Antiphospholipid-antibody syndrome: warfarin reduced thrombosis.

Clinical bottom line (level 4)

  1. About two-thirds of patients with antiphospholipid antibody syndrome had a recurrent thrombosis.
  2. Warfarin titred to an INR 3.0 or more reduced recurrence (NNF = 3 for 10 years) .
Khamashta et al: New England Journal of Medicine 1995; 332 (15): 993-997
Expires June 2003

The study

Retrospective cohort study with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, UK

147 patients (aged range 14 to 66 years; mean 33, 83% female) antiphospholipid antibody syndrome (positive lupus anticoagulant or positive anticardiolipin antibody, and history of arterial or venous thromboembolism)

Excluded if
  • lost to follow-up or follow-up <1 year
  • syndrome only manifest by recurrent foetal loss
  • no history of thrombosis
  • undocumented antibodies


    • Patients were on warfarin.

    100% followed for 6 years
    Outcomes studied:
  • recurrences

    • Patients consisted of antiphospholipid antibody syndrome: primary (62), associated with systemic lupus erythematosus (66) or lupus-like disease (19)

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    recurrences 6 years 101/147 69%
    (61% to 76%)

    prognostic factor for
    recurrences     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    warfarin INR = 3.0 10 years 101/147
    (69%)     		18.6
    (5.30 to 65.2)     		3
    (3 to 4)

    • 22% of patients on warfarin had major bleeds (all with INR = 3.0 at the time).

    Citation

    1. Khamashta MA, Cuardrado MJ, Mujic F, et al: The management of thrombosis in the antiphospholipid-antibody syndrome. New England Journal of Medicine 1995; 332 (15): 993-997
    Search Terms: atrial fibr* and anticoag* in Cochrane
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer:

    Clinical Question.
    Patient antiphospholipid antibody syndrome
    Intervention or Exposure warfarin INR=3.0
    Outcome recurrence of thrombosis