Frequently Asked Questions


Why conduct the BRAIN-AF study?

Recommendations in Canada changed in 2014, advancing the age at which patients with atrial fibrillation should start anticoagulation in the absence of other risk factors from 75 to 65.

Current guidelines do not recommend treatment for patients at low risk of stroke who are younger than 65.

In addition, Coumadin was replaced by new anticoagulant drugs that pose a lower risk of bleeding. These anticoagulant drugs are approved by health authorities such as Health Canada and the U.S. Food and Drug Administration (FDA) to reduce the risk of stroke in patients with atrial fibrillation. It is now possible to benefit from the anticoagulant effects by minimizing the risk of bleeding in a younger population.

With the BRAIN-AF study, we hypothesize that by starting low-dose anticoagulation therapy in patients with atrial fibrillation at low risk of stroke, we can reduce the risk of cognitive decline, stroke, and transient ischemic attack.

Why is the study only open to people aged between 30 and 62?

According to the most recent studies, patients under 30 have a low risk of silent cerebral ischemia. Therefore, there is no need to start anticoagulation therapy so early.

Subjects are eligible until 62 years old, as a minimum of 3 years of follow-up is required to complete this study. The Canadian Cardiovascular Society recommends starting anticoagulation therapy at age 65.

Where does the study take place?

The study takes place across Canada at approximately 40 participating centres.


Can a patient who is already taking anticoagulants or Aspirin® for atrial fibrillation enroll in the study if they meet the eligibility criteria?

Yes. The research team will evaluate each case. If appropriate, the investigating physician may sign a prescription to discontinue treatment at the time of entry into the study. The study medication can be started the next day.

Is a patient with atrial flutter eligible?

Only patients with atypical atrial flutter can enroll.

Is a patient who has undergone an atrial fibrillation ablation eligible?

Patients with recurrent atrial fibrillation after three months are eligible.


What is the frequency of visits?

Visits take place every six months: a midyear visit to distribute the study medication and a full yearly visit, including questions about your general health and a cognitive function test. Visits can be done remotely, via videoconference or phone, or in person at the clinic. If visits are done remotely, the study medication will be mailed to your home.

The research team can be contacted at any time if you have questions about the project or if you experience a problem that you believe is related to your participation in the study.

What is the duration of the study?

Patients are asked to participate in the study for a minimum of 3 years.


How many tablets will I have to take per day?

In general, you will take one (1) tablet per day unless you have a vascular disease, in which case you will take two (2) tablets per day.

Who decides which treatment I receive?

You will randomly (like a coin toss) receive rivaroxaban or a placebo (standard treatment). Your chance of receiving rivaroxaban is 50/50. The placebo is a pill that looks like the real drug but contains no active ingredient. The BRAIN-AF study is a double-blind study, which means that neither you nor the research team will know which treatment you are receiving. However, this information can be obtained by the study physician in case of an emergency.

Patients with vascular disease will receive rivaroxaban or Aspirin®.

Will study participants know what treatment they received at the end of the study?

Yes, through their investigating physician once the trial analysis are completed.


What are the risks associated with participating in the study or taking the drug?

There is a risk of increased bleeding with Aspirin® or anticoagulant medication. Before participation, a series of blood tests and the patient’s medical history are taken to ensure no factors could lead to bleeding.

What are the risks of bleeding?

The reported risk of major bleeding in low-risk patients using 20 mg rivaroxaban per day instead of 15 mg per day (the dose used in this project) is 0.1% to less than 1%.

Should a study participant who develops a risk of stroke (hypertension, diabetes, heart failure, or other) during the study stop taking the study medication?

Yes. If the participant develops an indication for long-term anticoagulation, the study medication will be discontinued. However, we will ask the participant to continue follow-up visits for study statistics.


What is a clinical study?

A clinical study is scientific research to determine if a new or known drug is effective in treating certain health conditions.

