POISE Study Group. Effects of extended-release metoprolol succinate in patients undergoing non-cardiac surgery (POISE trial): a randomised controlled trial. The Lancet Early Online Publication, 13 May 2008
Beta-bloqueador – especificamente succinato de metoprolol, único usado no estudo – aumenta o risco de acidente vascular cerebral e morte não-cardiovascular.
In an international, double-blind, industry-supported study, some 8350 patients with (or at risk for) atherosclerotic disease were randomized preoperatively to a 30-day regimen of extended-release metoprolol or placebo. Patients already receiving beta-blockers were excluded.
By 30 days, patients on metoprolol showed favorable results for the primary endpoint (a composite of cardiovascular death, nonfatal MI, and nonfatal cardiac arrest) — but they had significantly higher rates of death and stroke.
The authors write that current perioperative guidelines ought to be reconsidered. Commentators agree that the regimen used carries more risk than benefit; however, they recommend a lower-dose long-acting regimen that is "titrated to effect" at least 7 days before surgery. That regimen, they say, "is associated with overall benefit compared to risk."
Asked to comment, Journal Watch Cardiology editor-in-chief Harlan Krumholz says that using extended-release metoprolol to reduce risk in patients undergoing noncardiac surgery "has suddenly become a lot more controversial than it was yesterday. If this strategy is contemplated, then it should be done with the patient's knowledge of the potential trade-offs in outcomes."