title: Safety of Continued Clopidogrel Use in the Preoperative Course of Gastrointestinal Surgery: A Retrospective Cohort Study.
abstract: Our study aimed to estimate postoperative bleeding risk in older adults taking clopidogrel before gastrointestinal (GI) surgery, to aid surgeons in decisions regarding clopigogrel cessation.
  
  
  
  Balancing risks of postoperative bleeding associated with continued clopidogrel use and those associated with cessation is difficult for GI surgeons.
  
  
  
  Using 100% Texas Medicare Claims Data from 2006 to 2011, we identified patients undergoing emergent GI surgery. We propensity score matched patients on clopidogrel before surgery to patients not on clopidogrel. Using conditional logistic regression, we compared risks of bleeding events at 1-month postdischarge between groups, adjusting for bleeding risk factors.
  
  
  
  In total, 1240 patients undergoing emergent GI surgery while treated with clopidogrel were matched to emergency GI surgery patients not treated with clopidogrel. The only significant preoperative differences between groups were higher percent of clopidogrel-treated patients with congestive heart failure, cholecystectomy, and lower percent of clopidogrel-treated patients with colectomy. Mean age was 76.91 (±7.06) and 76.70 (±7.05) years (P = 0.47), and 63.84% and 59.41% of operations were cholecystectomy, in the clopidogrel and nonclopidogrel groups (P = 0.18). In multivariable analyses adjusting for Elixhauser index, hyperlipidemia, confounding drugs, and surgery type, odds ratio for bleeding within 30 days of discharge in those exposed to clopidogrel compared with those not exposed was 1.60 (95% confidence interval, 1.08-2.38), with raw rates of bleeding 6.85% and 4.84%.
  
  
  
  Clopidogrel use in older adults through the preoperative period of GI surgery does not significantly increase bleeding events in the month after surgery.
authors.affiliation: *Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX †Department of Surgery, University of Texas Medical Branch, Galveston, TX ‡Department of Surgery, University of Arizona, Tucson, AZ.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Jupiter
authors.forename: Xiao
authors.initials: X
authors.lastname: Fang
authors.forename: Deepak
authors.initials: D
authors.lastname: Adhikari
authors.forename: Hemalkumar B
authors.initials: HB
authors.lastname: Mehta
authors.forename: Taylor S
authors.initials: TS
authors.lastname: Riall
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000077144:Clopidogrel; D013505:Digestive System Surgical Procedures; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D019106:Postoperative Hemorrhage / Q000139:chemically induced* / Q000517:prevention & control; D011300:Preoperative Care / Q000379:methods*; D057216:Propensity Score; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D028761:Withholding Treatment
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine