Cardiology
CHA₂DS₂-VASc score calculator for stroke risk in atrial fibrillation
Calculate the CHA₂DS₂-VASc score for stroke risk in non-valvular atrial fibrillation, with the non-sex score shown separately as guidelines require. For use by licensed clinicians.
CHA₂DS₂-VASc score
0points
Score excluding female sex: 0. Guidelines read the anticoagulation threshold off the non-sex score, because female sex is a risk modifier rather than an independent risk factor. Applies to non-valvular atrial fibrillation only, and must be weighed against bleeding risk before starting anticoagulation.
For use by licensed clinicians as a calculation aid only. It does not account for the individual patient context, and it does not replace clinical judgement or your local protocol. Verify any value before it informs a dose or a decision.
Equation used
Congestive heart failure 1, Hypertension 1, Age ≥75 2, Diabetes 1, Stroke/TIA/thromboembolism 2, Vascular disease 1, Age 65–74 1, Sex category female 1. Maximum 9.
Source
Lip GYH et al., Chest, 2010
Applies to non-valvular atrial fibrillation. Guidelines read the anticoagulation threshold off the score excluding female sex, since female sex is a risk modifier rather than an independent risk factor.
Common questions
Why is the score excluding female sex shown separately?
Because current guidelines set the anticoagulation threshold on the non-sex score. Female sex modifies the risk conferred by other factors rather than creating risk on its own, so a woman with no other risk factors is not at elevated risk despite scoring 1.
Does CHA₂DS₂-VASc apply to valvular atrial fibrillation?
No. Moderate to severe mitral stenosis and mechanical heart valves carry a high thromboembolic risk independent of the score, and anticoagulation is indicated regardless.
Does a high score mean anticoagulation should start?
It means stroke risk is elevated enough to consider it. The decision also requires bleeding risk assessment, the patient’s values, and the practicalities of the specific agent chosen.