Deep vein thrombosis: a proximal DVT, cancer and previous venous thromboembolism increased the risk of further episodes

Clinical bottom line (level 1b)

  1. One in five patients with a first DVT had a further episode of venous thromboembolism in the next 5 years.
  2. One in four patients with a second DVT had a further episode of venous thromboembolism in the next 5 years.
  3. The risk of a another venous thromboembolism was increased with
    • a proximal DVT
    • cancer
    • a history of venous thromboembolism
  4. The risk of another venous thromboembolism was reduced with
    • a post-operative DVT
    • longer duration of oral anticoagulation
Hansson et al: Archives of Internal Medicine 2000; 160 : 769-774
Expires November 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: acute hospital, Sweden

738 patients (aged 17 to 95; mean 66, 51% female) with an objectively verified symptomatic DVT in the leg or arm (17% with cancer; 15% post-operatively)

Excluded if
  • died before discharge or within a month of follow-up
  • temporary visitors and emigrants


    Factors studied:
  • sex, age, duration of oral anticoagulation, location of DVT, level of DVT, any thrombolysis, history of venous thromboembolism, operation within previous 3 months, immobiliszation within previous week, known cancer
  • proximal DVT
  • cancer
  • history of venous thromboembolism
  • post-operative DVT
  • long duration of oral anticoagulation

    All patients were anticoagulated using unfractionated heparin iv for 5 days, and dicumarol or warfarin adjusted so INR 2.0 to 3.0. Anticoagulation was continued for 3 months with a distal DVT and 6 months for a proximal or recurrent DVT. Patients with a large proximal DVT were considered for surgical thrombectomy or thrombolytic therapy.

    A stepwise Cox proportional hazards model was used to adjust for confounding factors.

    100% followed for 3.87 to 8.8 years
    Outcomes studied:
  • recurrent VTE demonstrated objectively
  • recurrent VTE after first DVT
  • recurrent VTE after second DVT

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    recurrent VTE 5 years 146/738 20%
    (17% to 23%)    		 5
    (4 to 6)
    recurrent VTE after first DVT 5 years 109/591 18%
    (15% to 22%)    		 5
    (5 to 7)
    recurrent VTE after second DVT 5 years 37/136 27%
    (20% to 35%)    		 4
    (3 to 5)

    prognostic factor for
    recurrent VTE     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    proximal DVT 5 years 146/738
    (20%)     		2.30
    (1.55 to 3.42)     		6
    (4 to 13)
    cancer 5 years 146/738
    (20%)     		2.21
    (1.43 to 3.41)     		6
    (4 to 16)
    history of venous thromboembolism 5 years 146/738
    (20%)     		1.71
    (1.16 to 2.52)     		10
    (5 to 41)
    post-operative DVT 5 years 146/738
    (20%)     		0.27
    (0.13 to 0.55)     		-7
    (-13 to -6)
    long duration of oral anticoagulation 5 years 146/738
    (20%)     		0.95
    (0.92 to 0.98)     		-130
    (-310 to -80)

    Citation

    1. Hansson PO, Sarbo J, Eriksson H: recurrent venous thromboembolism after deep vein thrombosis: incidence and risk factors. Archives of Internal Medicine 2000; 160 : 769-774
    Search Terms: from ACP Journal Club
    Contributor: Chris Ball, November 2001
    Reviewer:

    Clinical Question.
    Patient symptomatic DVT
    Intervention or Exposure cancer, operation, proximal DVT, duration of anticoagulation, history of VTE
    Outcome recurrent venous thromboembolism