title: Prevention of venous thromboembolism in internal medicine with unfractionated or low-molecular-weight heparins: a meta-analysis of randomised clinical trials.
abstract: BACKGROUND
  The prevention of venous thromboembolic disease is less studied in medical patients than in surgery.
  
  
  METHODS
  We performed a meta-analysis of randomised trials studying prophylactic unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) in internal medicine, excluding acute myocardial infarction or ischaemic stroke. Deep-vein thrombosis (DVT) systematically detected at the end of the treatment period, clinical pulmonary embolism (PE), death and major bleeding were recorded.
  
  
  RESULTS
  Seven trials comparing a prophylactic heparin treatment to a control (15,095 patients) were selected. A significant decrease in DVT and in clinical PE were observed with heparins as compared to control (risk reductions = 56% and 58% respectively, p <0.001 in both cases), without significant difference in the incidence of major bleedings or deaths. Nine trials comparing LMWH to UFH (4,669 patients) were also included. No significant effect was observed on either DVT, clinical PE or mortality. However LMWH reduced by 52% the risk of major haemorrhage (p = 0.049).
  
  
  CONCLUSIONS
  This meta-analysis, based on the pooling of data available for several heparins, shows that heparins are beneficial in the prevention of venous thromboembolism in internal medicine.
authors.affiliation: Clinical Pharmacology Unit, University Hospital of Saint-Etienne, France. mismetti@univ-st-etienne.fr
authors.forename: P
authors.initials: P
authors.lastname: Mismetti
authors.forename: S
authors.initials: S
authors.lastname: Laporte-Simitsidis
authors.forename: B
authors.initials: B
authors.lastname: Tardy
authors.forename: M
authors.initials: M
authors.lastname: Cucherat
authors.forename: A
authors.initials: A
authors.lastname: Buchmüller
authors.forename: D
authors.initials: D
authors.lastname: Juillard-Delsart
authors.forename: H
authors.initials: H
authors.lastname: Decousus
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage*; D006493:Heparin / Q000008:administration & dosage*; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D020246:Venous Thrombosis / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D006493:Heparin