47 research outputs found
Evidence-based approach to thrombophilia testing
Thrombophilia can be identified in about half of all patients presenting with VTE. Testing has increased tremendously for various indications, but whether the results of such tests help in the clinical management of patients has not been settled. I use evidence from observational studies to conclude that testing for hereditary thrombophilia generally does not alter the clinical management of patients with VTE, with occasional exceptions for women at fertile age. Because testing for thrombophilia only serves limited purpose this should not be performed on a routine basis
Hereditary thrombophilia and fetal loss: a prospective follow-up study.
BACKGROUND: As the placental vessels are dependent on the normal balance of
procoagulant and anticoagulant mechanisms, inherited thrombophilia may be
associated with fetal loss. OBJECTIVES: We performed a prospective study to
investigate the relation between inherited thrombophilia and fetal loss, and the
influence of thromboprophylaxis on pregnancy outcome. PATIENTS AND METHODS:
Women were enrolled in the European Prospective Cohort on Thrombophilia (EPCOT).
These included women with factor (F)V Leiden or a deficiency of antithrombin,
protein C or protein S. Controls were partners or acquaintances of thrombophilic
individuals. A total of 191 women (131 with thrombophilia, 60 controls) had a
pregnancy outcome during prospective follow-up. Risk of fetal loss and effect of
thromboprophylaxis were estimated by frequency calculation and Cox regression
modelling. RESULTS: The risk of fetal loss appeared slightly increased in women
with thrombophilia without a previous history of fetal loss who did not use any
anticoagulants during pregnancy (7/39 vs. 7/51; relative risk 1.4; 95%
confidence interval 0.4, 4.7). Per type of defect the relative risk varied only
minimally from 1.4 for FV Leiden to 1.6 for antithrombin deficiency compared
with control women. Prophylactic anticoagulant treatment during pregnancy in 83
women with thrombophilia differed greatly in type, dose and duration, precluding
solid conclusions on the effect of thromboprophylaxis on fetal loss. No clear
benefit of anticoagulant prophylaxis was apparent. CONCLUSIONS: Women with
thrombophilia appear to have an increased risk of fetal loss, although the
likelihood of a positive outcome is high in both women with thrombophilia and in
controls
Risk of a first venous thrombotic event in carriers of a familial thrombophilic defect. The European Prospective Cohort on Thrombophilia (EPCOT)
Background. Reliable risk estimates for venous thrombosis in families with inherited thrombophilia are scarce but necessary for determining optimal screening and treatment policies. Objectives: In the present analysis, we determined the risk of a first venous thrombotic event in carriers of a thrombophilic defect (i.e. antithrombin-, protein C- or protein S deficiency, or factor V Leiden). Patients and methods: The asymptomatic carriers had been tested prior to this study in nine European thrombosis centers because of a symptomatic, carrier in the family, and were followed prospectively for 5.7 years on average between March 1994 and January 2001. Annually, data were recorded on the occurrence of risk situations for venous thrombosis and events (e.g. venous thrombosis, death). Results: Twenty-six of the 575 asymptomatic carriers (4.5%) and seven of the 1118 controls (0.6%) experienced a first deep venous thrombosis or pulmonary embolism during follow-up. Of these events, 58% occurred spontaneously in the carriers compared with 43% in the controls. The incidence of first events was 0.8% per year (95% CI 0.5-1.2) in the carriers compared with 0.1% per year (95% CI 0.0-0.2) in the controls. The highest incidence was associated with antithrombin deficiency or combined defects, and the lowest incidence with factor V Leiden. Conclusions: The incidence of venous events in asymptomatic individuals from thrombophilic families does not exceed the risk of bleeding associated with long-term anticoagulant treatment in the literature (1-3%)
Familial thrombophilia and lifetime risk of venous thrombosis
BACKGROUND: We started a large multicenter prospective follow-up study to
provide reliable risk estimates of venous thrombosis in families with various
thrombophilic defects. OBJECTIVES: This paper describes data collected at study
entry on venous events experienced before study inclusion, i.e. the baseline
data. PATIENTS/METHODS: All individuals (probands, relatives) registered in nine
European thrombosis centers with the factor (F)V Leiden mutation, a deficiency
of antithrombin, protein C or protein S, or a combination of these defects, were
enrolled between March 1994 and September 1997. As control individuals,
partners, friends or acquaintances of the thrombophilic participants were
included. Incidence and relative risk of objectively confirmed venous thrombotic
events (VTEs) prior to entry were calculated for the relatives with
thrombophilia and the controls. RESULTS: Of the 846 relatives with thrombophilia
(excluding probands), 139 (16%) had experienced a VTE with an incidence of 4.4
per 1000 person years. Of the controls, 15 of the 1212 (1%) controls had
experienced a VTE with an incidence of 0.3 per 1000 person years. The risk of
venous thrombosis associated with familial thrombophilia was 15.7 (95% CI
9.2-26.8) and remained similar after adjustment for regional and sex-effects
(16.4; 95% CI 9.6-28.0). The highest incidence per 1000 person years was found
in relatives with combined defects (8.4; 95% CI 5.6-12.2), and the lowest
incidence was found in those with the FV Leiden mutation (1.5; 95% CI 0.8-2.6).
