Abstract 9868: Novel Oral Anticoagulants versus Vitamin K Antagonists in Patients with Atrial Fibrillation and Bioprosthetic Valve Replacement: A Systematic Review and Meta-Analysis

Abstract

Background: Vitamin K antagonists (VKAs) such as warfarin are traditionally prescribed in patients with atrial fibrillation (AF) and bioprosthetic valves (BPVs) to prevent thromboembolic events. However, various studies have proposed novel oral anticoagulants (NOACs) as an effective and safer option to use. Therefore, we conducted a systematic review and meta-analysis to compare their relative efficacy and safety profiles. Methods: Pubmed, Cochrane Central, and Embase were searched up until May 15, 2021 for randomized clinical trials (RCTs) and observational studies determining efficacy and safety of NOACs or VKAs in AF patients who had undergone BPV replacement. Outcomes of interest were: stroke or systemic embolism (SSE), major bleeding, all-cause mortality, and intracranial hemorrhage (ICH). Subgroup analysis by study design (RCT and observational) was performed. Summary estimates were reported as random effects risk ratios (RRs) with 95% confidence intervals (CIs). Results: A total of 12 studies (4 RCTs and 8 observational) with 6436 patients (mean age 72.1 years; 51.4% males) were included in the analysis. In comparison to VKAs, NOACs demonstrated a significant reduction in ICH (RR 0.41 [95% CI 0.25,0.67]; p=0.0003; I 2 = 0%) and major bleeding (RR 0.63 [95% CI 0.53,0.74]; p<0.00001; I 2 = 0%) at a mean duration follow up of 23.8 months. However, no difference was observed in risk of SSE (RR 0.77 [95% CI 0.50,1.19]; p=0.23; I 2 = 53%) and all-cause mortality (RR 0.98 [95% CI 0.78,1.22]; p=0.84; I 2 = 15%). Observational studies and RCTs did not significantly differ across all outcomes in the subgroup analysis. Conclusions: This meta-analysis suggests that NOACs are effective at reducing risk of ICH and major bleeding in AF patients with BPVs in contrast to VKAs. Future large-scale RCTs can aid in corroborating the legitimacy of these results.