title: Role of family history of venous thromboembolism and thrombophilia as predictors of recurrence: a prospective follow-up study.
abstract: BACKGROUND
  Several studies have shown that the family history of venous thromboembolism (FHVTE) is a predictor of first venous thromboembolism (VTE). However its role in recurrent VTE is still controversial.
  
  
  OBJECTIVE
  To investigate whether the presence of FHVTE is a risk factor for VTE recurrence in patients from a well-characterized Malmö thrombophilia study.
  
  
  METHODS
  VTE patients from the Malmö Thrombophilia Study were followed from discontinuation of warfarin treatment until diagnosis of VTE recurrence or to the end of the study (maximum follow-up 9.8 years).
  
  
  RESULTS
  There were 127 events of VTE recurrence (12.2%) registered during the follow-up. Multivariate Cox regression analysis in patients with unprovoked first VTE showed that FHVTE was associated with higher risk of VTE recurrence (hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.2-2.9) compared with patients with no FHVTE. Stratification of data according to thrombophilia status of patients showed that compared with the reference group (no FHVTE or thrombophilia), thrombophilia together with FHVTE was associated with a higher risk of VTE recurrence (HR 3.2, 95% CI 1.8-5.9) than thrombophilia alone (HR 1.8, 95% CI 1.02-3.2) independent of DVT location and duration of warfarin treatment. FHVTE was mainly an important risk factor of VTE recurrence in women (HR 3.1, 95% CI 1.6-5.8) but not in men (HR 1.1, 95% CI 0.6-2.2).
  
  
  CONCLUSIONS
  Our results show that FHVTE is a risk factor for VTE recurrence in patients who had unprovoked first VTE. Furthermore, presence of FHVTE may be an additional risk factor of VTE recurrence in thrombophilia-positive patients.
authors.affiliation: Center for Primary Health Care Research, Lund University, Malmö, Sweden.|Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: K
authors.initials: K
authors.lastname: Sundquist
authors.affiliation: Center for Primary Health Care Research, Lund University, Malmö, Sweden.|Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: J
authors.initials: J
authors.lastname: Sundquist
authors.affiliation: Clinical Coagulation Research Unit, Lund University, Malmö, Sweden.
authors.forename: P J
authors.initials: PJ
authors.lastname: Svensson
authors.affiliation: Center for Primary Health Care Research, Lund University, Malmö, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Zöller
authors.affiliation: Center for Primary Health Care Research, Lund University, Malmö, Sweden.
authors.forename: A A
authors.initials: AA
authors.lastname: Memon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D005260:Female; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease; D040941:Heredity; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010375:Pedigree; D010641:Phenotype; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013548:Sweden; D019851:Thrombophilia / Q000150:complications / Q000175:diagnosis / Q000235:genetics*; D013997:Time Factors; D054556:Venous Thromboembolism / Q000175:diagnosis / Q000235:genetics*; D055815:Young Adult
keywords: clinical markers; recurrence; risk factors; thrombophilia; venous thromboembolism