Explore the Efficacy and Safety of Once-daily Oral Rivaroxaban for the Prevention of Cardiovascular Events in Subjects With Nonvalvular Atrial Fibrillation Scheduled for Cardioversion

• Composite number of the following events, adjudicated centrally: stroke, transient ischemic attack, non-central nervous system systemic embolism, myocardial infarction and cardiovascular death [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• Number of major bleedings as per central adjudication [ Time Frame: Up to 100 days ] [ Designated as safety issue: Yes ]

• Composite number of strokes and non-central nervous system systemic embolisms [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• Composite number of strokes, transient ischemic attacks, non-central nervous system systemic embolisms, myocardial infarctions and all-cause mortality [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• Number of strokes [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• Number of transient ischemic attacks [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• Number of non-central nervous system systemic embolisms [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• Number of myocardial infarctions [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• Number of cardiovascular deaths [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• All-cause mortality [ Time Frame: Up to 100 days ] [ Designated as safety issue: No ]
• Composite number of major and non-major bleeding events [ Time Frame: Up to 100 days ] [ Designated as safety issue: Yes ]

A study for patients with abnormal heart rhythm (atrial fibrillation) who need to undergo cardioversion (procedure to restore normal heart rhythm). The study will compare patients assigned randomly (like flipping a coin) to either Rivaroxaban or vitamin K antagonist (VKA). The study will measure common medical outcomes for this type of patient such as bleeding and stroke.

• Drug: Rivaroxaban (Xarelto, BAY59-7939)
  Rivaroxaban 20 mg orally once daily; subjects with moderate renal impairment (ie, CrCl of 30 to 49 mL/min, inclusive) will receive the adjusted dose of 15 mg orally once daily in the study
• Drug: Vitamin K antagonist (VKA)
  VKA orally once daily titrated to a target international normalized ratio (INR) of 2.5 (range 2.0-3.0, inclusive); the VKA type (eg, warfarin, acenocoumarol, phenprocoumon, fluindione, etc) will be assigned by the investigator according to local treatment standards

• Experimental: Rivaroxaban (Xarelto, BAY59-7939)
  A Direct Cardioversion Strategy can be performed only if sufficient anticoagulation is proven during the last 21 days prior to randomization and/or a transesophageal echocardiogram (TEE) is planned before cardioversion. Rivaroxaban will be given for 1-5 days before planned direct cardioversion. The run-in of 1-5 days is needed due to potential pretreatment with VKA. Treatment with rivaroxaban will be continued for 42 days after the cardioversion. A Delayed Cardioversion Strategy will be chosen if sufficient anticoagulation is not proven during the last 21 days prior to randomization and no TEE is planned. Rivaroxaban will be given for at least 21 (+4) days before the planned cardioversion, to a maximum of 56 (+4) days prior to planned cardioversion.
  Intervention: Drug: Rivaroxaban (Xarelto, BAY59-7939)
• Active Comparator: Vitamin K antagonist (VKA)
  A Direct Cardioversion Strategy can be performed only if sufficient anticoagulation is proven during the last 21 days prior to randomization and/or a transesophageal echocardiogram (TEE) is planned before cardioversion. VKA will be given for 1-5 days before planned direct cardioversion. The run-in of 1-5 days is needed due to potential pretreatment with VKA. Treatment with VKA will be continued for 42 days after the cardioversion. A Delayed Cardioversion Strategy will be chosen if sufficient anticoagulation is not proven during the last 21 days prior to randomization and no TEE is planned. VKA will be given for at least 21 (+4) days before the planned cardioversion, to a maximum of 56 (+4) days prior to planned cardioversion.
  Intervention: Drug: Vitamin K antagonist (VKA)

Inclusion Criteria:

• Men or women aged >= 18 years
• Hemodynamically stable nonvalvular atrial fibrillation longer than 48 hours or of unknown duration
• Scheduled for cardioversion (electrical or pharmacological) of nonvalvular atrial fibrillation
• Women of childbearing potential and men must agree to use adequate contraception when sexually active

Exclusion Criteria:

• Severe, disabling stroke (modified Rankin score of 4- 5, inclusive) within 3 months or any stroke within 14 days prior to randomization
• Transient ischemic attack within 3 days prior to randomization
• Acute thromboembolic events or thrombosis (venous/arterial) within the last 14 days prior to randomization
• Acute Myocardial infarction (MI) within the last 14 days prior to randomization
• Cardiac-related criteria: known presence of cardiac thombus or myxoma or valvular atrial fibrillation
• Active bleeding or high risk for bleeding contraindicating anticoagulant therapy
• Concomitant medications: indication for anticoagulant therapy other than atrial fibrillation, chronic aspirin therapy > 100 mg daily or dual antiplatelet therapy, strong inhibitors of both cytochrome P450 (CYP) 3A4 and P-glycoprotein (P-gp) if used systemically
• Concomitant conditions: childbearing potential without proper contraceptive measures, pregnancy, or breast feeding; hypersensitivity to investigational treatment or comparator treatment; calculated creatinine clearance (CrCl) < 30 mL/minute; hepatic disease which is associated with coagulopathy leading to a clinically relevant bleeding risk; any severe condition that would limit life expectancy to less than 6 months; planned invasive procedure with potential for uncontrolled bleeding; inability to take oral medication; ongoing drug addiction or alcohol abuse
• Any other contraindication listed in the local labeling for the comparator treatment or experimental treatment
• Participation in a study with an investigational drug or medical device within 30 days prior to randomization