CONCLUSIONS: Considerable differences in the lifetime risk of VTE were observed
among individuals with different thrombophilia defects
Familial thrombophilia and lifetime risk of venous thrombosis
Background. We started a large multicenter prospective follow-up study to provide reliable risk estimates of venous thrombosis in families with various thrombophilic defects. Objectives: This paper describes data collected at study entry on venous events experienced before study inclusion, i.e. the baseline data. Patients/methods: All individuals (probands, relatives) registered in nine European thrombosis centers with the factor (F)V Leiden mutation, a deficiency of antithrombin, protein C or protein S, or a combination of these defects, were enrolled between March 1994 and September 1997. As control individuals, partners, friends or acquaintances of the thrombophilic participants were included. Incidence and relative risk of objectively confirmed venous thrombotic events (VTEs) prior to entry were calculated for the relatives with thrombophilia and the controls. Results: Of the 846 relatives with thrombophilia (excluding probands), 139 (16%) had experienced a VTE with an incidence of 4.4 per 1000 person years. Of the controls, 15 of the 1212 (1%) controls had experienced a VTE with an incidence of 0.3 per 1000 person years. The risk of venous thrombosis associated with familial thrombophilia was 15.7 (95% CI 9.2-26.8) and remained similar after adjustment for regional and sex-effects (16.4; 95% CI 9.6-28.0). The highest incidence per 1000 person years was found in relatives with combined defects (8.4; 95% CI 5.6-12.2), and the lowest incidence was found in those with the FV Leiden mutation (1.5; 95% CI 0.8-2.6). Conclusions: Considerable differences in the lifetime risk of VTE were observed among individuals with different thrombophilia defects
Recurrence rate after a first venous thrombosis in patients with familial thrombophilia
OBJECTIVE: Few comprehensive data are available on the recurrence rate of venous thrombosis in carriers of thrombophilic defects from thrombophilic families. We prospectively determined the recurrence rate after a first venous thrombotic event in patients with familial thrombophilia attributable to factor V Leiden or deficiencies of protein C, S, or antithrombin. METHODS AND RESULTS: Data were gathered during follow-up on the occurrence of risk situations, anticoagulation treatment, and events (eg, venous thrombosis, hemorrhage). Over a mean follow-up period of 5.6 years, 44 of the 180 patients with familial thrombophilia who did not use long-term anticoagulation experienced a recurrent venous thromboembolic event (5.0%/year; 95% CI 3.6 to 6.7) compared with 7 of the 124 patients on long-term anticoagulation (1.1%/year; 95% CI 0.4 to 2.2). Spontaneous events occurred less often in patients on long-term anticoagulation (57%) than in patients without long-term anticoagulation (75%). The highest recurrence rate was found among men with a deficiency in natural anticoagulants or multiple defects and women with antithrombin deficiency. Although long-term anticoagulation treatment decreased the incidence of recurrent events by 80%, it also resulted in a risk of major hemorrhage of 0.8% per year. CONCLUSIONS: Extra care after a first event is required for men with a deficiency in natural anticoagulants or multiple defects and women with antithrombin deficiency