Lancet: No support for ACC/AHA guidelines for use of beta-blocker therapy
A review of 33 trials has provided evidence that does not support current American Heart Association(AHA)/American College of Cardiology (ACC) guidelines for use of beta-blocker therapy for prevention of adverse clinical outcomes in patients having non-cardiac surgery, according to a meta-analysis published early online in The Lancet.

Sripal Bangalore, MD, from Brigham and Women's Hospital in Boston, and Franz Messerli, MD, from St Luke's-Roosevelt Hospital and Columbia University College of Physicians and Surgeons in New York City, and colleagues suggested that the guidelines “should not be further promoted until conclusive evidence is available.”

The researchers performed a meta-analysis of 33 studies, which included 12,306 patients.

They found the use of beta-blockers were not associated with any significant reduction in the risk of all-cause mortality, cardiovascular mortality or heart failure; but they did reduce the risk of non-fatal heart attack by 35 percent and reduce the risk of less serious heart blood vessel blockage by 64 percent.

However, the authors wrote that the reductions came at the expense of the doubling of risk for non-fatal stroke, with one in every 293 patients given beta-blockers suffering a stroke of this kind. Beta-blockers were also associated with a high risk (1 in 22 patients) of bradycardia requiring treatment, and an even higher risk (one in 17 patients) of hypotension, requiring treatment.

The authors wrote that the “beneficial effects [of beta-blockers] were driven mainly by trials with a high risk of bias.”

“Beta-blockers should not be routinely used for perioperative treatment of patients undergoing non-cardiac surgery unless patients are already taking them for clinically indicated reasons [heart failure, coronary artery disease, previous MI]...The ACC/AHA guideline committee should soften their stance on perioperative beta-blockade until definitive evidence shows clear benefit,” the authors concluded.

In an accompanying commentary, Eric Boersma, MD and Don Poldermans, MD, from Erasmus Medical Center in Rotterdam, Netherlands, wrote that the net clinical outcome of beta-blocker treatment should not be based on the sum of its effects presented in this study.

However, Boersma and Poldermans called on all colleagues who are working on beta-blocker trials to release data about clinical conditions and perioperative changes that might have resulted in the complications listed by Messerli, Bangalore and colleagues.