title: Aspirin in patients undergoing noncardiac surgery.
abstract: BACKGROUND
  There is substantial variability in the perioperative administration of aspirin in patients undergoing noncardiac surgery, both among patients who are already on an aspirin regimen and among those who are not.
  
  
  METHODS
  Using a 2-by-2 factorial trial design, we randomly assigned 10,010 patients who were preparing to undergo noncardiac surgery and were at risk for vascular complications to receive aspirin or placebo and clonidine or placebo. The results of the aspirin trial are reported here. The patients were stratified according to whether they had not been taking aspirin before the study (initiation stratum, with 5628 patients) or they were already on an aspirin regimen (continuation stratum, with 4382 patients). Patients started taking aspirin (at a dose of 200 mg) or placebo just before surgery and continued it daily (at a dose of 100 mg) for 30 days in the initiation stratum and for 7 days in the continuation stratum, after which patients resumed their regular aspirin regimen. The primary outcome was a composite of death or nonfatal myocardial infarction at 30 days.
  
  
  RESULTS
  The primary outcome occurred in 351 of 4998 patients (7.0%) in the aspirin group and in 355 of 5012 patients (7.1%) in the placebo group (hazard ratio in the aspirin group, 0.99; 95% confidence interval [CI], 0.86 to 1.15; P=0.92). Major bleeding was more common in the aspirin group than in the placebo group (230 patients [4.6%] vs. 188 patients [3.8%]; hazard ratio, 1.23; 95% CI, 1.01, to 1.49; P=0.04). The primary and secondary outcome results were similar in the two aspirin strata.
  
  
  CONCLUSIONS
  Administration of aspirin before surgery and throughout the early postsurgical period had no significant effect on the rate of a composite of death or nonfatal myocardial infarction but increased the risk of major bleeding. (Funded by the Canadian Institutes of Health Research and others; POISE-2 ClinicalTrials.gov number, NCT01082874.).
authors.affiliation: The authors' affiliations are listed in the Appendix.
authors.forename: P J
authors.initials: PJ
authors.lastname: Devereaux
authors.forename: Marko
authors.initials: M
authors.lastname: Mrkobrada
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
authors.forename: Kate
authors.initials: K
authors.lastname: Leslie
authors.forename: Pablo
authors.initials: P
authors.lastname: Alonso-Coello
authors.forename: Andrea
authors.initials: A
authors.lastname: Kurz
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Villar
authors.forename: Alben
authors.initials: A
authors.lastname: Sigamani
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Biccard
authors.forename: Christian S
authors.initials: CS
authors.lastname: Meyhoff
authors.forename: Joel L
authors.initials: JL
authors.lastname: Parlow
authors.forename: Gordon
authors.initials: G
authors.lastname: Guyatt
authors.forename: Andrea
authors.initials: A
authors.lastname: Robinson
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
authors.forename: Reitze N
authors.initials: RN
authors.lastname: Rodseth
authors.forename: Fernando
authors.initials: F
authors.lastname: Botto
authors.forename: Giovanna
authors.initials: G
authors.lastname: Lurati Buse
authors.forename: Denis
authors.initials: D
authors.lastname: Xavier
authors.forename: Matthew T V
authors.initials: MT
authors.lastname: Chan
authors.forename: Maria
authors.initials: M
authors.lastname: Tiboni
authors.forename: Deborah
authors.initials: D
authors.lastname: Cook
authors.forename: Priya A
authors.initials: PA
authors.lastname: Kumar
authors.forename: Patrice
authors.initials: P
authors.lastname: Forget
authors.forename: German
authors.initials: G
authors.lastname: Malaga
authors.forename: Edith
authors.initials: E
authors.lastname: Fleischmann
authors.forename: Mohammed
authors.initials: M
authors.lastname: Amir
authors.forename: John
authors.initials: J
authors.lastname: Eikelboom
authors.forename: Richard
authors.initials: R
authors.lastname: Mizera
authors.forename: David
authors.initials: D
authors.lastname: Torres
authors.forename: C Y
authors.initials: CY
authors.lastname: Wang
authors.forename: Tomas
authors.initials: T
authors.lastname: VanHelder
authors.forename: Pilar
authors.initials: P
authors.lastname: Paniagua
authors.forename: Otavio
authors.initials: O
authors.lastname: Berwanger
authors.forename: Sadeesh
authors.initials: S
authors.lastname: Srinathan
authors.forename: Michelle
authors.initials: M
authors.lastname: Graham
authors.forename: Laura
authors.initials: L
authors.lastname: Pasin
authors.forename: Yannick
authors.initials: Y
authors.lastname: Le Manach
authors.forename: Peggy
authors.initials: P
authors.lastname: Gao
authors.forename: Janice
authors.initials: J
authors.lastname: Pogue
authors.forename: Richard
authors.initials: R
authors.lastname: Whitlock
authors.forename: André
authors.initials: A
authors.lastname: Lamy
authors.forename: Clive
authors.initials: C
authors.lastname: Kearon
authors.forename: Colin
authors.initials: C
authors.lastname: Baigent
authors.forename: Clara
authors.initials: C
authors.lastname: Chow
authors.forename: Shirley
authors.initials: S
authors.lastname: Pettit
authors.forename: Susan
authors.initials: S
authors.lastname: Chrolavicius
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
mesh_terms: D000368:Aged; D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000517:prevention & control*; D019990:Perioperative Care; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000517:prevention & control*; D019106:Postoperative Hemorrhage / Q000139:chemically induced*; D013514:Surgical Procedures, Operative / Q000401:mortality*; D017211:Treatment Failure
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin