Does the early administration of beta-blockers improve the in-hospital mortality rate of patients admitted with acute coronary syndrome?
OBJECTIVE
Beta-blockade is currently recommended in the early management of patients with acute coronary syndromes (ACS). This was a systematic review of the medical literature to determine if early beta-blockade improves the outcome of patients with ACS.


METHODS
The authors searched the PubMed and EMBASE databases for randomized controlled trials from 1965 through May 2009 using a search strategy derived from the following PICO formulation of our clinical question: Patients included adults (18+ years) with an acute or suspected myocardial infarction (MI) within 24 hours of onset of chest pain. Intervention included intravenous or oral beta-blockers administered within 8 hours of presentation. The comparator included standard medical therapy with or without placebo versus early beta-blocker administration. The outcome was the risk of in-hospital death in the intervention groups versus the comparator groups. The methodologic quality of the studies was assessed. Qualitative methods were used to summarize the study results. In-hospital mortality rates were compared using a forest plot of relative risk (RR; 95% confidence interval [CI]) between beta-blockers and controls. Statistical analysis was done with Review Manager V5.0.


RESULTS
Eighteen articles (total N = 72,249) met the inclusion/exclusion criteria. For in-hospital mortality, RR = 0.95 (95% CI, 0.90-1.01). In the largest of these studies (n = 45,852), a significantly higher rate (p < 0.0001) of cardiogenic shock was observed in the beta-blocker (5.0%) versus control group (3.9%).


CONCLUSIONS
This systematic review failed to demonstrate a convincing in-hospital mortality benefit for using beta-blockers early in the course of patients with an acute or suspected MI.
Brandler
Ethan
E
Department of Emergency Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA.
Paladino
Lorenzo
L
Sinert
Richard
R
D054058:Acute Coronary Syndrome / Q000188:drug therapy* / Q000401:mortality*; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000787:Angina Pectoris / Q000188:drug therapy*; D015982:Bias; D004334:Drug Administration Schedule; D017052:Hospital Mortality; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D018570:Risk Assessment; D013997:Time Factors
D000319:Adrenergic beta-Antagonists