CHA2DS2-VASc Score Calculator
The CHA2DS2-VASc score estimates the annual risk of stroke in patients with non-valvular atrial fibrillation (AF). It is the standard tool used worldwide to determine whether a patient with AF should be started on blood thinners to prevent stroke.
The CHA2DS2-VASc score assigns points for each risk factor:
- C - Congestive Heart Failure (1 point)
- H - Hypertension (1 point)
- A2 - Age 75 or older (2 points)
- D - Diabetes Mellitus (1 point)
- S2 - Prior Stroke, TIA, or thromboembolism (2 points)
- V - Vascular disease (1 point)
- A - Age 65-74 (1 point)
- Sc - Sex category: female (1 point)
The maximum score is 9 points. Higher scores mean higher annual stroke risk and a stronger recommendation for anticoagulation therapy.
Key guideline recommendations (AHA/ACC/ESC):
- Score 0 (males) or 1 (females with only the sex point): No anticoagulation needed. The stroke risk is very low.
- Score 1 (males) or 2 (females): Consider anticoagulation. This is a shared decision between patient and physician.
- Score 2+ (males) or 3+ (females): Anticoagulation is recommended. Direct oral anticoagulants (DOACs) are preferred over warfarin for most patients.
The female sex category point is handled differently because being female alone (without other risk factors) does not significantly increase stroke risk. It only adds meaningful risk when combined with at least one other clinical factor.
Note on bleeding risk: The HAS-BLED score is often used alongside CHA2DS2-VASc to assess bleeding risk with anticoagulation. However, a high bleeding risk score generally does not override the need for anticoagulation when stroke risk is high. Instead, it flags patients who need closer monitoring and modifiable bleeding risk factor management.
Disclaimer: This calculator is for educational purposes only. Anticoagulation decisions should always be made in consultation with a physician.