232EARLY ANTICOAGULATION THERAPY AFTER BIOPROSTHETIC AORTIC VALVE IMPLANTATION: COMPARING WARFARIN VERSUS ASPIRIN

Objectives: To compare warfarin therapy (target INR of 2.0 to 3.0) against aspirin 150 mg daily as anticoagulation therapy for the first three months after implantation of a bioprosthetic aortic valve. The aim was to evaluate thromboembolic complications (myocardial infarction [MI], stroke), bleeding complications and death. Methods: This was a single-centre, prospective, randomized controlled trial. During the enrolment period 2005-2012, 370 patients were included, of whom 333 were available for data analysis. Patients undergoing aortic valve replacement either isolated or in combination with coronary artery bypass grafting were included. Results: At baseline, the warfarin and aspirin groups were comparable, with a mean EuroSCORE of 5.7 ± 2.3 vs 5.4 ± 2.1, P = NS, respectively. Three-month results showed the following: MI occurred in two patients in the warfarin group vs five in the aspirin group, P = NS; stroke six vs four, P = NS; gastrointestinal bleeding eight vs one, P = 0.37; all-cause mortality eight vs five, P = NS. The final presentation will include multivariate analysis of factors. Conclusions: This is to date the largest randomized trial comparing warfarin to aspirin as early anticoagulation therapy after implantation of bioprosthetic aortic valves. The results are not conclusive, but aspirin therapy seems as safe as warfarin therapy, and with significantly fewer gastrointestinal bleeding events, three months after surgery.