title: Perioperative Aspirin for Prevention of Venous Thromboembolism: The PeriOperative ISchemia Evaluation-2 Trial and a Pooled Analysis of the Randomized Trials.
abstract: The PeriOperative ISchemia Evaluation-2 (POISE-2) trial compared aspirin with placebo after noncardiac surgery.
  
  
  
  The authors randomly assigned 10,010 patients undergoing noncardiac surgery to receive 200 mg aspirin or placebo 2 to 4 h before surgery and then 100 mg aspirin daily or placebo daily for up to 30 days after surgery. Herein, the authors report the effect of aspirin on venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, as well as an updated pooled analysis of randomized trials of antiplatelet therapy for VTE prevention in noncardiac surgery patients.
  
  
  
  Six thousand five hundred forty-eight patients (65.4%) received anticoagulant prophylaxis. VTE occurred in 53 patients (1.1%) allocated to aspirin and in 60 patients (1.2%) allocated to placebo (hazard ratio, 0.89; 95% CI, 0.61 to 1.28). Major or life-threatening bleeding occurred in 312 patients (6.3%) allocated to aspirin and in 256 patients (5.1%) allocated to placebo (hazard ratio, 1.22; 95% CI, 1.04 to 1.44). Concomitant use of anticoagulant prophylaxis did not modify the effect of aspirin on VTE or bleeding. Pooled analysis of the POISE-2 and Pulmonary Embolism Prevention trials demonstrated that symptomatic VTE occurred in 173 (1.3%) of 13,724 patients allocated to aspirin and in 246 (1.8%) of 13,730 patients allocated to placebo (odds ratio, 0.71; 95% CI, 0.56 to 0.89; heterogeneity P = 0.27; I = 17%); the impact of aspirin was very similar in those who did and did not receive pharmacologic prophylaxis. Pooled estimates for symptomatic VTE were similar to the pooled estimates for any deep vein thrombosis and pulmonary embolism from the POISE-2 trial, Pulmonary Embolism Prevention trial, and the Antiplatelet Trialists' Collaboration meta-analysis.
  
  
  
  Aspirin in the POISE-2 trial did not reduce VTE, but two thirds of patients received anticoagulant prophylaxis, there were few VTE events, and results were consistent with a wide range of aspirin effects. A pooled analysis of the randomized trials demonstrates evidence for the efficacy of aspirin for VTE prevention in hospitalized surgical patients.
authors.affiliation: From the Department of Medicine Hamilton, McMaster University, Hamilton, Ontario, Canada (J.W.E., C.K., G.G., S.Y., D.C., J. Douketis, A.P., E.D., P.J.D.); Departments of Outcomes Research and General Anesthesiology, Anesthesiology Institute, Cleveland Clinic, Cleveland, Ohio (D.I.S., A.K.); Department of Medicine Hamilton, St Joseph's Healthcare, Hamilton, Ontario, Canada (D.C., J. Douketis); Department of Anesthesiology, Queen's University and Kingston General Hospital, Kingston, Ontario, Canada (R.A.), Departments of Anesthesia and Perioperative Medicine and Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada (P.M.J.); Research Department, Fundaciòn Cardioinfantil, Bogotà, Colombia (R.J.D.); Department of Anaesthesia, University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia (T.W.P.); Departments of Anesthesiology and Neurological Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio (S.D.B.); Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, Melbourne, Victoria, Australia (K.L.); Toronto General Hospital, Li Ka Shing Knowledge Institute of St. Michael's Hospital and Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada (D.N.W.); Population Health Research Institute, Hamilton, Ontario, Canada (J.W.E., S.Y., K.B., E.D., S.M., J. Douketis, P.J.D.); Department of Anesthesia, Wake Forest School of Medicine, Winston-Salem, North Carolina (S.M.); and Department of Anaesthesiology, University of the Free State, Bloemfontein, South Africa (J. Diedericks).
authors.forename: John W
authors.initials: JW
authors.lastname: Eikelboom
authors.forename: Clive
authors.initials: C
authors.lastname: Kearon
authors.forename: Gordon
authors.initials: G
authors.lastname: Guyatt
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
authors.forename: Deborah
authors.initials: D
authors.lastname: Cook
authors.forename: James
authors.initials: J
authors.lastname: Douketis
authors.forename: Ameen
authors.initials: A
authors.lastname: Patel
authors.forename: Andrea
authors.initials: A
authors.lastname: Kurz
authors.forename: Rene
authors.initials: R
authors.lastname: Allard
authors.forename: Philip M
authors.initials: PM
authors.lastname: Jones
authors.forename: Rodolfo J
authors.initials: RJ
authors.lastname: Dennis
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Painter
authors.forename: Sergio D
authors.initials: SD
authors.lastname: Bergese
authors.forename: Kate
authors.initials: K
authors.lastname: Leslie
authors.forename: Duminda N
authors.initials: DN
authors.lastname: Wijeysundera
authors.forename: Kumar
authors.initials: K
authors.lastname: Balasubramanian
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Duceppe
authors.forename: Scott
authors.initials: S
authors.lastname: Miller
authors.forename: Johan
authors.initials: J
authors.lastname: Diedericks
authors.forename: P J
authors.initials: PJ
authors.lastname: Devereaux
mesh_terms: D000368:Aged; D001241:Aspirin / Q000627:therapeutic use*; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D016017:Odds Ratio; D019990:Perioperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D013514:Surgical Procedures, Operative; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000517:prevention & control*
chemical_list: D005343:Fibrinolytic Agents; D001241:Aspirin