Dr Karen Breen Consultant haematologist London

Dr Karen Breen is a Consultant Haematologist with a Specialist interest in Thrombosis. She currently practises at Guys and St Thomas NHS Foundation Trust, London.

Dr Karen Breen

About Dr Karen Breen MD MRCPI FRCPath

Her undergraduate training was at Trinity College, Dublin and postgraduate training including in Haematology was in Ireland before moving to the UK to conduct research leading to an MD. She is a member of the Royal College of Physicians of Ireland and Royal College of Pathologists, UK. She is currently involved in several clinical trials and in translational research in the Antiphospholipid syndrome, and has authored and co-authored on publications on thromboembolic disease.

She is also lead of acute management of thrombosis and anticoagulation and a member of the Trust Thromboprophylaxis and Thrombosis Committee at Guys and St.Thomas’ Foundation Trust.

She has authored several research papers and lectures nationally and internationally on a regular basis.

Special interests

  • Management of thrombotic (clotting) disorders
  • Antiphospholipid syndrome
  • Obstetric (pregnancy) management of thrombotic disorders

Specialist training

  • Trinity College, Dublin medical training scheme
  • Royal College of Physicians (Ireland) higher medical training scheme in haematology

Clotting disorders

Deep vein thrombosis Pulmonary embolism Antiphospholipid Antibody Syndrome (APLS) Factor V Leiden Prothrombin Gene Mutation Protein C Deficiency Protein S Deficiency Antithrombin Deficiency

Your appointment

How to find us


HCA at The Shard
St Thomas Street


The Outpatient & Diagnostic Centre is conveniently located at The Shard with its own private entrance on St Thomas Street situated next to the Shangri-La Hotel and AquaShard entrances. On arrival you will be greeted by a concierge who will direct you to the 4th floor for Registration.

It is easily accessible from both London Bridge Underground Station via the Jubilee and Northern Lines, and London Bridge National Rail Station by Southern, South Eastern and Thameslink services (from January 2018). Central London is at close reach via major routes such as the M25/ M23/ M40/ M4/ M1 and is also well connected via Heathrow, Gatwick, Stansted and Luton airports

Where appropriate we may also be able to arrange telephone/video Consultations – please contact the office to discuss.

Fees & Payment options

New patient consultation: £250

Follow up cost: £150

Following your consultation you may need certain tests (such as blood tests or imaging, for example an X-ray, MRI or CT scan) to help me diagnose your condition. If the test is undertaken by the clinic or hospital, and not by me, the fees for those tests will be determined by the clinic or hospital and charged to you, or your private medical insurer, separately.

If there are any fees, which I will charge in relation to any of the tests I advise that you have, I will let you know what those will be.

Private medical insurance

If you have private medical insurance, please contact your insurer before your consultation, to check the terms of your policy, particularly the level and type of outpatient cover you have, including any reimbursement limits on individual consultation fees.

I am recognised by the following Medical Insurers

CIGNA BUPA WPA AXA-PPP CS Healthcare Aviva Exeter Vitality

Patient Resources

Below are some websites you may find useful.

Thrombosis UK Anticoagulation UK APS Support UK


Recent news and updates.

GUIDANCE: COVID-19 The green book

View Document on gov.uk

April 29th 2021

Update on Astra Zeneca Covid-19 vaccine and thrombosis:

View ISTH statement

View Government response

March 26th 2020

Blood clots and Covid-19:

View Thrombosis UK article

March 26th 2020


Some of my recent research papers and publications.

Image-proven thromboembolism in patients with severe COVID-19 in a tertiary critical care unit in the United Kingdom.

View publication

September 2020

Effect of thrombophilia on clinical outcomes of chronic post-thrombotic patients after iliofemoral stenting with nitinol venous stents.

View publication

May 2020

Outcomes of patients receiving direct oral anticoagulants for myeloproliferative neoplasm-associated venous thromboembolism in a large tertiary centre in the UK.

View publication

February 2020

Midterm outcomes in postpartum women following endovenous treatment for acute iliofemoral deep vein thrombosis.

View publication

December 2019

Management of acute and chronic iliofemoral venous outflow obstruction: a multidisciplinary team consensus.

View publication

December 2019

Comparing APLS and oranges: caution with the use of direct-acting oral anticoagulants (DOACs) instead of warfarin in the treatment of antiphospholipid syndrome (APLS).

View publication

April 2019

Two Year Outcome After Chronic Iliac Vein Occlusion Recanalisation Using the Vici Venous Stent.

View publication

August 2018

The effect of hydroxychloroquine on haemostasis, complement, inflammation and angiogenesis in patients with antiphospholipid antibodies.

View publication

January 2018

Contact details

07510 056 120
Email: Rosanna.McGlone@hcaconsultant.co.uk
Medical Secretary:
Rosanna McGlone

Private Consultations

HCA at The Shard
St Thomas Street

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