- Enter the patient's age and select sex — age automatically scores 0, 1 (65–74), or 2 (≥75), and female sex adds 1 point only as a risk modifier.
- Check each CHA₂DS₂-VASc risk factor that applies: heart failure / LV dysfunction, hypertension, diabetes, prior stroke/TIA/thromboembolism, and vascular disease.
- The result shows the total score (0–9), the approximate adjusted annual stroke risk, and the oral-anticoagulation (OAC) recommendation per ESC/AHA thresholds.
- Optionally enter the eGFR or CrCl to activate the CKD overlay: a renal band-specific DOAC dosing note appears below the score.
- Pair with the HAS-BLED bleeding score — AF plus CKD raises both stroke and bleeding risk, so net clinical benefit must be weighed for each patient.
All computation runs in your browser; no values are stored or transmitted.
When to Use
Use CHA₂DS₂-VASc to estimate annual ischemic-stroke risk in adults with non-valvular atrial fibrillation or flutter and to decide whether to start oral anticoagulation (OAC). It is the guideline-endorsed first step in the AF thromboembolic-risk assessment, and it is most useful precisely at the lower end of the scale, where it identifies patients who are genuinely low-risk and can avoid anticoagulation.
Appropriate population
Adults with documented non-valvular AF or atrial flutter in whom an anticoagulation decision is being made. The CKD overlay adds renally-tailored DOAC dosing guidance for patients with reduced eGFR/CrCl, who carry both elevated stroke and elevated bleeding risk.
When NOT to rely on it
Do not use CHA₂DS₂-VASc in valvular AF — moderate-to-severe mitral stenosis or a mechanical heart valve — where anticoagulation with a vitamin-K antagonist is indicated regardless of score. The score estimates stroke risk only; it does not assess bleeding risk (use HAS-BLED for that) and does not by itself determine the agent or dose. The "female sex" point is a risk modifier, not an independent indication: a woman whose only point is sex is managed as low-risk.
Pearls & Pitfalls
Sex-aware thresholds
OAC is recommended at a score of ≥2 in men and ≥3 in women; it should be considered at 1 (men) / 2 (women). A score of 0 (men) or 1 from sex alone (women) needs no antithrombotic therapy. The female point only changes risk in the presence of at least one other risk factor — it never pushes an otherwise-low-risk patient into treatment on its own.
CKD raises both stroke and bleeding risk
Reduced eGFR is independently associated with higher thromboembolic and hemorrhagic risk in AF. CHA₂DS₂-VASc does not include renal function, so the net benefit of OAC must be individualized. In CKD, apixaban is generally the preferred DOAC, and renal dose-reduction rules differ by agent — confirm each against the current label.
Pitfalls
(1) Do not apply to valvular AF / mechanical valves — those require a VKA regardless of score. (2) The score does not assess bleeding — always pair with HAS-BLED. (3) Edoxaban is not recommended when CrCl >95 mL/min (reduced efficacy) — a high CrCl is a contraindication, not a green light. (4) DOAC renal thresholds are defined by Cockcroft-Gault CrCl, not indexed eGFR; in advanced CKD/dialysis, evidence is limited and warfarin's benefit is uncertain with higher bleeding/calciphylaxis risk.
Why Use It
CHA₂DS₂-VASc refined the older CHADS₂ score by adding vascular disease, the 65–74 age band, and female sex, which improved discrimination at the low end of risk — its main value is reliably identifying truly low-risk patients who can safely avoid anticoagulation. In CKD, the stroke–bleeding trade-off is sharper: the kidney both clears most DOACs and itself raises thromboembolic and hemorrhagic risk. Coupling the score with an eGFR/CrCl-driven dosing overlay and a parallel HAS-BLED assessment lets you choose the right agent at the right renal dose, rather than treating the score in isolation.
CHA₂DS₂-VASc Calculator + CKD Anticoagulation Overlay
Enter age and sex and check each risk factor to compute the CHA₂DS₂-VASc score (0–9), the approximate adjusted annual stroke risk, and the OAC recommendation. Add an eGFR or CrCl to activate the CKD-tailored DOAC dosing note.
⚕ CHA₂DS₂-VASc: Congestive HF (1), Hypertension (1), Age ≥75 (2) / 65–74 (1), Diabetes (1), prior Stroke/TIA/TE (2), Vascular disease (1), Sex category female (1); range 0–9. OAC is recommended at ≥2 (men) / ≥3 (women), considered at 1 (men) / 2 (women), and not indicated at 0 (men) / 1 (women, sex-only). DOAC renal thresholds use Cockcroft-Gault CrCl, not indexed eGFR. This is a decision aid, not a substitute for the current label or clinical judgment; pair with HAS-BLED. Source: Lip GYH et al. Chest. 2010;137(2):263–272; 2023 ACC/AHA/ACCP/HRS AF Guideline.
