Non-vitamin K antagonist oral anticoagulants (NOACs) are alternatives to vitamin K antagonists (VKAs) for the treatment of venous thromboembolism and the prevention of systemic embolism in atrial fibrillation. As with any other anticoagulant treatment, patients receiving these drugs have an increased risk of bleeding. But the perceived threat of major bleeding in the absence of specific reversal agents for NOACs may lead physicians to be unwilling to their use.

Caldeira et al. performed a meta-analysis of phase III randomised controlled trials comparing NOACs (rivaroxaban, apixaban, edoxaban and dabigatran) to VKAs in patients with atrial fibrillation (5 studies) or venous thromboembolism (6 studies), and compared the incidence of fatal bleeding and of all-cause mortality in patients who survived a major bleeding.

Whether in atrial fibrillation or in venous thromboembolism, NOACs were associated with a decreased risk of fatal bleeding. Patients treated with NOACs for atrial fibrillation who survived a major bleeding event had lower mortality compared to patients treated with VKAs.

This meta-analysis suggests that NOACs might decrease bleeding-related mortality compared to VKAs. Nevertheless, these results are based on phase III trials that do not reflect real-world conditions and patients. Furthermore, the incidence of bleeding-related mortality in VKA-treated patients might be particularly high in some of the included studies since the administration of reversal agents in the VKA groups was suboptimal. This could have biased the results in favour of NOACs.

– Fanny Bonhomme