Saturday, February 28, 2009


I spent a half day a week this month in preop clinic. While there, I took the time to go back and read the POISE trial that much ado was made about last year. POISE was a randomized placebo controlled, I believe double blinded study of extended release metoprolol in patients undergoing non-cardiac surgery. They had >8000 patients. MANY studies have shown the benefit of perioperative beta blockade in reducing perioperative MI, the internist's most feared perioperative complication.

POISE verified this finding, with reduction in nonfatal MI, but they discovered that more people died in the metoprolol group. Oops. What did they die of? Stroke. There was a 0.5% increase in stroke in the metoprolol group (statistically significant).

What the hell happened?

Well, if you look at their methods it is instantly obvious what went wrong. The treatment arm, whow as beta blocker naive, received a whopping 100 mg of extended release metoprolol 2-4 hours before their surgery. They chased it with another dose 6 hours postop, or earlier if they ad a HR > 80 or SBP >100. WOW! That's a lot of metoprolol for somebody who has never seen the drug before. 200 mg total of extended release metoprolol a day was then continued for patients that were able to tolerate it without severe bradycardia or hypotension. Gee, I wonder where the strokes came from? Any IM intern could have seen this coming.

Two take-home points here. Peri-operative betablockade doesn't need and shouldn't have the mega doses used in this trial. Also, if you have time before surgery, why not establish the drug for a week or two beforehand?

ACC/AHA 2007 guidelines for perioperative cardiovascular eval for non-cardiac surgery

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