day in patients with ST-segment elevation acute myocardial infarction and poor responsiveness to clopidogrel: results from the DOUBLE study.
abstract: BACKGROUND
  The antiplatelet effect of standard or increased clopidogrel doses in patients with ST- segment elevation acute myocardial infarction (STEMI) has never been studied. In this study we compared the antiplatelet effect of a 75 mg daily maintenance dose of clopidogrel with 150 mg in patients with STEMI undergoing primary percutaneous coronary intervention (PCI).
  
  
  METHODS
  Fifty-four patients with STEMI undergoing PCI were randomly allocated to receive either 75 mg/day clopidogrel (group 1) or 150 mg/day (group 2) for 1 month. Platelet function, measured by 5 different assays, was determined at 3 time points: 38+/-8 hours after the procedure, 1 week and 1 month after randomization.
  
  
  RESULTS
  In group 1, mean +/- SD platelet reactivity index (PRI) measured with the VASP assay was 57.7+/-15.7% and 46.9+/-15.7% at 1 week and 1 month, respectively, compared to 38.8+/-15.7% and 34.9+/-12.6% in group 2 (p=0.0001). Same results were observed for light transmittance aggregometry, whole blood aggregometry and VerifyNow, but not for thromboelastometry. In contrast to what may be expected, the 75 mg daily maintenance dose took longer than 1-week to provide the full clopidogrel antiplatelet effect. Furthermore, patients in group 2 had a nearly 50% reduction in C-reactive protein levels both at 1 week and 1 month.
  
  
  CONCLUSIONS
  In patients with STEMI and poor responsiveness to clopidogrel a 150 mg daily maintenance dose of clopidogrel is associated with a significant reduction of platelet aggregation and a trend towards reduced inflammation.
authors: Istituto di Cardiologia, Policlinico S. Orsola, Università di Bologna, Italy. tulliopalmerini@hotmail.com
authors: Tullio
authors: T
authors: Palmerini
authors: Chiara
authors: C
authors: Barozzi
authors: Luciana
authors: L
authors: Tomasi
authors: Diego
authors: D
authors: Sangiorgi
authors: Antonio
authors: A
authors: Marzocchi
authors: Stefano
authors: S
authors: De Servi
authors: Paolo
authors: P
authors: Ortolani
authors: Letizia Bacchi
authors: LB
authors: Reggiani
authors: Laura
authors: L
authors: Alessi
authors: Giulia
authors: G
authors: Lauria
authors: Mirna
authors: M
authors: Bassi
authors: Angelo
authors: A
authors: Branzi
mesh_terms: D056988:Anterior Wall Myocardial Infarction; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002097:C-Reactive Protein / Q000494:pharmacology / Q000627:therapeutic use; D015815:Cell Adhesion Molecules / Q000378:metabolism; D000077144:Clopidogrel; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy*; D010750:Phosphoproteins / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects*; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D000893:Anti-Inflammatory Agents; D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D010750:Phosphoproteins; D000098662:Vasodilator-Stimulated Phosphoprotein; D002097:C-Reactive Protein; D000077144:Clopidogrel; D013988:Ticlopidine