Beta Blockers Raise Stroke, Death Risk After Surgery

By Steven Reinberg
HealthDay Reporter
Tuesday, May 13, 2008; 10:00 AM

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TUESDAY, May 13 (HealthDay News) -- Patients who received the blood pressure-lowering drugs known as beta blockers after having non-cardiac surgery were at higher risk of dying or having a stroke, a new Canadian study found.

However, the patients receiving the medications were less likely to have a heart attack, according to the report in the May 13 online issue of The Lancet.

"For a decade now there are guidelines saying you should give beta blockers to people having non-cardiac surgery," said lead researcher Dr. P.J. Devereaux, an assistant professor in the Department of Clinical Epidemiology and Biostatistics at McMaster University in Hamilton, Ontario.

The reason for giving beta blockers is that surgery increases the heart's need for oxygen and beta blockers help reduce blood pressure and heart rate, reducing strain on the heart, Devereaux explained.

Around the world, an estimated 100 million people have major non-cardiac surgery each year, so the finding could have serious consequences for many patients, Devereaux noted.

"In the last decade, even if only 10 percent of patients undergoing non-cardiac surgery were given beta blockers, that means 100 million people were given beta blockers, and that means 800,000 people died unnecessarily and a lot of people suffered a major stroke because they were given a beta blocker," Devereaux said.

In the study, 8,351 patients at 190 hospitals across 23 countries who were at risk for atherosclerotic disease [hardening of the arteries] and undergoing non-cardiac surgery were randomly selected to receive a beta blocker or a placebo. The beta blocker was given two to four hours before surgery, and continued for 30 days after the procedure.

The researchers found that patients receiving beta blockers were 16 percent less likely to have died from heart disease, compared with those receiving a placebo. In addition, those taking a beta blocker were 27 percent less likely to have a heart attack than patients receiving a placebo.

But, more people taking a beta blocker died than those taking a placebo. In fact, patients taking a beta blocker had a 33 percent increased risk of dying compared with patients taking a placebo.