Anticoagulation for Aortic Bioprosthesis (ANTIPRO)

Study Overview
=================
Brief Summary
-----------------
This study evaluates the clinical and hemodynamic outcome in patients after aortic valve replacement. Half of the patients will receive warfarin + aspirin and the other half will receive only aspirin. The investigators will focus mainly on early bioprosthesis degeneration.

Detailed Description
-----------------
Aortic bioprosthesis have the advantage that they do not require life-long anticoagulation. Current guidelines support the use of aspirin (AAS) 100 mg as a class I indication. Current evidence, mainly derived from transaortic valve implantation (TAVI) patients, have shown that aortic bioprosthesis suffer subclinical thrombosis which may explain the increase in gradient and bioprosthetic degeneration. Anticoagulation in this cases improve leaflet mobility and decrease in gradient. Evidence supporting early anticoagulation in patients with aortic bioprosthesis is not as strong as in the case of mitral bioprosthesis. Nonetheless, current American Heart Association/American College of Cardiology (AHA/ACC) guidelines recommend (IIa) the use of warfarin for at least 3 months after aortic valve replacement. The aim is to conduct a single blinded (echocardiographist) randomized control study in patients who receive an aortic bioprosthesis. Comparison will be performed between the use of warfarin + aspirin vs aspirin alone. Duration of anticoagulation will be for 3 months and patients follow-up for 1 year. Clinical and echocardiographic evaluation will be performed in every patients. Some patients will undergo Positron Emission Tomography (PET-Scan).

Official Title
-----------------
Randomized Control Study of Anticoagulation With Warfarin Por Patients With Aortic Bioprosthesis vs Aspirin Only

Conditions
-----------------
Aortic Valve Stenosis, Aortic Valve Disease, Aortic Valve Insufficiency, Aortic Valve Regurgitation

Intervention / Treatment
-----------------
* Drug: Warfarin
* Drug: Aspirin


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients with indication of aortic valve replacement with porcine bioprosthesis Exclusion Criteria: Concomitant mitral valve replacement Previous atrial fibrillation Previous use oral anticoagulation Contraindication for the use of oral anticoagulation (high risk of bleeding, intolerance, allergy) Jehovah witness Platelet count below 90,000. Liver disease

Ages Eligible for Study
-----------------
Minimum Age: 18 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Warfarin<br>Warfarin will be started 48-72h after aortic valve replacement. Dose will be 5 mg daily in order to obtain an Internation normal ratio (INR) of 2-3. Warfarin treatment will continue for 3 months. Aspirin will be administered 100 mg daily. | Drug: Warfarin<br>* Oral anticoagulation<br>* Other names: Choice;Drug: Aspirin<br>* Antiplatelet treatment<br>* Other names: AAS;|
| Active Comparator: Aspirin only<br>Aspirin will be started 48-72h after aortic valve replacement. Dose will be 100 mg daily. Patients who undergo coronary artery revascularization will receive 325 mg daily. | Drug: Aspirin<br>* Antiplatelet treatment<br>* Other names: AAS;|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Transprosthetic aortic gradient | Change in Transprosthetic mean gradient | 3 months and 1 year | 
| Change in New York Heart Association (NYHA) class | NYHA class | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Major bleeding | number of patients admitted due to Genitourinary (GU) or Gastrointestinal (GI) bleeding, pericardial tamponade, pleural effusion | 3 months and 1 year | 
| Embolic events | Number of patients with cerebral and peripheral ischemic events | 3 months and 1 year | 
| Prosthetic leak | Change in severity of prosthetic and paraprosthetic leakage | 3 months and 1 year | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
aortic valve replacement, bioprosthesis, anticoagulation