It is most often aimed at finding potential new treatments, improved versions of drugs already in use, or new indications for existing treatments.

The safety of participants is the highest priority in any clinical trial. It must be approved by government health authorities and an ethics committee. It must also follow strict rules to protect the safety and privacy of participants.

Most of the time, the clinical study is double-blind and placebo-controlled. This protocol means that neither the patient nor the physician knows whether the drug being administered is the study treatment or the placebo.


What is atrial fibrillation?

Atrial fibrillation (AF) is the most common heart rhythm disorder. It occurs when the upper heart chambers (the atria) lose their normal synchronized contraction pattern. Contractions, therefore, become more rapid and irregular.

Since blood does not drain completely from the atria, clots can form, increasing the risk of a stroke and impaired neurocognitive functions. The risk of blood clots and neurocognitive impairment varies from person to person, depending on the presence or absence of other factors, such as diabetes, high blood pressure, and medical history. This risk can vary from low to high.

How many patients suffer from atrial fibrillation in Canada and around the world?

Atrial fibrillation affects about 700,000 Canadians. Published epidemiological studies have focused mainly on white North Americans and Europeans, estimating its prevalence to be between 1 and 2% in the general population. The prevalence of atrial fibrillation can reach 15% in patients suffering cerebral ischemic attacks. Over the age of 40, one in four adults will eventually develop atrial fibrillation.

What are the causes of atrial fibrillation?

Atrial fibrillation is particularly caused by high blood pressure, hyperthyroidism (overactive thyroid gland), sleep apnea, and alcohol consumption, among others.

What are the symptoms of atrial fibrillation?

People suffering from atrial fibrillation may have warning signs and symptoms such as:

  • Rapid heartbeat / palpitations
  • Shortness of breath
  • Fatigue
  • Dizziness
  • Chest pain

What are the risks associated with atrial fibrillation?

Atrial fibrillation is linked to increased risks of:

  • Strokes
  • Transient ischemic attacks (TIA)
  • Cognitive decline
  • Heart failure

What treatment is recommended in Canada for people with atrial fibrillation?

According to Canadian guidelines, anticoagulants are recommended for patients with atrial fibrillation who are at moderate-to-high risk of strokes. The same guidelines also state that no treatment is recommended for patients with atrial fibrillation who are at low risk of strokes.


What is a stroke?

A stroke occurs when blood flow to a part of the brain is interrupted. A stroke affects brain functions, preventing them from working properly.

The interruption of blood flow to the brain can be caused by:

  • Obstructed blood flow (ischemia)
    • A blood clot can cause a decrease in blood flow. A temporary blood flow obstruction with symptoms disappearing within minutes or hours is called a transient ischemic attack (TIA).
  • Hemorrhage
    • When there is a rupture of a blood vessel or abnormal vascular structure.

Silent cerebral ischemia occurs when tiny clots travel to the brain without causing a clinical CAV.

What is the risk of stroke in people with atrial fibrillation?

The risk is 0.7% in low-risk patients and 18% in high-risk patients annually.

What is the risk of silent cerebral ischemia in those suffering from atrial fibrillation?

The risk is 3 to 7 times higher than in patients with normal (sinus) rhythm. The number of brain lesions is also much higher.


What is neurocognitive decline?

Neurocognitive decline is an impairment of one or more mental abilities, such as memory, comprehension, reasoning, and attention.

Several studies confirm the link between silent cerebral ischemia, cognitive decline, and atrial fibrillation.

Is cognitive impairment caused by atrial fibrillation permanent?

It is difficult to determine if cognitive issues are permanent. In general, cognitive impairment caused by silent cerebral ischemia results in permanent damage. The goal is, therefore, to find a preventive treatment.

Are those with atrial fibrillation more likely to experience cognitive decline?

The link between atrial fibrillation, cognitive impairment, and dementia was established a few years ago. The presence of atrial fibrillation aggravates all types of dementia.