Calculates your stroke risk in atrial fibrillation and tells you whether anticoagulation is recommended — based on 2023 ACC/AHA guidelines. Tick the boxes that apply. Done in 30 seconds.
Lip GYH et al., Chest 2010 · Non-valvular atrial fibrillation · ACC/AHA 2023
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| Score | Annual stroke risk | Recommendation |
|---|
The CHA₂DS₂-VASc score was published by Lip GYH et al. in Chest in 2010. It was built to fix a problem with the original CHADS₂ score: CHADS₂ put too many patients into a "moderate risk" bucket where the right treatment decision wasn't clear. CHA₂DS₂-VASc added 3 more criteria (vascular disease, age 65–74, and female sex) to pull truly low-risk patients out of that grey zone.
It's now the guideline-recommended stroke risk tool in the US (ACC/AHA 2023), Europe (ESC 2020), and most other major cardiology societies worldwide.
A score of 0 in men carries roughly 0% annual stroke risk. At score 6, you're looking at 9.8% per year — nearly 1 in 10 chance of stroke annually without anticoagulation.
Score ≥2 in men (or ≥3 in women) is a class I indication for a DOAC. The decision also weighs your bleeding risk, kidney function, and patient preference.
Female sex adds 1 point but doesn't independently trigger anticoagulation. A woman with a score of 1 (female sex only) is still low risk per the 2020 ESC guidelines.
These annual stroke risk percentages come from the original Swedish registry validation study (Lip GYH et al., 2010) and have been confirmed in multiple external cohorts.
| Score | Annual stroke risk | Anticoagulation (ACC/AHA 2023) |
|---|---|---|
| 0 (men) / 1 female only | 0% | Not recommended |
| 1 (men) / 2 (women, excl. female sex only) | ~1.3% | Consider (Class IIb) |
| 2 | ~2.2% | Recommended (Class I) in men |
| 3 | ~3.2% | Recommended (Class I) |
| 4 | ~4.0% | Recommended (Class I) |
| 5 | ~6.7% | Recommended (Class I) |
| 6 | ~9.8% | Recommended (Class I) |
| 7 | ~9.6% | Recommended (Class I) |
| 8 | ~12.5% | Recommended (Class I) |
| 9 | ~15.2% | Recommended (Class I) |
The original CHADS₂ score (Gage BF et al., 2001) used 5 factors scored 0–6. It was decent at identifying high-risk patients but poor at identifying low-risk ones. About 60% of AFib patients landed in the "moderate risk" range (score 1–2), and the treatment decision for that group was unclear.
CHA₂DS₂-VASc extended the score to 0–9 and added 3 criteria. The extra granularity means fewer patients fall into the ambiguous middle. In validation studies, a CHA₂DS₂-VASc score of 0 in men has an annual stroke rate close to 0% — genuinely safe to withhold anticoagulation.
Your CHA₂DS₂-VASc score is one input in the anticoagulation decision. Your doctor will also consider:
Per 2023 ACC/AHA guidelines: a score of 2 or above in men, or 3 or above in women, is a class I (recommended) indication for anticoagulation. A score of 1 in men (or 2 in women, where female sex isn't the only contributing point) is a class IIb consideration — meaning it's reasonable to consider but not strongly recommended. Score 0 in men or 1 in women (female sex only) doesn't warrant anticoagulation.
Yes, female sex adds 1 point. But a woman with a score of 1 where female sex is her only point is still considered low risk. The ESC 2020 guidelines explicitly state that female sex is a risk modifier, not an independent stroke risk factor on its own. Anticoagulation guidance for women applies when there's at least 1 additional risk factor beyond sex.
CHADS₂ (2001) has 5 criteria and a max score of 6. CHA₂DS₂-VASc (2010) has 8 criteria and a max score of 9. The expanded score does a better job identifying patients with genuinely zero stroke risk, which means fewer people get anticoagulated unnecessarily. Most guidelines replaced CHADS₂ with CHA₂DS₂-VASc between 2012 and 2016.
No. CHA₂DS₂-VASc applies to non-valvular AFib only. Patients with moderate-to-severe mitral stenosis or a mechanical heart valve have a high enough stroke risk that anticoagulation (with warfarin specifically, not DOACs) is recommended regardless of their CHA₂DS₂-VASc score.
Yes. The HAS-BLED score estimates annual bleeding risk on anticoagulation. It doesn't override the anticoagulation decision, but a high HAS-BLED score (3 or above) flags modifiable bleeding risk factors worth addressing before or during anticoagulation. Your cardiologist will weigh both scores together.