Beta-blockade in the perioperative period: where do we stand after all the trials?

Perioperative myocardial infarction following noncardiac surgery is a complex process with a variety of proposed etiologic factors. Perioperative beta-blockade has been reported to reduce perioperative myocardial infarction and cardiac death, with possible direct effects on longer-term outcome, particularly after vascular surgery. Despite two high-profile studies that have pushed this topic into the mainstream of medicine, the number of patients studied and outcomes observed remains limited, especially for a therapy recommended for widespread adoption in millions of patients globally. Observational analyses, small meta-analyses, and newer randomized trial data (primarily in abstract format) suggest the therapy is of benefit in high-risk patients, whereas in patients at intermediate or low risk, it is either mildly efficacious or neutral in effect. Adverse effects appear to be limited to the expected primary hemodynamic side effects of bradycardia and hypotension, although a suggestion of increased mortality has been reported in one observational analysis in the lowest-risk group. beta-Blockade may be associated with reduction in length of stay and reduced analgesic requirements, although these effects remain controversial. A single mega-trial being conducted outside of the United States with a target goal of 10,000 patients is ongoing and promises to provide definitive data within the next few years. Ongoing research into various etiologies of perioperative myocardial infarction and other medications with potential efficacy in this setting, including the important antiplatelet agents, must also be considered in developing recommendations for widespread adoption of perioperative beta-blockade.