BREAKING NEWS: Wall Street Journal article puts spotlight on the potential of new anticoagulants taking fresh aim at one of cardiology’s toughest challenges.

June 28, 2023

ISTH 2023 Oral Presentation: Patient-Relevant Bleeding Events Among Patients Taking Anticoagulant Medication

Presenting author: Dan Bloomfield, MD
Co-authors: B Alexander Yi, Karen Lipworth, Steve Burrows, Mellanie True Hills, Tarin Patrikis, Karen Pieper,
Marc P. Bonaca, John Glasspool
Anthos Therapeutics, Inc.; Insocius;, American Foundation for Women’s Health;
National Blood Clot Alliance; Thrombosis Research Institute; CPC Clinical Research and University of
Colorado School of Medicine
Abstract ID: 1441167 Oral presentation: OC 21.4


I am an employee of and have a financial stake in Anthos Therapeutics [privately held company]

Learning Objectives

Understand the day-to-day bleeding problems (defined as bleeding not requiring medical intervention) experienced by patients on anticoagulants, and the impact on daily activities, emotional well-being, and adherence Review key results from a global survey on the impact of patient-relevant bleeding (PRB) events, including questions about their experiences, the effect on their emotions, and how it made them feel about their anticoagulant therapy.

The impact of bleeding events on quality of life for patients taking anticoagulation is not well studied

  • Bleeding events or bruising that do not require medical
    intervention are often referred to as “minor” bleeding
    events, but even minor bleeds may be relevant to
  • The term “minor” may also reduce HCP-patient
    communication on this type of bleeding
  • We suggest using the term patient-relevant bleeding
    (PRB) events instead of ‘minor’ bleeding
  • The impact of these PRB events among patients taking
    anticoagulant medications is underreported, poorly
    understood, and has not been well described
The objectives of this study were to explore the impact of PRB events in patients taking anticoagulants on:
  • Daily activities
  • Emotional well-being
  • Adherence

Global survey of 3,000+ patients prescribed anticoagulants

Under the leadership of and the National Blood Clot Alliance (NBCA), a
comprehensive patient questionnaire intended to gain quantitative and qualitative
insight on the impact of Patient-Relevant Bleeding (PRB) events, which we defined
as bleeding not requiring medical intervention.



Aims of Patient Survey: To explore the impact of PRB events on daily activities, emotional well-being, and adherence in patients taking anticoagulants

  • Participants aged ≥21 years currently taking anticoagulants were included (warfarin, low molecular weight heparin, or direct oral anticoagulant)
  • The online survey was made available in November 2022 and is accessible globally (English language only)
  • No personally identifiable information collected

Bleeding problems reported across multiple diagnoses, with AF patients experiencing the highest rates

59% of patients reported experiencing a bleeding problem since starting an anticoagulant



47% of patients acknowledged bleeding may have an emotional impact



A substantial proportion of patients adjusted their lifestyles to reduce risk or hide bleeding



Bleeding problems often lead patients to want to pause treatment or reduce their anticoagulant dose



Conclusion: Patient impact is significant

Survey shows the impact of PRB events on patients’ quality-of-life
and adherence to anticoagulant therapy

  • Patients withdraw from an active, healthy lifestyle to minimize bleeding risk
  • Women stay at home during menstrual bleed due to fear of heavy periods
  • Patient-reported emotional burden includes fear of a future bleed they are unable to control
  • Without informing their HCP, some patients temporarily stop taking their anticoagulant medication
  • Other studies suggest that consequences of poor adherence include a nearly 5X increased risk of thrombotic event but NO decrease in bleeding risk compared to fully adherent patients.

Instead of referring to these events as “minor”,
we propose the term “patient-relevant bleeding (PRB)”
to more appropriately reflect their impact and clinical significance

Clinical Significance

Need for a new generation of anticoagulants

In patients with atrial fibrillation being treated with an anticoagulant
  • Major bleeds are critical, but ALL bleeds matter
  • Bleeding and bruising that are relevant to patients, but may not require medical attention, should be considered relevant to the prognosis and clinical care of patients with atrial fibrillation
  • Patient-relevant bleeding has a significant impact on the quality of life of patients and may lead to poor adherence, leaving patients at a high risk for experiencing a stroke


  • Mellanie True Hills ( and Tarin Patrikis (National Blood Clot Alliance) for facilitating the survey in their respective organizations, and the 3,000+ patients who took the time to complete the survey
  • Karen Lipworth and Steve Burrows for the design of the questionnaire and analysis of the results