Anticardiolipin antibodies predict early recurrence of thromboembolism and death among patients with venous thromboembolism following anticoagulant therapy. Duration of Anticoagulation Study Group

Am J Med. 1998 Apr;104(4):332-8. doi: 10.1016/s0002-9343(98)00060-6.


Purpose: To compare the risk of recurrent venous thromboembolism in patients with and without antiphospholipid antibodies.

Patients and methods: Anticardiolipin antibodies were tested 6 months after a first or second episode of venous thromboembolism. Of the patients with a first episode of venous thromboembolism only the 412 who received 6 months of anticoagulation were studied. Two hundred and eleven patients with a second episode received oral anticoagulation for 6 months or indefinitely. The therapy was targeted at an international normalized ratio (INR) of 2.0 to 2.85. All patients were followed up for 4 years after enrollment.

Results: Among the 412 patients with a first episode of venous thromboembolism the risk of recurrence was 29% in patients with anticardiolipin antibodies and 14% in those without antibodies (P = 0.0013). In those with antibodies, there was an increased risk during the first 6 months after cessation of anticoagulation. The risk of recurrence increased with the titer of the antibodies. Four-year mortality rate was 15% in those with antibodies and 6% in those without (P = 0.01). Among 34 patients with a second event of venous thromboembolism and anticardiolipin antibodies, there were no recurrences during anticoagulant therapy versus 20% in those who received only 6 months of treatment (P = 0.08).

Conclusions: The presence of elevated titers of anticardiolipin antibodies 6 months after an episode of venous thromboembolism is a predictor for an increased risk of recurrence and of death. Patients with anticardiolipin antibodies and venous thromboembolism seem to benefit from prolonged oral anticoagulation.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Antibodies, Anticardiolipin / blood*
  • Anticoagulants / therapeutic use*
  • Cause of Death
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Prognosis
  • Recurrence
  • Risk
  • Thromboembolism / diagnosis
  • Thromboembolism / drug therapy
  • Thromboembolism / immunology*
  • Thromboembolism / mortality
  • Thromboembolism / prevention & control


  • Antibodies, Anticardiolipin
  • Anticoagulants