title: The long-term clinical course of acute deep venous thrombosis.
abstract: BACKGROUND
  In patients who have symptomatic deep venous thrombosis, the long-term risk for recurrent venous thromboembolism and the incidence and severity of post-thrombotic sequelae have not been well documented.
  
  
  OBJECTIVE
  To determine the clinical course of patients during the 8 years after their first episode of symptomatic deep venous thrombosis.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  University outpatient thrombosis clinic.
  
  
  METHODS
  355 consecutive patients with a first episode of symptomatic deep venous thrombosis.
  
  
  METHODS
  Recurrent venous thromboembolism, the post-thrombotic syndrome, and death. Potential risk factors for these outcomes were also evaluated.
  
  
  RESULTS
  The cumulative incidence of recurrent venous thromboembolism was 17.5% after 2 years of follow-up (95% CI, 13.6% to 22.2%), 24.6% after 5 years (CI, 19.6% to 29.7%), and 30.3% after 8 years (CI, 23.6% to 37.0%). The presence of cancer and of impaired coagulation inhibition increased the risk for recurrent venous thromboembolism (hazard ratios, 1.72 [CI, 1.31 to 2.25] and 1.44 [CI, 1.02 to 2.01], respectively). In contrast, surgery and recent trauma or fracture were associated with a decreased risk for recurrent venous thromboembolism (hazard ratios, 0.36 [CI, 0.21 to 0.62] and 0.51 [CI, 0.32 to 0.87], respectively). The cumulative incidence of the post-thrombotic syndrome was 22.8% after 2 years (CI, 18.0% to 27.5%), 28.0% after 5 years (CI, 22.7% to 33.3%), and 29.1% after 8 years (CI, 23.4% to 34.7%). The development of ipsilateral recurrent deep venous thrombosis was strongly associated with the risk for the post-thrombotic syndrome (hazard ratio, 6.4; CI, 3.1 to 13.3). Survival after 8 years was 70.2% (CI, 64.7% to 75.6%). The presence of cancer increased the risk for death (hazard ratio, 8.1; CI, 3.6 to 18.1).
  
  
  CONCLUSIONS
  Patients with symptomatic deep venous thrombosis, especially those without transient risk factors for deep venous thrombosis, have a high risk for recurrent venous thromboembolism that persists for many years. The post-thrombotic syndrome occurs in almost one third of these patients and is strongly related to ipsilateral recurrent deep venous thrombosis. These findings challenge the widely adopted use of short-course anticoagulation therapy in patients with symptomatic deep venous thrombosis.
authors.affiliation: University Hospital of Padua, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Prandoni
authors.forename: A W
authors.initials: AW
authors.lastname: Lensing
authors.forename: A
authors.initials: A
authors.lastname: Cogo
authors.forename: S
authors.initials: S
authors.lastname: Cuppini
authors.forename: S
authors.initials: S
authors.lastname: Villalta
authors.forename: M
authors.initials: M
authors.lastname: Carta
authors.forename: A M
authors.initials: AM
authors.lastname: Cattelan
authors.forename: P
authors.initials: P
authors.lastname: Polistena
authors.forename: E
authors.initials: E
authors.lastname: Bernardi
authors.forename: M H
authors.initials: MH
authors.lastname: Prins
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012008:Recurrence; D013577:Syndrome; D013924:Thrombophlebitis / Q000150:complications / Q000188:drug therapy / Q000401:mortality; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D006493:Heparin