Incidence of venous thromboembolism in first-degree relatives of patients with venous thromboembolism who have factor V Leiden.
The factor V Leiden (FVL) mutation, a genetic abnormality with an autosomal mode of inheritance, is associated with an increased risk of venous thromboembolism (VTE). We aimed to determine the annual incidence of VTE in first-degree relatives of patients with VTE and FVL and to identify factors in patients and the relatives that influence this incidence. In this retrospective and prospective cohort study, the incidence of objectively diagnosed first episodes of VTE was assessed in 553 first-degree relatives of 161 patients with acute VTE and FVL. The annual incidence of VTE was 0.43% (95% CI, 0.3 to 0.56) with FVL and 0.17% (95% CI, 0.07 to 0.27) without FVL (relative risk of 2.5,95% CI, 1.3 to 4.7). A majority (70%) of episodes of VTE were provoked, and this proportion was similar with and without FVL. A larger proportion of VTE was provoked in women (83%) that in men (33%), with the difference accounted for by pregnancy and use of oral contraceptives. The proportion of pregnancies complicated by VTE was 3.9% (95% CI, 2.0-5.8) with FVL and 1.4% (95% CI, 0.04-2.7) without FVL. FVL is associated with a two- to threefold increase in VTE in first-degree relatives of patients with VTE. No subgroup of relatives was identified who require more than routine prophylaxis because of a particularly high risk of VTE.
Couturaud
Francis
F
GETBO, EA 3878, Department of Internal Medicine and Chest Diseases, University Hospital Centre La Cavale Blanche, 29609 Brest, Cedex, France. francis.couturaud@chu-brest.fr
Kearon
Clive
C
Leroyer
Christophe
C
Mercier
Bernard
B
Abgrall
Jean Francois
JF
Le Gal
Grégoire
G
Lacut
Karine
K
Oger
Emmanuel
E
Bressollette
Luc
L
Ferec
Claude
C
Lamure
Michel
M
Mottier
Dominique
D
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000375:Aging; D015331:Cohort Studies; D003276:Contraceptives, Oral / Q000009:adverse effects; D005165:Factor V / Q000235:genetics*; D005260:Female; D005602:France / Q000453:epidemiology; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology* / Q000235:genetics; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012727:Sex Characteristics; D017678:Sex Distribution; D012737:Sex Factors; D020246:Venous Thrombosis / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics
D003276:Contraceptives, Oral; C095381:factor V Leiden; D005165:Factor V