Background: While non-vitamin K antagonist oral anticoagulants (NOACs) are more effective than single antiplatelets (mostly low-dose aspirin) at reducing stroke risk in patients with atrial fibrillation (AF), differences in bleeding risk between NOACs and single-dose antiplatelets across various populations remain unclear. Aim: We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing bleeding outcomes of NOACs versus single antiplatelet therapy. Methods: We searched MEDLINE, EMBASE, and CENTRAL to June 2024 for RCTs that compared NOAC (therapeutic doses used for stroke prevention in AF patients) versus single antiplatelet therapy for a treatment duration of ≥3 months. For the meta-analyses, we used fixed-effects models and reported results as summary risk ratios (RRs). We used Risk of Bias 2 and GRADE to assess the quality and certainty of the evidence. Results: Eight RCTs with 26,194 participants were included. Mean follow-up time was 18 (±13) months. NOACs included in the studies were apixaban (4 studies), rivaroxaban (2 studies), and dabigatran (2 studies). All studies used low-dose aspirin as the comparator. When compared to aspirin, NOACs had a higher risk of major bleeding (326/13107 [2.5%] vs. 239/13087 [1.8%] events; RR 1.36 95% CI 1.15-1.60, I 2 =52%, 8 trials; high certainty) (Figure A), gastrointestinal bleeding (104/8803 [1.2%] vs. 74/8788 [0.8%] events; RR 1.39; 95%CI, 1.04-1.87; I 2 =0%; 5 trials; high certainty), and clinically relevant non-major bleeding (318/10397 [3.1%] vs. 230/10395 [2.2%] events; RR 1.38; 95%CI, 1.17-1.63; I 2 =16%; 5 trials; high certainty). There was no difference in the risk of intracranial hemorrhage (88/13107 [0.7%] vs. 84/13087 [0.6%] events; RR 1.04, 95%CI 0.78-1.41; I 2 =48%; 9 trials; high certainty) (Figure B) nor fatal bleeding (22/12412 [0.2%] vs. 28/12392 [0.2%] events; RR 0.78; 95%CI, 0.45-1.36; I 2 =8%; 6 trials; high certainty). Conclusion: When compared to aspirin, NOACs are associated with an increased risk of major bleeding and clinically relevant non-major bleeding, but not intracranial hemorrhage. These data are important to inform patients about the risks of antithrombotic treatment.
Read full abstract