Anticoagulation service 

What is anticoagulation?

Anticoagulants are medicines that help prevent blood clots. They're given to people at a high risk of getting clots, to reduce their chances of developing serious conditions such as strokes and heart attacks.

Anticoagulation at UCLH

UCLH provides an integrated outpatient and inpatient specialist anticoagulation service for the following conditions:

  • Blood clot in a vein (venous thromboembolism or VTE) – including deep vein thrombosis (DVT) and pulmonary embolism (PE).
  • Prevention of stroke (a serious, life-threatening medical condition that occurs when the blood supply to part of the brain is cut off) in patients with atrial fibrillation (a heart condition that causes an irregular and often abnormally fast heart rate).
  • Thrombotic disorders, for example patients with mechanical heart valves or other heart disorders.
  • Complex anticoagulation needs such as patients with renal (kidney) impairment, bleeding problems, and at extremes of body weight.

We also provide a specialist service for the investigation, management and follow up of patients with VTE and with complex thrombotic disorders, including thrombotic APS - a rare condition that can cause severe and life-threatening thrombosis. We are committed to research to improve understanding of APS and treatments.

  • Inpatient anticoagulation service

    UCLH has a specialist anticoagulation service for inpatients (patients coming into hospital). The team is made up of a specialist registrar doctor in clotting, a senior clinical pharmacist and a clinical nurse specialist (CNS). The team is overseen by four thrombosis and haemostasis consultants on a rotating basis.

    The team provides specialist anticoagulation advice for any inpatient at UCLH. This includes patients that are having surgical procedures, patients that have been admitted through the Acute Medical Unit (AMU) or by a referral from staff across the hospital. There is a twice weekly ward round with the thrombosis and haemostasis consultant, who is also available for support and advice between these times. There is a daily visit to the adult wards at University College Hospital by the pharmacist and CNS (Mon-Friday), where patients are reviewed and anticoagulation advice is provided.

    The anticoagulation team provides education to medical, nursing and pharmacy staff on the wards and work with teams to solve anticoagulation issues for their own patients. They promote good working practices to ensure patients are provided with safe and effective anticoagulation throughout their inpatient stay and after they leave hospital.

    The team is responsible for writing and updating many UCLH clinical guidelines for anticoagulation and thromboprophylaxis. Members of the team are actively involved in the implementation of using direct oral anticoagulants (DOAC) within North Central London (NCL). This includes coauthoring of sector wide pathways and clinical guidelines.

    The inpatient service operates Monday to Friday between 09:00-17:00. Outside of these hours, advice is provided by the haematolgy specialist registrar doctor or the attending thrombosis and haemostasis consultant.

  • Outpatient anticoagulation service

    We have a dedicated nurse-led anticoagulation service for patients with thrombotic conditions that require anticoagulation. We see approximately 600 patients each week. The outpatient anticoagulant service at UCLH runs Monday-Friday 08:00-17:00.

    Our services includes:

    • Monitoring of the anticoagulation drug warfarin. Laboratory testing takes place in the clinic (point-of-care testing) to minimise waiting times for patients.
    • Anticoagulation treatment for DVT patients referred from A&E in order to avoid hospital admission
    • Anticoagulation treatment for newly diagnosed patients with PE and atrial fibrillation, to minimise hospital inpatient stay.
    • Consultations to provide advice and guidance on anticoagulation prior to surgical procedures and operations.
    • Telephone advice and consultations to discuss patient queries and anticoagulation with regard to dental treatment, travel arrangements, and any other patient concerns.
    • Supervision of patients who monitor their own warfarin, including telephone and email advice on dosing. This includes quality checks of self-monitoring devices such as coagulometers.
    • Anticoagulation of housebound patients in liaison with community services.
    • Advice and training to patients on administering their own injectable anticoagulation treatment.
    • Initiation of anticoagulation with the new direct oral anticoagulants (DOACs). Oral means the medication is taken by mouth.


Dr Hannah Cohen, Consultant Haematologist

Dr Hannah Cohen

Dr Hannah Cohen is a Consultant Haematologist at UCLH. She is trust clinical lead for anticoagulation and venous thromboembolism; and clinical lead for the thrombosis and haemostasis service to Women’s Health at UCLH.

Full consultant profile

Dr Marie Scully, Consultant Haematologist

Dr Marie Scully

Dr Scully was appointed as a consultant at UCLH in 2007, with an interest in haemostasis and thrombosis. She is clinical lead for haematopathology and blood transfusion at UCLH. She is also the lead for TTP and associated TMAs, including aHUS. UCLH is a specialist centre for TTP.

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Dr Mari Thomas, Consultant Haematologist

Dr Mari Thomas is a new Haematology consultant joining the Thrombosis team at UCLH. She recently completed a PhD at UCL looking into the role of antibodies in TTP. As part of the TTP team, she manages both inpatients and outpatients with TTP and other thrombotic microangiopathies, such as atypical HUS. Her other areas of interest include venous thromboembolism in cancer patients.

Dr Thomas is starting a new clinic for cancer VTE in the UCLH MacMillan Cancer Centre. She also specialises in obstetric haematology, running a joint antenatal clinic for high-risk pregnancies with Dr Cohen and obstetric colleagues. She acts as liaison between the transfusion laboratory and the Fetal Medicine Unit for women with red cell alloantibodies in pregnancy.

"The most rewarding part of my work is working with a great team and seeing our research findings translated into better outcomes for patients."

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Dr John-Paul Westwood, Consultant Haematologist

Dr John-Paul Westwood specialises in Haemostasis and Thrombosis, including Thrombotic Thrombocytopenic Purpura (TTP), Immune Thrombocytopenia (ITP), and bleeding disorders. He also work as a Transfusion consultant. His research intrests are in non-malignant haematology, including TTP and ITP. I am also involved in supporting clinical trials in these disease areas.

“The most rewarding part of my work at UCLH is treating patients with varied and often challenging diseases in the field of haemostasis and thrombosis”

Full consultant profile