Anticoagulation with Vitamin K Antagonists Versus Antiplatelet Therapy After Surgical Bioprosthetic Valve Implantation in the Prevention of Thromboembolism: A Meta-Analysis of Randomized Controlled Trials

Abstract

BACKGROUND: The optimum medical therapy in the first three months after surgical bioprosthetic valve implantation (BVI) remains controversial. Current guidelines of the American College of Cardiology recommend either anticoagulation with vitamin K antagonists (VKA) (level IIa) or antiplatelet (AP) using aspirin (level IIa) after surgery, which is based on non-randomized studies. Hence, we performed a meta-analysis of randomized controlled trials (RCT) comparing the efficacy and safety of VKA vs AP therapy early after surgical BVI. METHODS: An extensive search of PubMed, Medline, Cochrane and Ovid was performed for RCTs comparing VKA vs AP therapy among adult patients who underwent surgical BVI. Outcome measures for thromboembolism, all-cause mortality and major bleeding were extracted and analyzed using a random effect model via Review Manager V5.3. RESULTS: Three RCTs with 590 patients were included. There were no differences in the rates of thromboembolic events (5% vs 6.8%; p=0.37) or all-cause mortality (4.7% vs 5.8% p=0.64) between the VKA vs AP groups There was a higher incidence of major bleeding in the VKA group (6% vs 2.4%), which was statistically significant (OR 2.63 (95% CI 1.08–6.43; p=0.03)). CONCLUSION: Vitamin K antagonist and AP therapies have similar rates of thromboembolic events and all-cause mortality in the first three months among patients post-surgical BVI. However, VKAs have a significantly higher incidence of major bleeding, which suggests that AP therapy may be the preferable strategy for anticoagulation in BVI post-surgery. KEYWORDS: Prosthetic heart valve, Anticoagulation, Antiplatelet therapy, Bioprosthetic Valve Implantation