A 3-6-month anticoagulation therapy with warfarin is recommended after the BPV surgery. Patients allocated to the warfarin group will adhere to a target INR range of 2 to 3. Patients 65 > years old and low weight should take warfarin 2.5mg/day and all other patients should take 5mg/day. During hospitalization, the INR will be reassessed daily, and regular measurements (at least every four weeks) should be conducted post-discharge to ensure ongoing patient stability.

Patients allocated to the rivaroxaban group will be administered a dose of 20 mg orally once daily (to be taken with food), or 15 mg once daily in patients with moderate renal impairment at screening (defined as creatinine clearance rate, CrCl between 30 and 49 mL/min).

To compare the efficacy and safety of rivaroxaban as an early anticoagulant therapy for BPV patients with the traditional postoperative anticoagulant warfarin

Patients will be scheduled for outpatient clinic or phone visits at intervals of 0.5, 1, 3, and 6 months following enrollment. During these visits, patients will be instructed to document any symptoms indicative of clinical thromboembolic or bleeding events. If such symptoms are reported, patients may undergo necessary diagnostic and laboratory testing. Cardiac CT and transthoracic echocardiography will be conducted at the 3-month and 6-month marks post-randomization.

Patients will be scheduled for outpatient clinic or phone visits at intervals of 0.5, 1, 3, and 6 months following enrollment. During these visits, patients will be instructed to document any symptoms indicative of clinical thromboembolic or bleeding events. If such symptoms are reported, patients may undergo necessary diagnostic and laboratory testing. Cardiac CT and transthoracic echocardiography will be conducted at the 3-month and 6-month marks post-randomization.

Patients will be scheduled for outpatient clinic or phone visits at intervals of 0.5, 1, 3, and 6 months following enrollment. During these visits, patients will be instructed to document any symptoms indicative of clinical thromboembolic or bleeding events. If such symptoms are reported, patients may undergo necessary diagnostic and laboratory testing. Cardiac CT and transthoracic echocardiography will be conducted at the 3-month and 6-month marks post-randomization.

The Efficacy endpoint was defined as the composite of death from cardiovascular causes or Patients will be scheduled for outpatient clinic or phone visits at intervals of 0.5, 1, 3, and 6 months following enrollment. During these visits, patients will be instructed to document any symptoms indicative of clinical thromboembolic or bleeding events. If such symptoms are reported, patients may undergo necessary diagnostic and laboratory testing. Cardiac CT and transthoracic echocardiography will be conducted at the 3-month and 6-month marks post-randomization.