R4 문정락 / IC prof. 김진배 Lancet Haematol 2015;2: e150–59

Introduction NOACs (Non-vitamin K-antagonist oral anticoagulants, including dabigatran and rivaroxaban)  alternative to vitamin K antagonists for the prevention of arterial thromboembolism in patients with non- valvular A-fib. Subgroup analyses of the RE-LY and ROCKET-AF randomised trials have showed that patients switching from a vitamin K antagonist to NOAC had similar benefits as those starting a NOAC without previous VKA treatment. Little information exists about the risk of bleeding and arterial thromboembolism of switching from a VKA to NOAC.

Introduction We aimed to examine the risk of bleeding between switchers & non- switchers in those needing anticoagulation for non-valvular atrial fibrillation in real-world conditions. Also assessed the risk of arterial thromboembolism (ischaemic stroke or systemic embolism and MI) and composite events (including hemorrhage, ischemic stroke and MI)

Methods Study design and participants Nationwide, retrospective, matched-cohort study in France using information from a comprehensive French national health-insurance database [SNIIRAM] First prescription of a vitamin K antagonist for non-valvular atrial fibrillation between Jan 1, 2011, and Nov 30, Age ≥18 years Exclusion : who had switched from one type of vitamin K antagonist to another : dementia : surgery for valvular heart disease, recent cancer, dialysis for kidney failure, current or recent gastroduodenal ulceration, hepatic impairment or liver disease, and any lesion or condition with a substantial risk of severe bleeding such as anemia.

Methods Switchers - from a vitamin K antagonist to a NOAC, randomly selected up to two non-switchers (1:2) matched on basis of eight variables Age, sex, history of ischemic stroke or systemic embolism, ischemic heart disease, vitamin K antagonist type, date of vitamin K-antagonist initiation, duration of vitamin K-antagonist use before the index, and INR number

Methods Outcomes The primary endpoint  bleeding events ICD-10 codes for intracranial haemorrhage Gastrointestinal hemorrhage or others Secondary endpoint  ischemic stroke or systemic embolism,first or recurrent myocardial infarction and variables.

Results

Bleeding risk

Risk of arterial embolism

Risk of composite events

Conclusion In our large, observational, post-marketing study, we noted no evidence of increased risk of severe bleeding, ischemic stroke or systemic embolism, first or recurrent myocardial infarction, or composite events in individuals who switched from a vitamin K antagonist to a NOAC compared with those who were maintained on a K antagonist.