Please assess the completion status of the following clinical trial:

Trial Title: Comparison of Antithrombotic Treatments After Aortic Valve Replacement. Rivaroxaban: A New Antithrombotic Treatment for Patients With Mechanical Prosthetic Aortic Heart Valve.

Study Design Characteristics:
- Allocation: None
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: NONE
- Phase: PHASE2
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~* All patients receiving a mechanical aortic valve replacement. This includes also the following combined procedures:~* Coronary artery bypass~* Composite graft~* Coronary re-implantation~* Aortic root, ascending aorta, arch or hemi-arch replacement~* Redo surgery~* Aortic root enlargement~* Three days after end of the primary aortic valve surgery: no mechanical ventilation in the last 12 hours~* Left ventricular ejection fraction \>/=30% preoperative.~* Written informed consent~Exclusion Criteria~* Contraindication to Phenprocoumon or rivaroxaban treatment.~* Premenopausal and fertile women (menopause defined as 1 year free of period)~* Mitral valve surgery~* Aneurysmectomy~* Maze ablation~* Peripheral vascular surgery~* Aortic type A or B dissection~* Patients following mitral valve replacement~* Patients in need of platelets inhibitors other than Aspirin.~* Active infective endocarditis~* Preoperative atrial fibrillation~* Myocardial infarction or percutaneous coronary intervention within 6 months prior to start of rivaroxaban~* Stroke within 6 months prior to start of rivaroxaban~* Systemic embolism within 6 months prior to start of rivaroxaban~* Severe renal impairment (estimated creatinine clearance ≤30 mL/min)~* Conditions associated with an increased risk of bleeding within 6 months prior to start of rivaroxaban:~* Active liver disease, including but not limited to~* Anemia (hemoglobin level \<85g/L) or thrombocytopenia (platelet count \<100 × 109/L)~* Women who are pregnant or of childbearing potential who refuse to use a medically acceptable form of contraception throughout the study~* Patients considered unreliable by the investigator

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 70 Years
- Healthy Volunteers: f

Study Arms:
- All patients (Type: EXPERIMENTAL): CATHAR is a prospective, open-label, pilot, phase 2 study with independent evaluation of all outcomes. The trial is based on a Bayesian design by incorporating historical information for the control group for all analyses.

Based on this trial design, predict the completion outcome and termination type (if applicable).