Deep vein thrombosis: patients on LMWH could probably be sent home safely.

Clinical bottom line (level 1b-)

  1. In patients with acute proximal deep vein thrombosis, low molecular weight heparin administered primarily at home was probably as effective and safe as unfractionated heparin administered in the hospital.
Levine et al: New England Journal of Medicine 1996; 334 (11): 677-681
Expires May 2003

The study

Unblinded concealed randomised trial with intention-to-treat
Setting: fifteen hospitals, Canada

500 patients (aged mean 58 yeas, 60% male) acute proximal deep vein thrombosis (confirmed by venography or duplex ultrasonography)

Excluded if
  • two previous episodes of DVT or pulmonary embolism
  • active bleeding
  • active peptic ulcer disease
  • familial bleeding disorder
  • concurrent symptomatic pulmonary embolism
  • treatment for >48 hours with standard heparin for the DVT qualifying them for the study
  • inability to make follow-up visits
  • inability to be treated with LMWH because of coexisting condition or the likelihood of noncompliance
  • presence of known deficiency of antithrombin III, protein C or protein S
  • pregnant


    • Control Group: (n = 253, 253 analysed): heparin iv bolus of 5000 units followed by a continuous infusion of 20, 000 units of standard heparin in 500 ml 5% dextrose with 32 ml administered per hour, in the hospital. Infusion rate was adjusted to keep aPTT between 60 and 85 seconds.
    Experimental Group: (n = 247, 247 analysed): enoxaparin 1 mg per kg body weight subcutaneously twice daily, administered primarily at home. No laboratory monitoring was done in this group.
    All patients received warfarin starting on the second day (INR 2.0 to 3.0).
    100% followed for 90 days

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    symptomatic recurrent thromboembolism 90 days 17
    (6.72%)    		 13
    (5.26%)    		 22%
    (-58% to 61%)    		 1.46%
    (-2.70% to 5.61%)    		 69
    (NNT = 18 to infinity;
    NNH = 37 to infinity)
    major bleed 90 days 3
    (1.19%)    		 5
    (2.02%)    		 -71%
    (-600% to 59%)    		 -0.84%
    (-3.04% to 1.37%)    		 -120
    (NNT = 73 to infinity;
    NNH = 33 to infinity)

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    hospital stay (days) 6.5
    (3.4)     		1.1
    (2.9)     		5.4
    (4.8 to 6.0)

    Comments

    1. 120 patients (49%) assigned to LMWH were never hospitalised.
    2. Approximately two thirds of patients with acute proximal DVT were excluded; 40% unable to receive outpatient treatment with LMWH because of associated coexisting conditions, ie. treatment will only be successful in patients who were healthy before the DVT.
    3. No difference in quality of life scores for heparin or LMWH.

    Citation

    1. Levine M, Gent M, Hirsh J, et al: A comparison of low-molecular-weight heparin administered primarily at home with unfractionated heparin administered in the hospital for proximal deep vein thrombosis. New England Journal of Medicine 1996; 334 (11): 677-681
    Contributor: Chris Ball and Clare Wotton, May 2000
    Reviewer:

    Clinical Question.
    Patient acute proximal DVT
    Intervention or Exposure heparin in the hospital
    Comparison enoxaparin at home
    Outcome recurrent thromboembolism