title: Low-molecular-weight heparins vs. unfractionated heparin in the setting of percutaneous coronary intervention for ST-elevation myocardial infarction: a meta-analysis.
abstract: BACKGROUND
  The aim of the current study was to perform two separate meta-analyses of available studies comparing low-molecular-weight heparins (LMWHs) vs. unfractionated heparin (UFH) in ST-elevation myocardial infarction (STEMI) patients treated (i) with primary percutaneous coronary intervention (pPCI) or (ii) with PCI after thrombolysis.
  
  
  METHODS
  All-cause mortality was the pre-specified primary endpoint and major bleeding complications were recorded as the secondary endpoints. Relative risk (RR) with a 95% confidence interval (CI) and absolute risk reduction (ARR) were chosen as the effect measure.
  
  
  RESULTS
  Ten studies comprising 16,286 patients were included. The median follow-up was 2 months for the primary endpoint. Among LMWHs, enoxaparin was the compound most frequently used. In the pPCI group, LMWHs were associated with a reduction in mortality [RR (95% CI) = 0.51 (0.41-0.64), P < 0.001, ARR = 3%] and major bleeding [RR (95% CI) = 0.68 (0.49-0.94), P = 0.02, ARR = 2.0%] as compared with UFH. Conversely, no clear evidence of benefits with LWMHs was observed in the PCI group after thrombolysis. Meta-regression showed that patients with a higher baseline risk had greater benefits from LMWHs (r = 0.72, P = 0.02).
  
  
  CONCLUSIONS
  LMWHs were associated with greater efficacy and safety than UFH in STEMI patients treated with pPCI, with a significant relationship between risk profile and clinical benefits. Based on this meta-analysis, LMWHs may be considered as a preferred anticoagulant among STEMI patients undergoing pPCI.
authors.affiliation: Department of Cardiology and Internal Medicine, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland. eliano.navarese@alice.it
authors.forename: E P
authors.initials: EP
authors.lastname: Navarese
authors.forename: G
authors.initials: G
authors.lastname: De Luca
authors.forename: F
authors.initials: F
authors.lastname: Castriota
authors.forename: M
authors.initials: M
authors.lastname: Kozinski
authors.forename: P A
authors.initials: PA
authors.lastname: Gurbel
authors.forename: C M
authors.initials: CM
authors.lastname: Gibson
authors.forename: F
authors.initials: F
authors.lastname: Andreotti
authors.forename: A
authors.initials: A
authors.lastname: Buffon
authors.forename: J M
authors.initials: JM
authors.lastname: Siller-Matula
authors.forename: A
authors.initials: A
authors.lastname: Sukiennik
authors.forename: S
authors.initials: S
authors.lastname: De Servi
authors.forename: J
authors.initials: J
authors.lastname: Kubica
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D004562:Electrocardiography; D006493:Heparin / Q000627:therapeutic use*; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D009203:Myocardial Infarction / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*
chemical_list: D006495:Heparin, Low-Molecular-Weight; D006493:Heparin