title: Effect of beta-blocker prescription on the incidence of postoperative myocardial infarction after hip and knee arthroplasty.
abstract: BACKGROUND
  American College of Cardiology/American Heart Association guidelines recommend beta-blockade for selected low- and intermediate-risk noncardiac surgery patients. The authors evaluated the effect of perioperative beta-blockade on postoperative myocardial infarction (POMI) in low-risk patients undergoing intermediate-risk surgery.
  
  
  METHODS
  Patients who underwent elective hip or knee arthroplasty between January 1, 2002 and June 30, 2006 were identified. POMI was defined as a Troponin T value of more than 0.1 ng . ml(-1). Patients were divided into three groups: those prescribed a beta-blocker on the day of surgery and throughout their hospital stay (or 7 days, whichever came first), those prescribed a beta-blocker on the day of surgery but discontinued during the first 7 days, and those not prescribed a beta-blocker on the day of surgery. Propensity analysis and logistic regression were used to determine the independent association of beta-blocker exposure on POMI.
  
  
  RESULTS
  Of the 5,158 arthroplasty patients, 992 (18%) were treated with beta-blockers on the day of surgery. This beta-blocker was discontinued in 252 patients (25%). POMI occurred in 77 patients (1.5%). Discontinuation of beta-blocker prescription was significantly associated with POMI (odds ratio 2.0; 95% CI 1.1-3.9) and death (odds ratio 2.0; 95% CI 1.0-3.9).
  
  
  CONCLUSIONS
  After adjustment for confounders, discontinuation of beta-blocker prescription during the first week after surgery was significantly associated with POMI and death. These findings confirm the American College of Cardiology/American Heart Association Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery, which recommend not to withdraw beta-blocker therapy.
authors.affiliation: Department of Anesthesiology, The Ottawa Hospital, Civic Site, Ottawa, Ontario, Canada. w.a.vanklei@umcutrecht.nl
authors.forename: Wilton A
authors.initials: WA
authors.lastname: van Klei
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Bryson
authors.forename: Homer
authors.initials: H
authors.lastname: Yang
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Forster
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000009:adverse effects* / Q000627:therapeutic use; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000139:chemically induced* / Q000453:epidemiology* / Q000401:mortality; D019990:Perioperative Care; D011183:Postoperative Complications / Q000139:chemically induced* / Q000453:epidemiology* / Q000401:mortality; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
chemical_list: D000319:Adrenergic beta-Antagonists; D006454:Hemoglobins