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Updated: May 26, 2026
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Aspirin versus warfarin in atrial fibrillation: decision analysis may help patients' choice
Roman Romero-Ortuno1, Diarmuid O'Shea
1St Vincent's University Hospital, Department of Medicine for the Elderly, Elm Park, Dublin 4, Ireland. romeror@tcd.ie
Insights
For atrial fibrillation (AF) patients, treatment decisions balance stroke risk (CHA2DS2-VASc) and bleeding risk (HAS-BLED). Optimal therapy, including warfarin or aspirin, depends on individual risk scores to maximize net health benefit.
Area of Science:
- Cardiology
- Clinical Decision Making
- Pharmacoeconomics
Background:
- Primary stroke prevention in non-valvular atrial fibrillation (AF) traditionally involves aspirin or warfarin.
- CHA2DS2-VASc scores estimate stroke risk; warfarin reduces risk by 60%, aspirin by 20%.
- HAS-BLED scores assess major bleeding risk on warfarin, with aspirin posing a 0.5-1.2% annual risk.
Purpose of the Study:
- To determine patient preference for warfarin, aspirin, or no therapy based on maximizing the probability of avoiding stroke and major bleeding.
- To provide a decision-making framework for stroke prevention in AF patients.
Main Methods:
- A decision tree model was employed.
- Analyzed 60 possible combinations of CHA2DS2-VASc and HAS-BLED scores.
Main Results:
- No treatment recommended for CHA2DS2-VASc <2.
- Warfarin preferred for CHA2DS2-VASc 2-3 if HAS-BLED <2; otherwise, no treatment.
- For CHA2DS2-VASc =4, warfarin is best if HAS-BLED <3; otherwise, no treatment.
- Warfarin recommended for CHA2DS2-VASc ≥5 if HAS-BLED <4; otherwise, aspirin advised.
Conclusions:
- Decision analysis offers valuable insights into complex treatment choices for AF.
- This theoretical model highlights the potential benefits of quantitative risk-benefit analysis in managing AF.
- Further research may refine treatment strategies in areas of remaining uncertainty.
Background:
the primary prevention of ischaemic stroke in chronic non-valvular atrial fibrillation (AF) typically involves consideration of aspirin or warfarin. CHA(2)DS(2)-VASc estimates annual stroke rates for untreated AF patients, which are reduced by 60% with warfarin and by 20% with aspirin. HAS-BLED estimates annual rates of major bleeding on warfarin. The latter risk with aspirin is 0.5-1.2% per year.
Hypothesis:
given a 'warfarin, aspirin or no therapy' choice, AF patients will prefer the option that maximises the annual probability of not having a stroke and not having a major bleed.
Methods:
decision tree applied to the 60 possible combinations of CHA(2)DS(2)-VASc and HAS-BLED scores.
Results:
according to the pre-specified hypothesis, when CHA(2)DS(2)-VASc is <2, the balance of risk and benefit would advise no treatment; when CHA(2)DS(2)-VASc is 2 or 3, warfarin would be best when HAS-BLED <2, otherwise no treatment would be advised; for CHA(2)DS(2)-VASc =4, warfarin would be best when HAS-BLED <3, otherwise no treatment would be advised and for CHA(2)DS(2)-VASc ≥5, warfarin would be the preferred option if HAS-BLED <4, otherwise aspirin would be advised.
Conclusion:
this theoretical exercise illustrates the potential benefit of decision analysis in an area where high complexity and uncertainty still remain.
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