Practice Guideline

. 2025 Mar 25;9(6):1247-1260.

doi: 10.1182/bloodadvances.2024014219.

American Society of Hematology living guidelines on use of anticoagulation for thromboprophylaxis for patients with COVID-19: executive summary

Deborah M Siegal¹, Eric K Tseng², Holger J Schünemann^{3

4}, Pantep Angchaisuksiri⁵, Adam Cuker⁶, Kathryn Dane⁷, Maria T DeSancho⁸, David Diuguid⁹, Daniel O Griffin^{10

11}, Frederikus A Klok¹², Alfred Ian Lee¹³, Ignacio Neumann¹⁴, Ashok Pai¹⁵, Marc Righini¹⁶, Kristen M Sanfilippo¹⁷, Deirdra R Terrell¹⁸, Elie A Akl¹⁹, Reyad Al Jabiri²⁰, Yazan Al Jabiri²¹, Angela M Barbara²², Antonio Bognanni²³, Imad Bou Akl²⁴, Mary Boulos²⁵, Romina Brignardello-Petersen²⁶, Matthew Chan²⁷, Rana Charide²⁶, Luis E Colunga-Lozano²⁸, Karin Dearness²⁹, Andrea J Darzi²³, Heba Hussein³⁰, Samer G Karam²³, Philipp Kolb²³, Razan Mansour³¹, Gian Paolo Morgano²³, Rami Z Morsi³², Giovanna Muti-Schünemann³³, Menatalla K Nadim³⁴, Atefeh Noori^{26

35}, Binu A Philip²³, Thomas Piggott^{26

36}, Yuan Qiu³⁷, Yetiani Roldan Benitez²⁶, Finn Schünemann³⁸, Adrienne Stevens²³, Karla Solo²³, Wojtek Wiercioch²³, Reem A Mustafa³⁹, Robby Nieuwlaat^{23

31}

Affiliations

¹ Department of Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada.
² Division of Hematology/Oncology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada.
³ Department of Health Research Methods, Evidence, and Impact, Department of Medicine, Michael G. DeGroote Cochrane Canada Centre, and McMaster GRADE Centre, McMaster University, Hamilton, ON, Canada.
⁴ Institut für Evidenz in der Medizin, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany.
⁵ Division of Hematology, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
⁶ Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
⁷ Department of Pharmacy, The Johns Hopkins Hospital, Baltimore, MD.
⁸ Division of Hematology-Oncology, Department of Medicine, Weill Cornell Medicine, New York Presbyterian Hospital, New York, NY.
⁹ Division of Hematology, College of Physicians and Surgeons, Columbia University, New York, NY.
¹⁰ Division of Infectious Diseases, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY.
¹¹ Optum Tristate, Lake Success, NY.
¹² Department of Medicine, Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, The Netherlands.
¹³ Section of Hematology, Yale School of Medicine, New Haven, CT.
¹⁴ Escuela de Medicina, Facultad de Medicina y Ciencia, Universidad San Sebastian, Santiago, Chile.
¹⁵ Division of Hematology and Oncology, Kaiser Permanente, Oakland, CA.
¹⁶ Division of Angiology and Hemostasis, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
¹⁷ Division of Hematology, Washington University School of Medicine St. Louis, St. Louis, MO.
¹⁸ Department of Biostatistics and Epidemiology, Hudson College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK.
¹⁹ Department of Internal Medicine, American University of Beirut, Beirut, Lebanon.
²⁰ Faculty of Medicine, University of Jordan, Amman, Jordan.
²¹ Division of Hospital Medicine, Washington University in St. Louis, St. Louis, MO.
²² Canadian Agency for Drugs and Technologies in Health, Ottawa, ON, Canada.
²³ Department of Health Research Methods, Evidence, and Impact, Michael G. DeGroote Cochrane Canada Centre, and McMaster GRADE Centre, McMaster University, Hamilton, ON, Canada.
²⁴ Faculty of Medicine, American University of Beirut School of Medicine, Beirut, Lebanon.
²⁵ Postgraduate Medical Education, University of Toronto, Toronto, ON, Canada.
²⁶ Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.
²⁷ McMaster GRADE Centre, McMaster University Medical Centre, Hamilton, ON, Canada.
²⁸ Department of Clinical Medicine, Health Science Center, Universidad de Guadalajara, Guadalajara, Mexico.
²⁹ Library Services, St Joseph's Healthcare Hamilton, Hamilton, ON, Canada.
³⁰ Department of Oral Medicine, Oral Diagnosis, and Periodontology, Faculty of Dentistry, Cairo University, Cairo, Egypt.
³¹ University of Kansas Medical Center, University of Kansas, Kansas City, KS.
³² Department of Neurology, University of Chicago, Chicago, IL.
³³ Department of Emergency Medicine, University of Milan, Milan, Italy.
³⁴ Department of Clinical Pathology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
³⁵ Division of Plastic, Reconstructive and Aesthetic Surgery, Hand Program, University Health Network, Toronto Western Hospital, University of Toronto, Toronto, Canada.
³⁶ Department of Family Medicine, Queen's University, Kingston, ON, Canada.
³⁷ Department of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, Canada.
³⁸ Asklepios Klinik Wandsbek, Hamburg, Germany.
³⁹ Division of Nephrology, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS.

