CHA2DS2-VASc Score Calculator AFib Stroke Risk & Guidelines
Estimate the annual risk of stroke in patients with non-valvular atrial fibrillation (AFib) to determine whether oral anticoagulation (OAC) therapy is recommended.
Demographics
Clinical History
Select the patient’s criteria to generate the CHA₂DS₂-VASc Score and therapy recommendations.
Understanding the CHA₂DS₂-VASc Score
The CHA₂DS₂-VASc score is a highly validated clinical prediction rule used to estimate the risk of stroke in patients with non-valvular atrial fibrillation (AFib). It is an update to the older CHADS₂ score, introducing additional risk factors (Age 65-74, Vascular disease, and Female sex) to better identify “truly low-risk” patients who do not require anticoagulation.
Scoring Breakdown & Acronym
- C: Congestive heart failure or Left Ventricular dysfunction (1 point)
- H: Hypertension (1 point)
- A₂: Age ≥ 75 years (2 points)
- D: Diabetes mellitus (1 point)
- S₂: Stroke / TIA / Thromboembolism (2 points)
- V: Vascular disease (Prior MI, peripheral artery disease, or aortic plaque) (1 point)
- A: Age 65–74 years (1 point)
- Sc: Sex category (Female) (1 point)
Clinical Interpretation & Guidelines
Modern guidelines (AHA/ACC/HRS and ESC) dictate that oral anticoagulation (OAC)—preferably a Direct Oral Anticoagulant (DOAC) over Warfarin—should be prescribed based on the total score, with a critical caveat regarding the female sex point.
| Male Score | Female Score | Risk Category | Recommendation |
|---|---|---|---|
| 0 | 1 | Low Risk | No antithrombotic therapy is recommended. (Note: Female sex alone does not increase stroke risk enough to warrant OAC). |
| 1 | 2 | Moderate Risk | OAC may be considered. Decision should be individualized based on patient preference and bleeding risk. |
| ≥ 2 | ≥ 3 | High Risk | Oral anticoagulation is strongly recommended (Class I). DOACs (e.g., Apixaban, Rivaroxaban) are generally preferred over Warfarin. |
The “Sex Category” Caveat
While female sex grants 1 point in the formal calculation, large-scale registry data has proven that female sex only acts as a stroke risk modifier in the presence of other risk factors. Therefore, a 60-year-old female with no other medical history has a CHA₂DS₂-VASc score of 1, but her actual stroke risk is roughly equivalent to a male with a score of 0. Guidelines explicitly state that OAC should not be initiated if the only point comes from being female.
