3 Months' Versus 6 Months' Anticoagulation in Patients With DVT and/or PE

Clinical Trial of Two Durations of Warfarin Therapy in the Treatment of Deep Vein Thrombosis and/or Pulmonary Embolism

To determine whether 3 months' anticoagulation is as good as or better than 6 months' for the treatment of DVT/PE

Multi-centre trial involving 46 hospitals in the United Kingdom, with patients entered by 137 Consultant Physicians. Consenting patients were randomised in a central office to either 3 months' or 6 months' anticoagulation. Information on progress of the patients was requested by the co-ordinating office at 3 months, 6 months and 12 months. Outcomes were measured as death from DVT/PE, non-fatal extensions or recurrences of DVT/PE and major haemorrhages during and after anticoagulation.

Inclusion Criteria:

• Patients aged 18 years or more with suspected or proven DVT/PE whom the clinician intended to anticoagulate.

Exclusion Criteria:

• DVT/PE severe enough to require thrombolysis or pulmonary embolectomy.
• DVT/PE in the preceding 3 years.
• Neoplasia diagnosed/treated within previous 3 years.
• Pregnancy.
• Known major thrombophilias.
• Prolonged or continuous immobility or confinement to bed.
• Previous allergy to heparin or warfarin.
• Requirement for long-term anticoagulation.
• Inability to give informed consent.