CHADS₂ Score for AF Stroke Risk
Original CHADS₂ score for estimating stroke risk in non-valvular atrial fibrillation. Largely superseded by CHA₂DS₂-VASc but still widely referenced.
How to use & interpret
CHADS₂ is an earlier score for stroke risk in non-valvular atrial fibrillation (Congestive heart failure, Hypertension, Age ≥75, Diabetes, prior Stroke/TIA = 2 points). It has largely been superseded by CHA₂DS₂-VASc, which better identifies patients who are genuinely low-risk and do not need anticoagulation.
Broadly, CHADS₂ 0 is low, 1 is intermediate and ≥2 is high risk. If you are deciding on anticoagulation, prefer CHA₂DS₂-VASc; CHADS₂ may still be seen in older studies and protocols.
Score interpretation
CHADS₂ = 0: ~1.9% annual stroke risk. Low risk.
→ Aspirin or no antithrombotic therapy. Consider upgrading to CHA₂DS₂-VASc for decision-making.
CHADS₂ = 1: ~2.8% annual stroke risk.
→ Anticoagulation recommended. Use CHA₂DS₂-VASc for refined risk stratification. Discuss risks/benefits with patient.
CHADS₂ 2–3: ~4–6% annual stroke risk. Anticoagulation strongly indicated.
→ Anticoagulate — DOAC preferred (apixaban, rivaroxaban, edoxaban) unless contraindicated. Assess bleeding risk (HAS-BLED).
CHADS₂ ≥ 4: Very high stroke risk >8% per year.
→ Strong indication for anticoagulation. DOAC preferred. Ensure HAS-BLED risk also assessed and modifiable bleeding factors corrected.
Interpretation bands for the CHADS₂. Apply clinical judgement and local guidance.
Frequently asked questions
Should I use CHADS₂ or CHA₂DS₂-VASc?
Use CHA₂DS₂-VASc — it reclassifies many 'low-risk' CHADS₂ patients and is recommended by current guidelines for the anticoagulation decision.
References
- Gage BF, et al. Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation. JAMA. 2001;285(22):2864–2870.
Related
Curated clinical cross-links plus same-class fallbacks.
- ApixabanRecommendedDirect oral anticoagulant (DOAC) — Factor Xa inhibitor
- Edoxaban (AF Stroke Prevention / VTE)RecommendedDirect Factor Xa Inhibitor (DOAC)
- Dabigatran etexilateRecommendedDirect thrombin (factor IIa) inhibitor (DOAC)
- AspirinRecommendedAntiplatelet / NSAID / Antipyretic / Analgesic
- Acute Heart Failure · ESC 2021 Heart Failure Guidelines; NICE NG106
- NSTEMI / Unstable Angina · ESC 2020 NSTEMI Guidelines; NICE NG185
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines
Featured in these MRCEM clinical pathways
The CHADS₂ is covered in detail — with RCEM/NICE evidence base, indications and pitfalls — in the following exam-focused pathways on our sister siteReviseMRCEM.
MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.