Incidence of oral anticoagulant interruption among stroke patients with atrial fibrillation and subsequent stroke

Background and purpose: We analyzed the incidence and causes of oral anticoagulant (OAC) cessation and subsequent stroke after OAC withdrawal in a cohort of Korean stroke patients with atrial fibrillation. Methods: The Korean Atrial Fibrillation Evaluation Registry in Ischemic Stroke patients (K-ATTENTION) is a multicenter cohort study, merging stroke registries from 11 tertiary centers in Korea. The number of OAC interruption episodes and the reasons were reviewed from hospital records. Stroke after OAC withdrawal was defined when a patient experienced ischaemic stroke within 31 days after OAC withdrawal. Clinical variables were compared between patients who experienced stroke recurrence during OAC interruption and those who did not experience recurrence. Results: Among 3213 stroke patients with atrial fibrillation, a total of 329 episodes of OAC interruption were detected in 229 patients after index stroke (mean age 72.9 ± 8.3 years, 113 female patients). The most frequent reason for OAC withdrawal was poor compliance [103 episodes (31.3%)] followed by extracranial bleeding [96 episodes (29.2%)]. Stroke after OAC withdrawal was noted in 13 patients. Mean age, vascular risk factor profile and mean CHA₂DS₂-VASc score were not significantly different between patients with and without recurrent stroke. Conclusions: A considerable number of stroke patients with atrial fibrillation experienced temporary interruption of OAC after index stroke, which was associated with stroke recurrence of 4.0 cases per 100 interruption episodes.