Heart Health

Stroke risk high enough to anticoagulate

CHA2DS2-VASc — untreated stroke risk above ~2% a year? Yes (score >=2 men / >=3 women)

Recommendationaf-anticoag-indicatedNo one has reached this rule yet

Anticoagulation recommended; a DOAC preferred over warfarin

Clinical review

All reviewers

No clinician has signed off this rule yet. It reflects our reading of the guidelines cited below, which has not been independently checked.

What someone who reaches this rule is told

Word for word, as generated for the example person below. Figures in the text are theirs.

  • Strongly recommended

    Your stroke risk score is 5, which is in the range where a blood thinner is recommended. This is the single highest-value conversation on this page.

    Scored as: High blood pressure (1), Age 75 or over (2), Diabetes (1), Female (1). That puts your untreated stroke risk at about 7% a year, and the guideline recommends anticoagulation once that risk passes about 2% a year — which is a score of 2 or more for men and 3 or more for women, because being female shifts risk without being a driver in its own right. Anticoagulation cuts the risk of these strokes by roughly two-thirds, and AF-related strokes are more often fatal or disabling than other strokes.

    Ask a cardiologist about this one. Take this to a cardiologist, not a search engine. Whether to anticoagulate is well founded and worth raising — but the decision in your case turns on things this tool has not asked about, including any history of bleeding, and it is not one to act on from a web page.

    Outcome-provenTested in randomised trials measuring heart attacks, strokes, or death, not a stand-in for them.· Class I· Level A· checked 2026-09-12

    2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation · Class I

  • Strongly recommended

    Ask which anticoagulant is right for you — and whether a DOAC or warfarin.

    We are deliberately not naming a drug class here. For most people a DOAC is preferred over warfarin, but the exceptions are absolute rather than marginal: a mechanical heart valve or moderate-to-severe mitral stenosis means warfarin, not a DOAC. Dose then turns on kidney function, weight, age, bleeding history, and interactions. Those are the questions to take in, and they are worth asking in exactly that order.

    Why this is a question, not a recommendation. Being more specific would need whether you have a mechanical valve or significant mitral stenosis, your bleeding history. Add those to your intake and this becomes a direct recommendation.

    Outcome-provenTested in randomised trials measuring heart attacks, strokes, or death, not a stand-in for them.· Class I· Level A· checked 2026-09-12

    2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation · Class I

An example person who reaches it

Atrial fibrillation, blood thinner not yet discussed” — an illustrative profile, not a real user.

77-year-old womanBP 142/86 on medicationLDL 130diabetes, A1c 6.8%atrial fibrillation, diagnosed10-yr PREVENT-ASCVD 13.2%

Their path through atrial fibrillation

  1. Atrial fibrillation?Yes
  2. How was it found? (the evidence differs)Clinically diagnosed
  3. CHA2DS2-VASc — untreated stroke risk above ~2% a year?Yes (score >=2 men / >=3 women) ← this rule
  4. Applies whatever the scoreAlways
  5. Applies whatever the scoreAlways
  6. Applies whatever the scoreAlways

Where it sits

Asked after: Atrial fibrillation

Sources

Cited by the recommendations above.

What we are least sure of here

  • Q5Is the context gate set at the right threshold before naming a drug class, or does naming it still carry more risk than it removes?

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Runs in lib/engine/afPathway.ts as af-anticoag-indicated.