Beta-Bloqueadores no peri-operatório aumentam os riscos após cirurgia não-cardíaca

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."

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Prescrevendo beta-bloqueadores em pacientes idosos com insuficiência cardíaca

Galinier M and Emeriau JP. Prescribing beta blockers in elderly patients with heart failure. Presse Med. 2008 Apr 29 - Epub ahead of print.

Os beta-bloqueadores são ambos eficazes e bem tolerados em pessoas idosas com insuficiência cardíaca, independente da sua fração de ejeção, entretanto, os protocolos prescritivos devem ser seguidos estritamente – Estudo SENIORS.

Beta blockers remain underused in elderly patients with heart failure. Age is not a contraindication to beta blockers. The SENIORS study confirmed that beta blockers are both efficacious and well tolerated in elderly people with heart failure, regardless of their ejection fraction. Because adverse effects may be both more frequent and more serious in the elderly, prescription protocols must be strictly applied. Patients in stable NYHA stages II or III may begin beta blocker treatment, at least 1 month after any decompensation. The initial dose must be as low as possible (1.25mg/d for bisoprolol and nebivolol). Doses must be increased very progressively and stages longer than 15 days may be necessary. The objective is to reach the target dose (10mg/d for bisoprolol and nebivolol), given the dose-response effect that exists for beta blockers in elderly people with heart failure. In the case of low blood pressure, antihypertensive treatments must be reduced or stopped (for example, nitrate derivatives or calcium channel blockers). A reduction in the dosage of any diuretic dosage and finally of the beta blocker may follow, if necessary. Should bradycardia occur, any anti-bradycardia treatments (such as digoxin or amiodarone) must be reduced or stopped before the beta blocker dosage is reduced.