How should I manage a patient with a history of venous thromboembolism who tests positive for Factor V Leiden?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025Updated: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Management of a patient with a history of venous thromboembolism (VTE) who tests positive for Factor V Leiden:

  • Factor V Leiden is a hereditary thrombophilia that increases the risk of VTE recurrence, which may influence the decision to favour long-term anticoagulation rather than short-term treatment.
  • Long-term anticoagulation should be considered especially if the VTE was unprovoked or if there is a family history of VTE, as the presence of hereditary thrombophilia like Factor V Leiden increases recurrence risk.
  • Thrombophilia testing, including for Factor V Leiden, is generally recommended in people with unprovoked VTE who have a first-degree relative with VTE, and when there is a plan to stop anticoagulation, to guide treatment duration.
  • For patients already on anticoagulation for secondary prevention, thrombophilia testing does not usually alter management and is not routinely recommended.
  • Modifiable risk factors for VTE, such as obesity, should be addressed as part of management.
  • Patients with unprovoked VTE should be assessed for signs or symptoms of cancer, but further cancer investigations are not routinely recommended without clinical indications.
  • Patients should be counselled on the importance of anticoagulant adherence, potential adverse effects, and when to seek medical help for bleeding or recurrent VTE.

In summary, a patient with a history of VTE and positive Factor V Leiden is likely to benefit from long-term anticoagulation to reduce recurrence risk, especially if the initial event was unprovoked or there is a family history of VTE. Specialist haematology advice may be required for complex cases or if anticoagulation management is uncertain.

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