CHA₂DS₂-VASc calculator

What is the CHA2DS2-VASc score?

CHA2DS2-VASc is a point score for the risk of stroke in people with atrial fibrillation (AF). It was proposed by Lip and colleagues in 2010 (Chest) after testing it in 1,084 patients of the Euro Heart Survey on atrial fibrillation. The letters stand for Congestive heart failure (1 point), Hypertension (1), Age 75 or older (2), Diabetes (1), prior Stroke, TIA or thromboembolism (2), Vascular disease (1; prior heart attack, peripheral artery disease or aortic plaque), Age 65 to 74 (1), and Sex category, female (1). The maximum is 9.

What score means a blood thinner is recommended?

The 2023 ACC/AHA/ACCP/HRS guideline works from the estimated yearly risk: at 2% a year or more (for example a CHA2DS2-VASc of 2 or more in men and 3 or more in women), anticoagulation is recommended (Class 1, level of evidence A). At 1% to under 2% a year (a score of 1 in men and 2 in women) anticoagulation is reasonable (Class 2a, level A). Women get one point for sex, so their thresholds sit one point higher; that is why the page reads the score differently for men and women. The 2024 European guideline (ESC) drops sex from the score (CHA2DS2-VA): anticoagulation is recommended at 2 or more and should be considered at 1.

How big is the stroke risk at each score?

Published rates depend heavily on who was studied. The page shows ischemic stroke per 100 patient-years from the Finnish FinACAF registry (144,879 people with newly found AF who were not on anticoagulants), for 2017 to 2018: 0: 0.6, 1: 1.1, 2: 2.6, 3: 4.1, 4: 6.4, 5: 7.6, 6: 13.3, 7: 14.8, 8: 16.3. For scores 5 to 7 the six two-year periods of the same registry ranged widely (5: 7.6 to 12.9; 6: 13.3 to 21; 7: 14.8 to 28.2). The 2023 guideline makes the same point: among 15 cohorts, people with a score of 2 had yearly stroke rates below 1% in 4 cohorts, 1% to 2% in 6 and above 2% in 5.

Why does the page show Finnish data and not the original table?

Lip's 2010 paper tested the score in one European survey of 1,084 patients, and its text sits behind a paywall, so we could not check its rate table. The Finnish registry covers all levels of care in a whole country, is open access under a CC BY license, and reports rates by score for six periods up to 2018, which makes the variation visible. Neither source is a promise for an individual person, and rates in the US population may differ.

What about female sex and the CHA2DS2-VA score?

The 2023 guideline treats female sex as a risk modifier. In the Finnish registry, women had higher AF-related stroke risks than men in 2007 to 2008, but by 2017 to 2018 there was limited or no sex difference, and the score without sex was marginally better in the latest period. The 2023 US guideline still uses CHA2DS2-VASc with sex-specific thresholds. This page shows both scores: for the example of a 78-year-old woman, 5 on CHA2DS2-VASc and 4 on CHA2DS2-VA.

Does the score replace a bleeding assessment?

No. The 2023 guideline gives a Class 1 recommendation that people with AF be evaluated for factors that indicate a higher risk of bleeding, such as previous bleeding and medicines that raise it, so that steps to reduce it can be taken. It adds that bleeding scores such as HAS-BLED discriminate poorly between patients who bleed and those who do not, and that they include many factors that also raise stroke risk, such as age, hypertension, renal disease and previous stroke; assessing factors that predict bleeding but not stroke is more helpful when balancing the risks and benefits. This page does not assess bleeding, and it does not recommend a drug or a dose.

Is the score used for valve disease?

The thresholds are for AF without moderate to severe rheumatic mitral stenosis or a mechanical heart valve. The guideline handles AF in valvular heart disease in a separate section with its own recommendations on antithrombotic therapy, so do not use this page for those patients.

How the points are added

Take the person's age: 75 or older adds 2 points, 65 to 74 adds 1, younger adds none. Add 1 each for heart failure (or reduced left-ventricular function), hypertension, diabetes, vascular disease and female sex, and 2 for a previous stroke, TIA or thromboembolism. The score is a simple sum from 0 to 9. The CHA2DS2-VA variant used by the European guideline leaves out the sex point, so it runs from 0 to 8.

Worked example

A 78-year-old woman with hypertension and diabetes scores 5: 2 for age, 1 for hypertension, 1 for diabetes and 1 for sex. Her CHA2DS2-VA is 4. In the Finnish registry, people with a score of 5 had 7.6 strokes per 100 patient-years in 2017 to 2018 (95% CI 6.2 to 9.3). A 52-year-old man whose only risk factor is hypertension scores 1: the guideline's Class 2a range. A 66-year-old woman with no other risk factor scores 2 (age 1 plus sex 1), which the guideline treats as equivalent to 1 in a man (Class 2a). A 50-year-old woman with nothing else scores 1 from sex alone, below the guideline's thresholds.

Limits of this method

The score is a count of yes-or-no answers. It does not weigh how long a condition has lasted or how well it is controlled, and it leaves out the amount of AF (the guideline mentions AF burden among possible risk modifiers). The 2023 guideline stresses that any score is only an estimate, because the absolute rate for one score level varies widely across populations. It also adds that people at intermediate risk who remain uncertain can benefit from looking at other factors, including sex, blood pressure control and AF burden, to inform a shared decision. The Finnish rates are for first-year follow-up after a new AF diagnosis, with people leaving the count when anticoagulation began.

Common mistakes

Counting age twice: only one of the two age categories applies. Giving a woman the male thresholds: a woman's score of 1 comes from sex alone and does not mean the same as a man's 1. Treating the number as a verdict: the guideline links the decision to the estimated yearly risk, bleeding factors and the patient's preferences. And using the table of stroke rates as a prediction for one person.

Sources: Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJGM, “Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the Euro Heart Survey on atrial fibrillation,” Chest 2010;137:263–272; Joglar JA, Chung MK, et al., “2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation,” Circulation 2024;149:e1–e156 (recommendations on anticoagulation and risk scores); Van Gelder IC, Rienstra M, Bunting KV, et al., “2024 ESC Guidelines for the management of atrial fibrillation,” Eur Heart J (doi 10.1093/eurheartj/ehae176); Teppo K, et al., “Comparing CHA2DS2-VA and CHA2DS2-VASc scores for stroke risk stratification in patients with atrial fibrillation: a temporal trends analysis from the retrospective Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) cohort,” Lancet Reg Health Eur 2024;43:100967 (Table 2, CC BY 4.0). Related: blood pressure calculator, mean arterial pressure, QTc calculator.

For general information only — not medical advice, and not a tool for patient care decisions. Talk with a doctor before starting or stopping any medicine. How we check our calculators.