title: Beta blockers for elective surgery in elderly patients: population based, retrospective cohort study.
abstract: OBJECTIVE
  To test whether atenolol (a long acting beta blocker) and metoprolol (a short acting beta blocker) are associated with equivalent reductions in risk for elderly patients undergoing elective surgery.
  
  
  METHODS
  Population based, retrospective cohort analysis.
  
  
  METHODS
  Acute care hospitals in Ontario, Canada, over one decade.
  
  
  METHODS
  Consecutive patients older than 65 who were admitted for elective surgery, without symptomatic coronary disease.
  
  
  METHODS
  Death or myocardial infarction.
  
  
  RESULTS
  37,151 patients were receiving atenolol or metoprolol before surgery, of which the most common operations were orthopaedic or abdominal procedures. As expected, the two groups were similar in demographic characteristics, medical therapy, and type of surgery. 1038 patients experienced a myocardial infarction or died, a rate that was significantly lower for patients receiving atenolol than for those receiving metoprolol (2.5% v 3.2%, P < 0.001). The decreased risk with atenolol persisted after adjustment for measured demographic, medical, and surgical factors; extended to comparisons of other long acting and short acting beta blockers; was accentuated in analyses that focused on patients with the clearest evidence of beta blocker treatment; and reflected the immediate postoperative interval.
  
  
  CONCLUSIONS
  Patients receiving metoprolol do not have as low a perioperative cardiac risk as patients receiving atenolol, in accord with possible acute withdrawal after missed doses.
authors.affiliation: Sunnybrook and Women's College Health Sciences Centre, G-151, 2075 Bayview Ave, Ontario, Canada M4N 3M5. DAR@ICES.ON.CA
authors.forename: Donald
authors.initials: D
authors.lastname: Redelmeier
authors.forename: Damon
authors.initials: D
authors.lastname: Scales
authors.forename: Alexander
authors.initials: A
authors.lastname: Kopp
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D001262:Atenolol / Q000627:therapeutic use; D002170:Canada / Q000453:epidemiology; D017558:Elective Surgical Procedures; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use; D009203:Myocardial Infarction / Q000453:epidemiology / Q000517:prevention & control*; D019990:Perioperative Care / Q000379:methods; D011183:Postoperative Complications / Q000517:prevention & control*; D012189:Retrospective Studies
chemical_list: D000319:Adrenergic beta-Antagonists; D001262:Atenolol; D008790:Metoprolol