title: Individual patient data meta-analysis of enoxaparin vs. unfractionated heparin for venous thromboembolism prevention in medical patients.
abstract: BACKGROUND
  Unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) are both recommended for venous thromboembolism (VTE) prophylaxis in hospitalized medical patients.
  
  
  OBJECTIVE
  To perform an individual patient data meta-analysis to evaluate the relative efficacy and safety of the LMWH enoxaparin and UFH in preventing VTE in hospitalized medical patients.
  
  
  METHODS
  Randomized clinical trials comparing subcutaneous enoxaparin (4000 IU once-daily) and UFH (5000 IU subcutaneous two- or three-times daily) for VTE prevention were identified by a systematic search. Individual patient data were obtained from each eligible trial.
  
  
  RESULTS
  Overall, four trials were eligible, including 3600 patients randomized to receive enoxaparin (n = 1799) or UFH (n = 1801). Median patient age was 71 years, and 49.3% were female. Compared with UFH, enoxaparin was associated with risk reductions of 37% for total VTE [relative risk (RR) 0.63, 95% confidence interval (CI) 0.51-0.77] and 62% for symptomatic VTE (RR 0.38, 95% CI 0.17-0.85) at day 15. RR for total VTE in stroke and non-stroke patients was 0.59 (95% CI 0.47-0.74) and 0.87 (95% CI 0.51-1.50), respectively. Major bleeding rates were consistently low and similar between treatment groups at day 15 (RR 1.13, 95% CI 0.53-2.44). There was a trend towards reduced risk for mortality in patients receiving enoxaparin (RR 0.83, 95% CI 0.64-1.08), compared with UFH.
  
  
  CONCLUSIONS
  Enoxaparin significantly reduces VTE in hospitalized medical patients, compared with UFH, without increasing the risk for major bleeding, and was associated with a trend towards reduced all-cause mortality.
authors.affiliation: Université de Lyon, Université Jean Monnet, Saint-Etienne, France. silvy.laporte@chu-st-etienne.fr
authors.forename: S
authors.initials: S
authors.lastname: Laporte
authors.forename: J
authors.initials: J
authors.lastname: Liotier
authors.forename: L
authors.initials: L
authors.lastname: Bertoletti
authors.forename: F-X
authors.initials: FX
authors.lastname: Kleber
authors.forename: G F
authors.initials: GF
authors.lastname: Pineo
authors.forename: C
authors.initials: C
authors.lastname: Chapelle
authors.forename: N
authors.initials: N
authors.lastname: Moulin
authors.forename: P
authors.initials: P
authors.lastname: Mismetti
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D004311:Double-Blind Method; D017984:Enoxaparin / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D005260:Female; D005602:France / Q000453:epidemiology; D006470:Hemorrhage / Q000209:etiology; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000401:mortality / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin; D006493:Heparin