title: Meta-analysis of the effect of heart rate achieved by perioperative beta-adrenergic blockade on cardiovascular outcomes.
abstract: BACKGROUND
  Acute perioperative beta-adrenergic blockade may be cardioprotective in the high-risk cardiac patient for major non-cardiac surgery. We have investigated the association between the heart rate achieved with perioperative beta-blockade and the incidence of perioperative cardiac complications.
  
  
  METHODS
  We identified eight randomized studies (1931 patients) reporting acute perioperative beta-blockade and major perioperative cardiovascular outcomes after non-cardiac surgery. The mean heart rates within the first 72 h after operation were analysed. A meta-analysis of means was conducted using a random effects model. A bivariate correlation analysis was conducted using Spearman's correlation coefficient to assess for an association between the mean postoperative heart rate and the 30 day cardiac outcomes.
  
  
  RESULTS
  Acute perioperative beta-blockade did not significantly reduce 30 day cardiac death [odds ratio (OR) 0.35, 95% confidence interval (CI) 0.08-1.52] or non-fatal myocardial infarction (OR 0.90, 95% CI 0.52-1.56) in the studies with adequate methodology. The mean (95% CI) heart rate was 73 (71-74) beats min(-1) in the beta-blockade group, which was significantly lower than the placebo group (mean heart rate 82, P=0.0001). There was no correlation between heart rate and 30 day cardiac complications (P=0.848). The reduction in heart rate was associated with increased drug-associated adverse events (OR 2.53, 95% CI 2.05-3.13, P<0.0001). A major limitation of this analysis may be that postoperative heart rate was not a primary outcome in any of the studies identified and the mean postoperative heart rate achieved may be too high to realize optimal cardioprotection.
  
  
  CONCLUSIONS
  This meta-analysis cannot confirm that heart rate control with beta-adrenergic blockade is cardioprotective. A randomized controlled trial examining the effect of tight perioperative heart rate control with beta-adrenergic blockade on clinically important outcomes and adverse events is warranted.
authors.affiliation: Department of Anaesthetics, Nelson R. Mandela School of Medicine, Private Bag 7, Congella, Kwazulu-Natal 4013, South Africa. bruce.biccard@nda.ox.ac.uk
authors.forename: B M
authors.initials: BM
authors.lastname: Biccard
authors.forename: J W
authors.initials: JW
authors.lastname: Sear
authors.forename: P
authors.initials: P
authors.lastname: Foëx
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002316:Cardiotonic Agents / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000401:mortality / Q000517:prevention & control*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D019990:Perioperative Care / Q000379:methods*; D016032:Randomized Controlled Trials as Topic
chemical_list: D000319:Adrenergic beta-Antagonists; D002316:Cardiotonic Agents