CHA₂DS₂-VASc Score Calculator
Stroke risk in atrial fibrillation with the CHA₂DS₂-VASc score — congestive heart failure, hypertension, age, diabetes, prior stroke, vascular disease and sex — with annual stroke rate and anticoagulation guidance.
How it works
CHF 1 + Hypertension 1 + Age 65–74 1 / ≥75 2 + Diabetes 1 + Stroke/TIA 2 + Vascular disease 1 + Female 1 (max 9)
CHA₂DS₂-VASc refines the older CHADS₂ score by adding vascular disease, the 65–74 age band and female sex, which sharpens the identification of truly low-risk patients with atrial fibrillation who can safely skip anticoagulation. European and American guidelines both use it: a score of 0 in men (1 in women) means no therapy; 1 in men (2 in women) means anticoagulation should be considered; 2 or more in men (3 in women) means it is recommended, usually with a direct oral anticoagulant. Annual event rates come from the Swedish national cohort and rise steeply — under 1% at low scores to over 10% at the top. Female sex is now treated as a risk modifier rather than an independent indication.
Worked example
A 70-year-old woman with hypertension and diabetes: age 1 + HTN 1 + DM 1 + female 1 = 4, about 4.8% a year — anticoagulation recommended (score 3 excluding sex).
Frequently asked questions
How is this different from CHADS₂?
CHADS₂ has five items (max 6) and lumps everyone under 75 together; VASc adds vascular disease, the 65–74 band and sex, reclassifying many “low-risk” CHADS₂ patients as intermediate.
Does it apply to atrial flutter?
Yes — guidelines treat flutter the same as fibrillation for anticoagulation decisions.
Does a high HAS-BLED score cancel the indication?
Rarely. A high bleeding score means address modifiable bleeding risks and review more often, not withhold anticoagulation, because stroke risk usually outweighs bleeding risk.
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Clinical decision tool for education and for use by trained clinicians alongside judgement — not a diagnosis and not a substitute for medical assessment. Scores validated in specific populations may not apply to every patient.