CardiologyCardiology

CHADS₂ Score — Stroke Risk in Atrial Fibrillation

Estimates annual stroke risk in non-valvular atrial fibrillation to guide anticoagulation decisions.

C — Congestive heart failure (history or reduced EF)

H — Hypertension (resting BP >140/90 or on antihypertensives)

A — Age ≥75 years

D — Diabetes mellitus

S₂ — Prior stroke, TIA, or thromboembolism (+2 points)

CHADS₂ Score/ 6

Low risk — ~1.9%/year

Estimated annual stroke risk: 1.9%. CHADS₂ score ≥2 is an indication for anticoagulation. Note: CHA₂DS₂-VASc is the preferred contemporary score — CHADS₂ is retained for historical reference.

Reference: Gage BF et al. JAMA 2001

Medical Disclaimer: This calculator is a clinical decision support tool for qualified healthcare professionals. It does not replace clinical judgement. Always interpret results in the full clinical context. Reference: Gage BF et al. JAMA 2001.

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