title: High rate of unprovoked recurrent venous thrombosis is associated with high thrombin-generating potential in a prospective cohort study.
abstract: OBJECTIVE
  To determine the predictive value of measurement of parameters of thrombin generation for unprovoked recurrent venous thrombosis.
  
  
  METHODS
  Measurements were made of thrombin generation in a prospective cohort study of 188 patients with a first episode of venous thrombosis that was unprovoked, or provoked by a non-surgical trigger.
  
  
  RESULTS
  The endogenous thrombin potential (ETP) was the only parameter associated with unprovoked recurrent thrombosis in a multivariate model [hazard ratio (HR) 1.3 per 100 nmol L min(-1) increase, 95% confidence interval (CI) 1.0-1.6]. Patients with a high ETP had a significantly higher rate of unprovoked recurrence than those with a low ETP (HR 2.9, 95% CI 1.3-6.6, cumulative recurrence at 4 years 27% vs. 11%). Patients with an unprovoked first event had a significantly higher rate of unprovoked recurrence than those with a provoking factor (HR 2.7, 95% CI 1.2-6.1), and in these patients there was a significantly higher rate of unprovoked recurrence in association with a high ETP (HR 4.0, 95% CI 1.3-11.8). After adjustment for D-dimer, thrombophilia, sex, and whether or not the first event was unprovoked, a high ETP remained a significant predictor of recurrence (HR 2.6, 95% CI 1.2-6.0).
  
  
  CONCLUSIONS
  This study demonstrates a high rate of unprovoked recurrent venous thrombosis in patients presenting with a first episode of venous thrombosis and a high ETP.
authors.affiliation: Department of Haematology, Cambridge University Hospitals NHS Trust, Cambridge, UK.
authors.forename: M
authors.initials: M
authors.lastname: Besser
authors.forename: C
authors.initials: C
authors.lastname: Baglin
authors.forename: R
authors.initials: R
authors.lastname: Luddington
authors.forename: A
authors.initials: A
authors.lastname: van Hylckama Vlieg
authors.forename: T
authors.initials: T
authors.lastname: Baglin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D013917:Thrombin / Q000032:analysis / Q000096:biosynthesis*; D020246:Venous Thrombosis / Q000175:diagnosis* / Q000209:etiology
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D013917:Thrombin