A Meta-Analysis of Randomized Controlled Trials of the Risk of Bleeding With Apixaban Versus Vitamin K Antagonists

• The results are based on data from 24,435 patients across 5 trials.
• Apixaban is associated with a lower risk of bleeding compared with vitamin K antagonists (VKAs).
• Apixaban may be associated with reduced all-cause mortality compared with VKAs.
• Apixaban may represent an effective and safe alternative to the standard VKA therapy.

Apixaban is one of the new oral anticoagulants, which is prescribed as an alternative to vitamin K antagonists (VKAs). Concerns regarding its bleeding profile persist and require further evaluation. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) to compare the risks of bleeding and all-cause mortality between apixaban and VKAs. The MEDLINE, EMBASE, and Cochrane Library of Clinical Trials databases were systematically searched for RCTs comparing the risks of bleeding and all-cause mortality of apixaban (2.5 or 5 mg twice daily) with those of VKAs. We included RCTs conducted in adults and published in English or French. Data were pooled across RCTs using random-effects meta-analytical models. Our systematic search identified 5 RCTs meeting our inclusion criteria (n = 24,435). They included patients with atrial fibrillation (n = 18,358), total knee replacement surgery (n = 458), and venous thromboembolism (n = 5,619). Data pooled across RCTs revealed that apixaban was associated with reduced risks of any bleeding (relative risk [RR] 0.73, 95% confidence interval [CI] 0.59 to 0.90) and a composite of major or clinically relevant nonmajor bleeding (RR 0.60, 95% CI 0.40 to 0.88). Apixaban was also associated with a lower risk of intracranial bleeding (RR 0.42, 95% CI 0.31 to 0.58) whereas analyses of major and minor bleeding were inconclusive. Moreover, apixaban was associated with decreased all-cause mortality (RR 0.89, 95% CI 0.81 to 0.99) although this finding was driven by the results of the ARISTOTLE trial. In conclusion, our meta-analysis found that apixaban is associated with a lower risk of bleeding than VKAs, providing some reassurance regarding its safety.