A Phase 4 interventional study of Apixaban and Rivaroxaban in Atrial Fibrillation, sponsored by Ottawa Hospital Research Institute. Recruiting at 8 sites in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-01.
Sponsored by Ottawa Hospital Research Institute · Phase 4, Interventional, and Treatment
Atrial Fibrillation (AF) affects 200,000 Canadians and increases risk of stroke, morbidity and mortality. Having a stroke can affect a patient's ability to speak, eat, walk, work, care for themselves, and interact with others. Not only can it ruin one's life, but it can also be fatal. A stroke occurs when blood flow to the brain is blocked by a clot, depriving brain cells of oxygen. In people with atrial fibrillation, blood flow is sluggish in the top chambers of the heart, and blood clots can form there. When a piece of a clot breaks off, it can travel to the brain and cause a stroke. That's where blood thinners come in. Blood thinners, or anticoagulants, decrease the chances of blood clots forming in the heart, reducing the risk of stroke. Studies show that blood thinners are highly effective at reducing the risk of stroke by up to 95%.
The conventional blood thinner is warfarin, taken by mouth. Warfarin requires regular blood tests to make sure a patient getting the correct dose. The patient also may have to avoid certain foods since the medication can interact with them. Newer blood thinners, known as direct-oral anticoagulants (DOACs) are available, which do not require regular blood tests and do not interact with foods. Two of the new blood thinners are called rivaroxaban and apixaban. Like warfarin, they can be taken by mouth, and studies have shown them to be as effective as warfarin.
Both rivaroxaban and apixaban have been approved for stroke prevention in AF by Health Canada. However, there have been no direct head-to-head comparisons of these two anticoagulants, meaning comparative safety data is not available. Increasing use of DOACs for stroke prevention in AF and patient values around bleeding highlight the need for a comparison trial to ensure patients receive the anticoagulant with the greatest balance of benefit to potential harm.
The trial is to assess bleeding rates and superiority of using apixaban versus rivaroxaban in patients with non-valvular atrial fibrillation.
Atrial Fibrillation (AF) affects 200,000 Canadians and increases risk of stroke, morbidity and mortality. Oral anticoagulants such as Vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) are highly effective at reducing the risk of stroke by up to 95%. Randomized controlled trials (RCTs) have compared apixaban and rivaroxaban (both DOACs) to VKAs for stroke prevention in AF, and are approved for this use by Health Canada. However, there have been no direct head-to-head comparisons of these two anticoagulants, meaning comparative safety data is not available. Increasing use of DOACs for stroke prevention in AF, patient values around bleeding, and litigation highlight the need for a comparison trial to ensure patients receive the anticoagulant with the greatest balance of benefit to potential harm.
The objective of this RCT is to compare the safety of the first 12 months of apixaban twice daily to rivaroxaban once daily in patients with non-valvular AF (NVAF). Patients will be monitored for the primary outcome of clinically relevant bleeding (CRB; a composite of major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) events during follow-up. This trial will directly inform clinical practice and the choice of first-line therapy.
3,870 studies on the registry are indexed under Atrial Fibrillation; 924 are open to participants now.
This study's planned enrollment of 3,018 is above the median of 144 across 2,380 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →Ottawa Hospital Research Institute is the lead sponsor of 538 studies on the registry; 100 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Any contraindication for anticoagulation with apixaban or rivaroxaban as determined by the treating physician such as, but not limited to:
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
Drug: Apixaban
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
Drug: Rivaroxaban
Refer to Apixaban group
Also known as: Eliquis
Refer to Rivaroxaban group
Also known as: Xarelto
The rate of adjudicated clinically relevant bleeding (CRB) events
CRB events are defined as the composite of major bleeding (MB) events and clinically relevant non-major bleeding (CRNMB) events
Time frame: For the duration of the study: 12 months
Adjudicated Major Bleeding events
Major Bleeding includes clinically overt bleeding and is associated with: * Fatal bleeding, and/or * Symptomatic bleeding in a critical area or organ, such as intracranial, intraspinal, intraocular, retroperitoneal, intra-articular or pericardial, or intramuscular with compartment syndrome, and/or * A fall in hemoglobin of ≥20 g/L, or * Leading to transfusion of ≥2 units of whole blood or red cells.
Time frame: For the duration of the study: 12 months
Adjudicated Clinically Relevant Non-Major Bleeding events
Clinically relevant non-major bleeding will be defined as: • Any sign or symptom of hemorrhage (e.g., more bleeding than would be expected for a clinical circumstance, including bleeding found by imaging alone) that does not fit the criteria for the ISTH definition of major bleeding but does meet at least one of the following criteria: * Requiring medical intervention by a healthcare professional * Leading to hospitalization or increased level of care * Prompting a face to face (i.e., not just a telephone or electronic communication) evaluation
Time frame: For the duration of the study: 12 months
Adjudicated stroke/TIA events
Stroke is defined as non-traumatic focal neurologic deficit lasting ≥ 24 hours and confirmed on cerebral imaging (computed tomography or magnetic resonance imaging). Transient ischemic attack (TIA) is defined as a temporary loss of blood flow to a part of the brain with focal neurologic deficit lasting \< 24 hours without imaging evidence of acute infarction. Strokes are to be classified as ischemic, hemorrhagic stroke, or uncertain. Hemorrhagic strokes are considered and will be reported as both bleeding events as well as stroke endpoints. The location of the bleeding can be determined from the diagnostic imaging reports.
Time frame: For the duration of the study: 12 months
All-cause mortality
Using a binary outcome of an event or no event (Individual rates of death, all causes).
Time frame: For the duration of the study: 12 months
Medication adherence
Reported as the number of patients self-reporting "all assigned medications were taken" "missing at least one dose of study medication", or "not able to take all of the study medications" out of the total number of medication compliance assessments done respectively
Time frame: For the duration of the study: 12 months
Incremental cost-effectiveness ratio
We will model the prognosis of a cohort of patients receiving rivaroxaban versus apixaban. The results will be presented as incremental cost per QALY gained, incremental costs per one clinically relevant bleeding cases prevented, and incremental cost per one life year saved.
Time frame: For the duration of the study: 12 months
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Ottawa Hospital Research Institute