Metoprolol around the time of surgery increases the risk of death and stroke: POISE trial

Hamilton, ON (May 12, 2008) - Beta-blocker drugs may help prevent heart attacks during surgery, but they may increase the risk of death and major stroke, says a major study to be published online today by the prestigious medical journal, The Lancet.

POISE is the world’s largest randomized trial addressing perioperative cardiac complications. POISE evaluated the effects of a beta-blocker versus placebo given to patients around the time of surgery.

“POISE demonstrates that a beta-blocker given around the time of surgery decreases a patient’s risk of a heart attack but increases their risk of a major stroke and death,” said Dr. P.J. Devereaux, POISE co-principle investigator, McMaster University, Hamilton, Canada.

Worldwide approximately 100 million adults have major non-cardiac surgery (i.e., all surgeries excluding heart surgeries) each year. Among them, more than one million will suffer a major heart complication such as a heart attack or death.

Surgery increases patients’ catecholamines, or stress hormones, which increase the heart’s requirement for oxygen. The stress on the heart can lead to serious events like a heart attack. Because beta-blockers reduce the effects of increased catecholamines some physicians believed they may prevent serious heart complications around the time of surgery.

“Initial small trials suggested beta-blockers were beneficial around the time of surgery but more recent moderate sized trials did not show any benefit,” Dr. Homer Yang, POISE co-principal investigator, University of Ottawa, Ottawa, Canada. “We undertook POISE to provide a clearer understanding of the effects of a beta-blocker around the time of surgery.”

“A major accomplishment of POISE was that anesthesiologists, cardiologists, internists, and surgeons at 190 centres in 23 countries came together and randomized 8,351 patients - more than 4 times as many patients than all the previous perioperative beta-blocker trials combined. Such efforts are rare, but essential in order to make progress in the management of these patients,” said Dr. Salim Yusuf, POISE steering committee chair, McMaster University, Hamilton, Canada.