Outcomes among patients with atrial fibrillation and appropriate anticoagulation control

BACKGROUND: Atrial fibrillation (AF) patients on a vitamin K antagonist (VKA) with time in therapeutic range (TTR) ≥70% are not recommended to switch to a direct oral anticoagulant according to guidelines.OBJECTIVES: This study sought to assess future TTR and risk of stroke/thromboembolism and major bleeding among AF patients on VKA with TTR ≥70%.METHODS: The authors used Danish nationwide registries to identify AF patients on VKA from 1997 to 2011 with available international normalized ratio values. Patients were included 6 months after VKA initiation, divided according to TTR, and followed for 12 months after inclusion. Cox proportional hazard models estimated hazard ratios (HRs). TTR was examined both as a baseline variable and as a time-dependent covariate in the Cox models.RESULTS: Of the 4,772 included AF patients still on VKA 6 months after initiation, 1,691 (35.4%) had a TTR ≥70%, and 3,081 (65.6%) had a TTR CONCLUSIONS: Among AF patients on VKA, almost one-half of patients with prior TTR ≥70% had TTR