Should patients on vitamin K antagonists be treated differently?

Extract

This editorial refers to ‘Edoxaban vs. warfarin in vitamin K antagonist-experienced and naive patients with atrial fibrillation’^†, by M.L. O'Donoghue et al., on page 1470.

Relative to warfarin, non-vitamin K oral anticoagulants (NOACs) are at least as good at preventing stroke or systemic embolism, cause less haemorrhagic stroke, and result in modestly lower mortality.¹ Thus, the European Society of Cardiology has recommended NOACs in place of vitamin K antagonists (VKAs) in most patients with atrial fibrillation (class IIa, level of evidence A).² According to one report, the use of NOACs in the USA has increased to > 60% of prescriptions for patients being initiated on oral anticoagulation.³ However, patients already treated with VKAs are usually not switched to NOACs.⁴ The low rates of switching from VKAs to NOACs relate to multiple factors including patient preference, medication cost, and clinical factors such as severe renal impairment. There is a common perception that a patient who is stable on a VKA will derive less benefit from a NOAC than a “VKA-naïve”, patient who has not been previously treated with a VKA. The question remains whether or not this perception is supported by evidence.