How strong is the evidence for the use of perioperative beta blockers in non-cardiac surgery? Systematic review and meta-analysis of randomised controlled trials.
OBJECTIVE
To determine the effect of perioperative beta blocker treatment in patients having non-cardiac surgery.


METHODS
Systematic review and meta-analysis.


METHODS
Seven search strategies, including searching two bibliographic databases and hand searching seven medical journals. STUDY SELECTION AND OUTCOMES: We included randomised controlled trials that evaluated beta blocker treatment in patients having non-cardiac surgery. Perioperative outcomes within 30 days of surgery included total mortality, cardiovascular mortality, non-fatal myocardial infarction, non-fatal cardiac arrest, non-fatal stroke, congestive heart failure, hypotension needing treatment, bradycardia needing treatment, and bronchospasm.


RESULTS
Twenty two trials that randomised a total of 2437 patients met the eligibility criteria. Perioperative beta blockers did not show any statistically significant beneficial effects on any of the individual outcomes and the only nominally statistically significant beneficial relative risk was 0.44 (95% confidence interval 0.20 to 0.97, 99% confidence interval 0.16 to 1.24) for the composite outcome of cardiovascular mortality, non-fatal myocardial infarction, and non-fatal cardiac arrest. Methods adapted from formal interim monitoring boundaries applied to cumulative meta-analysis showed that the evidence failed, by a considerable degree, to meet standards for forgoing additional studies. The individual safety outcomes in patients treated with perioperative beta blockers showed a relative risk for bradycardia needing treatment of 2.27 (95% CI 1.53 to 3.36, 99% CI 1.36 to 3.80) and a nominally statistically significant relative risk for hypotension needing treatment of 1.27 (95% CI 1.04 to 1.56, 99% CI 0.97 to 1.66).


CONCLUSIONS
The evidence that perioperative beta blockers reduce major cardiovascular events is encouraging but too unreliable to allow definitive conclusions to be drawn.
Department of Medicine, McMaster University, Hamilton, ON, Canada. philipj@mcmaster.ca
P J
PJ
Devereaux
W Scott
WS
Beattie
Peter T-L
PT
Choi
Neal H
NH
Badner
Gordon H
GH
Guyatt
Juan C
JC
Villar
Claudio S
CS
Cinà
Kate
K
Leslie
Michael J
MJ
Jacka
Victor M
VM
Montori
Mohit
M
Bhandari
Alvaro
A
Avezum
Alexandre B
AB
Cavalcanti
Julian W
JW
Giles
Thomas
T
Schricker
Homer
H
Yang
Carl-Johan
CJ
Jakobsen
Salim
S
Yusuf
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors
D000319:Adrenergic beta-Antagonists