Día Mundial de la Trombosis

ISTH Consensus Statement: A Systematic Approach For Managing Venous Thromboembolism in Patients With COVID-19

A Systematic Approach for Managing Venous Thromboembolism in Patients with COVID-19: A Multinational Consensus Statement from the International Society on Thrombosis and Haemostasis (ISTH) on Behalf of the International Thrombosis Community


With more than 6.7 million confirmed cases worldwide[i] and nearly 400,000 deaths to date (7th June 2020) during 2020,[ii] the COVID-19 pandemic is one of the most significant healthcare crises of our time. The spread of COVID-19 has been varied, with some regions having sporadic transmission and relatively few hospitalized patients with COVID-19 pneumonia, and others where significant transmission has overwhelmed health services. While the disruption to health services continues, it is vital for the World Health Organization (WHO) to share the lessons of how best to prevent, diagnose, and treat patients with COVID-19 with health systems globally, and to learn about agreed clinical best practice approaches, which may improve patient outcomes.

The WHO should be congratulated on the publication of interim guidance on the Clinical Management of hospitalized patients with COVID-19[iii], the second iteration of which was published by the WHO in late May, which serves as a useful first step resource for health systems internationally. However, more must be done to meet the needs of front-line clinicians caring for patients with COVID-19 to ensure quality care, by addressing significant gaps in expert clinical guidance surrounding the prevention and management of venous thromboembolism (VTE) in COVID-19 patients.

COVID-19 and Venous Thromboembolism (VTE)

Venous thromboembolism (VTE) is a condition in which a blood clot forms most often in the deep veins of the leg, groin or arm (known as deep vein thrombosis , DVT) and travels in the circulation, lodging in the lungs (known as pulmonary embolism, PE). Together, DVT and PE are known as VTE - a dangerous, potentially deadly, medical condition.[iv] Hospital-associated VTE (describes VTE occurring in hospital and 90 days post discharge) accounts for 60% of all VTE.

Emerging research indicates that:

  • People with COVID-19, especially those hospitalized with the moderate (requiring supplementary oxygenation) and severe (requiring mechanical ventilation) COVID-19 pneumonia have a high incidence of VTE[v]
  • COVID-19 pneumonia is associated with a marked hypercoagulability, including high levels of fibrinogen and very high D-dimer levels;
  • In patients with COVID-19 pneumonia, there is a major inflammatory response which can lead to micro-clots – immunothrombosis - within the lungs. This likely contributes to the high levels of mortality seen in patients with COVID-19 pneumonia;
  • Some countries are facing difficulties in accessing low molecular weight heparins (blood thinners), a WHO essential medicine, that is a vital prophylactic and treatment for VTE in hospitalized patients with COVID-19.

Call to Action on WHO in Relation to COVID-19-Related VTE

To reduce harm from COVID-19 associated VTE, the International Society on Thrombosis and Haemostasis, together with the undersigned national, continental and international clinical representative organizations, urgently calls on the WHO to endorse and share the application of a system-wide approach to VTE management on a global scale, as part of the international COVID-19 response that seeks to:

  • Highlight the importance of a systematic approach to VTE prevention, diagnosis and treatment for patients with COVID-19; including those isolating at home, those hospitalized and those post discharge;
  • Meet the needs of front-line clinicians caring for patients with COVID-19 to ensure quality care by improving health worker education about VTE in COVID-19 management that incorporates up-to-date consensus recommendations in the next iterations of WHO interim guidance on the Clinical Management of COVID-19 (ensuring a VTE expert(s) is enlisted to the Guideline Development Group);
  • Signpost hospitals to accredited up-to-date evidence based clinical information portals on VTE related COVID-19 clinical guidance, such as the ISTH COVID-19 Resource Page;
  • Highlight to member states the importance of making available all WHO Essential Medicines, in particular low molecular weight heparins (blood thinners), which provides vital prophylactic and treatment for VTE;
  • Improve COVID-19 VTE data collection and research to support regular updates of evidence-based clinical recommendations; and
  • Encourage the implementation of a global VTE risk assessment tool for hospitalized patients.

