The effects of perioperative β-blockers on mortality in patients undergoing non-cardiac surgery in real world: A meta-analysis of cohort studies

Background: Despite the fact that recent evidence from meta-analysis of randomized trials indicates an increase in mortality, perioperative treatment with beta-blockers is still widely advocated. We therefore performed a meta-analysis of cohort studies to evaluate the effects of perioperative beta-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 beta-blockers on mortality in patients undergoing non-cardiac surgery. Adjusted relative risk (RR) with 95% confidence interval (Cl) was pooled using random effect models. Results: Eight cohort studies with a total of 470,059 participants (180,441 patients in the beta-blocker group and 289,618 patients in the control group) were included in this meta analysis, Perioperative beta-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 beta-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 beta-blockers does not seem to reduce the risk of death. Moreover, those who are taking beta-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. (C) 2014 Elsevier Ireland Ltd. All rights reserved.