CHA₂DS₂-VASc calculator (stroke risk in AF)
Score the risk of stroke and thromboembolism in atrial fibrillation (AF) from age, sex and five clinical risk factors. This calculator uses the CHA₂DS₂-VASc score from Lip and colleagues (2010) and shows the annual risk band from the 2023 ACC/AHA/ACCP/HRS AF guideline.
How the CHA₂DS₂-VASc score works
The CHA₂DS₂-VASc score was published by Lip and colleagues in Chest in 2010, and tested in 1,084 patients with AF from the Euro Heart Survey. It adds vascular disease, age 65 to 74 and female sex to the older CHADS₂ score, and gives 2 points each for age 75 or older and for prior stroke, TIA or thromboembolism. Each other factor scores 1 point, so the total runs from 0 to 9. The 2023 ACC/AHA/ACCP/HRS guideline describes it as the most validated stroke risk score in AF.
CHA₂DS₂-VASc = C + H + A₂ + D + S₂ + V + A + Sc (0 to 9 points)
A₂ (age 75 or older) and S₂ (prior stroke, TIA or thromboembolism) score 2 points each. Every other factor scores 1 point.
| Letter | Risk factor | Points |
|---|---|---|
| C | Congestive heart failure: signs and symptoms of heart failure confirmed by objective evidence of cardiac dysfunction | 1 |
| H | Hypertension: resting blood pressure over 140/90 mmHg on at least 2 occasions, or current antihypertensive treatment | 1 |
| A₂ | Age 75 or older | 2 |
| D | Diabetes: fasting plasma glucose 7.0 mmol/L (126 mg/dL) or more, or treatment for diabetes | 1 |
| S₂ | Prior stroke, TIA or thromboembolism (ischemic stroke, TIA, peripheral embolism or pulmonary embolism) | 2 |
| V | Vascular disease: coronary artery disease (prior MI, angina, PCI or CABG) or peripheral vascular disease | 1 |
| A | Age 65 to 74 | 1 |
| Sc | Sex category: female | 1 |
CHA₂DS₂-VASc risk categories
The 2023 ACC/AHA/ACCP/HRS AF guideline ties CHA₂DS₂-VASc scores to an estimated annual risk of stroke or thromboembolism, with thresholds one point higher for women than for men. A score of 2 or more in men, or 3 or more in women, matches an annual risk of 2% or more. A score of 1 in men, or 2 in women, matches 1% to under 2%.
| Risk band | Men | Women | 2023 ACC/AHA/ACCP/HRS guideline |
|---|---|---|---|
| Low | 0 | 1 | Under about 1% a year, the guideline's low-risk level |
| Intermediate | 1 | 2 | About 1% to under 2% a year. Anticoagulation is reasonable (Class 2a) |
| High | 2 or more | 3 or more | About 2% a year or more. Anticoagulation is recommended (Class 1) |
The 2024 ESC AF guideline uses CHA₂DS₂-VA instead: the same score without the point for female sex, which it treats as an age-dependent risk modifier rather than a risk factor on its own. In the ESC guideline, anticoagulation is recommended at a CHA₂DS₂-VA of 2 or more and should be considered at 1. This calculator shows the CHA₂DS₂-VA score under the result.
Absolute rates at each score depend on the cohort. In the ATRIA cohort of 10,927 patients with AF (Singer and colleagues, 2013), counted during time off anticoagulation and reproduced in the 2023 guideline, thromboembolic events per 100 person-years were:
| Score | Events per 100 person-years (ATRIA) |
|---|---|
| 0 | 0.04 |
| 1 | 0.55 |
| 2 | 0.83 |
| 3 | 1.66 |
| 4 | 2.80 |
| 5 | 4.31 |
| 6 | 4.77 |
| 7 | 4.82 |
| 8 | 7.82 |
| 9 | 16.62 |
When the CHA₂DS₂-VASc score is less accurate
The CHA₂DS₂-VASc score ranks patients by risk better than it predicts an exact risk. In the original Euro Heart Survey cohort its C-statistic was 0.606, and the 2023 guideline reports that among 15 cohort studies, the annual stroke rate at a score of 2 was under 1% in 4 cohorts, 1% to 2% in 6 and over 2% in 5. The score leaves out factors that also raise stroke risk, such as higher AF burden, persistent or permanent AF, obesity, eGFR under 45, proteinuria and an enlarged left atrium, and the guideline suggests weighing these when the score falls in the intermediate band. It does not apply where another condition sets the risk: the guideline's recommendations for AF with rheumatic or moderate or worse mitral stenosis do not depend on the score, and it notes that in hypertrophic cardiomyopathy stroke risk is high regardless of the score. Risk changes with age and new diagnoses, so the guideline recommends reassessing it at regular intervals.
Questions
What is the highest CHA₂DS₂-VASc score?
9 points: 2 for age 75 or older, 2 for prior stroke, TIA or thromboembolism, and 1 each for heart failure, hypertension, diabetes, vascular disease and female sex. Age 65 to 74 and age 75 or older never both count.
Why are the thresholds one point higher for women?
Female sex adds a point, but on its own it does not move a woman out of the low band: a woman whose only point is her sex scores 1, the same band as a man scoring 0. So the 2023 ACC/AHA/ACCP/HRS guideline uses 1 point in men and 2 in women for the intermediate band, and 2 in men and 3 in women for the high band.
What is the difference between CHA₂DS₂-VASc and CHA₂DS₂-VA?
CHA₂DS₂-VA is the same score without the point for female sex. The 2024 ESC AF guideline adopted it so that one set of thresholds applies to everyone, including people who are non-binary, transgender or on sex hormone therapy. The 2023 ACC/AHA/ACCP/HRS guideline still uses CHA₂DS₂-VASc.
Is my data sent anywhere?
No. The calculation runs in your browser, and the answers you pick are not sent or stored.
Sources
- Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJGM. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the Euro Heart Survey on Atrial Fibrillation. Chest. 2010;137(2):263–272. doi:10.1378/chest.09-1584
- Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS guideline for the diagnosis and management of atrial fibrillation. Circulation. 2024;149(1):e1–e156. doi:10.1161/CIR.0000000000001193
- Van Gelder IC, Rienstra M, Bunting KV, et al. 2024 ESC guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2024;45(36):3314–3414. doi:10.1093/eurheartj/ehae176
- Singer DE, Chang Y, Borowsky LH, et al. A new risk scheme to predict ischemic stroke and other thromboembolism in atrial fibrillation: the ATRIA study stroke risk score. J Am Heart Assoc. 2013;2(3):e000250. doi:10.1161/JAHA.113.000250