PMID: 39437797
PMCID: PMC11950770
DOI: 10.1182/bloodadvances.2024014219

Practice Guideline

American Society of Hematology living guidelines on use of anticoagulation for thromboprophylaxis for patients with COVID-19: executive summary

Deborah M Siegal et al. Blood Adv. 2025.

. 2025 Mar 25;9(6):1247-1260.

doi: 10.1182/bloodadvances.2024014219.

Authors

Affiliations

¹ Department of Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada.
² Division of Hematology/Oncology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada.
³ Department of Health Research Methods, Evidence, and Impact, Department of Medicine, Michael G. DeGroote Cochrane Canada Centre, and McMaster GRADE Centre, McMaster University, Hamilton, ON, Canada.
⁴ Institut für Evidenz in der Medizin, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany.
⁵ Division of Hematology, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
⁶ Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
⁷ Department of Pharmacy, The Johns Hopkins Hospital, Baltimore, MD.
⁸ Division of Hematology-Oncology, Department of Medicine, Weill Cornell Medicine, New York Presbyterian Hospital, New York, NY.
⁹ Division of Hematology, College of Physicians and Surgeons, Columbia University, New York, NY.
¹⁰ Division of Infectious Diseases, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY.
¹¹ Optum Tristate, Lake Success, NY.
¹² Department of Medicine, Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, The Netherlands.
¹³ Section of Hematology, Yale School of Medicine, New Haven, CT.
¹⁴ Escuela de Medicina, Facultad de Medicina y Ciencia, Universidad San Sebastian, Santiago, Chile.
¹⁵ Division of Hematology and Oncology, Kaiser Permanente, Oakland, CA.
¹⁶ Division of Angiology and Hemostasis, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
¹⁷ Division of Hematology, Washington University School of Medicine St. Louis, St. Louis, MO.
¹⁸ Department of Biostatistics and Epidemiology, Hudson College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK.
¹⁹ Department of Internal Medicine, American University of Beirut, Beirut, Lebanon.
²⁰ Faculty of Medicine, University of Jordan, Amman, Jordan.
²¹ Division of Hospital Medicine, Washington University in St. Louis, St. Louis, MO.
²² Canadian Agency for Drugs and Technologies in Health, Ottawa, ON, Canada.
²³ Department of Health Research Methods, Evidence, and Impact, Michael G. DeGroote Cochrane Canada Centre, and McMaster GRADE Centre, McMaster University, Hamilton, ON, Canada.
²⁴ Faculty of Medicine, American University of Beirut School of Medicine, Beirut, Lebanon.
²⁵ Postgraduate Medical Education, University of Toronto, Toronto, ON, Canada.
²⁶ Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.
²⁷ McMaster GRADE Centre, McMaster University Medical Centre, Hamilton, ON, Canada.
²⁸ Department of Clinical Medicine, Health Science Center, Universidad de Guadalajara, Guadalajara, Mexico.
²⁹ Library Services, St Joseph's Healthcare Hamilton, Hamilton, ON, Canada.
³⁰ Department of Oral Medicine, Oral Diagnosis, and Periodontology, Faculty of Dentistry, Cairo University, Cairo, Egypt.
³¹ University of Kansas Medical Center, University of Kansas, Kansas City, KS.
³² Department of Neurology, University of Chicago, Chicago, IL.
³³ Department of Emergency Medicine, University of Milan, Milan, Italy.
³⁴ Department of Clinical Pathology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
³⁵ Division of Plastic, Reconstructive and Aesthetic Surgery, Hand Program, University Health Network, Toronto Western Hospital, University of Toronto, Toronto, Canada.
³⁶ Department of Family Medicine, Queen's University, Kingston, ON, Canada.
³⁷ Department of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, Canada.
³⁸ Asklepios Klinik Wandsbek, Hamburg, Germany.
³⁹ Division of Nephrology, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS.

