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 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.