What is the CHA₂DS₂-VASc score?

The CHA₂DS₂-VASc score estimates stroke risk in patients with non-valvular atrial fibrillation (AF). It is used to determine whether anticoagulation therapy is recommended. The score ranges from 0 to 9 and considers factors including heart failure, hypertension, age, diabetes, prior stroke, vascular disease, and sex.

What score requires anticoagulation?

Current guidelines generally recommend anticoagulation for men with a score of 1 or more, and women with a score of 2 or more. A score of 0 in men or 1 in women (where the only point is for female sex) is considered low risk, and anticoagulation may not be needed. Always discuss with a cardiologist or GP.

CHA₂DS₂-VASc Score — Stroke Risk in AF

⚠️ For Australian clinical practice, use CHA₂DS₂-VA (no sex point). Australian guidelines (NHFA / CSANZ 2018) recommend the “sexless” version — CHA₂DS₂-VA — with anticoagulation recommended at score ≥ 2 and considered at score = 1, the same threshold for men and women. The CHA₂DS₂-VASc below is the international version (US, EU). Use the Australian AF management reference → for the VA version with full guidance.

The CHA₂DS₂-VASc score is used for patients with non-valvular atrial fibrillation (AF). Tick each risk factor that applies to the patient. The score calculates automatically.

C — Congestive Heart Failure

History of heart failure or reduced ejection fraction (EF ≤40%)

H — Hypertension

Resting BP >140/90 on at least 2 occasions or current antihypertensive treatment

A₂ — Age ≥ 75

Patient is 75 years or older

D — Diabetes Mellitus

Fasting glucose ≥7 mmol/L or on hypoglycaemic treatment

S₂ — Stroke / TIA / Thromboembolism

Prior stroke, transient ischaemic attack, or systemic embolism

V — Vascular Disease

Prior MI, peripheral artery disease, or aortic plaque

A — Age 65–74

Patient is between 65 and 74 years old

Sc — Sex Category (Female)

Patient is female

The CHA₂DS₂-VASc score is a clinical prediction tool used to estimate the risk of stroke in patients with non-valvular atrial fibrillation (AF). AF is the most common heart rhythm disorder and significantly increases stroke risk.

The acronym stands for: Congestive heart failure, Hypertension, Age ≥75 (doubled), Diabetes, Stroke history (doubled), Vascular disease, Age 65–74, and Sex category (female).

It replaced the older CHADS₂ score by adding vascular disease, age 65–74, and female sex as additional risk factors, providing better discrimination in lower-risk patients.

Source: Lip GYH et al, Chest 2010;137(2):263-272.

Current Australian and international guidelines recommend:

Score 0 (males) or 1 (females, where sole point is sex): Low risk. Anticoagulation is generally not recommended. Reassess periodically as risk factors accumulate with age.

Score 1 (males): Moderate risk. Consider anticoagulation based on individual risk-benefit assessment and patient preference.

Score ≥2: High risk. Oral anticoagulation is recommended. Direct oral anticoagulants (DOACs) such as apixaban, rivaroxaban, or dabigatran are preferred over warfarin in most patients.

Bleeding risk should be assessed separately (e.g. using HAS-BLED). However, a high bleeding risk score is not a contraindication to anticoagulation — it identifies patients who need closer monitoring and modifiable risk factor management.

Female sex is considered a stroke risk modifier rather than an independent risk factor. Importantly, female sex alone (score of 1 in women with no other risk factors) is not considered sufficient to warrant anticoagulation.

The point for female sex reflects epidemiological data showing that women with AF have a slightly higher stroke risk than men with the same comorbidity profile, particularly at older ages. However, this risk increase only becomes clinically relevant when combined with other risk factors.

For treatment decisions, women with a CHA₂DS₂-VASc of 1 (sole point for sex) are treated equivalently to men with a score of 0.