Next Steps
Use the score to support — not replace — a shared anticoagulation decision.
- Calculate HAS-BLED in parallel: a high bleeding score should prompt correction of modifiable risk factors, not automatic withholding of OAC.
- When OAC is indicated, prefer a DOAC over warfarin in non-valvular AF unless a mechanical valve or moderate-to-severe mitral stenosis is present.
- In CKD, confirm the renal dose against the current label using Cockcroft-Gault CrCl; apixaban is generally preferred in advanced CKD and dialysis.
- Reassess the score and renal function over time — risk factors accrue, and eGFR changes can move a patient across DOAC dosing thresholds.
- Document the indication, agent, dose, and the stroke/bleeding trade-off discussed with the patient.
Evidence & References
Scoring & thresholds
| Risk factor | Points |
|---|---|
| Congestive HF / LV dysfunction | 1 |
| Hypertension | 1 |
| Age ≥75 | 2 |
| Age 65–74 | 1 |
| Diabetes mellitus | 1 |
| Prior Stroke / TIA / thromboembolism | 2 |
| Vascular disease (MI, PAD, aortic plaque) | 1 |
| Sex category female | 1 |
Adjusted annual stroke risk & recommendation
| Score | Approx. adjusted stroke rate / yr | Recommendation |
|---|---|---|
| 0 | ~0.2% | No antithrombotic (men 0 / women sex-only) |
| 1 | ~0.6% | Consider OAC (men); women: no therapy if sex-only |
| 2 | ~2.2% | OAC recommended (men); consider OAC (women) |
| 3 | ~3.2% | OAC recommended |
| 4 | ~4.8% | OAC recommended |
| 5 | ~7.2% | OAC recommended |
| 6 | ~9.7% | OAC recommended |
| 7 | ~11.2% | OAC recommended |
| 8 | ~10.8% | OAC recommended |
| 9 | ~12.2% | OAC recommended |
Adjusted annual stroke rates are approximate, drawn from the validation cohort; absolute rates vary by population. OAC thresholds: recommend at ≥2 (men) / ≥3 (women); consider at 1 (men) / 2 (women).
DOAC renal dosing in CKD
| Agent | Renal dosing |
|---|---|
| Apixaban | 5 mg BID; reduce to 2.5 mg BID if ≥2 of: age ≥80, weight ≤60 kg, SCr ≥1.5 mg/dL. Preferred in advanced CKD; usable with caution in dialysis (5 mg BID per label; many use 2.5 mg BID). |
| Rivaroxaban | 20 mg daily; 15 mg daily if CrCl 15–50; avoid if CrCl <15. |
| Dabigatran | 150 mg BID; consider 110/75 mg by region if CrCl 30–50; avoid if CrCl <30. |
| Edoxaban | 60 mg daily; 30 mg if CrCl 15–50; NOT recommended if CrCl >95 (reduced efficacy) or <15. |
| Warfarin (INR 2–3) | Use in valvular AF / mechanical valves. In advanced CKD / dialysis, benefit is uncertain and bleeding / calciphylaxis risk is higher — apixaban generally preferred. |
DOAC renal thresholds are defined by Cockcroft-Gault CrCl (mL/min), not indexed eGFR. Always confirm against the current prescribing information.
Evidence & References
CHA₂DS₂-VASc was derived and validated by Lip and colleagues (2010) to refine stroke-risk stratification in non-valvular AF, improving identification of truly low-risk patients over the older CHADS₂. The 2023 ACC/AHA/ACCP/HRS AF guideline endorses it as the primary risk-stratification tool. DOAC renal-dosing recommendations follow each agent's regulatory label and supporting trials; apixaban has the strongest evidence base in advanced CKD and dialysis.
- 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.
- 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.
- Apixaban (Eliquis), rivaroxaban (Xarelto), dabigatran (Pradaxa), edoxaban (Savaysa/Lixiana) — U.S. prescribing information (renal dosing sections).
- Stanifer JW, Pokorney SD, Chertow GM, et al. Apixaban Versus Warfarin in Patients With Atrial Fibrillation and Advanced Chronic Kidney Disease. Circulation. 2020;141(17):1384–1392.
