Arrhythmias & electrophysiologyCohort study
Stroke and bleeding risk in atrial fibrillation with CHA2DS2-VASC risk score of one: the Norwegian AFNOR study
- Nationwide cohort study
- Norwegian
Authors' conclusion
In AF patients at intermediate risk of stroke, OAC use was associated with overall favourable clinical outcomes. Non-anticoagulated AF patients had higher risk of ischaemic stroke compared to the general population without AF with the same risk profile.
Study context
- Population
- Individuals with non-sex CHA2DS2-VASc score of one, Norway, 2011–1834,460 atrial fibrillation (AF) patients
- Participants
- 1,118,762 individuals
- Exposure
- Oral anticoagulant (OAC) users vs non-users; non-anticoagulated AF vs non-AF
- Outcome
- Ischaemic stroke and bleeding risk in AF with and without OAC
- Follow-up
- One-year IR
Main finding
Ischaemic stroke (AF patients)
Adjusted hazard ratio
0.47
95% CI 0.37–0.59
By group
OAC users
0.51%/py
Non-users
1.05%/py
OAC users vs Non-users
aHR 0.47 (95% CI 0.37–0.59)
As reported in the abstract
Observational data: associations, not effects.
Further findings
Combined ischaemic stroke, major bleeding and mortality
- OAC use associated with lower risk of the combined outcome, aHR
- 0.57 [0.51-0.63] (95% CI)
Ischaemic stroke, non-anticoagulated AF vs non-AF individuals with the same risk profile
- Higher risk of ischaemic stroke in non-anticoagulated AF vs non-AF individuals, aHR
- 2.47 [2.17-2.81] (95% CI)
Safety
| Outcome | OAC users | Non-users | Non-AF | aHR (95% CI) | |
|---|---|---|---|---|---|
| Intracranial haemorrhage · 1 year | IR 0.28%/py | IR 0.19%/py | Not reported in the abstract | 1.23 (0.88–1.72) | |
| 0.512Adjusted hazard ratio (log scale) |
Major bleeding
- OAC use associated with increased risk of major bleeding, aHR
- 1.37 [1.16-1.63] (95% CI)
Original publication
Stroke and bleeding risk in atrial fibrillation with CHA2DS2-VASC risk score of one: the Norwegian AFNOR study. Eur Heart J. Published 23 November 2023. doi:10.1093/eurheartj/ehad659
Summarised from the published abstract; every number is checked against it