title: The risk of recurrent venous thromboembolism in men and women.
abstract: BACKGROUND
  Whether a patient's sex is associated with the risk of recurrent venous thromboembolism is unknown.
  
  
  METHODS
  We studied 826 patients for an average of 36 months after a first episode of spontaneous venous thromboembolism and the withdrawal of oral anticoagulants. We excluded pregnant patients and patients with a deficiency of antithrombin, protein C, or protein S; the lupus anticoagulant; cancer; or a requirement for potentially long-term antithrombotic treatment. The end point was objective evidence of a recurrence of symptomatic venous thromboembolism.
  
  
  RESULTS
  Venous thromboembolism recurred in 74 of the 373 men, as compared with 28 of the 453 women (20 percent vs. 6 percent; relative risk of recurrence, 3.6; 95 percent confidence interval, 2.3 to 5.5; P<0.001). The risk remained unchanged after adjustment for age, the duration of anticoagulation, and the presence or absence of a first symptomatic pulmonary embolism, factor V Leiden, factor II G20210A, or an elevated level of factor VIII or IX. At five years, the likelihood of recurrence was 30.7 percent among men, as compared with 8.5 percent among women (P<0.001). The relative risk of recurrence was similar among women who had had their first thrombosis during oral-contraceptive use or hormone-replacement therapy and women in the same age group in whom the first event was idiopathic.
  
  
  CONCLUSIONS
  The risk of recurrent venous thromboembolism is higher among men than women.
authors.affiliation: Department of Internal Medicine I, Division of Hematology and Hemostasis, Ludwig Boltzmann-Institut fur Thromboseforschung, Vienna, Austria. paul.kyrle@meduniwien.ac.at
authors.forename: Paul A
authors.initials: PA
authors.lastname: Kyrle
authors.forename: Erich
authors.initials: E
authors.lastname: Minar
authors.forename: Christine
authors.initials: C
authors.lastname: Bialonczyk
authors.forename: Mirko
authors.initials: M
authors.lastname: Hirschl
authors.forename: Ansgar
authors.initials: A
authors.lastname: Weltermann
authors.forename: Sabine
authors.initials: S
authors.lastname: Eichinger
mesh_terms: D000328:Adult; D003276:Contraceptives, Oral / Q000009:adverse effects; D005260:Female; D020249:Hormone Replacement Therapy / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging; D011859:Radiography; D011877:Radionuclide Imaging; D012008:Recurrence; D012306:Risk; D012307:Risk Factors; D012737:Sex Factors; D013923:Thromboembolism; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000000981:diagnostic imaging
chemical_list: D003276:Contraceptives, Oral