Beta-blocker drugs can help prevent heart attacks during surgery, but may increase the risk of death and stroke, according to a study recently published in The Lancet.

The POISE trial is the world's largest randomized study to address perioperative cardiac complications. The trial randomized 4,174 patients in 23 countries to receive extended-release metoprolol succinate (Lopressor, Toprol-XL) and 4,177 to receive a placebo.

Of patients who received metoprolol, 176 had heart attacks during surgery, against 239 who received a placebo — a 27% difference. But 129 metoprolol patients died, versus 97 placebo patients, a 33% difference; and 41 metoprolol patients suffered a stroke, compared to just 19 placebo patients.

Guidelines have recommended beta-blockers before noncardiac surgery for more than a decade, said co-principal investigator Dr. P.J. Devereaux of McMaster University in Hamilton, Ontario.

The trial shows those guidelines need to be reconsidered, he said.

Eurekalert.org, "Metoprolol around the time of surgery increases the risk of death and stroke: POISE trial." 2008. http://www.eurekalert.org/pub_releases/2008-05/mu-mat051208.php/ (12 May 2008).