Researchers
Deborah Siegal

Deborah Siegal

MD MSc FRCPC

Scientist, Inflammation and Chronic Disease

Ottawa Hospital Research Institute

Associate Professor, Department of Medicine

University of Ottawa

Associate Professor, School of Epidemiology and Public Health

University of Ottawa

Contact

dsiegal@toh.ca

613-737-8899 x78804

ORCID 0000-0003-3806-3245
@DebSiegal

Bio

Dr. Deborah Siegal MD MSc FRCPC is a hematologist (thrombosis medicine) and clinician-scientist, Associate Professor of Medicine and School of Epidemiology and Public Health at the University of Ottawa, and Associate Scientist at the Ottawa Hospital Research Institute. She holds a Tier 2 Canada Research Chair in Anticoagulant Management of Cardiovascular Disease. Dr. Siegal received a B.Sc. in Physiology (McGill University, 1998), M.Sc. in Pharmacology (University of Toronto, 2001), M.D. (Queen’s University, 2009), and M.Sc. in Health Research Methodology (McMaster University, 2017).

Research Goals and Interests

  1. Management of anticoagulant-related bleeding.
  2. Restarting anticoagulants after bleeding
  3. Perioperative management of anticoagulation for urgent surgery
  4. Ischemic stroke in patients with cancer

Summary of Research Program
Dr. Siegal’s research program aims to improve the outcomes of patients with cardiovascular disease by optimizing the use of antithrombotic therapies in the following areas: 1) Management of anticoagulant-related bleeding complications; 2) Prevention of anticoagulant-related gastrointestinal bleeding; 3) Perioperative management and outcomes of anticoagulated patients requiring urgent (unplanned) surgery; 4) Epidemiology, antithrombotic management and outcomes of patients with cancer who experience ischemic stroke; and 5) Reducing iatrogenic blood loss and transfusion in critically ill patients.

Selected Research Contributions as Principal Investigator
1. Dr. Siegal had a significant role in the clinical development of andexanet alfa for the reversal of factor Xa inhibitor anticoagulants, including leading the ANNEXA-A/-R studies and analysis and publication of the ANNEXA-4 studies published in the New England Journal of Medicine (2015, 2016, 2019).

2. Post-Bleed Management of Antithrombotic Therapy (PANTHER) research program: Funded by HSFC/CanVECTOR, ASH, CIHR, this series of studies aims to develop an evidence-based strategy for restarting anticoagulants after bleeding, an area of substantial uncertainty with no high-quality evidence to inform clinical decision-making. Ongoing PANTHER studies include the PANTHER-GI Pilot Study evaluating a thrombosis-risk adapted strategy for restarting anticoagulation after major gastrointestinal (GI) bleeding, and PANTHER-VP mixed-methods study which is evaluating patient/caregiver values and preferences regarding restarting anticoagulation after GI bleeding.

3. Perioperative Anticoagulant Use for Surgery Evaluation - Emergency Registry (PAUSE-ER): An international multi-centre prospective cohort study evaluating outcomes of anticoagulated patients requiring urgent procedures.

4. Small-Volume Tubes to Reduce Anemia and Transfusion (STRATUS) study: A stepped wedge cluster randomized trial conducted at 25 hospitals in Canada evaluating whether small-volume blood collection tubes reduce red blood cell transfusion in critically ill patients.

5. Venous Thrombosis Virtual Surveillance in COVID (VVIRTUOSO): Prospective cohort study evaluating the incidence of venous thromboembolism after hospitalization for COVID-19. 

6. Intensive Cancer Screening after Cryoptogenic Stroke (INCOGNITO): Pilot randomized trial assessing the feasibility of a definitive randomized trial to evaluate whether FDG PET/CT in addition to usual care increases the number of occult cancers detected in patients with cryptogenic ischemic stroke compared to usual care alone. 

News

Publications

The CLUE postsurgery VTE risk instrument for abdominal and pelvic surgery: validation of patient risk factor component

2025-08-12 Go to publication

Venous thromboembolism after hospitalization for COVID-19: venous thrombosis virtual surveillance in COVID study

2025-08-01 Go to publication

Measuring Direct Oral Anticoagulant (DOAC) Levels: Applications, Limitations, and Future Directions

2025-04-22 Go to publication

Risk of ischemic stroke after cancer diagnosis: a population-based matched cohort study

2025-04-01 Go to publication

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

2025-03-25 Go to publication
View More on ORCiD

Dr. Siegal has obtained $1.9 million in peer-reviewed grant support as principal investigator or co-principal investigator from the Canadian Institutes of Health Research (CIHR), American Society of Hematology (ASH), Ontario AHSC AFP Innovation Fund, Heart and Stroke Foundation of Canada/CanVECTOR, Canadian Stroke Consortium/Brain Canada, TOHAMO, and Hamilton Health Sciences. She has received an additional $17 million of peer-reviewed grant funding as a co-investigator.

