Understanding the CHA2DS2-VASc Score
The CHA2DS2-VASc score is a standard clinical risk-prediction tool used to estimate the one-year risk of ischemic stroke and systemic thromboembolism in people with non-valvular atrial fibrillation (AFib). It assigns points across eight risk factors — Congestive heart failure, Hypertension, Age ≥75 (2 points), Diabetes, prior Stroke/TIA/thromboembolism (2 points), Vascular disease, Age 65-74, and Sex category (female) — for a total ranging from 0 to 9. The score, first published by Lip et al. (2010) and validated in the Euro Heart Survey, is now recommended by the ACC/AHA/HRS and ESC atrial fibrillation guidelines to help decide whether oral anticoagulation is appropriate.
How the score is calculated
- C — Congestive heart failure or LV dysfunction: +1
- H — Hypertension: +1
- A2 — Age 75 or older: +2 (age 65-74 instead earns +1, and under 65 earns 0)
- D — Diabetes mellitus: +1
- S2 — Prior stroke, TIA, or thromboembolism: +2
- V — Vascular disease (prior myocardial infarction, peripheral artery disease, or aortic plaque): +1
- Sc — Sex category, female: +1
From score to stroke risk
Each total maps to a published adjusted annual stroke rate: 0 points ≈ 0%, rising through roughly 1.3% at 1 point, 2.2% at 2 points, 3.2% at 3, 4.0% at 4, 6.7% at 5, 9.8% at 6, 9.6% at 7, 6.7% at 8, and 15.2% at the maximum of 9 points. These commonly cited rates come from validation cohorts and vary somewhat between studies, so treat them as a guide to relative risk rather than an exact individual prediction. Guidelines generally recommend oral anticoagulation at a score of 2 or higher in men or 3 or higher in women; a score of 1 in men (or 2 in women) is intermediate, where anticoagulation may be considered based on bleeding risk and patient preference; a score of 0 in men, or 1 in women driven only by the sex-category point, is treated as low risk.
When to consult a professional
This calculator provides an educational estimate of a standard clinical scoring tool — it is not a diagnosis and does not replace a physician's assessment. Anticoagulation decisions must also weigh bleeding risk (for example the HAS-BLED score), kidney function, drug interactions, fall risk, and patient preference. Always confirm your CHA2DS2-VASc score and any treatment decision with a licensed healthcare provider.