Last updated: 2026-06-29

CHA₂DS₂-VASc Score

The CHA₂DS₂-VASc score estimates the yearly risk of ischemic stroke in people with non-valvular atrial fibrillation, the most common sustained heart-rhythm disorder. It is the score most guidelines use to decide whether the benefit of long-term oral anticoagulation outweighs its bleeding risk. Clinicians, trainees, and patients use it to turn a list of risk factors into a single number and an estimated annual stroke risk.

How the score is built

CHA₂DS₂-VASc is an additive point score with a maximum of 9. Each clinical factor contributes a fixed number of points:

The two "2-point" factors — age 75 and over, and a prior stroke or transient ischemic attack — give the score its subscript notation. Age is scored as a step function, so it is entered once as a number rather than chosen from bands:

The total is the sum of every factor, for example $1_{\text{HTN}} + 1_{\text{age 65–74}} = 2$ for a 70-year-old with treated hypertension and no other risk factors.

Reading the result

Higher scores correspond to higher observed stroke rates. Using the cohort table from Friberg et al. 2012, a score of 0 carries an adjusted annual stroke risk near 0.2%, a score of 4 near 4.8%, and a score of 6 near 9.7%. The figures for scores of 8 and 9 rest on small patient numbers and carry wide confidence intervals, so they are best read as estimates.

The anticoagulation threshold is sex-adjusted because the female-sex point only raises risk when other factors are present. Under AHA/ACC/HRS guidance, oral anticoagulation is recommended at a score of 2 or more in men and 3 or more in women; a score of 1 in men or 2 in women is an individualized decision; and a score of 0 in men or 1 in women (the sex point alone) generally does not warrant anticoagulation for stroke prevention.

CHA₂DS₂-VA and the 2024 ESC update

The 2024 European Society of Cardiology guidelines adopt CHA₂DS₂-VA, which keeps every factor except the female-sex point. The rationale is that sex behaves as a risk modifier rather than an independent risk factor, and dropping it gives a single sex-neutral threshold. This calculator reports both scores so the current ESC approach can be compared with the long-established CHA₂DS₂-VASc that many protocols still use.

Limits and related tools

The score estimates stroke risk only; it does not weigh bleeding risk, which is assessed separately and combined with patient preference before starting anticoagulation. Reported annual percentages also vary between cohorts — the original Lip 2010 derivation differs from the Friberg 2012 table used here — so the output is a guide, not an exact probability. For related cardiovascular context, see the Blood Pressure Classifier, the Mean Arterial Pressure Calculator, and the Cholesterol Ratio Calculator.