title: Platelet aggregation according to body mass index in patients undergoing coronary stenting: should clopidogrel loading-dose be weight adjusted?
abstract: BACKGROUND
  A 300 mg clopidogrel loading-dose (LD) is widely used as an adjunct antithrombotic treatment to reduce the risk of thrombotic events early after coronary stenting (CS). Antithrombotic drugs commonly used during percutaneous coronary interventions, such as heparin and platelet glycoprotein IIb/IIIa inhibitors, but not clopidogrel LD, are weight-adjusted, and few data are available on which is the most effective clopidogrel LD regimen. The aim of this study was to assess whether body mass index (BMI) influenced platelet response to clopidogrel LD in patients undergoing CS.
  
  
  METHODS
  Adenosine diphosphate (ADP)-induced platelet aggregation (PA) was assessed by light transmittance aggregometry in 48 patients on aspirin treatment undergoing CS receiving a 300 mg clopidogrel LD at intervention time. PA was assessed at baseline and up to 24 hours after intervention. Patients were divided into 2 groups according to BMI: overweight (BMI greater than or equal to 25 kg/m2; 29 patients) and normal weight (BMI<25 kg/m2; 19 patients). PA was significantly higher in overweight than in normal weight patients at baseline (60.1+/-18.6%; versus 47.6+/-13.5%; p=0.01), at 24 hours (42.3+/-18.4% versus 38.5+/-18.3%; p=0.02) and during the overall study time (p=0.025). Percentage of inhibition of PA 24 hours following clopidogrel LD was suboptimal (<40%) in 59% and 26% of overweight and normal weight patients, respectively (p=0.04). An elevated BMI was the only independent predictor of suboptimal platelet response.
  
  
  CONCLUSIONS
  These data suggest that overweight patients may need a higher loading-dose of clopidogrel and/or an adjunct antithrombotic treatment to adequately inhibit platelet aggregation early after CS.
authors.affiliation: Interventional Cardiology Unit-Cardiovascular Institute, San Carlos University Hospital, Plaza Cristo Rey s-n-planta 2N, 28040 Madrid, Spain. dominickjangiolillo@hotmail.com
authors.forename: Dominick J
authors.initials: DJ
authors.lastname: Angiolillo
authors.forename: Antonio
authors.initials: A
authors.lastname: Fernández-Ortiz
authors.forename: Esther
authors.initials: E
authors.lastname: Bernardo
authors.forename: Carlos
authors.initials: C
authors.lastname: Barrera Ramírez
authors.forename: Manel
authors.initials: M
authors.lastname: Sabaté
authors.forename: Cristina
authors.initials: C
authors.lastname: Fernandez
authors.forename: Rosana
authors.initials: R
authors.lastname: Hernández-Antolín
authors.forename: Javier
authors.initials: J
authors.lastname: Escaned
authors.forename: Fernando
authors.initials: F
authors.lastname: Alfonso
authors.forename: Carlos
authors.initials: C
authors.lastname: Macaya
mesh_terms: D000368:Aged; D019917:Blood Vessel Prosthesis Implantation; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D000077144:Clopidogrel; D023921:Coronary Stenosis / Q000503:physiopathology* / Q000628:therapy*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D013030:Spain; D015607:Stents; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D016896:Treatment Outcome; D014894:Weights and Measures
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine