What the CHA₂DS₂-VASc score does
The CHA₂DS₂-VASc score estimates the yearly risk of stroke and systemic embolism in people with non-valvular atrial fibrillation (AF). It refines the earlier CHADS₂ score by adding vascular disease, a wider age band, and sex, improving the identification of genuinely low-risk patients who may not need anticoagulation. The score is central to the decision of whether to start an oral anticoagulant.
How it works
The acronym maps to points:
- C — Congestive heart failure / LV dysfunction: +1
- H — Hypertension: +1
- A₂ — Age
≥75: +2 - D — Diabetes mellitus: +1
- S₂ — Prior Stroke, TIA, or thromboembolism: +2
- V — Vascular disease (prior MI, peripheral artery disease, aortic plaque): +1
- A — Age 65–74: +1
- Sc — Sex category female: +1
The points are summed to a maximum of 9. Higher scores correspond to higher annual stroke risk (roughly 0% at 0, rising to over 10% at scores of 8–9). Guidelines recommend anticoagulation at ≥2 in men and ≥3 in women, with a shared-decision discussion at 1 (men) or 2 (women).
Tips and example
A 78-year-old woman (age ≥75 = 2, female = 1) with hypertension (+1) and diabetes (+1) scores 5, indicating a high annual stroke risk and a clear recommendation for oral anticoagulation. Female sex alone never tips a patient into the treatment range — it only counts when another risk factor is present. Always pair the stroke estimate with a bleeding-risk assessment and shared decision-making.