CHA2DS2-VASc Score Calculator
Estimate annual stroke risk in atrial fibrillation by selecting the patient profile below.
This tool supports educational use and should not replace clinician judgment.
What is the CHA2DS2-VASc score?
The CHA2DS2-VASc score is a clinical risk-stratification tool used to estimate stroke risk in patients with non-valvular atrial fibrillation (AF). It improves on older schemes by adding additional risk granularity, especially in people previously considered “low risk” under CHADS2.
In practice, this score helps support decisions about anticoagulation therapy. A higher score generally means a higher annual risk of ischemic stroke and a stronger rationale for oral anticoagulation, balanced against bleeding risk and patient preferences.
How the score is built
Each letter corresponds to a known stroke risk factor:
| Component | Description | Points |
|---|---|---|
| C | Congestive heart failure / left ventricular dysfunction | 1 |
| H | Hypertension | 1 |
| A2 | Age 75 years or older | 2 |
| D | Diabetes mellitus | 1 |
| S2 | Prior stroke, TIA, or thromboembolism | 2 |
| V | Vascular disease (prior MI, PAD, or aortic plaque) | 1 |
| A | Age 65-74 years | 1 |
| Sc | Sex category (female) | 1 |
How to interpret results
General approach
While exact guideline thresholds may vary by region and update year, a common approach is:
- Low risk: no non-sex risk factors present.
- Intermediate risk: one non-sex risk factor present.
- Higher risk: two or more non-sex risk factors present.
Many clinicians assess bleeding risk (for example, with HAS-BLED), renal/liver function, frailty, fall risk context, medication interactions, and patient goals before making final treatment decisions.
Why sex-specific interpretation matters
Female sex contributes one point in CHA2DS2-VASc, but in most frameworks it is interpreted as a risk modifier, not usually a sole indication for anticoagulation by itself. This calculator therefore highlights the count of non-sex risk factors in its recommendation text.
Example use case
Consider a 78-year-old woman with hypertension and diabetes, no prior stroke, and no known vascular disease:
- Age ≥75: +2
- Hypertension: +1
- Diabetes: +1
- Female sex: +1
- Total: 5
A score in this range suggests a clinically meaningful stroke risk, and anticoagulation is commonly recommended unless contraindications or strong patient-specific concerns are present.
Important limitations and safety notes
- This calculator is intended for educational and decision-support purposes.
- It does not diagnose atrial fibrillation and does not replace a full clinical evaluation.
- Stroke-risk estimates are population-based and may not match an individual’s exact risk.
- Final therapy decisions should be made with a licensed clinician.
Frequently asked questions
Is this the same as CHADS2?
Not exactly. CHADS2 is an older, simpler tool. CHA2DS2-VASc includes more risk factors (age 65-74, vascular disease, sex category) and is more widely used today for AF stroke risk assessment.
Does a higher score automatically mean anticoagulation?
Often yes for higher-risk groups, but treatment choices still depend on bleeding risk, contraindications, patient values, and shared decision-making.
Can this score be used for everyone?
It is primarily used in non-valvular AF. Certain valve conditions, mechanical heart valves, and complex scenarios require condition-specific guidance.
Medical disclaimer: This page is informational and not medical advice. Always consult a qualified healthcare professional.