Comparing DOACs and warfarin in atrial fibrillation patients with bioprosthetic valves: a systematic review and meta-analysis

Abstract Introduction Patients with atrial fibrillation (AF) who have bioprosthetic valves usually need anticoagulation to lower the risk of blood clots and stroke. Although warfarin has been the traditional treatment, direct oral anticoagulants (DOACs) are gaining popularity as an alternative. However, the current data on the safety and effectiveness of DOACs compared to warfarin is still incomplete. This meta-analysis brings together existing studies to compare how DOACs and warfarin perform in this high-risk group. Purpose The goal of this study is to evaluate key clinical outcomes, such as overall mortality, bleeding complications, thromboembolic events, and hospitalizations, in AF patients with bioprosthetic valves who are treated with either DOACs or warfarin. Methods A systematic review and meta-analysis of 14 studies (including randomized controlled trials, observational studies, retrospective studies, and prospective cohort studies) was performed. The analysed outcomes included all-cause mortality, cardiovascular (CV) mortality, thromboembolic events, stroke, transient ischemic attack (TIA), myocardial infarction (MI), intracardiac thrombus, hospitalization and various bleeding events intracranial, gastrointestinal (GI), major, non-major, and overall. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models. Heterogeneity was assessed using I², Chi², Tau² statistics. Results DOACs were linked to reduced all-cause mortality compared to warfarin (OR 0.75; 95% CI 0.62, 0.91; P=0.004), while CV mortality showed no significant difference between the two groups (OR 0.72; 95% CI 0.42, 1.23; P=0.23). Additionally, DOACs significantly lowered the risk of GI bleeding (OR 0.74; 95% CI 0.56, 0.98; P=0.04) and thromboembolic events (OR 0.78; 95% CI 0.62, 0.98; P=0.04). Hospitalization rates were also notably lower with DOACs (OR 0.75; 95% CI 0.62, 0.91; P=0.003). While there was a trend toward reduced stroke or systemic embolism (OR 0.45; 95% CI 0.10, 1.91; P=0.28), the high level of variability (I²=84%) makes interpretation challenging. No significant differences were found in intracranial bleeding (OR 0.83; 95% CI 0.48, 1.42; P=0.49), but major bleeding was significantly lower with DOACs (OR 0.71; 95% CI 0.52, 0.97; P=0.03). The risk of MI was similar between the two treatments (OR 1.00; 95% CI 0.72, 1.38; P=0.98). Conclusion Our findings suggest that DOACs may offer a safer alternative to warfarin for patients with AF and bioprosthetic valves. In particular, DOACs are linked to significant reductions in overall mortality, gastrointestinal bleeding, thromboembolic events, and hospitalizations. On the other hand, rates of cardiovascular mortality, intracranial bleeding, and myocardial infarction are similar between the two treatments. However, the wide range of results in stroke and systemic embolism data indicates that more research is needed to better understand these outcomes.