title: Early intravenous beta-blockers in patients with acute coronary syndrome--a meta-analysis of randomized trials.
abstract: BACKGROUND
  Intravenous (IV) beta-blockade is currently a Class IIa recommendation in early management of patients with acute coronary syndromes (ACS) without obvious contraindications.
  
  
  METHODS
  We searched the PubMed, EMBASE and the Cochrane Register for Controlled Clinical Trials for randomized clinical trials from 1965 through December, 2011, 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 (in-hospital mortality-with maximum follow up duration of 90 days) 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.
  
  
  RESULTS
  Sixteen studies enrolling 73,396 participants met the inclusion ⁄ exclusion criteria. In- hospital mortality was reduced 8% with intravenous beta-blockers, RR=0.92 (95% CI, 0.86-1.00; p=0.04) when compared with controls. Moreover, intravenous beta-blockade reduced the risk of ventricular tachyarrhythmias (RR=0.61; 95 % CI 0.47-0.79; p=0.0003) and myocardial reinfarction (RR=0.73, 95 % CI 0.59-0.91; p=0.004) without increase in the risk of cardiogenic shock, (RR=1.02; 95% CI 0.77-1.35; p=0.91) or stroke (RR=0.58; 95 % CI 0.17-1.98; p=0.38).
  
  
  CONCLUSIONS
  Intravenous beta-blockers early in the course of appropriate patients with ACS appears to be associated with significant reduction in the risk of short-term cardiovascular outcomes, including a reduction in the risk of all-cause mortality.
authors.affiliation: Maimonides Medical Center, Brooklyn, NY, USA. Electronic address: sauravchatterjeemd@gmail.com.
authors.forename: Saurav
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Debanik
authors.initials: D
authors.lastname: Chaudhuri
authors.forename: Rajesh
authors.initials: R
authors.lastname: Vedanthan
authors.forename: Valentin
authors.initials: V
authors.lastname: Fuster
authors.forename: Borja
authors.initials: B
authors.lastname: Ibanez
authors.forename: Sripal
authors.initials: S
authors.lastname: Bangalore
authors.forename: Debabrata
authors.initials: D
authors.lastname: Mukherjee
mesh_terms: D054058:Acute Coronary Syndrome / Q000188:drug therapy* / Q000453:epidemiology* / Q000503:physiopathology; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D006801:Humans; D007262:Infusions, Intravenous; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D013997:Time Factors
chemical_list: D000319:Adrenergic beta-Antagonists