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.


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.
Department of Clinical Epidemiology, Leiden University Medical Center, PO box 9600, 2300 RC Leiden, The Netherlands.
Carla Y
CY
Vossen
Isobel D
ID
Walker
Peter
P
Svensson
Juan C
JC
Souto
Inge
I
Scharrer
F Eric
FE
Preston
Gualtiero
G
Palareti
Ingrid
I
Pabinger
Felix J M
FJ
van der Meer
Mike
M
Makris
Jordi
J
Fontcuberta
Jacqueline
J
Conard
Frits R
FR
Rosendaal
D000293:Adolescent; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D017678:Sex Distribution; D019851:Thrombophilia / Q000188:drug therapy / Q000453:epidemiology*; D020246:Venous Thrombosis / Q000188:drug therapy / Q000453:epidemiology*
D000925:Anticoagulants