Recruiting

COBRRA-AFBleeding Risk in Atrial Fibrillation Patients Using Rivaroxaban vs Apixaban

Study Aim

This study evaluates the risk of bleeding in people with atrial fibrillation who are taking either Rivaroxaban or Apixaban to see which medication has fewer bleeding events.

What is being tested

Apixaban

+ Rivaroxaban

Drug

Who is being recruted

Arrhythmias, Cardiac+4

+ Atrial Fibrillation

+ Cardiovascular Diseases

Over 18 Years

+4 Eligibility Criteria

See all eligibility criteria

How is the trial designed

Treatment Study

Phase 4

Interventional

Study Start: July 2021

See protocol details

Summary

Principal SponsorOttawa Hospital Research Institute

Study ContactLana Castellucci, MD, FRCPCMore contacts

Last updated: January 28, 2026

Sourced from a government-validated database.Claim as a partner

Study start date: July 6, 2021

Actual date on which the first participant was enrolled.

Atrial Fibrillation is a heart condition that affects many people and increases the risk of having a stroke. To prevent strokes, doctors often prescribe blood thinners. Two common blood thinners, Rivaroxaban and Apixaban, are effective but have not been directly compared to each other in terms of safety. This study is important because it aims to find out which of these medications might be safer when it comes to bleeding risks, which is a major concern for patients taking these drugs. By understanding the safety profiles, healthcare providers can make better decisions to protect patients who have non-valvular Atrial Fibrillation. In this study, participants with non-valvular Atrial Fibrillation will be given either Apixaban, taken twice a day, or Rivaroxaban, taken once a day. The main focus is to observe and compare the amount of bleeding events that occur in each group over the course of a year. The study will closely track any significant bleeding episodes or other relevant bleeding events to determine which medication poses less risk. This information will help doctors choose the best treatment for their patients, minimizing the risk of bleeding complications.

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

NCT04642430

Principal SponsorOttawa Hospital Research Institute

Study ContactLana Castellucci, MD, FRCPCMore contacts

Last updated: January 28, 2026

Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.

Design Details

3018 patients to be enrolled

Total number of participants that the clinical trial aims to recruit.

Treatment Study

These studies test new ways to treat a disease, condition, or health issue. The goal is to see if a new drug, therapy, or approach works better or has fewer side effects than existing options.

Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.

Conditions

Criteria

Any sex

Biological sex of participants that are eligible to enroll.

Over 18 Years

Range of ages for which participants are eligible to join.

Healthy volunteers not allowed

If individuals who are healthy and do not have the condition being studied can participate.

Conditions

Pathology

Arrhythmias, CardiacAtrial FibrillationCardiovascular DiseasesHeart DiseasesHemorrhagePathologic ProcessesPathological Conditions, Signs and Symptoms

Criteria

2 inclusion criteria required to participate

Age ≥ 18 years old

Confirmed new diagnosis of AF on ECG with an indication to start anticoagulation according to Canadian Cardiovascular Society guidelines

2 exclusion criteria prevent from participating

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

Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.

Treatment Groups

Study Objectives

2 intervention groups are designated in this study

This study does not include a placebo group

Treatment Groups

Group I

Active Comparator

5 mg PO, twice daily for 12 months of treatment. A dose reduction\* to 2.5 mg twice daily will apply if patients meet 2 of 3 following criteria: age \> 80 years; weight \< 60 kg; creatinine \>133 micromol/L. \*Patients with AF who are receiving DOAC should have their renal function assessed at baseline and at least annually

Group II

Active Comparator

20 mg PO, once daily for 12 months of treatment. A dose reduction\* to 15 mg daily will apply to patients with creatinine clearance \<50 ml/min. \*Patients with AF who are receiving DOAC should have their renal function assessed at baseline and at least annually

Study Objectives

Primary Objectives

Secondary Objectives

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.

This study has 8 locations

Recruiting

Victoria Cardiac Arrhythmia Trials

Victoria, CanadaOpen Victoria Cardiac Arrhythmia Trials in Google Maps

Recruiting

QEII Health Science Centre

Halifax, Canada

Recruiting

Kingston General Hospital

Kingston, Canada

Recruiting

The Ottawa Hospital - General Campus

Ottawa, Canada

Recruiting

8 Study Centers