Abstract 15943: Early and 1 Year Outcomes of Antithrombotic Therapy After Bioprosthetic Aortic Valve Replacement

BackgroundUS and European guidelines recommend antithrombotic therapy for at least 3-6 months after surgical bioprosthetic aortic valve replacement (BAVR). However, there is little evidence to support these recommendations and the optimal post-surgical antithrombotic regimen remains uncertain. The aim of this study is to evaluate the early and 1-year outcomes of antithrombotic therapy in patients undergoing BAVR.Methods1111 consecutive patients underwent surgical BAVR at Yale University (2013-2017) and were reviewed retrospectively to determine the effectiveness of antithrombotic therapy at 3 and 12 months. Kaplan-Meier estimates and Cox hazard regressional analysis were used to compare the outcomes and survival between groups.ResultsThe median patient age was 71 years (mean 69, range 22-87). Patients were stratified into four groups based on post-discharge therapy receivedantiplatelet-only (n=544, 48.9%), anticoagulant therapy (warfarin or factor Xa inhibitors (n=106, 9.5%)), antiplatelet plus anticoagulants (n=326, 29.3%), and no therapy (n=135, 12.5%). Patients who received only antiplatelet medications had low rates of adverse events after surgeryhemorrhage 4.5%, thromboembolic events 2.9%, 1-year mortality 2.2%. In the anticoagulants group, hemorrhagic events were high at 8.4% (p=0.08), thromboembolic events 4.1%, 1-year mortality 6.6%. In the group receiving antiplatelet agents and anticoagulants, hemorrhage was high 7.9% (p=0.02), thromboembolic events 5.2% and 1-year mortality 4.6%. Among those patients receiving no therapy, adverse events were also very low (hemorrhage 1.4%, thromboembolic events 4.4%, mortality 3.7%). Actuarial survival at 3- and 12-months was no different between the no therapy group and anticoagulation group (p=0.15 and p=0.33, respectively). Patients with atrial fibrillation regardless of therapy are at increased odds of mortality (HR=2.71, 95% CI 1.36-5.40, p=0.0045).ConclusionsEarly and 1-year outcomes reveal no significant difference in survival and thromboembolic events but increased rate of hemorrhage in patients on anticoagulation agents. Anticoagulation and antiplatelet therapy does not appear to produce benefit in patients undergoing surgical BAVR.