Apixaban for the Prevention of Stroke in Subjects With Atrial Fibrillation

This study is comparing two blood-thinning medicines — apixaban and warfarin — to see which one better prevents strokes and dangerous blood clots in people who have an irregular heart rhythm called atrial fibrillation (AF). AF increases the risk of stroke, and blood thinners help lower that risk. Warfarin is already approved for this purpose. Apixaban is a newer medicine being tested. Participants will be randomly assigned to one of the two treatments and followed over time. You may be eligible if: - You are 18 years or older with atrial fibrillation - You have one or more stroke risk factors, such as: being 75 or older, previous stroke or TIA, heart failure, diabetes, or high blood pressure requiring medication You may NOT be eligible if: - Your AF is caused by a reversible condition (e.g., thyroid disease) - You have significant mitral valve narrowing - You have a high risk of bleeding, including previous bleeding in the brain - You need long-term blood thinners for another reason (e.g., a mechanical heart valve) - Your blood pressure is very high and uncontrolled - You are planning major surgery or an AF ablation procedure - You take high-dose aspirin (more than 165 mg per day) - You had an ischemic stroke in the past 7 days Talk to your doctor about whether this trial might be right for you.