Please assess the completion status of the following clinical trial:

Trial Title: D-Dimer Determined Anticoagulation INTENSITY in Patients With Mechanical Valve Replacement

Study Design Characteristics:
- Allocation: None
- Intervention Model: None
- Observational Model: COHORT
- Primary Purpose: None
- Time Perspective: PROSPECTIVE
- Masking: None
- Phase: None
- Number of Arms: None

Eligibility Criteria:
Inclusion Criteria:~1. age\>18years,male or female without pregnancy;~2. Suffered the mechanical valves replacement in Wuhan Asia Heart Hospital;~3. The operation type was Mitral valve replacement or Double valves replacement(aortic and mitral valve replacement).~Exclusion Criteria: Patients with following diseases within 3 months.~1. deep venous thromboembolism~2. Pulmonary embolism~3. Aortic dissection~4. stroke~5. Cerebral hemorrhage~6. Myocardial infarction

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 80 Years
- Healthy Volunteers: t

Study Arms:
- Standard intensity of anticoagulation (Type: None): After mechanical valve replacement，patients should be gave oral anticoagulants，such as warfarin.and The intensity of anticoagulation for this group was standard intensity (INR:2.5-3.5).
- Low intensity and adjusted by elevated D-dimer (Type: None): The intensity of anticoagulation maintained at low level initiatively, D-dimer testing were analyzed at 3 month later. In case of D-dimer level elevated, adjusted the intensity to standard level.
- Low intensity without adjustment (Type: None): The intensity of anticoagulation for this group was kept at low intensity without adjustment (INR:1.8-2.6),

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