A Trial of Genotype-based Warfarin Initiation in Patients With Mechanical Prosthetic Heart Valve

Study Overview
=================
Brief Summary
-----------------
Until very recently, warfarin is still the best drug of choice for long-term anticoagulation for patients with mechanical prosthetic heart valve. However, the complication of warfarin account for 75 percent of the whole complication after the mechanical prosthetic heart valve replacement. Interindividual variation in warfarin dose is mediated by multiple factors.Advanced models using combinations of clinical attributes and genetic factors(CYP2C9, VKORC1, and CYP4F2) explain 50-75% of variability in warfarin dose requirements.These warfarin dosing models have the potential to improve patient safety by reducing or eliminating serious adverse events. The investigators conducted a prospective, randomized, blinded, two arm trial to test this hypothesis.

Official Title
-----------------
Academic Leader，Head of Cardiac Surgery,Principal Investigator, Clinical Professor

Conditions
-----------------
Anticoagulation Treatment Overdose, Heart Valve Diseases

Intervention / Treatment
-----------------
* Other: Genotype-based Warfarin Initiation model
* Other: clinical factor-based warfarin initiation model


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: the first time to receive elective mitral and/or aortic mechanical prosthetic valve replacement willing to join in the clinical trial and comply with the protocol. Exclusion Criteria: other ethnic groups than Han previously receive any other cardiac surgery emergent surgery simultaneously carry out other cardiac surgeries,such as CABG age younger than 18y or older than 65 year drug abuser and wine abuser any malignancy moderate or severe hepatic or kidney insufficiency any thyroid disease the history of warfarin or VitK consumption 2 week before the surgery any hematological disease or history of bleeding combination with any drugs that significantly influence warfarin other than Cordarone pregnancy any contraindication of warfarin infectious endocarditis advanced valvular disease pathological obesity psychological disease any patient having joined in other clinical trial in the previous 30d basic INR > 1.4

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Genotype-based Warfarin Initiation<br> | Other: Genotype-based Warfarin Initiation model<br>* Based on previous retrospective study,investigators established a genotype-based warfarin model to estimate the drug dosage.<br>|
| Active Comparator: clinical factor-based warfarin initiation<br> | Other: clinical factor-based warfarin initiation model<br>* Based on previous retrospective study,investigators established a clinical factor-based warfarin model to estimate the drug dosage.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time to steady dosage |  | from seven days after the operation to thirty days after the operation | 
| Time in Therapeutic Range |  | from five days after the operation to thirty days after the operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| first time to treatment window |  | from five days after the operation to thirty days after the operation | 
| the ratio of INR≥3.0 and INR≤1.5 |  | from five days after the operation to thirty days after the operation | 
| the monitoring frequency of INR |  | 30 days after the operation | 
| the whole-cause mortality |  | 30 days after the operation | 
| major bleeding event |  | 30 days after the operation | 
| major thrombosis rate |  | 30 days after the operation | 
| absolute difference between the stable dose and initial dose |  | 30 days after the operation | 
| the frequency of dosage change |  | 30 days after the operation | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
anticoagulation, bleeding, CYP2C9, CYP4F2, VKORC1, warfarin dosing, Heart Valve Diseases, pharmacogenomics