title: Effect of clopidogrel on bleeding and transfusions after off-pump coronary artery bypass graft surgery: impact of discontinuation prior to surgery.
abstract: OBJECTIVE
  The use of antiplatelet drugs to treat acute myocardial infarction, unstable angina, acute coronary syndrome and secondary prevention following percutaneous coronary interventions is well accepted. However, it constitutes a serious risk of bleeding for patients undergoing coronary artery bypass grafting surgery (CABG). We evaluated the effect of aspirin and clopidogrel (CPDG), both irreversible platelet aggregation inhibitors, on operative bleeding and determined the optimal timing for their discontinuation before surgery.
  
  
  METHODS
  Between July 2001 and December 2004, we reviewed our experience with 453 patients undergoing off-pump CABG surgery (OPCAB) who received CPDG (n=101) or not (n=352) preoperatively, and compared the intraoperative and postoperative bleeding to determine risks factors associated with blood or platelet transfusions.
  
  
  RESULTS
  Clopidogrel in OPCAB surgery is associated with higher intraoperative (702.24 ml vs 554.13 ml, p=0.03) and postoperative bleeding (864.93 ml vs 603.75 ml, p=0.03). The mean operative blood loss is higher in patients still on CPDG at the time of surgery compared to patients off CPDG at least 72 h before surgery (802 ml vs 554.13 ml, p<0.0001). Blood loss in the later subgroup of patients is comparable to the control group without CPDG (p=NS). Clopidogrel is associated with more platelet transfusions (OR=11.79, [1.48; 93.86]).
  
  
  CONCLUSIONS
  Blood loss is higher in OPCAB patients receiving clopidogrel before surgery. However, discontinuation of clopidogrel three days (72 h) prior to the operation demonstrated a similar blood loss pattern compared to a control group. Clopidogrel is associated with more platelets, but not red blood cell transfusions following OPCAB surgery.
authors.affiliation: Department of Cardiac Surgery, CHUM-Hôpital Notre-Dame, Montreal, QC, Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Maltais
authors.forename: Louis P
authors.initials: LP
authors.lastname: Perrault
authors.forename: Quoc-Bao
authors.initials: QB
authors.lastname: Do
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D016063:Blood Loss, Surgical / Q000517:prevention & control; D001803:Blood Transfusion; D000077144:Clopidogrel; D047549:Coronary Artery Bypass, Off-Pump; D004334:Drug Administration Schedule; D006801:Humans; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D019106:Postoperative Hemorrhage / Q000139:chemically induced / Q000517:prevention & control / Q000628:therapy; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D012307:Risk Factors; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine