Comparing bleeding risks of two blood thinners in patients with atrial fibrillation

COmparison of Bleeding Risk Between Rivaroxaban and Apixaban in Patients With Atrial Fibrillation

Phase 4 Interventional Ottawa Hospital Research Institute · NCT04642430

This study is testing which of two blood thinners, apixaban or rivaroxaban, is safer for people with atrial fibrillation by looking at their bleeding risks over a year.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment3018 (estimated)
Ages18 Years and up
SexAll
SponsorOttawa Hospital Research Institute Academic / other
Locations8 sites (Victoria, British Columbia and 7 other locations)
Trial IDNCT04642430 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to compare the safety of two direct oral anticoagulants, apixaban and rivaroxaban, in patients diagnosed with non-valvular atrial fibrillation (AF). Participants will be monitored for clinically relevant bleeding events over the first 12 months of treatment. The study addresses a critical gap in existing research by providing direct head-to-head comparisons of these two medications, which are both approved for stroke prevention in AF. The findings will help inform clinical practice and guide the choice of anticoagulant therapy for patients.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 18 and older with a confirmed diagnosis of atrial fibrillation who require anticoagulation.

Not a fit: Patients with contraindications for anticoagulation or severe renal impairment may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could help identify which anticoagulant provides a better balance of stroke prevention and bleeding risk for patients with atrial fibrillation.

How similar studies have performed: While there have been studies comparing anticoagulants to warfarin, this trial is novel as it directly compares apixaban and rivaroxaban, which have not been previously evaluated against each other.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age ≥ 18 years old
* Confirmed new diagnosis of AF on ECG with an indication to start anticoagulation according to Canadian Cardiovascular Society guidelines

Exclusion Criteria:

* Creatinine clearance =\<15 ml/min calculated using the Cockcroft-Gault formula
* Any contraindication for anticoagulation with apixaban or rivaroxaban as determined by the treating physician such as, but not limited to:

  * active bleeding
  * history of mechanical valve
  * other indication for anticoagulation (e.g. mechanical valves, venous thrombosis)
  * dual antiplatelet agent use
  * known liver disease with coagulopathy
  * use of contraindicated medications (strong inducers/inhibitors of CYP 3A4/5, P-glycoprotein)
  * pregnancy or breastfeeding

Where this trial is running

Victoria, British Columbia and 7 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Atrial FibrillationStroke PreventionBleed
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.