Risk factors for recurrence of venous thromboembolism associated with the use of oral contraceptives.
BACKGROUND
Combined oral contraceptives (COC) increase the risk of venous thromboembolism (VTE), but the risk of recurrent VTE is not precisely determined. In this retrospective cohort study, we sought the risk factors for recurrence after a first VTE that occurred in women taking COC.


METHODS
Time-to-event analysis was done with Kaplan-Meier estimates. In total, 172 patients were included (43% with pulmonary embolism): 82% had no other clinical risk factor for VTE.


RESULTS
Among the 160 patients who stopped anticoagulation, the cumulative incidence of recurrent VTE was 5.1% after 1 year and 14.2% after 5 years. Significant factors associated with recurrence were renewed use of COC [hazard ratio (HR)=8.2 (2.1-32.2)], antiphospholipid syndrome [HR=4.1 (1.3-12.5)] and protein C deficiency or factor II G20210A [HR=2.7 (1.1-7)]. Pure-progestin contraception [HR=1.3 (0.5-3.0)] or factor V Leiden [HR=1.3 (0.5-3.4)] did not increase recurrence. Postsurgical VTE had a lower risk of recurrence [HR=0.1 (0.0-0.9)].


CONCLUSIONS
Further studies are warranted to determine whether testing for antiphospholipid syndrome, protein C deficiency or the factor II G20210A could modify the duration of anticoagulation. This study confirms the safety of pure-progestin contraception.
Department of Family Medicine, Université de Clermont-Ferrand, Clermont-Ferrand, France. vaillanthelene@yahoo.fr
Hélène
H
Vaillant-Roussel
Lemlih
L
Ouchchane
Claire
C
Dauphin
Pierre
P
Philippe
Marc
M
Ruivard
D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage* / Q000009:adverse effects; D018572:Disease-Free Survival; D005260:Female; D005602:France; D006801:Humans; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000139:chemically induced* / Q000453:epidemiology*; D055815:Young Adult
D003277:Contraceptives, Oral, Combined