VTE not only can kill, but can also have devastating co-morbidities, which significantly impact the quality of life for patients who survive COVID-19 and an associated VTE[vi] .

Until there is a vaccine for COVID-19, there is no better way to address this public health challenge than for the WHO to prioritize the development of systematic and integrated approaches to COVID-19-related VTE prevention that can be implemented in secondary and tertiary settings globally.

We urge the WHO to act now and offer our collective resources and expertise to assist in such an endeavor.


Signed on behalf of ISTH


Claire McLintock                            Jeffrey Weitz                                    Beverley Hunt, O.B.E.

President                                          President-Elect                               Chair, World Thrombosis Day




Aktionsbündnid Thrombose


American Heart Association

American Society of Hematology

Anticoagulation Forum




APS Foundation of America



Armenian Association of Hematology and Oncology



Armenian Association of Hemophilia


Armenian Hematology Association

Asian Pacific Society of Cardiology



Asian Pacific Society of Thrombosis and Haemostasis



Asociación Peruana de Trombosis y Hemostasia

Associazione per la Lotta alla Trombosi ealle malattie cardiovascolari – Onlus



Belgian Society on Thrombosis and Haemostasis

Brazilian Association of Hematology, Hemotherapy and

Cell Therapy

Brazilian Society on Thrombosis and Haemostasis


Canadian Venous Thromboembolism Research Network

Centre of Excellence in Thrombosis and Anticoagulation Care

Clinical Leaders of Thrombosis




ČSTH ČLS JEP, Česká společnost pro trombózu a hemostázu ČLS JEP

Deutsche Gefäßliga e.V.

Deutschen Gesellschaft für Gefäßchirurgie und Gefäßmedizin

Deutschen Gesellschaft für Phlebologie

Dutch Society for Thrombosis and Haemostasis

European Thrombosis & Haemostasis Alliance

European Association for Haemophilia and Allied Disorders


Gesellschaft für Thrombose- und Hämostaseforschung

Global Innovative Foundation For Transforming Society (GIFTS NGO)


Grupo Cooperativo Latino Americano de Hemostasia y Trombosis

Health First Europe

Hospital de Clínicas, Facultad de Medicina, Universidad de la República

Hungarian Society of Thrombosis and Haemostasis

International Society on Thrombosis and Haemostasis

Institute for the Study and Education on Thrombosis and Antithrombotic Therapy

Iranian Association for Hemophilia and Thrombophilia

Japanese Society on Thrombosis and Hemostasis


Kenya Society on Thrombosis and Haemostasis (KSTH)


Korean Society on Thrombosis and Haemostasis

Kyrgyz Society of Cardiology

Lithuanian Heart Association

Macedonian Society for Transfusion Medicine

Moroccan Society of
Vascular Diseases

National Blood Clot Alliance

Norwegian Society on Thrombosis and Haemostasis


PERT Consortium



Preventative Cardiovascular Nurses Association


Romanian Society for Vascular Surgery


Romanian Society of Hemostasis and Thrombosis

Russian National Association on Thrombosis and Hemostasis


Russian Scientific Inflammation Society


Slovak Society on Haemostasis and Thrombosis


Sociedad de Hematología del Uruguay


Sociedad de Medicina Interna del Uruguay

Sociedad Espanola de Trombosis y Hemostasia


Sociedad Uruguaya de Patología Clínica

Società Italiana per lo Studio dell’Emostasi e della Trombosi (SISET)


South Asian Society on Atherosclerosis and Thrombosis

Stroke Association of Ghana

Swedish Society on Thrombosis and Haemostasis


Swiss Society of Hematology


Thai Society of Hematology

Thrombosis Hemostasis And Angiology Society of Turkey