Questions Continue About Using Beta Blockers Before Surgery
MONDAY Oct. 20, 2008 -- A new study adds to doubts about using beta blockers to reduce the risks of surgery.
The death rate for people given beta blockers before non-cardiac surgery was 10 times higher in the 30 days after an operation than for those not getting the drugs (2.52 percent vs. 0.25 percent), according to a report in the October issue of the Archives of Surgery. The incidence of heart attacks was four times higher (2.94 percent vs. 0.74 percent).
"This is very much in line with the latest publications showing that one has to be very careful in using them," said study co-author Dr. Kamal Itani, chief of surgery at the Veterans Affairs Boston Health Care System and a professor of surgery at Boston University.
Beta blockers are commonly given before surgery to reduce cardiac risk by slowing the heartbeat. The Boston study found that the risk of problems was concentrated in those whose heart rates remained high despite beta-blocker treatment.
The new results differ somewhat from those of a major international study reported earlier this year. The POISE study of 8,351 people having non-cardiac surgery found a 27 percent reduction in heart attacks but an overall 33 percent higher death rate for those getting beta blockers.
Despite those results, beta blockers do have a role in surgery, Itani said. "I think we have to be careful about which patients receive beta blockers," he said. "There are clearly benefits for those drugs in patients at the highest risk of complications and with risk factors for heart disease."
The important point is to be sure that the target heartbeat rate is achieved, Itani said. The American College of Cardiology recommends 50 beats to 60 beats per minute before surgery, not to exceed 80 beats per minute, he noted.
"Those patients who do not have the target rate going into surgery will not do as well," Itani said. "Giving the drugs without achieving the full potential might be dangerous."
But the study indicates that the guidelines "need to be revisited," said Dr. Jeffrey H. Peters, chief of surgery at the University of Rochester, New York.
"This paper adds to a growing body of evidence suggesting that the routine use of beta blockers to reduce cardiac morbidity in surgery needs to be reconsidered," Peters said.
Unlike the POISE study, which was carefully designed with controls built in, the Boston study was retrospective, comparing 238 people given beta blockers before surgery with 480 who underwent surgery at the same center without being given the drugs, Peters noted.
"This is a retrospective study that is far from definitive, but it suggests that we should reconsider," he said.
"We recommend beta blockers for high risk patients, but we currently use them less and less," Peters said. He does not give beta blockers before surgery to people with no major risk factors for heart disease, such as diabetes or high blood pressure, he said.
Another paper published in the Oct. 28 issue of the Journal of the American College of Cardiology raises doubts about the use of beta blockers to control high blood pressure.
Analysis of data from nine controlled trials found a higher incidence of deaths, heart attacks, strokes and heart failure for people whose heart rate was lowered by beta-blocker treatment, said the report from cardiologists at Columbia University College of Physicians and Surgeons.
Learn why and how beta blockers are used from the Texas Heart Institute.
Posted: October 2008