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Anticoagulant

Blood Thinners for Atrial Fibrillation (COBRRA-AF Trial)

Phase 4
Recruiting
Led By Lana Castellucci, MD, FRCPC
Research Sponsored by Ottawa Hospital Research Institute
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Confirmed new diagnosis of AF on ECG with an indication to start anticoagulation according to Canadian Cardiovascular Society guidelines
Age ≥ 18 years old
Must not have
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
Timeline
Screening 3 weeks
Treatment Varies
Follow Up for the duration of the study: 12 months
Awards & highlights
Pivotal Trial
Drug Has Already Been Approved
No Placebo-Only Group

Summary

This trial is to compare two blood thinners, rivaroxaban and apixaban, to see which one is more effective in reducing strokes in patients with atrial fibrillation.

Who is the study for?
This trial is for adults over 18 with a new diagnosis of atrial fibrillation confirmed by ECG who need blood thinners according to guidelines. It's not for those with severe kidney issues, active bleeding, mechanical heart valves, other anticoagulation needs, certain liver diseases, or if pregnant/breastfeeding.
What is being tested?
The study compares the bleeding risks when using two oral blood thinners—Apixaban and Rivaroxaban—in patients with non-valvular atrial fibrillation. It aims to determine which drug has a better balance between benefits and potential harm.
What are the potential side effects?
Potential side effects of Apixaban and Rivaroxaban include bleeding complications such as nosebleeds, heavier periods, bruising easily, persistent bleeding from cuts or gums, red or brown urine and stools indicating internal bleeding.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
Select...
I have a new diagnosis of atrial fibrillation and need blood thinners.
Select...
I am 18 years old or older.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
Select...
I can safely take blood thinners like apixaban or rivaroxaban without any health risks.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~for the duration of the study: 12 months
This trial's timeline: 3 weeks for screening, Varies for treatment, and for the duration of the study: 12 months for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
The rate of adjudicated clinically relevant bleeding (CRB) events
Secondary study objectives
Medication adherence

Awards & Highlights

Pivotal Trial
The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.
Drug Has Already Been Approved
The FDA has already approved this drug, and is just seeking more data.
No Placebo-Only Group
All patients enrolled in this study will receive some form of active treatment.

Trial Design

2Treatment groups
Active Control
Group I: Rivaroxaban GroupActive Control1 Intervention
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
Group II: Apixaban groupActive Control1 Intervention
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

Find a Location

Who is running the clinical trial?

Ottawa Hospital Research InstituteLead Sponsor
575 Previous Clinical Trials
3,091,865 Total Patients Enrolled
6 Trials studying Atrial Fibrillation
2,795 Patients Enrolled for Atrial Fibrillation
Canadian Institutes of Health Research (CIHR)OTHER_GOV
1,388 Previous Clinical Trials
26,515,055 Total Patients Enrolled
20 Trials studying Atrial Fibrillation
646,903 Patients Enrolled for Atrial Fibrillation
Canadian Venous Thromboembolism Clinical Trials and Outcomes Research (CanVECTOR) NetworkNETWORK
11 Previous Clinical Trials
14,465 Total Patients Enrolled

Media Library

Apixaban (Anticoagulant) Clinical Trial Eligibility Overview. Trial Name: NCT04642430 — Phase 4
Atrial Fibrillation Research Study Groups: Rivaroxaban Group, Apixaban group
Atrial Fibrillation Clinical Trial 2023: Apixaban Highlights & Side Effects. Trial Name: NCT04642430 — Phase 4
Apixaban (Anticoagulant) 2023 Treatment Timeline for Medical Study. Trial Name: NCT04642430 — Phase 4
~1161 spots leftby Dec 2026