title: The effects of perioperative β-blockers on mortality in patients undergoing non-cardiac surgery in real world: a meta-analysis of cohort studies.
abstract: BACKGROUND
  Despite the fact that recent evidence from meta-analysis of randomized trials indicates an increase in mortality, perioperative treatment with β-blockers is still widely advocated. We therefore performed a meta-analysis of cohort studies to evaluate the effects of perioperative β-blockers on mortality in patients undergoing non-cardiac surgery in the real world scenarios.
  
  
  METHODS
  We searched PubMed and Embase from the inception to April 2014 for cohort studies, assessing the effect of perioperative β-blockers on mortality in patients undergoing non-cardiac surgery. Adjusted relative risk (RR) with 95% confidence interval (CI) was pooled using random effect models.
  
  
  RESULTS
  Eight cohort studies with a total of 470,059 participants (180,441 patients in the β-blocker group and 289,618 patients in the control group) were included in this meta-analysis. Perioperative β-blockers were not associated with a reduced risk of mortality (RR=0.88, 95% CI, 0.75 to 1.04), postoperation myocardial infarction (RR=1.30, 95% CI, 0.76 to 2.23), and postoperation stroke (RR=1.17, 95% CI, 0.53 to 2.57). However, in subgroup analysis of mortality, taking β-blockers on the day of surgery caused statistically significant increase in mortality of 91% (RR=1.91, 95% CI, 1.01 to 3.62).
  
  
  CONCLUSIONS
  In the real world scenarios, for patients undergoing non-cardiac surgery, the routine use of β-blockers does not seem to reduce the risk of death. Moreover, those who are taking β-blockers on the day of surgery may have an increased risk of postoperative mortality. However, these results should be interpreted with caution because of the significant heterogeneity across the studies.
authors.affiliation: Department of Integrated ICU, The First Affiliated Hospital of Zhengzhou University, PR China.
authors.forename: You-Dong
authors.initials: YD
authors.lastname: Wan
authors.affiliation: Department of Integrated ICU, The First Affiliated Hospital of Zhengzhou University, PR China.
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Zhang
authors.affiliation: Department of Integrated ICU, The First Affiliated Hospital of Zhengzhou University, PR China. Electronic address: suntongwen@163.com.
authors.forename: Tong-Wen
authors.initials: TW
authors.lastname: Sun
authors.affiliation: Pharmacy, The First Affiliated Hospital of Zhengzhou University, PR China.
authors.forename: Quan-Cheng
authors.initials: QC
authors.lastname: Kan
authors.affiliation: School of Biomedical Sciences, Charles Sturt University, PR China. Electronic address: LWang@csu.edu.au.
authors.forename: Le-Xin
authors.initials: LX
authors.lastname: Wang
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D006801:Humans; D010346:Patient Care Management / Q000379:methods*; D019990:Perioperative Care; D012307:Risk Factors; D013514:Surgical Procedures, Operative / Q000401:mortality*
chemical_list: D000319:Adrenergic beta-Antagonists
keywords: Meta-analysis; Mortality; Non-cardiac surgery; β-Blockers