Objective: To study the efficacy and safety of apixaban as stroke prophylaxis in patients with chronic kidney disease (CKD) stage 5 and atrial fibrillation (AF) with or without dialysis treatment. The study hypothesis is that compared to no anticoagulation, apixaban reduces the incidence of ischemic stroke without causing an unacceptable increase in fatal or intracranial bleeding events. The secondary objectives are to evaluate the risk of all-cause mortality, cardiovascular events, and major bleeding in people with CKD stage 5 and AF treated with apixaban compared to standard of care without anticoagulation. Trial design: Pragmatic Prospective Open Label Randomized Controlled Clinical Trial, phase 3b over 12-72 months. Trial population: 1000-1400 patients at ≈50 sites in Sweden, Finland, Norway, Iceland and Poland Eligibility criteria: Adults ≥18 years with CKD stage 5 (ongoing treatment with any chronic dialysis treatment OR an estimated glomerular filtration rate (eGFR)\* \<20 ml/min/1.73 m2 at least twice 3 months apart of which at least one occasion is \<15 ml/min/1.73 m2 due to CKD during the last 12 months) and a diagnosis of chronic, paroxysmal, persistent, or permanent AF or atrial flutter (AFL) with CHA2DS2-VASc score ≥2 for men or ≥3 or more for women as an indication for oral anticoagulation. The exclusion criteria are AF or AFL due to reversible causes, rheumatic mitral stenosis or moderate-to-severe non-rheumatic mitral stenosis at the time of inclusion into the study, a condition other than AF or AFL that requires chronic anticoagulation, contraindications for anticoagulation, active bleeding or serious bleeding within 3 months, planned for surgery within 3 months, and current use of strong inhibitors of both CYP3A4 and P-glycoprotein. Interventions: Randomization 1:1 to treatment with apixaban 2.5 mg twice daily and standard of care, or standard of care and no anticoagulation. Outcome measures: primary efficacy (time to first ischemic stroke); primary safety (the composite of time to first intracranial bleeding or fatal bleeding); secondary efficacy (time to all-cause mortality, time to cardiovascular event or cardiovascular death); secondary safety (time to first major bleeding according to International Society on Thrombosis and Hemostasis (ISTH) criteria)