title: Does the use of preoperative aspirin increase the risk of bleeding in patients undergoing coronary artery bypass grafting surgery? Systematic review and meta-analysis.
abstract: BACKGROUND
  The traditional recommendation has been to stop Aspirin seven to 10 days prior to coronary artery bypass surgery to reduce the potential risk of bleeding. A few reports have shown that Aspirin did not increase the risk of bleeding and may be beneficial to be continued until the time of surgery. The objective of this review was to evaluate the effect of preoperative Aspirin on bleeding in patients undergoing elective bypass surgery.
  
  
  METHODS
  A meta-analysis of 10 randomized and nonrandomized studies reporting comparisons between Aspirin and control was undertaken. The primary outcome was the total amount of postoperative chest tube drainage. Secondary outcomes were the number of units of packed red blood cell transfusion, platelet transfusion, fresh frozen plasma transfusion, and number of patients reexplored for bleeding.
  
  
  RESULTS
  Ten studies, involving 1748 patients, met the inclusion criteria for this review of whom 913 were in the Aspirin group and 835 were in the control group. Pooling the results of all studies showed a significant increase in blood loss and transfusion of red blood cells and fresh frozen plasma in the Aspirin group (p < 0.05). There was no significant difference between the two groups in the rate of platelet transfusion, or the incidence of reexploration (p > 0.05). Included studies were heterogeneous and of low methodological quality.
  
  
  CONCLUSIONS
  Aspirin is associated with increased chest tube drainage and may be associated with a greater requirement for blood products. High-quality prospective studies are warranted to reassess the effect of Aspirin on important postoperative outcomes.
authors.affiliation: Division of Cardiac and Vascular Surgery, Department of Surgery, University of Toronto and Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. abdullah.alghamdi@utoronto.ca
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Alghamdi
authors.forename: Fuad
authors.initials: F
authors.lastname: Moussa
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Fremes
mesh_terms: D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects*; D001803:Blood Transfusion; D015505:Chest Tubes; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003324:Coronary Artery Disease / Q000188:drug therapy; D004322:Drainage; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D019106:Postoperative Hemorrhage / Q000139:chemically induced* / Q000209:etiology / Q000628:therapy; D011300:Preoperative Care; D012307:Risk Factors; D013907:Thoracostomy
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin