Abstract 11971: Early Intravenous Beta Blockers Improve In-Hospital and Short-Term Mortality without Increasing the Risk of Cardiogenic Shock in Patients with Acute Coronary Syndrome-A Meta-Analysis
Background: Intravenous (IV) beta-blockade is currently only a Class IIa recommendation in the early management of patients with acute coronary syndromes (ACS) even for subjects without obvious contraindications. We performed a systematic review and meta-analysis of the medical literature to determine if early intravenous beta-blockade improves outcomes of patients with ACS.
Methods: We searched the PubMed, EMBASE and the Cochrane Register for Controlled Clinical Trials for randomized and controlled clinical trials from 1965 through December, 2010 comparing intravenous beta-blockers administered within 12 hours of presentation of ACS with standard medical therapy and/or placebo. The primary outcome assessed was the risk of short-term (up to short terms) all-cause mortality in the intervention group versus the comparator group. The secondary outcomes assessed were ventricular tachyarrhythmias, myocardial reinfarction, cardiogenic shock, and stroke. Pooled treatment effects were estimated using relative risk with Mantel-Haenszel risk ratio, using a random-effects model.
Findings: Nineteen studies enrolling 106,288 participants met the inclusion / exclusion criteria. In-hospital mortality was reduced 11% with intravenous beta-blockers, RR = 0.89 (95% CI, 0.80-1.00; p=0.05) when compared with controls. Moreover, intravenous beta-blockade reduced the risk of ventricular tachyarrhythmias (RR=0.53; 95 % CI 0.41-0.69; p<0.01,) and myocardial reinfarction (RR=0.80, 95 % CI 0.67-0.94; p=0.007) without increase in the risk of cardiogenic shock, (RR=0.78; 95% CI 0.37-1.62; p=0.50) or stroke (RR=0.88; 95 % CI 0.56-1.39; p=0.59).
Interpretation: Intravenous beta-blockers early in the course of appropriate patients with ACS are associated with significant reduction in the risk of short-term cardiovascular outcomes, including a reduction in the risk of all-cause mortality.
- © 2011 by American Heart Association, Inc.