Long-term Anticoagulation With Oral Factor Xa Inhibitor Versus Vitamin K Antagonist After Mechanical Aortic Valve Replacement

Inclusion criteria

• Age 19 and more
• At least 3 months after mechanical aortic valve replacement
• At least one of the conditions(as defined below) is met

• The New York Heart Association (NYHA) Functional Classification I or II; or
• According to the Valve Academic Research Consortium(VARC)2 criteria, confirmed proper valve function: no prosthesis-patient mismatch and mean aortic valve gradient <20 mm Hg or peak velocity <3 m/s, AND no moderate or severe prosthetic valve regurgitation
• Voluntarily participated in the written agreement

Exclusion criteria

• Old-generation mechanical valve
• History of mechanical valve implantation in the mitral valve, pulmonary valve, or tricuspid valve
• Valvular atrial fibrillation(atrial fibrillation with moderate or severe mitral stenosis)
• Moderate to severe mitral stenosis or regurgitation
• History of hemorrhagic stroke
• Clinically overt stroke within the last 3 months
• Renal failure(creatinine clearance <15mL/min) or on hemodialysis
• Left ventricular dysfunction: Left ventricular ejection fraction (LVEF) ≤40%
• Child-Pugh B and C hepatic impairment or any hepatic disease associated with coagulopathy
• Clinically significant active bleeding
• Bleeding or hemorrhagic disorder
• The increased risk of bleeding due to the following reasons

• History of gastrointestinal ulcers or active ulcerations within the last 6 months
• History of intracranial or intracerebral hemorrhage within the last 6 months
• Spinal cord vascular abnormalities or intracerebral vascular abnormalities
• History of the brain, spinal cord, or ophthalmic surgery within the last 6 months
• History of the brain or spinal cord injury within the last 6 months
• History of the brain or spinal cord injury or spinal tap, major regional anesthesia, or spinal anesthesia within the last 6 months
• Esophageal varices
• Arteriovenous malformation
• Vascular aneurysms
• Malignant tumor with a high risk of bleeding
• Bleeding tendencies associated with overt bleeding of

• gastrointestinal, genitourinary, respiratory tract, or colorectal cancer
• cerebrovascular hemorrhage
• aneurysms- cerebral, dissecting aorta
• pericarditis and pericardial effusions
• bacterial endocarditis
• Hemodynamically unstable or pulmonary embolism required thrombolysis or embolectomy
• Combination therapy with other anticoagulants(Unfractionated heparin(UFH), enoxaparin, dalteparin, fondaparinux, etc.) However, the following cases are permitted

• Switching anticoagulants
• Intravenous UFH to keep central/arterial lines open
• Uncontrolled moderate or severe hypertension
• Anemia at least one among the conditions(as defined below) is met 1) Hemoglobin level <10.0 g/dL or platelet count < 100 x 10x9/L within the last 6 months 2) Diagnosed and documented ongoing anemia
• Infective endocarditis
• Hypersensitivity to the main component or constituents of Rivaroxaban or Vitamin K antagonist
• Positive pregnancy test results (all pregnant women should undergo urinary human chorionic gonadotropin (hCG) testing within 7 days before screening and/or randomization) or during pregnancy or lactation
• A genetic problem with galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption
• The unsuitable condition of the protocol
• Actively participating in another drug or device investigational study, which has not completed the primary endpoint follow-up period
• Terminal illness with life expectancy <12 months
• Vitamin K deficiency
• Alcoholic or psychical disorder
• Threatened abortion, eclampsia, or preeclampsia
• Concomitant use with antiplatelet in patients with a history of stroke or transient ischemic attack for the treatment of the acute coronary syndrome