title: Anticardiolipin antibodies predict early recurrence of thromboembolism and death among patients with venous thromboembolism following anticoagulant therapy. Duration of Anticoagulation Study Group.
abstract: OBJECTIVE
  To compare the risk of recurrent venous thromboembolism in patients with and without antiphospholipid antibodies.
  
  
  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.
authors.affiliation: Department of Medicine, Karolinska Hospital, Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Schulman
authors.forename: E
authors.initials: E
authors.lastname: Svenungsson
authors.forename: S
authors.initials: S
authors.lastname: Granqvist
mesh_terms: D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000097:blood*; D000925:Anticoagulants / Q000627:therapeutic use*; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012008:Recurrence; D012306:Risk; D013923:Thromboembolism / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology* / Q000401:mortality / Q000517:prevention & control
chemical_list: D017153:Antibodies, Anticardiolipin; D000925:Anticoagulants