Anticardiolipin antibodies predict early recurrence of thromboembolism and death among patients with venous thromboembolism following anticoagulant therapy. Duration of Anticoagulation Study Group.
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.
Schulman
S
S
Department of Medicine, Karolinska Hospital, Stockholm, Sweden.
Svenungsson
E
E
Granqvist
S
S
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
D017153:Antibodies, Anticardiolipin; D000925:Anticoagulants