Bleeding and recurrent thrombosis in definite antiphospholipid syndrome: analysis of a series of 66 patients treated with oral anticoagulation to a target international normalized ratio of 3.5.
BACKGROUND
Prolonged anticoagulation is the treatment of choice for patients with thrombosis and the antiphospholipid syndrome. However, there is still debate about the optimum intensity of anticoagulation.


METHODS
The study included 66 patients with antiphospholipid syndrome (Sapporo criteria) and previous thrombosis. All were receiving oral anticoagulation to a target international normalized ratio of 3.5. Every patient was individually interviewed to recall major bleeding and thrombotic episodes during the previous 12 months.


RESULTS
Patients were mainly women and white. The rate of major bleeding was 6 cases per 100 patient-years (95% confidence interval [CI] 1.6-15.0). The rate of intracranial bleed was 1.5 per 100 patient-years (95% CI, 0.04-8.4). None of the bleeding episodes was fatal. The rate of thrombotic recurrences was 9.1 cases per 100 patient-years (95% CI, 3.3-19.6). Most recurrences took place in the same vascular bed as the original thrombosis. Age, time receiving anticoagulant therapy, primary vs secondary antiphospholipid syndrome, positivity for anticardiolipin antibodies, positivity for lupus anticoagulant, previous arterial thrombosis, previous stroke, previous venous thrombosis, and previous thrombocytopenia were not predictive of bleeding events. However, the risk of thrombotic recurrences was independently higher in patients who were receiving anticoagulation for longer periods.


CONCLUSIONS
The risk of intracranial and fatal bleeding in patients with definite antiphospholipid syndrome and previous thrombosis treated with oral anticoagulation to a target international normalized ratio of 3.5 is similar than in groups of patients treated to lower target ratios. The risk of thrombotic recurrences, even during anticoagulation, was high. Most recurrences took place in the same territory as original thromboses.
Ruiz-Irastorza
Guillermo
G
Lupus Research Unit, The Rayne Institute, St Thomas' Hospital, London SE1 7EH, England. 106404.2325@compuserve.com
Khamashta
Munther A
MA
Hunt
Beverley J
BJ
Escudero
Alejandro
A
Cuadrado
Maria J
MJ
Hughes
Graham R V
GR
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D016736:Antiphospholipid Syndrome / Q000150:complications / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D013927:Thrombosis / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects
D000925:Anticoagulants; D014859:Warfarin