How have the initiation patterns of oral anticoagulation treatment changed over time according to age among patients with atrial fibrillation?
There has been a substantial shift from VKA to NOACs for atrial fibrillation in Denmark, with older age strongly associated with the preferential initiation of apixaban and rivaroxaban.
Among atrial fibrillation (AF) patients, Danish nationwide registries (2011-2015) were used to examine temporal trends of initiation patterns of oral anticoagulation (OAC) treatment according to age. Overall, 43,299 AF patients initiating vitamin K antagonists (VKA) (42%), dabigatran (29%), rivaroxaban (13%), or apixaban (16%) were included with mean age (SD) 72.1 (11.3), 71.5 (11.0), 74.3 (11.1), and 75.3 (11.1) years, respectively. Patients aged ≥85 years comprised 15%. Trend tests showed increase in patients ≥85 years initiating OAC (p < 0.0001). VKA usage decreased from 92% to 24% (p < 0.0001). This decrease was independent of age. Dabigatran was the most common non-VKA OAC (NOAC) (40% users), but usage decreased from 2014 until study end (6%) (p < 0.0001). Apixaban was the most used OAC at study end (41%), in particular among those ≥85 years (44%). Compared with patients aged <65 years, the odds ratios associated with initiating VKA, dabigatran, rivaroxaban, or apixaban for patients aged ≥85 years were 0.81 (95% CI 0.75-0.86), 0.65 (95% CI 0.60-0.70), 1.52 (95% CI 1.38-1.67), and 2.09 (95% CI 1.89-2.30), respectively. In conclusion, substantial increase in NOAC usage has occurred. Increasing age was associated with upstart of rivaroxaban or apixaban with reference to age <65 within the specific agent.
Stærk et al. (2016) studied this question.