Peer Reviewed Funding as Principal Investigator

Reducing Gastrointestinal Bleeding with Proton Pump Inhibitor Therapy in Acute Venous Thromboembolism (RADIANT) Pilot Randomized Trial, CIHR Project Grant ($543,149) 2023-2026

Intensive Cancer Screening after Cryptogenic Stroke (INCOGNITO): Pilot Randomized Trial, OHRI ELEVATE Grant ($35,000) 2023-2024

Intensive Cancer Screening after Cryptogenic Stroke (INCOGNITO): Pilot Randomized Trial, TOHAMO Ontario AFP Innovation Grant ($87,088) 2023 – 2024

Intensive Cancer Screening after Cryptogenic Stroke (INCOGNITO): Pilot Randomized Trial, Canadian Stroke Consortium/Brain Canada Catalyst Grant ($99,088) 2022 – 2023

Post-Bleed Management of Antithrombotic Therapy after Gastrointestinal Bleeding (PANTHER-GI): A Mixed-Methods Study of Patient Values and Preferences, Canadian Institutes of Health Research Fall 2020 Project Grant ($179,776) 2021 - 2023

Venous Thrombosis Virtual Surveillance in COVID (VVIRTUOSO), Canadian Institutes of Health Research COVID-19 Rapid Research Funding Opportunity ($303,658) 2020 - 2021

Post-Bleed Management of Antithrombotic Therapy after Gastrointestinal Bleeding (PANTHER-GI): A Pilot Randomized Trial of Lower vs. Higher Dose Anticoagulation, American Society of Hematology Scholar Award ($150,000USD) 2020 - 2023

A Population Cohort Study to Evaluate the Risk of Ischemic Stroke, Stroke Treatments and Post-Stroke Outcomes Among Individuals with Cancer Compared to Matched Cancer-Free Controls, HAHSO Ontario AFP Innovation Grant ($94,570) 2020 - 2021

Peer-Reviewed Funding as Co-Investigator

Understanding research priorities for Cerebral Venous Thrombosis, Canadian Institutes of Health Research Planning and Dissemination Grant, (PI: Field, $15,000) 2022

Timely Hip Fracture Care Pathway Implementation: A Feasibility Study - Orthopaedic Trauma Association Full Grant. (PI: Schneider, $65,000 USD) 2022

Antiplatelet Secondary Prevention International Randomised trial after INtracerebral haemorrhaGe: a pragmatic,randomised, parallel group, open, phase 3, international superiority trial -ASPIRING, Canadian Institutes of Health Research Project Grant (PI: Shoamanesh, $1,264,998) 2022 - 2028

Evaluating Individual Cancer-associated Thrombosis Mechanisms to Inform Personalized Thromboprophylaxis in Patients with Metastatic Bone Disease, Canadian Institutes of Health Research Project Grant (PI: Schneider, $1,043,615) 2022-2027

Hip Fracture Care Pathway for those on Oral Anticoagulation -Heart and Stroke Foundation of Canada Grant-in-Aid pilot implementation study (PI: Schneider, $266,900) 2022 - 2025

Evaluating Provincial Implementation of Timely Hip Fracture Care Pathways for Patients on Pre-injury Oral Anticoagulation -University of Calgary Pathways to Success Grant (PI: Schneider, $50,000) 2022 - 2025

HIP fracture thromboPROphylaxis (HIP PRO) Pilot: A Pilot Randomized Controlled Trial -Canadian Institutes of Health Research Project Grant (PI: Schneider, $577,575) 2022 - 2024

Strategies for Anticoagulation in patients with thrombocytopenia and cancer- associated Thrombosis -START pilot randomized controlled trial (PI: Wang/Carrier, $93,700) 2022 - 2023

Anticoagulation for stroke prevention in patients with recent episodes of perioperative atrial fibrillation after noncardiac surgery - The ASPIRE-AF study (PI: Conen, $4,639,726) 2021 - 2026

Perioperative Anticoagulant Use for Surgery Evaluation -Virtual Visit, PAUSE-Virtual (PI: James/Douketis, $707,626) 2021 - 2024

Primary Thromboprophylaxis with Rivaroxaban in Patients with Malignancy and Central Venous Catheters: TRIM-Line, Canadian Institutes for Health Research Fall 2020 Project Grant (PI: Carrier, $1,850,000) 2021 - 2026

Catalyzing research innovation: Developing a web-based application with social media capabilities to coordinate thrombosis research efforts, New Frontiers in Research Fund - Exploration 2020 (PI: Skeith, $250,000) 2021 - 2023

CanVECTOR (Canadian Venous Thromboembolism Clinical Trials and Outcomes Research Network), Operating Grant: PANTHER, Canadian Institutes of Health Research (PI:Kahn/Rodger, $150,000) 2020 - 2021

Global assessment of hemostatic TGA indices following the use of prothrombin complex concentrates for major bleeding or urgent surgery in patients treated with factor Xa inhibitors (GAUGE) - a prospective observational cohort study (PI: Shaw/Carrier, $100,000) 2020 - 2022

Statins for Venous Event Reduction in patients with venous thromboembolism (The SAVER Trial), Project Grant, Canadian Institutes of Health Research (PI: Delluc/Rodger, $3,460,341) 2019 - 2024

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