Anticoagulation and DVT: subcutaneous heparin leads to fewer recurrences than continuous intravenous heparin.

Clinical bottom line (level 1a)

  1. In patients with confirmed venous thromboembolism, subcutaneous heparin reduces recurrence or extension of pulmonary embolism or deep vein thrombosis, compared with intravenous heparin (NNT = 27 at unknown) .
  2. There is no clear difference in the number of major bleeds.
Hommes et al: Annals of Internal Medicine 1992; 116 (4): 279-284
Expires June 2003

The study

Systematic review of all randomised trials of
  • Patients: confirmed venous thromboembolism
  • Intervention: subcutaneous heparin in divided dose for 5-14 days compared with continuous iv heparin as above
  • Outcome: extension/recurrence PE/DVT


    • Articles found in all using MEDLINE, 1966 to 1991 (search terms: not detailed ) and search of Current Contents, bibliographies, authors and experts contacted for unpublished studies or other relevant articles.

    Selection criteria: as above
    Appraisal criteria: number of reviewers not detailed. Set criteria used (detailed in text)
    Articles excluded if: not stated

    Eight studies were identified; six had strong methodology
    There was no significant heterogeneity for recurrent venous thromboembolism, but heterogeneous for bleeding.

    The evidence

    Outcome Time to outcome CER OR
    (95% CI)    		 NNT
    (95% CI)
    extension/recurrent PE/DVT unknown 40/382
    (10.5%)    		 0.62
    (0.39 to 0.98)     		27
    (16 to 530)
    major bleed unknown 20/386
    (5.18%)    		 0.79
    (0.42 to 1.48)     		96
    (NNT = 34 to infinity;
    NNH = 43 to infinity)

    Comments

    1. Unclear if trials selected by number of independent reviewers.
    2. Heparin 24,000-37,000 units/day. In four studies patients received more subcutaneous heparin (difference 2100-5000 units/day). Dose monitored with aPTT- range not stated.
    3. Note wide conference intervals- ?from combining trials with small numbers. Is using subcutaneous heparin cheaper?

    Citation

    1. Hommes DW, Bura A, Mazzolai L, et al: Subcutaneous heparin compared with continuous intravenous heparin administered in the initial treatment of deep vein thrombosis: a meta-analysis. Annals of Internal Medicine 1992; 116 (4): 279-284
    Search Terms: heparin in Cochrane
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer:

    Clinical Question.
    Patient venous thromboembolism
    Intervention or Exposure subcutaneous heparin
    Comparison iv heparin
    Outcome recurrence and major bleed