Arrhythmias & electrophysiology
Predictors of ischemic stroke and major bleeding among patients with atrial fibrillation in clinical practice
Authors' conclusion
The CHA₂DS₂-VASc score provides modest discrimination for ischemic stroke and major bleeding across AF/AFL populations, including patients already treated with OAC. Incorporation of routinely available clinical factors substantially improves risk discrimination and highlights important sources of residual risk not captured by existing models.
Study context
- Population
- Individuals with atrial fibrillation or flutter (AF/AFL) in 2 electronic health records datasets (DUHS 2009–2018; 7 health systems in PCORnet 2015–2019)unique patients with AF/AFL, 41.1% not on oral anticoagulation (OAC), 32.1% on direct oral anticoagulant (DOAC), 26.8% on warfarin · DUHS (median CHA₂DS₂-VASc score 3) 43,896 · PCORnet (median CHA₂DS₂-VASc 3) 170,853
- Participants
- 214,749 individuals
- Comparison
- Discrimination of the final model for ischemic stroke was assessed against the CHA2DS2-VASc model alone.
Methodological detailsdeveloped in the DUHS prevalent AF/AFL population, independently replicated in an incident AF/AFL within the PCORnet population, stratified by OAC status at cohort entry
- Developed in the DUHS prevalent AF/AFL population
- Independently replicated in an incident AF/AFL within the PCORnet population
- Stratified by OAC status at cohort entry
Further findings
| Outcome | No OAC | DOAC | Warfarin |
|---|---|---|---|
| Discrimination for ischemic stroke with routinely available clinical variables | C-index 74%-76% | C-index 74%-75% | C-index 70%-72% |
| Discrimination for major bleeding with routinely available clinical variables | C-index 75%-76% | C-index 75%-76% | C-index 72%-73% |
Discrimination of CHA₂DS₂-VASc model alone for ischemic stroke
- C-index range across OAC strategies
- 64%-69%
Factors independently associated with ischemic stroke risk
- Several factors not captured by CHA₂DS₂-VASc, including race and prior major bleeding, were independently associated with ischemic stroke risk
Original publication
Predictors of ischemic stroke and major bleeding among patients with atrial fibrillation in clinical practice. Am Heart J. Published 19 May 2026. doi:10.
Summarised from the published abstract; every number is checked against it