RIvaroxaban for Valvular Heart diseasE and atRial Fibrillation Trial -RIVER Trial

Patients assigned to rivaroxaban will receive oral rivaroxaban, 20 mg od. Patients with a calculated creatinine clearance of 30 to 49 mL/min per 1.73 m2 received a reduced dose of rivaroxaban of 15 mg od.

"Patients will take the warfarin once daily (q.d.). The individual doses will be titrated as needed to maintain a target INR of 2.0-3.0.~Patients with 65 \> years old, should take warfarin (2,5mg/day) and all others patients should take 5mg/day."