title: Preoperative thienopyridine use and outcomes after surgery: a systematic review.
abstract: BACKGROUND
  Although studies have demonstrated excess risk of ischemic events if aspirin is withheld preoperatively, it is unclear whether preoperative thienopyridine use influences postoperative outcomes.
  
  
  METHODS
  We conducted a systematic review of 37 studies (31 cardiac and 6 noncardiac surgery, 3 randomized, 34 observational) comparing postoperative outcomes in patients who were versus were not exposed to thienopyridine in the 5 days before surgery.
  
  
  RESULTS
  Exposure to thienopyridine in the 5 days preceding surgery (compared with no exposure) was not associated with any reduction in postoperative myocardial infarction (23 studies, 12,872 patients, 3.4% vs 3.0%, odds ratio [OR] 0.98; 95% confidence interval [CI], 0.72-1.34), but was associated with increased risks of stroke (16 studies, 10,265 patients, 1.9% vs 1.4%, OR 1.54; 95% CI, 1.08-2.20), reoperation for bleeding (32 studies, 19,423 patients, 4.3% vs 1.8%, OR 2.62; 95% CI, 1.96-3.49), and all-cause mortality (28 studies, 22,990 patients, 3.7% vs 2.6%, OR 1.38; 95% CI, 1.13-1.69). Results were identical when analyses were restricted to long-term users of thienopyridines who continued versus held the medication in the 5 days before surgery. Although all associations were similar in direction for the subset of patients undergoing noncardiac surgery, 97% of the outcome data in this meta-analysis came from cardiac surgery trials.
  
  
  CONCLUSIONS
  These data support withholding thienopyridines 5 days before cardiac surgery; there was insufficient evidence to make definitive recommendations for elective noncardiac surgery although the direction and magnitude of associations were similar.
authors.affiliation: Division of General Internal Medicine, Department of Medicine, University of Alberta, Edmonton, Canada.
authors.forename: Anita G
authors.initials: AG
authors.lastname: Au
authors.forename: Sumit R
authors.initials: SR
authors.lastname: Majumdar
authors.forename: Finlay A
authors.initials: FA
authors.lastname: McAlister
mesh_terms: D000075202:Contraindications; D006801:Humans; D009203:Myocardial Infarction / Q000139:chemically induced; D011183:Postoperative Complications / Q000139:chemically induced* / Q000401:mortality; D057234:Preoperative Period; D011725:Pyridines; D012086:Reoperation; D020521:Stroke / Q000139:chemically induced
chemical_list: D011725:Pyridines; C446540:thienopyridine