Direct Oral Anticoagulants vs. Vitamin K Antagonists for Atrial Fibrillation in Cardiac Amyloidosis: A Systematic Review and Meta-analysis

Background: This study aimed to systematically review and synthesize evidence comparing direct oral anticoagulants (DOACs) with vitamin K antagonists (VKAs) for anticoagulation in patients with atrial fibrillation (AF) and cardiac amyloidosis (CA). Methods: A comprehensive search of PubMed and EMBASE databases was conducted through January 2024 to identify studies comparing DOACs and VKAs in AF patients with CA. Eligible studies underwent rigorous screening and data extraction to evaluate safety and efficacy outcomes. Results: Four studies met the criteria. The first study reported similar embolic event rates between DOACs (3.9%) and VKAs (2.9%) per 100 patient years, while major bleeding rates were 5.21% and 3.74%, respectively. The second paper found stroke rates of 2% for DOACs and 4% for VKAs, with bleeding complications observed in 10% of DOAC patients compared to 20% in VKA patients. The third cohort demonstrated that DOACs were associated with significantly lower risks of stroke and major bleeding compared to VKAs. The last study reported embolic event rates of 1.6 and 2.0 per 100 patient years for DOACs and VKAs, respectively. In the pooled analysis, DOACs were associated with a reduced risk of thromboembolic events (odds ratio [OR] = 0.52; 95% confidence interval [CI]: 0.32-0.84), and no difference in major bleeding between the two groups (OR = 0.61, 95% CI: 0.25-1.51). Conclusions: Existing studies support the use of DOACs as a non-inferior therapeutic option compared to VKAs for preventing thromboembolism in patients with AF and cardiac amyloidosis. DOACs may also offer practical advantages, including reduced bleeding risks and ease of management, but further high-quality randomized controlled trials are needed to confirm these findings and guide clinical practice.