The hazards of interrupting anticoagulation therapy in atrial fibrillation

This editorial refers to ‘Increased short-term risk of thrombo-embolism or death after interruption of warfarin treatment in patients with atrial fibrillation’, by J. Raunso et al. , doi:10.1093/eurheartj/ehr454 Atrial fibrillation (AF) is the most commonly encountered clinical arrhythmia and is associated with a substantial burden of morbidity (mainly thrombo-embolism) and mortality. Vitamin K antagonists such as warfarin are highly effective for the prevention of stroke and systemic embolism in patients with AF,1 but their use is hampered by multiple food and drug interactions, the need for routine coagulation monitoring, and a high risk of bleeding complications.2 Hence warfarin not only is underutilized, but among those who are prescribed warfarin the treatment is frequently interrupted or permanently discontinued.3,4 No large studies have explored the possible impact of stopping warfarin on the short-term risk of subsequent major adverse cardiovascular outcomes, such as stroke and death, in patients with AF.Raunso and co-workers have now reported the results of a Danish nationwide retrospective cohort study in which they explored outcomes after warfarin interruption in patients with AF.5 Patients with a first hospitalization for AF in the period 1 January 1997 to 31 December 2008 were identified using the Danish National Patient Registry, and warfarin interruption was determined by cross-linkage with prescription claims from the Danish Registry of Medicinal Product Statistics. The primary outcome of the study was hospitalization for thrombo-embolism (ischaemic stroke, transient ischaemic attack, or unspecified stroke), pulmonary …