POISE

Effects of Extended-Release Metoprolol Succinate in Patients Undergoing Non-Cardiac Surgery: a Randomised Controlled Trial - The Lancet. 2008

Brief Summary:

Although metoprolol reduced the risk of perioperative MI among patients undergoing non-cardiac surgery, this benefit was more than nullified by a higher rate of mortality and strokes.

Reference: http://www.ncbi.nlm.nih.gov/pubmed/18479744