title: The risk of recurrent venous thromboembolism in patients with and without factor V Leiden.
abstract: Thromboprophylaxis with oral anticoagulants up to six months is established in patients after a first venous thromboembolic event (VTE). The risk of recurrent VTE is still considerable thereafter, and it is uncertain whether some patients might benefit from extended anti-coagulation. We performed a prospective, multicenter trial (4 thrombosis centers) and evaluated in 380 patients with a first or recurrent VTE (patients with a deficiency of antithrombin, protein C, protein S or plasminogen; cancer; or an antiphospholipid antibody syndrome were excluded) the risk of recurrence after discontinuation of secondary thromboprophylaxis with oral anticoagulants. It was the aim of the study to evaluate whether patients, with factor V Leiden are at an increased risk of recurrent VTE. 112 (29.5%) patients were carriers of factor V Leiden (26.9% heterozygous, 2.6% homozygous). After a median observation time of 19.3 months the overall recurrence rate of VTE was 9.9%. Recurrent deep vein thrombosis and/or pulmonary embolism occurred in 26 of 268 patients without factor V Leiden (9.7%) and in 10 of 112 patients with factor V Leiden (8.9%). The probability of recurrent VTE two years after discontinuation of oral anticoagulants was 12.4% (95% CI 7.8-17) in patients without factor V Leiden and was 10.6% (95% CI 3.8-17.4) in carriers of the mutation. This difference was statistically not significant. Patients with factor V Leiden are not at a higher risk of recurrent VTE within two years after discontinuation of oral anticoagulants than patients without factor V Leiden. Balancing the risk of recurrent VTE and bleeding from oral anticoagulants, patients with factor V Leiden are not likely to benefit from oral anticoagulant therapy extended beyond six months.
authors.affiliation: Department of Internal Medicine I, University of Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Eichinger
authors.forename: I
authors.initials: I
authors.lastname: Pabinger
authors.forename: A
authors.initials: A
authors.lastname: Stümpflen
authors.forename: M
authors.initials: M
authors.lastname: Hirschl
authors.forename: C
authors.initials: C
authors.lastname: Bialonczyk
authors.forename: B
authors.initials: B
authors.lastname: Schneider
authors.forename: C
authors.initials: C
authors.lastname: Mannhalter
authors.forename: E
authors.initials: E
authors.lastname: Minar
authors.forename: K
authors.initials: K
authors.lastname: Lechner
authors.forename: P A
authors.initials: PA
authors.lastname: Kyrle
mesh_terms: D000328:Adult; D000368:Aged; D005165:Factor V / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D013923:Thromboembolism / Q000188:drug therapy / Q000235:genetics*
chemical_list: C095381:factor V Leiden; D005165:Factor V