PMID: 39437797
PMCID: PMC11950770
DOI: 10.1182/bloodadvances.2024014219

Abstract

Background: COVID-19-related critical and acute illness is associated with an increased risk of venous thromboembolism (VTE). These evidence-based recommendations of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about using anticoagulation for thromboprophylaxis for patients with COVID-19-related critical illness; patients with COVID-19-related acute illness; and those being discharged from the hospital, who do not have suspected or confirmed VTE.

Methods: ASH formed a multidisciplinary panel, including patient representatives. The Michael G. DeGroote Cochrane Canada and MacGRADE Centres at McMaster University supported guideline development, including performing systematic reviews (up to June 2023). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess certainty in the evidence and make recommendations.

Results: This is an executive summary of 3 updated recommendations that have been published, which concludes the living phase of the guidelines. For patients with COVID-19-related critical illness, the panel issued conditional recommendations suggesting (a) prophylactic-intensity over therapeutic-intensity anticoagulation and (b) prophylactic-intensity over intermediate-intensity anticoagulation. For patients with COVID-19-related acute illness, conditional recommendations were suggested (a) prophylactic-intensity over intermediate-intensity anticoagulation, and (b) therapeutic-intensity over prophylactic-intensity anticoagulation. The panel issued a conditional recommendation suggesting against the use of postdischarge anticoagulant thromboprophylaxis.

Conclusions: These conditional recommendations were made based on low or very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials for patients with COVID-19.

© 2025 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.

PubMed Disclaimer

Conflict of interest statement

Conflict-of-interest disclosure: All authors were members of the guideline panel or members of the systematic review team or both. As such, they completed a disclosure of interest form, which was reviewed by ASH and is available as supplemental Files 1 and 2.

References

1. Nopp S, Moik F, Jilma B, Pabinger I, Ay C. Risk of venous thromboembolism in patients with COVID-19: a systematic review and meta-analysis. Res Pract Thromb Haemost. 2020;4(7):1178–1191. - PMC - PubMed
1. Katneni UK, Alexaki A, Hunt RC, et al. Coagulopathy and thrombosis as a result of severe COVID-19 infection: a microvascular focus. Thromb Haemost. 2020;120(12):1668–1679. - PMC - PubMed
1. Lowenstein CJ, Solomon SD. Severe COVID-19 is a microvascular disease. Circulation. 2020;142(17):1609–1611. - PMC - PubMed
1. Jimenez D, Garcia-Sanchez A, Rali P, et al. Incidence of VTE and bleeding among hospitalized patients with coronavirus disease 2019: a systematic review and meta-analysis. Chest. 2021;159(3):1182–1196. - PMC - PubMed
1. Schunemann HJ, Al-Ansary LA, Forland F, et al. Guidelines International Network: principles for disclosure of interests and management of conflicts in guidelines. Ann Intern Med. 2015;163(7):548–553. - PubMed

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American Society of Hematology living guidelines on use of anticoagulation for thromboprophylaxis for patients with COVID-19: executive summary

Affiliations

American Society of Hematology living guidelines on use of anticoagulation for thromboprophylaxis for patients with COVID-19: executive summary

Authors

Affiliations

Abstract

Conflict of interest statement

References

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LinkOut - more resources

Full Text Sources

Medical

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