title: An international prospective cohort study evaluating major vascular complications among patients undergoing noncardiac surgery: the VISION Pilot Study.
abstract: OBJECTIVE
  among patients undergoing noncardiac surgery, our objectives were to: (1) determine the feasibility of undertaking a large international cohort study; (2) estimate the current incidence of major perioperative vascular events; (3) compare the observed event rates to the expected event rates according to the Revised Cardiac Risk Index (RCRI); and (4) provide an estimate of the proportion of myocardial infarctions without ischemic symptoms that may go undetected without perioperative troponin monitoring.
  
  
  METHODS
  An international prospective cohort pilot study.
  
  
  METHODS
  Patients undergoing noncardiac surgery who were >45 years of age, receiving a general or regional anesthetic, and requiring hospital admission.
  
  
  METHODS
  Patients had a Roche fourth-generation Elecsys troponin T measurement collected 6 to 12 hours postoperatively and on the first, second, and third days after surgery. Our primary outcome was major vascular events (a composite of vascular death [i.e., death from vascular causes], nonfatal myocardial infarction, nonfatal cardiac arrest, and nonfatal stroke) at 30 days after surgery. Our definition for perioperative myocardial infarction included: (1) an elevated troponin T measurement with at least one of the following defining features: ischemic symptoms, development of pathologic Q waves, ischemic electrocardiogram changes, coronary artery intervention, or cardiac imaging evidence of myocardial infarction; or (2) autopsy findings of acute or healing myocardial infarction.
  
  
  RESULTS
  We recruited 432 patients across 5 hospitals in Canada, China, Italy, Colombia, and Brazil. During the first 30 days after surgery, 6.3% (99% confidence interval 3.9-10.0) of the patients suffered a major vascular event (10 vascular deaths, 16 nonfatal myocardial infarctions, and 1 nonfatal stroke). The observed event rate was increased 6-fold compared with the event rate expected from the RCRI. Of the 18 patients who suffered a myocardial infarction, 12 (66.7%) had no ischemic symptoms to suggest myocardial infarction.
  
  
  CONCLUSIONS
  This study suggests that major perioperative vascular events are common, that the RCRI underestimates risk, and that monitoring troponins after surgery can assist physicians to avoid missing myocardial infarction. These results underscore the need for a large international prospective cohort study.
authors.affiliation: Population Health Research Institute, David Braley Cardiac, Vascular, and Stroke Research Institute, RoomC1-116, Perioperative Medicine and Surgical Research Unit, c/o Hamilton General Hospital, 237 Barton Street East, Hamilton, ON, Canada, L8L2X2. philipj@mcmaster.ca
authors.forename: P J
authors.initials: PJ
authors.lastname: Devereaux
authors.forename: David
authors.initials: D
authors.lastname: Bradley
authors.forename: Matthew T V
authors.initials: MT
authors.lastname: Chan
authors.forename: Mike
authors.initials: M
authors.lastname: Walsh
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Villar
authors.forename: Carisi Anne
authors.initials: CA
authors.lastname: Polanczyk
authors.forename: Beatriz Graeff S
authors.initials: BG
authors.lastname: Seligman
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Guyatt
authors.forename: Pablo
authors.initials: P
authors.lastname: Alonso-Coello
authors.forename: Otavio
authors.initials: O
authors.lastname: Berwanger
authors.forename: Diane
authors.initials: D
authors.lastname: Heels-Ansdell
authors.forename: Nicole
authors.initials: N
authors.lastname: Simunovic
authors.forename: Holger
authors.initials: H
authors.lastname: Schünemann
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
mesh_terms: D000368:Aged; D001938:Brazil; D002170:Canada; D002681:China; D003105:Colombia; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D038622:Internationality; D007431:Intraoperative Complications / Q000453:epidemiology* / Q000401:mortality; D007558:Italy; D008297:Male; D008875:Middle Aged; D019990:Perioperative Care; D010865:Pilot Projects; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D014336:Troponin / Q000097:blood*; D014652:Vascular Diseases / Q000601:surgery*
chemical_list: D014336:Troponin