Anticoagulation for Aortic Bioprosthesis (ANTIPRO)

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.

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).